Okay this is another problem i need to sort out and again i need your guys help. Okay as some of you know im trying to break the 11 second mark and go to high 10's i know this is not going to be easy but i think i can do it. from what i have been told the transaxles for our cars will not hold the power or the clutch will slip under high torque. So i need to figure out if i could put a longitude tran on it and would it hold the massive 600 HP and would the clutch hold. OR should i look into Japanese transaxles like the 3000GT, that can hold the power and have CRAPPY gearing. this wont be my daily driver so i dont have to worry about gas but i need for this transaxle to hold and not break. I need some help...... J
------------------ 86' Black Fiero GT
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02:15 PM
PFF
System Bot
skitime Member
Posts: 5765 From: Akron, PA, USA Registered: Aug 2000
porsche 4 speeds as used in the early turbo's or older race type ZF or hewlands all would work in a high tork V-8 but are hard to find cheap.porsche 928 tran/axel has any one used that? 928 aren't very in and maybe cheapest. old 66 corvair 4 speed was a rockcrusher guts trans 66 only year that it was used but was easy to adpt to a V-8 but thats the only GM unit that would work ecpt autos like the early eldo unit but how much power will the stock 125 take?? maybe cheaper to just blow 125's every so offten.
Are you planning on using this as a street car or a drag only car that might occasionally cruise?
If you're just gonna race it, here's some suggestions for using the stock transaxle. You might want to look into a multi disk clutch setup, see how many disks and floaters you can get in the stock trans bellhousing. You might want to look into a programmable timing computer. NMCA Real Street (maybe it was a different class, but it's a DOT tire stock suspension class) drivers use them to retard the timing on launch so the engine doesn't overpower the (relatively) narrow tires they have to run. You could use it to reduce the shock loads on the driveline. You might be able to get away with tuning the engine more for top end HP than low end torque also.
If you're gonna drive it alot and plan on investing alot of money into the car, go with one of the longitudinal transaxles mentioned.
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06:24 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
The eldorado/toronado/riviera automatic transaxle can be beefed up to handle just about anything a SBC can give it. The first problem is that it is a big heavy trans. The second problem is that half of the engine and all of the trans is behind the rear wheels. No matter what you do you will not be able to get it to handle as well as a Fiero should. It looks pretty cool and the wow factor is high, but it's just too much weight in the wrong place. For a car that is on display more than it is on the road, it is great, but if you want a good driving car I'd find something else. I drove my 350/TH325-4L Countach for a about a year with no problems. I was happy with it but only because I was real easy on it for fear of wrecking the body. It was also 10" wider than a Fiero and had 305/50/15 tires.
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07:34 PM
Aug 22nd, 2001
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
well rockcrawl how heavy is this tornado transaxle, where can i get one, how much to beef it up, and how hard to put it in all correctly. If i do this i will put 295 on and use KONI racing suspension, think that will help????????? J
------------------ 86' Black Fiero GT
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03:27 PM
PFF
System Bot
mrfixit58 Member
Posts: 3330 From: Seffner, Fl, USA Registered: Jul 99
The ROCK is our resident expert on this topic but I've heard that you can modify the differential to make it run backwards. The benefit to doing this is it allows you to turn the transmission around and place most of the weight in front of the rear axles. The motor then faces backwards and is centered over the axles. The benefit is more front weight bias and easier maintenance since the water pump and belts are now facing the rear of the car.
Does anyone have any detailed information on this modification?
------------------ Roy :D 87 GT
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04:40 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
I'm no expert, but I did learn a lot from doing it and I've looked at a few others in kitcars and such. The TH425 is the older stronger one. You don't get the overdrive as in the 325-4L, but I've been told it is basicly a TH400 converted for FWD. flipping the diff and pointing the engine out the back will put the entire weight of the trans in front of the axle instead of behind it. I don't know how much it actually weighs, but you won't catch me trying to pick one up. It uses a cast iron differential housing that looks like a RWD unit without the axle tubes. The pinion shaft goes right into the trans case and there ar like 6 bolts holding it together. You can take the bolts out and rotate the diff 180*, drill some new holes and bolt it back on. This also puts the centerline of the axles above the pinion. So if you leave the axles at the same position, the engine will sit lower in the chassis, another benefit. It's all really confusing unless you know what the trans looks like, and trust me, it looks like no other. I think you'd need to cut the trunk no matter which way it's done.
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06:45 PM
mrfixit58 Member
Posts: 3330 From: Seffner, Fl, USA Registered: Jul 99
With the differential flipped, don't you have to modify the oil pan to clear one of the axles? seems like I saw a web site somewhere that showed the pan being modified. Then again, I think the motor was a SBC so it may have needed modification without rotating the differential.
------------------ Roy :D 87 GT
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06:56 PM
rockcrawl Member
Posts: 2528 From: Lehigh Valley, PA Registered: Jul 2000
The SBC oil pan needs to be modified either way. I made my own, but it looks like a 4x4 S-10 V8 oil pan from Summit racing will work. here's a pic of the TH325 (top) and TH425 (bottom)
Hugh on the forum has a TH425 and 350 (pulleys front) in one of his 88 Fieros. He has done everything he can do to make it handle well but it doesn't. We are discussing pulling it out and putting in a 3800SC.
[This message has been edited by rockcrawl (edited 08-22-2001).]
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07:17 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
when you say handle well what do you mean? not take turns going 100MPH. or do you mean just driving?? and how much will the trunk need to be cut??? There was a site that i was given that used a sbc with a automatic set up in the normal fiero position that ran 10's ill see if i can find the link and see if we can find out what transaxle he used. J
------------------ 86' Black Fiero GT
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07:26 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
Quote: "There was a site that I was given that used a sbc with a automatic set up in the normal fiero position that ran 10's ill see if i can find the link and see if we can find out what transaxle he used."
It's probably a built up T125... a regular Fiero transmission. If your interested in using that system, then V-8 Archie is the man. The longitudinal system is probably cheaper but, as was mentioned, handling will suffer. There are things that can be done to help make it better:
- Reverse the transmission (as mentioned earlier). - Build the motor as light a possible (i.e., use aluminum heads, intake, shorty headers, etc.) - Moved the battery up front.
You will still be heavy in the rear but handling should improve. You just need to ask yourself, "What do I want to accomplish with this car?". If it WOW appeal and low bucks with rock solid dependability with regular abusability (read - no broken transmissions) this is a pretty good swap. If it's tire blistering cornering ability, then this is not what you want.
------------------ Roy :D 87 GT
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07:44 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
Dude, what the hell do you want? You want a Fiero in the 10's. You want a manual transmission. You want it to handle well. You want to keep your trunk.
You like cake, don't you?
Thoroughly beefed up Fiero automatic transmission, with a forged internals SBC, a 250-300 shot of N2O, and drag slicks ought to do it.
If you have $5000 for a tranmission and the wherewithal to do the conversion, you could use one of the six speed VW racing transaxles from www.eiptuning.com
Call EIP about 3:00 pm EST and ask for RC if you're serious about that transmission.
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09:22 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
yes i love cake!! but anyways uh i saw a 5 speed for 3000 and they said they rebuild transaxles too so it might even be cheaper. i might have to give them a call. But that high still and would rather try to beef up a different standard. but thanks for the link. J
------------------ 86' Black Fiero GT
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10:23 PM
Aug 23rd, 2001
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
Originally posted by JayUSA77: but would it all fit in the fiero engine bay? Withough cutting the trunk??? J
Any longitudinal engine swap will require cutting the trunk. I am in the midst of making such a swap using a TH425 which, by the way, is a bullet-proof transmission. Originally I had planned to mount the engine facing forward but I have since decided that I am not satisfied with this arrangement and I am now trying to turn the differential around to reverse the rotation and thus allowing the engine to face rearward. There are two problems with using this setup with a forward facing engine: 1. the majority of the weight is behind the rear wheels and 2. the engine sits too high in the engine bay requiring the use of a tall (3-4") hood scoop to cover the carb (or FI unit) and distributor. not good for a sleeper '84 2M4. I am working to solve this problem of turning the diff around, i know it has been done but not sure by whom. If anyone has info they want to share i would be happy to share my experiences in this swap with them also. I also have a good contact for TH425 transmissions if any one is in need of one.
[This message has been edited by TONY_C (edited 08-23-2001).]
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08:33 AM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
well tony c what i am going to do now is stick with the stock t 125 auto transaxle and pay a guy that has run 10's to beef it up to be bulletproof. Thats good enough for me and i wont have to worry about handling problems. J
Here's someone who's doing it now... BIG BLOCK caddy motor ('76 Fuel Injected something or another) placed longitudally (sp?) in an '84 Formula. I'm just showing the pics 'cause I didn't even have the guy's name (he's here in Minn- met him at Calhoun a few weeks ago). Maybe someone else who was there knows him. Enjoy!
------------------ Medium Metallic Green 87 GT 3.1L High Output 4 Spd OD Tranny Open (read: Loud) Exhaust and More! -Rob Bartlett
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05:16 PM
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
well i found the solution for the 5 speed if i still can afford it. it will cost around 3500 for the transaxle and its for EFI i have a hyperlink if you want it. It can hold 800 hp and is a 5 speed. KInda expensive though. i dont know what to do. MONEY is now a issue due to that high price. J
------------------ 86' Black Fiero GT
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05:30 PM
mrfixit58 Member
Posts: 3330 From: Seffner, Fl, USA Registered: Jul 99
Originally posted by JayUSA77: i dont know what to do. MONEY is now a issue due to that high price. J
WELCOME to the real world! It called "compromise". Everyone would love to have a mega HP small block that got 24 MPGs, ran the quarter in 10 seconds, and had a bullet proof transmission all for under $5,000. If you find it, please let me in on it!
Tony_C, I'm interested! I've still go a CD I bought from someone who outlined his longitudinal swap. I actually considered doing this but have since fallen for the 4.9L swap. But, that doesn't mean I don't think a 500 cu-in Caddy motor wouldn't be ULTRA cool! Please, keep us posted on your build-up.
Were using the rear transaxle from a c5 vette , with an adaptor to mount it directly to a LS1 for a mid engine corvair setup.
Our 2.9ltr flat 6 vair has blown "built" corvair transmissions , steer clear of that , you can get HD input shafts , spider gear sets ect , but they are still old tech.
a 901 911 tranny is a good choice as well , try looking up rod simpson hybirds , he builds SBC porsche's and has all the tools you will need. A toronado tranny is bulletproof , but weighs a ton.
Try and find a 911 tranny with a 40% LSD . there rare but out there. Steer clear of early 914 tranny's with the tail mounted shift linkage ..ewwww...not fun to play with.
I have seen the c5 tranny run a street driven c5 into the 9's , so it should be good for your purposes. I will try and get some pics of the tranny mated to the LS1 this week , as soon as I get a chance to head out to the shop
Jonathan M.
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08:08 PM
PFF
System Bot
Aug 24th, 2001
JayUSA77 Member
Posts: 364 From: San Leandro CA Registered: Jun 2001
OK, does anyone know whose car this is? I really want to talk with him about this swap. from my limited knowledge of Caddy 500 ci motors it appears that the front of the engine is facing the back of the car which means the final drive gearset has been reversed. any help locating this guy would be greatly appreciated...
quote
Originally posted by MinnGreenGT: Here's someone who's doing it now... BIG BLOCK caddy motor ('76 Fuel Injected something or another) placed longitudally (sp?) in an '84 Formula. I'm just showing the pics 'cause I didn't even have the guy's name (he's here in Minn- met him at Calhoun a few weeks ago). Maybe someone else who was there knows him. Enjoy!
[This message has been edited by TONY_C (edited 09-07-2001).]
Contact Brian Cornelius (sp?) at bcornel@jboxford.com for questions about the Big Block Caddy. He's the one that told us the guy was coming to the gathering,and can probably hook you up with him. The guy working on it uses Caddy BigBlocks as his hobby- Has a 6-wheeled Pickup with a Caddy in the back. As well as plans for a minivan "sleeper" with a big block caddy in the back (but that's a secret project, so "shhhh...."). Hope this helps!
------------------ Medium Metallic Green 87 GT 3.1L High Output 4 Spd OD Tranny Open (read: Loud) Exhaust and More! -Rob Bartlett
[This message has been edited by MinnGreenGT (edited 08-24-2001).]
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12:44 PM
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
MinnGreenGT.....thanks for the help in pointing me in the direction of that car..already fired off an email to him....If anyone else can add anything please do so...thanks all...
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01:22 PM
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
Tony_C, I'm interested! I've still go a CD I bought from someone who outlined his longitudinal swap. I actually considered doing this but have since fallen for the 4.9L swap. But, that doesn't mean I don't think a 500 cu-in Caddy motor wouldn't be ULTRA cool! Please, keep us posted on your build-up.
Mrfixit...please elaborate on this CD. would like to know more about it.....thanks
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01:27 PM
mrfixit58 Member
Posts: 3330 From: Seffner, Fl, USA Registered: Jul 99
Originally posted by TONY_C: Mrfixit...please elaborate on this CD. would like to know more about it.....thanks
It's a CD book written by a fellow Fiero enthusiast. He mounted a longitudinal LT-1 in his GT. His book reviews a lot of the research he did for the swap and gives a very general How-To. His name is Joe Wynman and his telephone number listed on the CD is: 201-457-9507 , 6 PM to 9 PM EST ONLY. He also lists an address of: 500 South River Street, Suite 110 Hackensack, NJ 07601
Sorry, no E-mail listed.
Hope this helps,
------------------ Roy :D 87 GT
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02:36 PM
Aug 29th, 2001
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
Joe Wynman's web page: http://www.fortunecity.com/silverstone/impala/403/longv8.html Joe is the Longitudianal V-8 Fiero expert who has created the CD covering exactly how to do this swap. He has been in the Fiero community from way back. In fact one of the originals.
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11:40 AM
rockcrawl Member
Posts: 2528 From: Lehigh Valley, PA Registered: Jul 2000