I was reading a few threads about engines & such and came across these words......i'm taking a stab in the dark and saying Transverse means mounted sideways(like a Fiero) and Longitudital is mounted..umm regularways lol(like a Firebird for instance) also if i'm right on that. Which is better?? Also is the "regular" way possible ina Fiero?? I'm guessing you would have to get rid of the trunk but that would allow for a bigger engine . Thx and any more explanation & benefits of each are apreciated guys.

-Josh-

You can do it either way. check out Held Motor Sports. They make a rear assembly to accept your engine. However, Transverse, (like the Fiero in much cheaper)
Kevin

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85 Fiero-based ASPP GT-40 MarkII. 3800 S/C, Auto, Held suspension all around with 2" drop spindles and sport fr. end. RCC bump-steer correction. Mr. Mike's interior.

Most people that do a long. swap are the guys doing body kits and are going for that look. They also have alot more room since most of them are extending the rear frame rails. 3" on a 355 kit, 7" on a 512, 11" 0r 12" on a Lambo kit.

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My build thread

Check out Bubbajoe's builup thread. He's mounting his Northstar longitudinally.
The advantage of a longitudinal install is the transmissions are stronger. A transverse engine has far fewer options for transmissionis and they are typically not as strong.

So Transverse mounted is what we haved? Mounted sideways like in Fieros?? Also I coulda sworn I saw a few pics of guys with Fieros not extending the frame at all just completely getting rid of the trunk(cutting out the trunk wall & well you know the rest) and still look normal outside just you don't have the benefits of a trunk no more. I'm just wondering how possible it is(without extending the frame) and thats awesome that you can have a more stronger/powerful tranny. Plus's given and more to come for more help lol.

EDIT: Can someone link me to this BubbaJo's buildup thread cause I can't find it on search. Thx.

[This message has been edited by Fiero Finale (edited 12-29-2004).]

Correct, the Fiero is transverse. And yes, you can remove the trunk and mount a longitudinal engine in back and keep the body the same length. The problem with doing that is you are usually putting most of the engine behind the wheels instead of in front, making the car rear engined, not mid engined. That's fine for cruising and drag racing, but it will destroy the handling.

So you can't have it mid engined still??? I mean I don't see how much further "back" it will make it having it longitudial cuz it doesn't seem like it would be that much "longer" turning the engine longitudital. So I guess that if I wanted to do that I would have to extend the frame

it is still a midengine. there is an indy here in MN running around with a caddy 500 in the back. it looks stock. the only thing that gives it away is wheny ou are following it, the motor is mounted very low to clear the decklid. you can see the oil pan from behind then. its fast as hell too, and its s tock caddy motor. he uses a GM transmission found in the old torinados/caddys of the 70's. it all fits back there also.

bubba's thread cant be more than a couple of pages off the main page, it was jsut updated recently. it is like 27 pages long, you cant miss it

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the unfortunate history of my GT here

The easy way to think of it is longitudinal is the LONG way down the car. The only real choice to put a longitudinal setup in the Fiero is using the TH325/425 trans. Otherwise you'll need to stretch the rear to make it fit. Even Dave Held's tubular cradles are meant for a stretched car. Check out Jon's site(rockcrawl) for more info on the non-stretch build:
http://www.fieroaddiction.com/SBCLa.html

Bob

As for the mid/rear engine debate, if you mount the engine facing rearward, the engine will be BEHIND the wheels, thus rear engined. There is a way to use the TH425 and flip the differential or something that allows you to turn the whole mess around, so the engine is facing the front of the car (drive belts closest to the rear window). That should retain the mid-engine setup since the engine would be in front of the drive wheels.

A longitudinal setup is MUCH larger. Get a tape measure and measure how wide your engine is, then measure how long the engine and transmission are together. Now consider a longitudinal transaxle will likely be longer, you can see how big of a difference this will make. That's why GM used the transverse mounting in the first place - because it saves a LOT of space.

Maybe this will will help...........

Here is a picture of a longitudinal V8 in a tube chassis. The wheel base is stock, but you can see how much it goes into the cabin. This can be corrected or minimized in several ways. Since this is a race motor, The dry sump sticks off the front and taks up much more space than if there was a flat pully for the water pump and the alternater was mounted in the back. The advantage, as mentioned before is that the tranny's are typically stronger in this direction and the CG is generally further forward in the car.

In about 2 months I'll have the engine back in and you can stop by and see it. Or if you want you can wait until the Gateway show. (End of April / Beginning of May). I might have a track day at Gateway before that if you want to see it run.

Good Questions

Paul

[This message has been edited by R Runner (edited 12-29-2004).]

Thanks Paul, i'll have to check it out. Hey you have a PM by the way I have a little question..

Lt1/thm325

Although shown in a Diablo w tubular chassis, the engine/trans/cradle assy will fit directly into a stock Fiero chassis, cutting out the center section of the front wall of the trunk.

Not an AutoX'r, but able to handle the heavy foot in all instances :>

David Breeze

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Pantera Rebody Kits

Ok so i'm a bit confused now.....lol. That's what I was thinking, was just cutting out the trunk wall, I could care less bout the no more trunk space. But what i'm asking are the advantages & disadvantages of doing a longitudital over the stock fiero transverse. I mean I know if you do long, it you have better options of stronger trannies, but you can't turn corners real good or something??(guessing from the autox remark??) correct? Thx guys.

The pic OPM200 is showing has the TH325/425 trans. This is the only (GM) trans that will fit long. without a stretch. The biggest problem is that it is an automatic. If you want a manual, then the longer Audi/Porsche trans is what you need.

Is the transmission you just stated strong & race worthy?? And without stretching the frame you said you can do this, but it looks like it will be partially over the rear axle so wont' that throw off the CG a little?? And make handling effected?? I'm not wanting to change the "look"(length) of the Fiero by doing extending so yeah.

quote Originally posted by Fiero Finale: ...Which is better?? ...

Engine torque in any longitudinal installation has the drawback of trying to lift one side of the car body, taking weight off the tires on that side, causing traction problems. In the transverse installations the engine torque is balanced from left to right, this torque is now trying to lift one end of the car instead. In a transverse installation the issues center around getting the affect of the physical weight (center of gravity) of the engine/transaxle assembly equally distributed between the drive wheels in a more limited space.

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RickN
White 88GT 5spd
White 85GT Auto

[This message has been edited by RickN (edited 12-30-2004).]

quote Is the transmission you just stated strong & race worthy??

The TH325/425? The TH425 is pretty much bullet proof from what I've read. It's based upon the TH400, which is a pretty solid trans. And yes, it is a pretty heavy trans. It will move some weight back behind the axles, unlike the smaller manual trans' or a transverse setup.

This picture should help clarify the weight distribution issue:

With the GM TH325, 325-4L & 425 transaxles the weight of the engine is always pretty much centered right over the rear axle center line. So, no matter how you configure it you're going to have more weight behing the rear axle. With the transverse setup almost all the weight is in front of the rear axle center line, between the wheels where you want it ideally.

If you mount the TH-series tranaxles the way they were designed the pulleys will face forward, and be right behind the rear firewall. As seen in David's pic this will put almost the entire weight of the transmission behind the axle center line.

If you reverse it, by flipping the differential, the pulleys will face the rear of the car, the weight of the transmission will be in front of the rear axle center line, and you'll have more favorable weight distribution. It will also lower the engine slightly for a lower CG. You are still moving half the mass of the engine behind the rear axle center line though (as compared to the transverse arrangement).

Here's what you have now (sort of):

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Todd Perkins - the member formerly known as "perkidelic"
todd's hot rods

[This message has been edited by toddshotrods (edited 12-30-2004).]

What vehicles do these transmissions come in from the factory,
Astro's???

Maetrix66 what transmissions r u asking about??

there is a few different ones pls be more to the point

The TH325/425.

It's for a little project I have going with my brother.

quote Originally posted by Maetrix66: What vehicles do these transmissions come in from the factory, Astro's???

Here's a couple of links that might help!

http://www.drivetrain.com/autotranscrossref.html

http://dtcc.cz28.com/transmission/index.htm