Thanks 85-308. I thought "Excavation" sounded a little more constructive than "Demolishion"

My original plan was to use the Arraut bump steer control arms and if I find that my final control arm length is still within their available range I may still go that route. If not, I'll have to build my own with a similar bump steer arrangement.

With regard to aluminum, I don't weld it either. However, the shipyard I work for builds alot of aluminum vessels and we have some of the most talented aluminum welders on this side of the country. So I have that in my favor. I know there is some doubt whether an aluminum cradle will yield significant weight savings but considering my cradle will be a little larger than stock, I think I can come up with a design that is strong and light(ish).

Well, all the parts have been blasted and primed and are now balanced precariously for a photo opportunity. Next step is to carefully weld it all in place without warping what's left of the original chassis.

Okay, maybe I should move to Nova Scotia and become neighbour's with you and Dave. It seems like you all have more time in a day than the rest of us! Are there 36 hour days in NS? Just kidding. Excellent work so far.
Shayne

Thanks Shayne. I wish there were more hours in the day sometimes. It must only seem like a lot gets done fast because for me, my project seems to go very slow. I spend weeks and months figuring out what I want to do and then complete the design before I start any fabrication. Then I have a short spurt of actual build time. I don't have an artistic bone in my body and could never attempt to "freestyle" my build. It would be a complete disaster ha-ha-ha. You really have to admire and envy guys like Car-Lo that can visualize something in their mind and then bring it to life with their hands and in the end produce something that is both beautiful and functional.

edit: for typos

[This message has been edited by Yarmouth Fiero (edited 12-30-2014).]

Looking really nice Yarmouth Fiero;

That is one clean looking engine bay....

I still say that Audi V8 with an 012 transaxle like engine man did would look amazing in the engine bay. Shorter by a bit as well so it would fit in much nicer than an SBC and no need for an adaptor plate. The engine management system would end up the same as your adaptor plate build and the rubber belt system. Just a thought.....

Happy New Year.
Don

Thanks for your input Don. I was just shutting down for 5pm. I agree with you and I am still throwing engine / gearbox possibilities around. There are a number of options and they all have their strengths and weaknesses for sure. I still have lots of fab work to do so until then, I'll keep researching. Have a safe and prosperous New Year.

Graham

I took a few hours today to lay out a preliminary design for my new engine cradle and hopefully alleviate a few members concerns regarding my misfitting stock cradle.

I based the design on an aluminum structure so at the moment the longintudinal frames as 4" x 3" x 1/4" HSS and the cross frames are 3" x 2" x 1/4" HSS. I've also included poly bushings at this time. Once I have an engine and gearbox finalized, I'll locate the cross members and suitable gussets properly to strengthen the structure and support the require engine / gearbox mounts.

Edit to add: aluminum cradle as shown weights approx 52 lbs.





Here are a couple pictures showing the suspension in place. I added a simple tubular control arm to give an idea of the horizontal orientation.







And of cousre...... the money shot.

[This message has been edited by Yarmouth Fiero (edited 01-01-2015).]

If the Ferrari F355 wheel base is 96.5" and they can fit the driveline in longitudinally. Your wheel base, with the added 3", is very close to the Ferrari (within .100"). Can you not use/find a different transaxle with the output shaft's closer to the rear of the engine? This belt drive system, while cool, adds much complexity and weight to your build. I know the SBC is long at the front with the water pump, pulleys, etc and I'm sure the Ferrari has a shorter engine. (I don't know, I've never seen one up close). Just curious.

PS-The Porsche 914 transaxle is about 8" from bellhousing to output shaft.


The overall is close to 24",

[This message has been edited by Lunatic (edited 01-02-2015).]

Thanks Lunatic. If it's possible to avoid the belt drive, I certainly will. I still have to lower my engine in my drawing which will allow me move it forward a bit more. I still haven't found a good technical drawing of the LS1 so I may try to find a blown LS1 to mock up the arrangement. Here is a drawing of an Audi 016 gearbox which I'm told is very similar to the 01E. The dimensions seem to be similar to your pictures. Thanks for posting them btw. I appreciate all the input I can muster.

Just for info, the O1E is 7.5" from the bellhousing surface to the centre of the output axles; and you 'might' consider an LS4 which is the shortest of the LS series engines; they did a few things to it to make it shorter overall to fit in the transverse arrangement of the Impala SS etc etc... where every fraction of an inch counts maybe that would help?
The block itself isn't shorter or different except that the starter gets mounted on the trans instead of the engine and the accessories on the front, as well as the LS4 crankshaft 'snout' is shorter/shallower to make the overall finished 'length' or width in the case of the Impala, Monte etc, shorter to fit in the engine bay. All this might help....

Here is a rough dimension pics. You can print them out larger and use some calipers and the known "scale" to get the other important dimensions as well. :



Not sure if you could use this one:
http://grabcad.com/library/ls1-race-engine

[This message has been edited by fieroguru (edited 01-03-2015).]

Thanks Fieroguru.... printing an engine drawing to scale is exactly what I am going to do. I have a 42" wide plotter in my office. I have the Grabcad images but they are only pdf's. Good for reference though. I think I'll be able to generate a pretty close 3D model from the selection of images and measurements I have. Thank you for the additional drawings you have posted.

Yarmouth, I love watching your build, and bloozberry's too. The engineering and fabrication is amazing. I just wanted to interject some measurement info here since I have already been down the longitudinal route myself.

The Chrysler 3.5HO engine / 42LE transaxle I used was 26.5" long from the face of the harmonic balancer to axle centerline. Even clearancing the lower frame and firewall to move the engine as far forward as possible left me with a 2.5" axle offset with the wheel centerline without a stretch. Looking at the LS measurements, the engine alone is 24" long without accessories on the front, add in 8" for the transmission, another 3.5" for accessories brings the total to 35 1/2" long. That being said, you would need at least an 11.5" stretch to have a zero axle offset with the LS/01e setup. The other issue is the slope of the firewall will interfere with the waterpump pulley which would require cutting a hole ine the firewall, moving the engine back even further, or running a remote pump. It would be interesting to know what the Ferrari engine measures from the front of the engine to the axle centerline. Even though your wheelbase will be close to the F355, I'd bet the Ferrari engine is tucked up in the body a little further than would be possible with the Fiero spaceframe.

[This message has been edited by seajai (edited 01-03-2015).]

Thanks for the comments Seajai. I find it very satisfying to put the effort into the design of the project and almost as satisfying as the actual build itself. Your supplied measurements confirm exactly what I am finding in my 3D model..... basically everything behind the LS1 bellhousing has to be accounted for in either chassis stretch, shaft offset angle, offset drive system (a.k.a belt drive) or a combination of these parameters. When you add the thickness of the adapter plate, engine bay insulation etc, the length becomes even greater. As I have pointed out a while back, Blooz and I will be developing our 355 bodies together off the same plug so stretching the 355 any further than 3" is not an option. I am totally onboard with that. However, on a side note, I think the 355 spider would look very interesting stretched out like a lambo. I think the wide rear track of the 355 would accommodate such an extreme stretch and still be aesthetically pleasing. I wish I was an artist.......

Yarmouth, go over to 85SEnotchie's link on Fiero Chat. He is an artist skilled in Photoshop and has helped others in your situation. He did a beautiful stretch of an Archie's widebody for someone over there.

Ken

------------------
'88 Formula V6
'88 GT TPI V8

Thanks for the heads up Ken. I'll check it out.

Graham

Edit to add: Just picked up a blown Gen III engine to use for mocking up my engine bay. I'll also use the cold weather as an excuse to sit down and measure and model the engine in 3D since I've had little luck finding a suitable model online.

[This message has been edited by Yarmouth Fiero (edited 01-06-2015).]

Uhhh... by "blown", I suspect you mean "junked" rather than "with supercharger" right?

Yes, I mean this........



as opposed to this........

Rats.

Taking a little breather from the engine / gearbox work, I decided to put some thought into the rear suspension again. Having a basic arrangement for the new engine cradle, I have begun working on the rear control arms. I am going to build my own control arms to suit the wide track of my project. As well, I want to try and incorporate the bumpsteer correction, similar to what is on the market currently. Having read through archived threads on the topic for reference, I have attemped to get the control arm at the desired position at ride height and keep the bump steer linkage in the same plane as the control arm with the outer end linkage in the same line as the ball joint. Here are a few images of the arrangement. I have yet to confirm the kinematics of the linkages so it's likely going to take some tweeking yet.













Edit to add last image

[This message has been edited by Yarmouth Fiero (edited 01-18-2015).]

Superb drawings, as always. You should consider making a nice poster for the shop walls some day when it's finished.

The configuration looks like it should work... the nice wide spacing on the inboard control arm mounts will resist toe and apply accel and decel forces to the frame better than stock. You shouldn't get any toe throughout the range of suspension travel other than through bushing compliance under load. When that does happen, you'll want to make sure that the outside tire toes in rather than out otherwise you'll be battling oversteer. With the powertrain configuration you're planning, you'll probably have a greater rear weight distribution than stock and a greater propensity to oversteer too. Anxious to see the analysis.

Nice! I like your toe-defeat solution. Very similar to what I was thinking of (I don't have nice dwgs like that to post..) Obviously you're keeping the 84-87 spindles and the lengths of the 'tie rod' should be perfect.

Question - if you're there yet: How do you plan on connecting the outboard end of this 'tie rod' to the spindle itself; ie right at/near the ball joint? Welding? it is at the pinch nut location.
I was looking at bolting it to the spindle but still playing with that a bit.

Keep it up; great tech article in all respects!
GP

Thanks for asking 85-308. I have designed an albeit, rudimentary bracket that will be bolted at the lower end to the ball joint pinch bolt ( there is a nice flat surface already ) with the upper end being bolted to the spindle stock tie rod location. I'll drill the taper out of that hole first. I'll likely use grade 8 bolts and nuts with locking wire for added safety. I may also add a small gusset to this fabricated bracket for extra strength. I don't advocate welding to the OEM cast spindle unless you know what you are doing.

When I am designing / drawing, I tend to leave the fasteners out of the picture so that I can easily see if I have accidently shifted a part because the holes no longer line up. Its too easy to "bump" a part in the drawing if I haven't locked the layers first and then keep on drawing like everything is ok. Plus its easier to snap to centers of holes when the fasteners are hidden from view. I hope this answered your question.

Ok s you're not using a ball joint there; similar to what some of the kits do, and bolting it solid. The spindle is cast steel, I guess, since it does 'flex' at the pinch bolt, but I agree, in my bit of research on welding different materials I don't think I want to touch it with weld...

No, I am using a ball joint and using the pinch bolt to hold the ball joint and the extended bracket for the bump steer correction. Unfortunately I don't have my updated drawing on my work computer so I can't post more detailed pictures until tonight. I'll capture a few images that show that area in better detail. Sorry about that.

Yarmouth Fiero;

I went through a bunch of this analysis back when I was building my extended rear suspension. Albeit, my drawings were very crude and not nearly to yours and Blooz's standards..... I came up with an option that does not require a a trailing arm of any sort.

I would be interested in yours and Blooz's opinions on the setup I thought about.... You replace the ball joint at the bottom of the hub with a bolt and nut setup and make a cross bar setup at the bottom. As per my drawing. I always though that this would allow the hub to move up and down and not introduce bump but, again, I did not go through a lot of analysis on this. It was more of a drawing exercise than anything.

In the end, I moved my trailing arm pivots outward from their original locations on the cradle so that they pivoted pretty much over the suspension pivots on the cradle. Through moving the tire and rim through its entire motion, I removed all but about 1/16" or bump at full extension and contraction. By that time, I was already rolling so not so worried about bump by then......

Back to my thought, the picture below shows what my thought was. The top image is what I ended up going with for my wider suspension but the middle image is what I was thinking about after I had built the top one.

Cheers
Don

Thanks Don. That is an interesting concept. So is that showing a custom spindle with two pivots on the bottom end? If so, that would cure the bumpsteer for sure. I guess because I am changing my engine cradle quite a bit, I decided to get away from mounting the inboard end of the tie rod there. I think once I tweek my design and then test the kinematics, it should give results more than acceptable for my project. I don't plan on racing it anyway

Edit to add: To 85-308, here is a shot of my design with the bump steer bracket bolted in place. Hope this helps.

[This message has been edited by Yarmouth Fiero (edited 01-19-2015).]

ahhhh
NOW I get it; good idea. Thx!
GP

I had the exact same idea even down to using the pinch bolt as the attachment surface! It's floating around here somewhere.

I designed it to not be in single shear however and had a U shaped piece that went over the ball joint so the pinch bolt would go through both sides. I also had some additional reinforcement gusseting at the 90*, but I am sure you will too, excited to see how it turns out!

Graham;

The setup I drew was very similar to how you are set up except instead of having the training arm going to the inner mount location, I made a square bar that connects to the control arm both sides and then the Fiero hub bolts to the square bar and an arm comes up from the square bar to the trailing arm mount on the hub. The Fiero hub bolts to the square bar and the trailing arm mount.

If you took your drawing and made a square tube that bolts to the Fiero hub where the ball joint currently is, and extended your trailing arm hub mount down to that square tube, you would have my design. The ends of the square tube would connect to the control arm ends through hiem joints or pivot points similar to the inner control arm mounts.

I will see if I can do up a quick side view to show how the Fiero hub mates to the square tube on the control arm.

Cheers
Don

Hi Don. I am having a hard time visualizing your idea. Perhaps a side view would clear it up for me.

I saw your drawings in a thread from 2012 zkhennings and it certainly inspired my current design. I have some concern regarding your idea of pinching the ball joint pinch point though. If the piece restricts the clamping force on the ball joint shaft at all because of the extra stiffness of the additional material, it could possibly allow the ball joint to pull out due to reduced clamping load on the ball joint shaft. The OEM spindle design relies on the material deforming to provide the clamping force on the ball joint shaft. Even in my current arrangement I have concerns that the ball joint clamp is restricted on one side causing the casting to be deformed more on one side of the ball joint than the other. With regard to having the bolts in double shear, I think having the assembly bolted to the ball joint shaft as well as up at the tie rod connection should be adequate considering the most significant force on the tie rod is compression or tension as the spindle ( wheel assembly) tries to pivot about the ball joint axis. Like your earlier design, I will add a gusset between the horizontal and vertical parts of the assembly. I'll try to update the drawing accordingly tonight

Edit to add: as seen in the drawing below, is there a concern that the additional structure will prevent the green side of the ball joint clamp from deforming as much as the red side, causing the red side deform more and possibly crack under load? The spindle casting is machined to an specific thickness to allow the correct deformation when the ball joint bolt is torqued.

Input on this always appreciated.

[This message has been edited by Yarmouth Fiero (edited 01-20-2015).]

Doesn't the ball joint stud have a groove for the pinch bolt? That would positively hold the two together.

Indeed it does Blooz. So theoretically, they shouldn't come apart regardless of the clamping force applied.

I guess that's my green light to proceed.

Yarmouth Fiero;

Hopefully this crude drawing shows more of what I am talking about. Looks like you are going down a solid path though so good luck.

Cheers
Don

Thanks for the great drawing Don. Its not crude at all. Your design is very clear to me now. Its an interesting concept and has great merit as a functional and practical solution to the common problem many of us have been contemplating. I think in the end, we all recognize what has to be achieved and there are certainly many ways to catch this mouse. I think the key thing to recognize is that any changes to the suspension of a car need to be well thought out and the solution / design needs to take into account the extreme forces that each component of the suspension will experience. In the end, we have to be comfortable with our design and our construction techniques because its us who will ultimately drive it and enjoy it......... someday

Thanks for sharing your design.

Continuing on with the design of the rear suspension, I ordered a set of rear poly bushings from TFS, a set of QA1 spherical rod ends with jam nuts and a length of 1 1/4" x 0.120" and a length of 1" x 0.120" DOM mechanical tube for my lower control arms. I got a new set of rear ball joints from Blooz in exchange for some FRP supplies last weekend and he also has a spare set of 9" tie rod swaged tubes that I hope to purchase.

I worked on the control arm design this week and made a few changes to get the tie rod aligned with the ball joint to minimize toe in change. I also realized that my new engine cradle deign was 0.6" too low so I raised it up to give a true 5" of ground clearance. This changed my static control arm angle from 3.64 deg to 6.23 degrees below horizontal. I think I can live with this but I'll see how the geometry performs.

With these suspension updates, I proceeded to plot the kinematics of the rear suspension. This is quite new to me so I started with plotting the camber vs the suspension travel. Here are the results in tabular and graphical form. I also borrowed the stock suspension data from Blooz's page 16. I guess its really comparing apples to oranges considering my suspension is '85 and his is '88 but atleast it gives some idea where my design stands. While I was at it, I recorded the amount of strut travel and the amount of lateral travel of the spindle. For the most part, it was less than 1/16" until the car becomes airborn......... and then I'll be smiling too much to really worry about it.





The next step will be to measure body roll and calculate the effect on the suspension geometry. That is a whole other can of lobster.

Edit: to swap graph axis and correct units

[This message has been edited by Yarmouth Fiero (edited 01-24-2015).]

Just so you don't think you're seeing things, I have updated my camber data and corresponding graph. It was pointed out that my graph appeared too linear so I collected the data a second time. This time I used my actual 3D model to calculate the results and the new data does seem to be significantly different...... hopefully in a good way. As I had mentioned above, I had to raise my cradle 0.6" to give the proper 5" ground clearance. This altered the static control arm angle and while I thought I had originally allowed for this, it's likely that I made a mistake. So the new results are posted above by replacing the original table and graph. Sorry for the change.

what software are you using? I think, likely knowing less than you (or anyone) about suspension.. that the next step is to see what happens when you redraw it with varying degrees of body roll and see how far laterally (and vertically) the roll centre moves at increasing body roll amounts.
If I understand the science in this, the less movement the better - in any direction - .. it is almost ike you start your dwg/design WITH body roll and try to minimize movement, and see where things end up at 'normal' (ie no roll situation).

As one book explains it, you don't need great geometry when the car is on the straight-away or at rest ( ) but you really want stability (as in minimal, sudden, roll centre changes!) when you're half-way thru the corner etc!
My unqualified 2 cents.... if you don't mind!
GP

I'm just using my 3D modeling program Rhinoceros. I am reading up on body roll at the moment and then I'll get to rolling the model and shoot some new suspension projection lines. I think the 18" high CG is a pretty good estimate. Thanks Blooz.