Picking away at the cradle and the Fiero chassis, I got the fire wall stripped of all the brackets getting ready to cut the rear section off and start on building the tube frame from the firewall back. I put the cradle into the chassis to see how it lined up, if you look at the photo from the back straight on you can see the center vertical tube are the same distance from the Fiero frame (which will be gone soon) Tranny coming off engine this weekend then off to be rebuilt...
I guess since I will be cutting most of the rear section away I couldn't really call this a "Stock" engine compartment any more...so if you wanted to put this into a Stock Fiero I would retain the rear frame section (trunk still has to go) make the cradle suspension mounting points to use the fiero suspension components. You could use my lower suspension arms in conjunction with the Fiero rear shocks (or a coilover kit) and the stock shock tower...I still believe if you wanted to you could stuff this setup into a Fiero...which would be cool...Maybe my next project, a Fiero with the BMW V12 twin turbo!!!!
[This message has been edited by 88lambo (edited 02-05-2018).]
Transmission is still out for rebuild, waiting on 2 parts (new chain and shift kit) coming next saturday...
Well I did it, crossed the point of No Return with the chassis , the rear section back of the fire wall is pretty well gone!!! only thing left is the back piece to support the upper tube until I tie then into the lower 2 x 3 frame. I'm hoping to have the rear frame and cradle totally done in a couple of weeks, I should have the transmission back buy then. Then its onto wiring up the engine and test firing it
Thanks for the comments...I wish I had more time, I usually only get a few hours a week to work on the car. My wife and daughter go to bed fairly early which gives me some time, but our bedroom is over the garage which kills using cutoff saw, grinder, air compressor...etc, so I have to plan noisy stuff during the days and weekends and welding and assembly at nights
FYI anyone building a house (or getting ready to buy) and you are a car nut, make sure the bedrooms are NOT over the garage
Could you go a bit into the how, and why's of where you located the A-arms, decided on length, etc.?
I originally was going to use the Fiero suspension (why I labled the topic "Longitudinal BMW V12 in a Stock Fiero Engine Compartment ") but after stripping the chassis and finding a lot of rust at the rear drivers side I decided to go with a partial tube chassis for extra strength. The countach kit and wheels were designed to use the original rear suspension (not lengthened like other kits used) so I kept the length of the lower A-arms the same as the fiero's and the length of the uppers were goverened by the upper bolt hole of the spindle and the location of the attachment points of the frame rail. as you can see I have built a lot of adjustment into the A-Arms for camber, castor and toe...I am still working on geometery of the mounting height of the the upper A-Arm, I read on this forum that 1° is the standard setting, but I have to verify that, Now I must admit I am NOT very knowledgable about suspension geometery, I tend to play with it on the computer, at this point I have a -1° camber @ static heigth, -2.1° at fully compressed and -1.6° at fully extended, I not sure if this is good or bad, I will be working with My local mechanic/friend who is also a mechanic for a local stock car team and an avid hotrodder/collector (he also helped me with my Lotus front double wish bone suspension and that handled really well). I will be picking his brains before welding the upper mounting points in. In the long run I am not overly conserned about going all out on suspension setup, I will not be racing the car and with 700 pounds of engine and transmission in the rear (approx 80% of that in fromt of the axle) and with 345 wide rear tires and 225 wide front tires I don't expect the car to handle like a race car...
if anyone has any suggestions, i am always open to them...
John
[This message has been edited by 88lambo (edited 05-06-2011).]
I wish there were a forum where geeks of suspension design would congregate, share ideas, critique designs, and help each other out. Anyone ever found one?
I'm still learning about suspension design myself, but most books in bookstores seem really old, and limited. (I know suspension design doesn't change much, but I would love to see feedback on modern systems released on supercars.)
I wish there were a forum where geeks of suspension design would congregate, share ideas, critique designs, and help each other out. Anyone ever found one?
More from the professional engineer perspective than the kit car perspective, though.
Got my transmission back from being rebuilt, and a bit more done on the engine cradle including adding adjustable height/removable castors so I can easily remove, install and move the engine/transmission
if anyone has any suggestions, i am always open to them...
Get this book:
How To Make Your Car Handle has detailed information on suspension and chassis design from both a layman's point of view as well as going in depth with the geometry and mathematics. Highly recommended.
At the risk of sounding stupid ( which I do real good) , wasn't there a problem with clearance between the crankshaft of the v12 and the axle that passes through on a previous attempt. Anyway, nice work! I'm impressed.
[This message has been edited by dratts (edited 06-27-2011).]
At the risk of sounding stupid ( which I do real good) , wasn't there a problem with clearance between the crankshaft of the v12 and the axle that passes through on a previous attempt. Anyway, nice work! I'm impressed.
Using off the shelf components to flip the differential places the axle in line with one of the counterweights on the crankshaft and causes interference. For the axle to fit, it must pass below a main cap bearing to avoid the crank throws and counterweights. This required a much thicker than normal adapter plate between the transmission and the differential.
Here is the setup the last guy who tried this used, notice the thickness of the adapter plate:
[This message has been edited by fieroguru (edited 06-28-2011).]
Just curious, it looks to me as though the engine is pretty much centered over the axles and the tranny is behind the axles. Do you know what the f/r weight ratio is. For sure you have a tranny that will hold whatever hp you throw at it. Again nice work, I'm not criticizing.
fieroguru is correct i needed the larger adapter plate to space the axle under the main bolts to avoid the crank counter weights... it clears the tube going thru the oil pan. as for weight distribution the axle does go under the center of the engine but since this is a reverse rotation setup (transmission is forward of the axle) i am guesstimating that 70-75% of the weight in engine/transmission package is forward of the axle, also since the chassis is stretched in the passenger compartment the fuel tank is now 5" further towards the front and the battery will be moved up front also which will help. The tranny has been rebuilt with all new and heavy duty components and should be good for 450HP the bmw v12 puts out 300 HP and 330 FT-Lbs torque...
Update... The engine cradle is complete The engine/transmission/differential have been bolted together and are waiting to go onto the cradle. (i want to attach the cradle to the chassis and throw the body on to make sure that the axles/wheels are centered in the wheelwell, better and easier to do this before bolting everything together I have a few more tubes to weld to complete the rear tube section of the chassis (hopefully done in the next couple weeks) then the engine/transmission/differential/cradle will go in, then rear suspension.
if your 325 is rebuilt and the v12 only makes 330lbs of torque you will not have any problem. I have mine with a 330 hp 375 lbs of torque 350 that ran for a lot of mile with no problems. Only when i boosted the engine and make 500lbs of torque it went out very fast.
if your 325 is rebuilt and the v12 only makes 330lbs of torque you will not have any problem. I have mine with a 330 hp 375 lbs of torque 350 that ran for a lot of mile with no problems. Only when i boosted the engine and make 500lbs of torque it went out very fast.
Yup sounds about right, i was told by a couple places you can build them to take about 400-450 HP not sure of the torque, but i would guess not much more than 400 Lbs. the TH325 shares a lot of components with the TH200 transmission. If you want a bullet proof version go with the TH425 (basicly a TH400 inside) but not sure if it has a long enough output spline for the differential to engage for reverse rotation. I could have used the TH425 since i had to make a spline adapter anyway...The i also heard TH425 is also a lot heavier which could help put more weight in front of the axle.
are you running reverse rotation? Have you gone to the TH425? what let go on the Th325? i heard usually the chain or the bands go first...
The 425 is heavier than the 325 but about the same weight as 325 4L. The chain did not go out they are very stout so no worries there. I got rid of the 325 so I don't know exactly what failed but it smellet burnt like the clutch packs failed? I do not run reverse rotaion. It was a very nice trasmission it churped the tires between gears and if i had not ran boost on my engine it would still be a strong runner. Yes, I am runnig the 425, it's nice because it is basicaly a 400 and there are so many 400 parts available
[This message has been edited by buildamonster (edited 07-05-2011).]
Slow going on car, Great summer here in Ontario Canada, sunny and hot, Lots going on, 2 weeks vacation in Hampton Beach NH, and weekends up at the Lake, changing Jobs after 18 years...SOOO not working that much on the car, but picking away at rear tube frame...still hoping to have driveable chassis by the fall...a few photos to show what it will look like (I will be welding soon)
Poking away at the car SLOWLY... Painted engine bay and cradle. Engine/tranny/differential all together on cradle. Purchased exhaust tubing, muffler, coilovers, and axles...working on throttle linkage, exhaust, suspension. Waiting for A/C bracket to come back from machineshop...
We are going to get a sound clip of it BEFORE the mufflers go on ..... right? Pretty please ... LOL.
Here you go...Not my engine but same model and year as mine, Video is from Choice Auto Wiring http://www.choiceautowiring.com/ (they made my engine management system) as soon as I get mine started I will post a video...
Do you know how much Choice charges for the harness setup?
All depends on the engine harness (V6, V8 or V12 he makes many systems) I can only tell you what I paid for the V12 harness...and it was custom (not the standard V12 one he does, my engine is facing backwards and his normal V12 harness is for engines facing forward) I paid about $1400 a year ago and that included the harness, two programmed computer chips (i have to get my own computers) a trigger ring that goes on the flywheel and installation instructions which included a list of which sensors, throttle bodies and computers to get... the reason I had a custom harness done is the BMW V12's are really hard to set up using the BMW computers and harness, Choice's harness is a stand alone system that uses GM components which makes parts really easy to source... Give them a call they are great to deal with...
UPDATE still picking away at car, have the throttle controls done, had new 6 cylinder exhaust flanges made 1/2" thick 304 stainless steel, no alignment issues compared to the 3 cylinder ones. I was going to make 4x 3 into 1 headers but didn't have the room thats why I went 6 into 1 but with the 3 cylinder flanges is was hard to align the 2 flanges. Once header are done then the engine/tranny/cradle assy goes back into the car and upper mounts for coilovers will be aligned and welded in, that will finish the suspension. next on the list: connecting the engine (wiring), fuel tank, brake system, shifter and cable, cooling system = driveable chassis
[This message has been edited by 88lambo (edited 01-16-2012).]
, the rear section back of the fire wall is pretty well gone!!! only thing left is the back piece to support the upper tube until I tie then into the lower 2 x 3 frame.
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