Hehehe... Here I go again It's been a while since I have probed the minds of the gang here - hope you're still willing to play!
I have noticed that the people on the forum who have lowered cars with big rims and low-pros always seem to point out the fact that the ride is pretty harsh. Sometimes there is the slightly silly/slightly serious joke/recommendation about wearing a kidney belt, or some similar device. My question for the day:
Is it possible to lower a Fiero, throw in big brakes, big wheels, and rubber band tires, and still have a nice ride???
One tire combination I am looking at would have 35-series rubber up front, and 30-series in back. Both would have sidewalls of just about 3". I have noticed that the new car manufacturers are able to develop vehicles that have nice ride, and excellent handling, characteristics - with these radical wheel/tire combos. Is it possible for us?
My car is already down three inches (via cut springs - harsh, kidney belt ride) but I will reproduce this ride height soon with 2" spindles and either a one-inch spring, or coil-over, up front - and coil-over converted struts in back. Not sure what shocks yet, but I want double-adjustable at all corners. I know it will not have much travel, but one of my Accords is lowered three inches, with about three inches of ground clearance, and it actually rode pretty nice until the shock cartridges in the struts went bad.
I know one of the essential elements is to have a very rigid chassis, which allows you to use softer valving in the shock tuning. It seems that we have a nice start here because the Fiero "space frame" is already decent in this regard (or am I misinformed?).
I am thinking about doing the same seam welding idea to my street car, that I am planning for the street-legal race car. Also, I am replacing the whole rear sheet metal upper frame section with a tubular cage type setup that will have the upper strut mounts and tie into the factory lower main frame rails, just over the rear cradle mounts. The trunk is history. I am also going to go inside the b-pillars and weld the reinforcement pads where the factory upper frame rails attach to the cabin - since my new tubular rails will also mount there. The front seems pretty stout to me so I may just seam weld it and leave it be.
Thoughts, comments, theories, suggestions, ideas, two cents....?
perk
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10:53 AM
PFF
System Bot
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
nope. when you lower the car, you lose suspension travel. when you have less travel, you need stiffer springs to keep from hitting the stops or bottoming out. and also, the big steel wheels, big steel rotors & monster calipers add alot to the weight of the wheel, which makes things even worse. and also, the tire height has alot to do with the fine smoothness of the ride. but anyways, to only way to compensate for all the stuff that wrecks the ride, is to ADD WEIGHT to the car. instead of a spare tire donut under the front, put manhole covers in its place. in the back, well, a nice heavy V8 would help . the heavier the car, the more resitance it has to bumps & stuff that try to move & jar it around. thats something most truck guys have noticed. a loaded truck rides SO much better than an unloaded truck.
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11:24 AM
Nov 7th, 2003
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Unsprung weight is the biggest ride quality killer out there. For the front, use the new Street Dreams aluminum knuckles and hubs, two piece rotors with aluminum hats, the smallest, thinnest brake rotor that will be adequate to your application, aluminum calipers, aluminum caliper brackets, and the smallest wheels that will fit over your brakes. Now, for a realistic parts list... Street Dreams aluminum knuckles and hubs 11.25" LeBaron rotors (can be replaced with two piece rotors eventually) Wilwood GM Metric Aluminum calipers instead of 3rd Gen Camaro iron calipers The aluminum brackets I'm designing for the LeBaron/Camaro brake upgrade. 15" wheels. Koni shocks, converted to be double adjustable (Koni will do this for $300 per shock)
The rear is a bit different. The Fiero rear wheels bearings, etc. are inadequate to high performance use. Road racers on the Fiero racing list routinely go through a set of wheel bearings every 2-3 race weekends. Upgraded bearings are a MUST. The A-body knuckle upgrade fits larger, stronger bearings & CV's and heavy duty brakes to the rear, but adds 13 lbs(!) of unsprung weight to each rear corner.
The other obvious possibility is using the aluminum hub carriers from a more modern GM vehicle. W-bodies and N-bodies come to mind. The W-body is the larger car and would have the stronger hardware that we seek. W-body hub carriers take a ball joint that is not compatible with the Fiero control arm, so a custom tubular control arm would be necessary. That's not a bad thing, since we're talking about reducing unsprung weight. GMPP just released Koni struts for the W-body, and Koni should be able to convert these to double adjustment for $250/each. The only question that remains is whether or not the W-body hardware can get the camber positive enough to be something we'd want to drive around (say -1.5 to -2.0 degrees). A GM III caliper from Wilwood would further reduce unsprung weight by getting rid of the stock cast iron W-body caliper. Since the front rotors are 11.25", the 10.6" W-body front rotors should be fine on the rear, and are lighter than the 12" rotors also available. Fit lightweight 15" wheels to the rear as well.
I've done some math and figured that in order to have bullet proof wheel bearings in the rear of a Fiero that routinely sees 1G cornering loads, we'd have to use wheel bearings from a vehicle that weighs 5,300 lbs. The only thing close is a Cadillac. I haven't been able to get a good look at the suspensions of new Caddies, but using that hardware is another possibility.
Or maybe using Caddy bearings with a custom fabricated aluminum knuckle...
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
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10:53 AM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
I was hoping you would chime in I am definitely planning on using the new Street Dreams aluminum knuckles and hubs. That is where two inches of my front drop is coming from.
I have to give your suggestions on the brakes some serious consideration. I was planning on going bigger than that. I realized that there was a weight penalty, but never considered it in the context of ride quality. I have C5 rotors that I was planning on using - heavy! Since I don't have them yet, getting lightweight aluminum calipers would not be a problem. Any thoughts on C5 or 4th Gen F-body calipers?
Definitely something to look into with the rear setup. Adding 13lbs is not good, so I think I will definitely be looking into the W-body aluminum - or possibly even something custom. I guess the ideal setup would be a custom aluminum hub carrier, designed to be a bolt in replacement for the stock Fiero unit - that would mount a larger stronger bearing. Maybe one that could take either the Caddy or a C5 hub assembly, to suit more people.
Any thoughts on the C5 rear hub/bearing? Think it would be strong enough? The car only weighs 3400lbs, but has almost 50/50% weight distribution. It's not the 5300lbs you came up with but it is a bearing designed for high performance usage.
quote
a Fiero that routinely sees 1G cornering loads
Man does that conjure up nice mental images!
My other problem is with wheels, because I will be running something considerably larger than 15's. I guess my best bet there is to go with forged wheels. If all else fails, and a decent ride is out of the question with what I want on this car, I will just have to use it as a toy and tow it on long distance trips. I was trying to see if it would be possible to come up with something that the wife and I could stand to take on longer trips.
The custom Konis sound good.
perk
[This message has been edited by perkidelic (edited 11-07-2003).]
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12:25 PM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
I have to give your suggestions on the brakes some serious consideration. I was planning on going bigger than that. I realized that there was a weight penalty, but never considered it in the context of ride quality. I have C5 rotors that I was planning on using - heavy! Since I don't have them yet, getting lightweight aluminum calipers would not be a problem. Any thoughts on C5 or 4th Gen F-body calipers?
C5 calipers are expensive. Local yard wanted $107 each and had to have them shipped in. '98+ F-body calipers appear to be virtually the same and are much cheaper ($40 each). The F-body calipers are what I want to use with the 12" rotors that are common to '98+ F-bodies and '98+ W-bodies. Check this out: http://www.clubgp.com/newforum/tm.asp?m=973047&p=&mpage=1&tmode=1&smode=1&key=&languag e=
One nice thing about C5 rotors is that you can buy two piece rotors without having anything custom made. C4 rotors are thinner and lighter... so if all you need is brake torque and don't need unreasonable fade resistance, then you might want to check out C4 rotors. I'm sure 2 piece rotors are readily available there, too.
quote
Any thoughts on the C5 rear hub/bearing? Think it would be strong enough? The car only weighs 3400lbs, but has almost 50/50% weight distribution. It's not the 5300lbs you came up with but it is a bearing designed for high performance usage.
I think the Vette bearing would be fine. It's a heavier car than the Fiero and pulls 1G from the factory in ZO6 trim. The 5300 lbs figure came from making the load that the bearing experiences in a 1G corner in a Fiero the same as what it experiences in every day driving in it's intended application. I will be looking into rear bearings eventually. I need to get together enough information on CV and axle splines to put together a big spreadsheet and see what the best combination of parts for various bolt circles would be... then go from there.
quote
My other problem is with wheels, because I will be running something considerably larger than 15's. I guess my best bet there is to go with forged wheels. If all else fails, and a decent ride is out of the question with what I want on this car, I will just have to use it as a toy and tow it on long distance trips. I was trying to see if it would be possible to come up with something that the wife and I could stand to take on longer trips.
That's one thing you have to decide how much you want to compromise. There's no need on a Fiero to go larger than 17". 17's in the front to clear 13" brakes and 17's in the rear to clear the suspension and go as wide as possible. You can fit 17x9's with coil overs and 17x10's with strut blocks. 17x8's are all you need in the front. The 10's will fit a 275/40-17 rear tire and the 8's a 225/50-17 front tire. That's the same sidewall as a C5 Vette has, and a lot more than what many people are running
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
[This message has been edited by Will (edited 11-07-2003).]
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09:39 PM
Nov 8th, 2003
OutlawFiero Member
Posts: 262 From: San Diego,CA,USA Registered: Sep 2002
Good post!! Will keep us posted on what set-up your going to go with. I like how you're tackling the problems with the Fiero's and the hub/axle strength with bigger engines. I have a coilover setup in my 88 GT and am now preparing for a 3.4 TDC install. After that comes the brakes, and I want the most effective but lightest setup available. With that it sounds like 11.25 inch rotors are the way to go compared to 12' rotors.
------------------ Help, Someone has lit a Fiero in my a#@!
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01:07 AM
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
The ride is going to be harsh if set up for performance.
It comes down to damper tuning if nothing else. The optimum damping ratio for road-holding is .45 while the optimum for ride is .15. Most US manufactures are using a .25 ratio which means a 25% critical damping of the unsprung mass.
You bought "Race Car Vehicle Dynamics" like I suggested in your Porsche thread right? Turn to page 807 and look at the graphs. Compromise is not going to happen without active suspension.
Your best bet is to buy a set of dampers off of a car that you like the ride and hanlding characteristics. Have them dyno'd or buy a dyno. Then calculate the CG and sprung and unsprung weights of the car the they came from. Use that data to calculate what kind of force curves you want and then tell someone(koni, penske, moton, jrz . . .) to make them for you.
The fiero's chassis is not as stiff as one would think. A friend of mine does hill climbs in one and his car was noticibly stiffened by the roll cage he had installed. A cage like Doug's that ties in strut towers is probably even more effective.
I like that people here are now wanting DAs. Once you have them on your racecar, singles won't do!
There's an SAE book on road car suspension design that I think would be good for you. The name escapes me, but if spending $100 on a book doesn't phase you I'll get the name. The parts I read on civic/integra suspension were excellent.
I don't see a problem in using 17 inch wheels. It's hard to get good 15 inch tires for the street.
quote
Originally posted by perkidelic:
Hehehe... Here I go again It's been a while since I have probed the minds of the gang here - hope you're still willing to play!
Is it possible to lower a Fiero, throw in big brakes, big wheels, and rubber band tires, and still have a nice ride??? . . . perk
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10:37 AM
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
There's an SAE book on road car suspension design that I think would be good for you. The name escapes me, but if spending $100 on a book doesn't phase you I'll get the name.
Please post. Thanks.
------------------ '88 Formula Project Testostarossa "Anything worth doing is worth overdoing."
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10:55 AM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
Originally posted by Will: That's one thing you have to decide how much you want to compromise.
quote
Originally posted by Howard_SacksThe ride is going to be harsh if set up for performance.
And there we have it. My first Fiero was my daily driver for a year, then I traded it on a Chevy truck (I still had another one). It didn't ride bad (stock) but I wanted morre room, more comfort. Ten years later, I can't see myself being comfortable in a Fiero for long periods of time again. That, with your help, brings me to my conclusion:
I am building my street-legal race car project to blow my mind - I am building this street car to have fun and help me make decisions about which way to go on the racer. This question about decent ride quality came up because I was considering doing the Hot Rod Power Tour next year - Texas to Wisconsin (+ to Texas and back hoem from WI).
If I do, it ain't gonna be driving a Fiero! I might as well accept the fact that both of my Fieros are toys, and use them as such. I will just concentrate on having the best ride possible WITH the performance goals I set for this car. I will use the info brought out here to help me make good component choices. I think a reasonable goal is a car that I won't mind spending an hour or so in to go to Cleveland, etc. Other that that it will probably be on the trailer. Here are the main reasons:
*End Goal - Will and Howard made it very clear that it's all in what you want to do with the car. Even though this is my "street" car I want to have fun, performance-wise. That's more important than a Cadillac-class highway ride. *Limited space - even though Fieros are relatively roomy for a two-seat sports car *Limited range - small gas tank *Skin Deep - The race car is the project where I value ultimate performance above all else. This street car is supposed to be a fun expression of me. I will ultimately have wheels a good bit larger than 17"
Thanks again guys, and don't stop the discussion - I still want the best ride possible with the other choices I make. If I must have a two hundred pound wheel at each corner I can at least compensate for it in other places.
perk
[This message has been edited by perkidelic (edited 11-08-2003).]
for the best ride quality start with a 1988 fiero there is a lot of difference between the earlyer cars and the 88's softer shocks and struts or koni set full soft find softer springs to cut or softer lowering springs lower rated psi tyres even if low 30/40's wll not be as hard riding as higher psi ones
------------------ Question wonder and be wierd are you kind?
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03:27 PM
Boricuasoy Member
Posts: 312 From: killeen, TX , Fort hood army base. Registered: Aug 2003
one thing i did to maintain the ride Q" when i lowered the fiero was to shorten the bump stop tower by 3/4" in the front this allowed for wheel travel to be keeped close to factory specs.
We recommended you some books because if you're serious about engineering performance rather than just buying the parts available, you have to understand the concept of what makes the car handle. Once you understand the concepts, it'll be much more clear what compromises have to be made to achieve different handling characteristics.
Bryce 88 GT
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09:01 PM
Nov 9th, 2003
madcurl Member
Posts: 21401 From: In a Van down by the Kern River Registered: Jul 2003
Is it realy possible to have a good ride with 30- 35 series?
Sure it is....only if you have two cars.
Will it ride like stock? Yeah if your smok'n on something, he,he.
All jokes aside...30-35 series are OEM for "all" Porsches today. If you have any question.....just go down to your local Porshes dealer. You will find that their stiffer than most and the noise level is increased.
However, they "sell" Maybe a customer might complain about the ride's "stiffness but I don't think ther're gonna put 60-50 series on the car. Besides the tires are "run-flats." 60-50 series tires pre-date our cars.
Our Fiero's outer design is 15-20 ahead but the suspenion (NOT 88'S) and tires are all outdated. What cars produced today run with 60 series? Cadillac's..now thats scary!
So if you can live with 30-35 series go for it. Yes it may mean you cant fly over rail road track, pot holes, and a quiet conversation w/friends, but who cares? The uses of proper coil-overs f/r without tring to go two low will give you a some what tolable ride...low as you can go will result in a harsh ride.
Me.....I dont like living in the past when it comes to engine, suspension, and rims/tires. Lets move on...rather it be 3800/V8, brakes, or rim/tires. When I want a smooth ride I'll roll n the Mercedes.
[This message has been edited by madcurl (edited 11-09-2003).]
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01:41 AM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Originally posted by ray b: lower rated psi tyres even if low 30/40's wll not be as hard riding as higher psi ones
Once we translate from Ray-speak this is true. The 255/50-16's that I run at 40 psi to maintain consistent contact patch with 125 mm of sidewall probably ride harder than 275/40-17's at thirty-couple psi with 110 mm of sidewall.
Don't forget that Corvettes handle as well as any exotic but run taller sidewalls for the most part.
Also, Re: 15" wheels... I suggested those because most serious AutoXers run 13 to 15" wheels in order to keep rotating and unsprung mass to a minimum. Good handling is possible with smaller wheels. I don't think they should be discounted outright if you're looking for the best compromise between ride and handling.
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
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09:59 AM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
Originally posted by madcurl: ...When I want a smooth ride I'll roll n the Mercedes.
That's kind of where I am headed (minus the Benz) "smooth" being relative. I don't want it to ride like a cement truck but it doesn't have to pamper me. I'll just deal with the slightly rougher ride on the straights until I can get my anesthesia in the next curve When all else fails, it's like I said - put her on the trailer until we get to the next "playground".
quote
Originally posted by Will: I don't think they should be discounted outright if you're looking for the best compromise between ride and handling.
I am not discounting them outright Will, it's just a matter of priorities. In this case, image is just as important to me as performance so I am going with some really big hoops and rubber bands. That will keep my smile on even when I am on the outside looking in On the racer your points will be well taken and weight will be a bigger factor in determining the actual sizes. There performance rules. Can't say I will go with 15's, but they probably won't be as big as the street car's hoops.
perk
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11:30 AM
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
Perkidelic, I've got to agree 100% with Bryce here. The Carroll Smith books are great . Also are the Forbes Aird ones. I guarantee if you if you buy either, you will not do anything with your spare time or watch TV until you are done. They are that good. I'm not writing to read books to talk down to you(or other people on the forum . . . I recently got flamed on a nitrous thread . . .kids with their NAWZ) either. It will help you a lot to better understand where YOU want to go.
If you haven't read anything yet, buy "Race Car Chassis Design and Construction" by Aird. It is a great book that is only $20 and explains basic suspension geometry, chassis theory (from ladder frames, to space frames, to stressed skin), loads and basic engineering principles, and material engineering. It has lots of clear pictures of diagrams and is very easy to understand.
When you're done that, PM me or Bryce and we'll point you in the direction for book number 2.
We recommended you some books because if you're serious about engineering performance rather than just buying the parts available, you have to understand the concept of what makes the car handle. Once you understand the concepts, it'll be much more clear what compromises have to be made to achieve different handling characteristics.
Bryce 88 GT
Marvin, I'm working on getting the title of the book (I'm 90% sure it's Fundamentals of Vehicle Dynamics or something similar .. ..I'm wrong it's "The Automotive Chassis Engineering Principles") and if I find the scans from the chapter I read, I'll send 'em to you.
Bryce, This is kind of off topic but while I'm editing the post I got prepreg in this past week and did my first lay up with it this weekend. Very, very cool stuff. You gotta try it. Best part is, when you're done, there's no mess. No epoxy puddles or random fibers all over the place. And it's SOOO much stiffer then even the $100/gal rtc epoxy. Now, all I gotta do is design the monocoque lol.
[This message has been edited by Howard_Sacks (edited 11-09-2003).]
[This message has been edited by Howard_Sacks (edited 11-27-2003).]
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10:20 PM
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
Yup. Bouncing off bumpstops isn't going to do anything for ride or handling.
but I've got the feeling Perk's suspension isn't going to be anything close to stock.
quote
Originally posted by Boricuasoy:
one thing i did to maintain the ride Q" when i lowered the fiero was to shorten the bump stop tower by 3/4" in the front this allowed for wheel travel to be keeped close to factory specs.
Is there anyone that makes a progressive rated spring ?? So that the ride isn't as harsh while just cruising down the highway or at low speeds, then the higher rate kicks in bout the time you hit the twisties hard..
------------------
3.4 DOHC Turbo swap in progress
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11:05 PM
Nov 10th, 2003
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
Not a bad idea. That paired with a damper that has both high speed and low speed adjustments would work nicely. It would probably end up costing five figures after development though.
The Eibach prokit's are progressive in the rear. I don't think they are in the front.
Progressive springs are both expensive to develop and to produce.
quote
Originally posted by Kameo Kid:
Is there anyone that makes a progressive rated spring ?? So that the ride isn't as harsh while just cruising down the highway or at low speeds, then the higher rate kicks in bout the time you hit the twisties hard..
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12:03 AM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
Originally posted by Howard_Sacks:...I've got the feeling Perk's suspension isn't going to be anything close to stock.
That's for the (street-legal) race car Howard. It will as you say be light-years away from the stock Fiero suspension (84-87 or 88). I could care less about ride quality on that car. I only care about big performance numbers, huge smiles, and something to get my eyes back in the sockets.
I am inquiring about ride quality for a different project - my street car. I decided to "throw together" a "lesser" Fiero while I hammer out the details of the race car. It will be based on upgraded Fiero suspension systems. I want to use Wil/Street Dreams aluminum front hubs and dropped spindles - with RCC or Held tubular arms. In back aluminum W-body uprights with coil-over conversion. Double adjustable shocks/cartridges at each corner. Nice setup but no where near the madness I have planned for the other car.
quote
Originally posted by Howard_Sacks: I guarantee if you if you buy either, you will not do anything with your spare time or watch TV until you are done. They are that good.
As for the books that you guys suggested, I have the list - actually I printed the entire "Porsche-ish potential" thread for reference. When the appointed time comes I will dive deep into that list. Just what you just said is why I haven't done it yet. I know me - it will happen just like you said it. I am working twelve to sixteen hours a day right now and just can't do it yet.
There's another, more relative, reason that I ask so many questions here. Books are full of theory, fact, priniciple, and similar experiences. PFF is full of very Fiero specific wisdom that is the result of years of learning and experimenting. Take a look at Will's posts. They are full of very specific hard data, as well as good ideas. There is also subjective information about Fieros here. People's opinion about their experiences in actual Fieros.
I know, I know, I have a wierd way of going about things. Always been that way and probably always will be. If you tire of my incessant questions just ignore me
perk
[This message has been edited by perkidelic (edited 11-10-2003).]
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01:02 AM
Nashco Member
Posts: 4144 From: Portland, OR Registered: Dec 2000
Perk, I'm sure it's obvious, but Will has read some (probably all) of the recommended books, that's why he understands what is necessary to develop X type of handling. The advantage he has on most of us is that he's a couple steps ahead and has already investigated a few potential setups using parts from other cars.
A note for the future...never use the word DEVELOPING unless you have a lot of time. Developing anything takes way more time than it's supposed to.
You really need to just focus on one thing at a time...at the rate you're going, you'll have researched XXXX hours and still not have a finished project! I don't know how much business sense that makes...it sure as hell doesn't make any project sense. I think we're all just antsy to see you build something, it's much more fun helping you BUILD something rather than dream something!
Bryce 88 GT *edit: way too damn late to be typing
[This message has been edited by Nashco (edited 11-10-2003).]
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03:48 AM
PFF
System Bot
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
Originally posted by Nashco:...You really need to just focus on one thing at a time...at the rate you're going, you'll have researched XXXX hours and still not have a finished project! I don't know how much business sense that makes...it sure as hell doesn't make any project sense. I think we're all just antsy to see you build something, it's much more fun helping you BUILD something rather than dream something!...
Actually Bryce, what I "really need to just focus on" is what I choose to focus on. I don't have to satisfy anyone but myself. I am not trying to start anything with you - I actually used to like talking to you. Everyone else here has offered knowledge, wisdom, experience, ideas, suggestions, etc, and you have sunk to the level of coming into a thread and donating nothing but your opinion about why I shouldn't even be asking the questions. If it irritates you that I have not read the books, or finished my car, ignore my threads. When you see my name next to the title of the thread spit on it and keep on stepping.
To everyone else that has donated a couple cents worth of knowledge here - thanks a million and I appreciate your patience. As a result of this thread, I am checking into something that may offer the ability to have the best of both worlds. A decent ride and 1G lateral acceleration. I was about to give up on it when another bright idea hit me. I am working on getting the parts. Combined with some of Will's ideas for a lighter weight, affordable, suspension it should be pretty nice.
I actually have a lot of things that I will reveal to the PFF community in the future. Most of it will be things that I don't make a dime on - just my way of saying thanks for your help. Sorry that I am not giving any more details, but I learned early on not to share certain things on PFF because sometimes you get more opinions than help.
perk
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11:26 AM
cardealer Member
Posts: 511 From: austin tx usa Registered: Jan 2001
just an idea: decide and build the power plant and transmission first, then build the suspension around that. for the most part, even after all the research its hard to tell how the characteristic car will operate untill you get it on the road. always think "combination".
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04:23 PM
Nashco Member
Posts: 4144 From: Portland, OR Registered: Dec 2000
Everyone else here has offered knowledge, wisdom, experience, ideas, suggestions, etc, and you have sunk to the level of coming into a thread and donating nothing but your opinion about why I shouldn't even be asking the questions.
perk
Damn...I wasn't expecting that, you either took what I said way too seriously or you just woke up on the wrong side of the bed today. Either way...simma down.
Regardless, if you want to look at it that way, the reason I haven't offered, "knowledge, wisdom, experience, ideas, suggestions, etc," to this thread is not because I don't want to.
Along with others, I've been heavily involved in some of your past threads brainstorming how to accomplish something with the Fiero. I'm always game to coming up with new ideas, but it seems like you're not even listening to our advice? We recommend a few books, tell you how much better off you'll be after reading them, but you ignore the books. So be it, what you do with your time is up to you, but then six months later you're asking questions that would have been answered if you read the book.
Am I wrong for repeating that you should read the books? I *guarantee* you'll save time, money, and effort in the long run if you only bought a couple of those books and read them. Howard recommended book number 1, and I'd agree that is the best place to start off.
Just like Howard said, I'm not saying you should read the books to talk down to you; I'm saying I learned so much just from a few hours spent reading a book that I think EVERYBODY interested in vehicle performance should do the same. You said you'd read the books when, "the appointed time comes." In reality, you're stepping over dollars to pick up quarters....you're spending time trying to understand something by picking it up from bits and pieces of what other people tell you, instead of just going straight to the source. You'll save time if you read a few of the books recommended to you. Do you think it would be quicker to ask us about Africa, or just open an encyclopedia?
There's no reason to get hostile, dude, we're all on the same team.
I'm always game to coming up with new ideas, but it seems like you're not even listening to our advice? We recommend a few books, tell you how much better off you'll be after reading them. Am I wrong for repeating that you should read the books? I *guarantee* you'll save time, money, and effort in the long run if you only bought a couple of those books and read them. Howard recommended book number 1, and I'd agree that is the best place to start off.
Bryce 88 GT
Hey Bryce, I'm not building an all out balls to the wall race car but I'm planning on redoing my suspension after the engine swap. I want to goto coilovers and adjustable shocks all the way around... (sorry perk don't mean to bust into your thread, but won't side track it too far i hope) I would like to know what you and the others that know from the "books" that you've read.. So would you be so kind as to list them in an order that you think they should be read. Title and authur: I have some knowledge in suspensions but nothing the likes of the gurus in this and the thread that perk had posted... thanks ahead of time for your time.
Kelly
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06:55 PM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Originally posted by perkidelic:I want to use Wil/Street Dreams aluminum front hubs and dropped spindles - with RCC or Held tubular arms. In back aluminum W-body uprights with coil-over conversion.
I would suggest Held upper coil over mounts and upper control arms with RCC lower control arms.
The Held upper mounts bolt in while the RCC mounts require cutting the crossmember. The Held upper arms are obviously made for the Held upper mounts. The RCC lower arms are adjustable for caster while the Held lower arms are not.
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Originally posted by Nashco:I'm saying I learned so much just from a few hours spent reading a book that I think EVERYBODY interested in vehicle performance should do the same. You said you'd read the books when, "the appointed time comes." In reality, you're stepping over dollars to pick up quarters....you're spending time trying to understand something by picking it up from bits and pieces of what other people tell you, instead of just going straight to the source.
I agree with what he said about learning things. I however abhor starting with the basics. I learn so much faster by identifying the first principles at work, then emplying deductive learning from there. With that motivation, I go straight for the advanced texts. If you want to read an extremely in depth book on the subject, try "Tires, Suspension, and Handling" by John Dixon. It's much more expensive than the other books because it's a college text on vehicle dynamics and has something on the order of 5 or 6 hundred pages.
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
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08:06 PM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
There's a nice suspension setup presented here for 84-87 Fieros for anyone out there who is looking to develop a well-balanced setup.
* Will/Street Dreams aluminum front hubs and spindles - to lighten up the front suspension and get an almost penalty free 1-2" drop. *Held tubular upper control arms and RCC lowers up front. *Hopefully someone will be able to come up with a tubular lower rear control arm that will allow the use of the aluminum W-body uprights. *Will touched on some of the brake upgrade offerings from Lebaron to Corvette (see his thread on the new hubs and spindles for specific details.
Tune all of this to your specific application with the right springs and shocks and it should make for a nice handling car. What's really nice about it is it can all be done in stages. If enough people would do it eventually the exact spring rates and shock valving for different motor/trans combos would start to emerge.
That is one thing I was after here. On some other forums I frequent there are guys experienced enough in particular types of vehicles (especially Corvettes and Camaros) that they can tell you almost exactly what parts to use to get a desired end result. Usually they are based around some main components that are the "norm" with a few changes to fit the car/owner.
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Originally posted by cardealer: decide and build the power plant and transmission first, then build the suspension around that. for the most part, even after all the research its hard to tell how the characteristic car will operate untill you get it on the road. always think "combination".
Agreed cardealer, I have the engine trans combo that I plan to use sorted out and a pretty good idea of where I need to go with it. The only reason I haven't started putting it together is I may be getting some of the parts through sponsorship and was taking a little extra time to think about what I wanted. Don't wanna go back and say, "hey this isn't what I really wanted, can I have a *#$@% instead"!
Most, if not all, of what has been brought out here is good for almost any vehicle - e.g. reducing unsprung weight. The methods of doing that brought out here are pretty universal and pretty strong so they could be used in virtually any setup - with the right tuning.
perk
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10:22 PM
Nov 11th, 2003
Nashco Member
Posts: 4144 From: Portland, OR Registered: Dec 2000
Hey Bryce, I'm not building an all out balls to the wall race car but I'm planning on redoing my suspension after the engine swap. I want to goto coilovers and adjustable shocks all the way around... (sorry perk don't mean to bust into your thread, but won't side track it too far i hope) I would like to know what you and the others that know from the "books" that you've read.. So would you be so kind as to list them in an order that you think they should be read. Title and authur: I have some knowledge in suspensions but nothing the likes of the gurus in this and the thread that perk had posted... thanks ahead of time for your time.
Kelly
Ok, here goes. Of course, the order which they should be read is going to differ from every person you ask. I'm the type to start with the basics and work my way up, which is also helpful in my case because the basic books are usually the cheapest. I only buy an expensive book if I KNOW it's going to be something I'm actually interested in, with the exception of school books.
Also, I've found that Amazon's used books are about the cheapest you're ever going to find and I've always had good service. If you keep an eye out, you can usually get any one of these books for about half of retail, which is how I've got almost all of them. So, here's the list:
Herb Adams - Chassis Engineering Forbes Aird - Race Car Chassis Design and Construction Carrol Smith - ANY AND ALL! Much more in depth than the previous two books, but all of his books are great reading. Fred Puhn - How To Make Your Car Handle Paul Van Valkenburgh - Race Car Engineering and Mechanics
That's plenty enough to get you started! Another great thing about Amazon is that you can see how others have rated the book, as well as seeing what other books are purchased by people that buy that book. You can tell pretty quickly what books are good or not and if they fit your interests based on the reviews.
I really like Forbes Aird, Carrol Smith, and Herb Adams. They're all very straight forward, down to earth, well experienced guys. Herb Adams even has a connection with the Fiero racing program! Carrol Smith has written several books, and every single one of them is worth purchasing. Forbes Aird has also written several books, with quite a broad range of topics; Aird's stuff is great for beginners because he breaks things down so you understand them, but he doesn't kill you with the details. Carrol Smith's are just as easy to understand as Aird's, but he'll go down to the most minute of details most of the times, which is good if you're interested and you make time to read.
I've still got a few books on the shelf that I haven't had time to read yet. Oddly enough, I wish I had to go to the bathroom more often, because that's about the only place I find time to read anymore!
Bryce 88 GT
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11:57 PM
Nov 12th, 2003
Whuffo Member
Posts: 3000 From: San Jose, CA Registered: Jul 2003
Is it possible to lower a Fiero, throw in big brakes, big wheels, and rubber band tires, and still have a nice ride???
Thoughts, comments, theories, suggestions, ideas, two cents....?
perk
Yes it is - almost. The key is to minimize your unsprung weight; you want the wheels, rotors, calipers, spindles, etc. to be as light as possible.
What kind of driving will you be doing in this car? Full-out track racing is a whole different thing than daily driving with a little street racing thrown in.
If, as I suspect, you'll be driving it on the street primarily - you'll want to choose your parts wisely and temper your desire for style with sensible selections.
When shopping for wheels, consider how much they weigh. It's the heaviest part of your unsprung weight (usually), but lightweight alloy wheels are available and some of them look pretty doggone nice. Same with the tires; they're not all the same weight.
Take a look at my thread "Score - snatched up a good one" to see what I chose. Not the fanciest around, but it works good and the weight is as low as I could get it. This made a substantial improvement in ride quality and handling - and it didn't cost a whole bunch of money.
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01:27 AM
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
The order to read books is tough. In the past year, I suggested to a lot of mechanical engineers what they needed to read in order to be brought up to speed on race car engineering. when you have someone 6 months away from graduating ask you "which part is the spring and which is the shock" on a coil-over damper setup, you know they've got some reading to do.
Herb Adams - Chassis Engineering - This book would not be on my list. I'm not going to tell someone not to read it, but it certainly wouldn't put it number one.
Forbes Aird - Race Car Chassis Design and Construction First on list.
Staniforth - Competition Car Suspension. Number two. Clearly explains in detail many suspension basics that are quickly gone over in number 1.
Carrol Smith - Anything by Carroll is a must read. Some people argue they need to be read in order they were writting. I think it really depends on what the person is intending on doing. I think, if the person is going to fabricate, "Prepare" and then "Engineer" in a hurry. If the person is into motorsports and not quite into the construction aspect yet, "drive" I might(and have) even hand them "Drive" before the top two. If the person is going to be designing components, "Engineer" and then "Prepare." I used to suggest "Tune" as the first book most people should read, but I now feel that the top two books read a little easier. However, I have now read "Tune" three times now and some chapters many more. So, I'm not saying "tune" should be neglected.
Fred Puhn - How To Make Your Car Handle I've read it. Wouldn't be on my list. Everyone that reads that wants to over-bar their car.
Paul Van Valkenburgh - Race Car Engineering and Mechanics Good book. I think I'd recommend that and some of his articles in Racecar Engineering as a nice intermission from the Carroll set.
Competition Car Preparation Again, depends how much you're going to be fabricating.
Maybe a book thread in tech or OT wouldn't be a bad idea?
quote
Originally posted by Kameo Kid:
I would like to know what you and the others that know from the "books" that you've read.. So would you be so kind as to list them in an
[This message has been edited by Howard_Sacks (edited 11-12-2003).]
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04:48 PM
PFF
System Bot
Nashco Member
Posts: 4144 From: Portland, OR Registered: Dec 2000
...when you have someone 6 months away from graduating ask you "which part is the spring and which is the shock" on a coil-over damper setup, you know they've got some reading to do.Maybe a book thread in tech or OT wouldn't be a bad idea?
I know what you mean...some of the people in my senior level internal combustion engine class ask me some of the most obvious questions. I understand everybody has to start somewhere, but don't you think that by the SENIOR YEAR of your degree program in AUTOMOTIVE ENGINEERING you could have picked up a book and expressed some personal interest? It's scares me that people are spending almost a hundred grand (expensive private school, don't get me started) to get a degree in something they haven't even bothered to learn a little about on their own.
In reference to a thread about books to read...ugh, I could see that becoming a big pain in a hurry. The fact that there's easily 100 books out there that could keep us entertained, but two you're going to have different takes on different books. For example, I haven't read Puhn's book yet, just glanced it over, and it seemed quite complete. I also haven't bought Staniforth's book yet, although it's approaching the "next to buy" spot. I'm going to buy the rest of Carrol Smith's books next, his stuff is great.
Bryce 88 GT
PS: Howard, I sent you an email the other day..did you get it? Email me back and let me know, thanks.
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07:41 PM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Hey Will, before I remember you writing that you didn't like the Held geometry. Is this stuff now using stock geomertry or what gives?
eh?? The Held sport suspension uses stock geometry (except for the wide-track versions of course). I've heard that their scratch designed Slalom geometry coulb be better, but I've never heard a good explanation of why.
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Fred Puhn - How To Make Your Car Handle I've read it. Wouldn't be on my list. Everyone that reads that wants to over-bar their car.
As far as ride goes, bars accentuate one-wheel bumps. As far as handling goes, they should be a fine-tuning tool only, not a primary source of roll stiffnes. If you think about it, you'll see that using a bar actually reduces contact patch load on the inside tire and leads to premature inside wheel spin coming off a corner. Several cars characterized by sublime handling either don't use bars at all or use very small bars. The Morgan Aero 8 and Lotus Elise come to mind.
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
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11:38 PM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Originally posted by perkidelic: There's a nice suspension setup presented here for 84-87 Fieros for anyone out there who is looking to develop a well-balanced setup.
*Hopefully someone will be able to come up with a tubular lower rear control arm that will allow the use of the aluminum W-body uprights.
I just bought some W-body control arms today, and I already have a set of RCC arms that were carved up a little bit for a previous project...
The W-body upgrade is looking even better. I did some research today and found that C5 Corvette hubs will bolt into W-body hub carriers. The W-body uses 33 spline CV's, while the C5 uses 30 spline CV's, so Corvette CV's would be necessary.
I haven't been able to find out how many splines the Corvette axles have yet, but the Fiero manual trans axles (and P6K HD components) have 32 spline axles, while the W-bodies have 34 spline axles.
Anyway, custom axles may be required for the W-body hub carrier swap, but may also open the door for the C5 hub swap once they are made... More as I find out.
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
Originally posted by Will: I just bought some W-body control arms today, and I already have a set of RCC arms that were carved up a little bit for a previous project...
Did you get the hub carriers too, or just the arms for now? Curious about how the geometry will work out.
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Originally posted by Will: The W-body upgrade is looking even better. I did some research today and found that C5 Corvette hubs will bolt into W-body hub carriers...
Wait, I have something on my face ... oh, my bad, that's a smile You know that's right up my alley, right? With your front hubs, I will have the C5 bolt pattern and brakes at each corner (plus bearings up to the task). The final compliment to this will have to be a set of forged wheels. I should end up with a light strong setup that still looks like I wanted.
For my street car my goal is to use as many off-the-shelf components as possible to bring the project together as quick as possible and reduce down time during upgrades - it will be done as a progressive series of mods. I will use the knowledge in the books to fine tune the end result to my personal tastes. View it sort of like what guys have to do to be competitive and win in some race classes. Certain combinations are mandatory, but you have leeway in the fine tuning of those combinations to accomodate your driver, and find an advantage. Will pointed out what I believe is the best reasonable combination of parts that can be pretty much bolted on a Fiero, and still yield great results.
My race car project is on the other end of the spectrum. It is being designed basically from bare bones and it gets whatever it takes - no rules, almost no limits - to be what I want it to be. That one will be based on the theories, facts, and experiences, of the books and key people I have come in contact with - rather than having them subsequently applied to it.
I have a little more research to do and then I will share my idea for a almost luxury class highway ride and excellent 1G-capable handling in one car - a short wheelbase Fiero at that!
perk
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01:04 AM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
Originally posted by perkidelic: Did you get the hub carriers too, or just the arms for now? Curious about how the geometry will work out.
I also have a pair of hub carriers (or I have one now and will collect the 2nd today). For a while I was looking for a ball joint that would fit the hub carriers but be somewhat adaptable to the Fiero control arm. I couldn't find such a piece so I'm resorting to having custom arms made.
I need to see how far out my friend's GTP will go in terms of camber. 0 degrees on a W-body would translate to about -4 degrees on a Fiero because of the difference in strut top locations. If there's not enough adjustment range in the W-body hardwar, I may be able to fit strut blocks that would both allow wheels with more back spacing and camber adjustability to a more streetable range (like -2 degrees). Another possibility is to gain camber back by making the control arm shorter, which would make preferred wheel sizes and cornering loads more wheel bearing friendly and make the camber curve more aggressive, but would require shortening the axles a little bit.
You have fabrication facilities, right? Once I have the prototype arms done, would you be willing to make jigs to make more if I send them to you?
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
[This message has been edited by Will (edited 11-13-2003).]
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10:29 AM
Will Member
Posts: 14250 From: Where you least expect me Registered: Jun 2000
As far as ride goes, bars accentuate one-wheel bumps. As far as handling goes, they should be a fine-tuning tool only, not a primary source of roll stiffnes. If you think about it, you'll see that using a bar actually reduces contact patch load on the inside tire and leads to premature inside wheel spin coming off a corner. Several cars characterized by sublime handling either don't use bars at all or use very small bars. The Morgan Aero 8 and Lotus Elise come to mind.
One more thing... having a lot of bar means that you can't properly damp roll motions AND plain jounce/rebound motions. If you have a huge bar and you get your jounce/rebound damped correctly, then roll motion will be under-damped. If you get roll motion damped correctly, then jounce/rebound will be overdamped. But that's getting pretty in depth into tuning principles and has to do with balance and optimisation.
------------------ '87 Fiero GT: Northstar, Getrag, TGP wheels, rear sway bar, rod end links, bushings, etc. '90 Pontiac 6000 SE AWD: Leaking ABS unit fixed, load levelling rear suspension fixed, still slow
[This message has been edited by Will (edited 11-13-2003).]
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11:12 AM
perkidelic Member
Posts: 772 From: Masury Ohio USA Registered: Aug 2002
Originally posted by Will: You have fabrication facilities, right? Once I have the prototype arms done, would you be willing to make jigs to make more if I send them to you?
Most definitely. I was actually going to ask you about collaborating on the rear setup, but figured I'd better calm down and go one step at a time. Sounds like fun
I kind of have an advantage on the rear because I am replacing the upper frame rails, strut towers, etc, with tubular frame rails - so I can locate the upper strut mounts for the proper camber. I want to help develop a true bolt-on application for people who are not so inclined to pick up the saws and welders.
I have a question about the front suspension for you: What are the "technical difficulties" in the geometry. I have a spare front suspension system that I planned to study, but just figured if someone already knows the numbers it would save me the trouble of setting up something to measure it.
perk
[This message has been edited by perkidelic (edited 11-13-2003).]
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01:01 PM
Howard_Sacks Member
Posts: 1871 From: Cherry Hill, NJ Registered: Apr 2001
I remember reading in another thread you writing about being less then impressed by how things looked in Racing By the Numbers, but can't find it and really don't have the time to look. Search here bites. (Cliff won't take me up on my offer to host HTdig . . .)
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Originally posted by Will: Give me you silver car, $10K and a TiG welder, and it'll pull more than 1G.
I've measured the geometry of the Held Slalom setup. It's better than stock, but it's really not that good. I'll do better when I get around to building my own suspension.
Convent
I don't think you need facilities to make jigs Will. We draw a grid on a sheet of plywood and then fix the tubes to it. When Pete gets really crazy, we used the CNC mill to drill holes in the sheet to help line things up, but that's not really necessary.
Making control arms isn't that tough. Making the tool to stake the bearings is .. .