Miraz

I'm doing a little research for a project car...

I'm wanting to install an LS1 in a mid engine rear drive chassis - there seem to be a number of companies who have been using modified Porsche transaxles for many years with SBC V8's.

Suitable Porsche transaxles are starting to get expensive - I'm wondering if it would be possible to make use of the transaxle from the C5 vette for this installation.

I don't have any decent technical info on the C5 setup, so this is a wild stab in the dark - any help or information would be greatly appreciated.

Brother J

Only other option that comes to mind would be using transaxle from a 92-96 Acura Legend. They have a FWD V6 mounted in a 90 degree configuration, if I remember correctly. Available mostly in automatic, some manual trannys. Kinda doubt they could handle the torque of the LS1, though.

Miraz

Not sure the Acura thing would work in this situation.

I'm after a strong 5 or 6 speed manual with a LSD that will take the power of a well tuned 500bhp+ LS1.

Is the transaxle in the c5vette a standard T56 with a diff unit bolted onto the back of it? or are the changes more fundamental than that?

To give you an idea of what I'm talking about - this is a picture of a similar car using a SBC with a Hewland race gearbox ($35k!!!) - I'd like to get a lighter, more powerful engine and a cheaper, stronger gearbox!

<img src="http://gdcars.com/images/gallery/gdt70/Pic1_800.jpg" alt="" />
<img src="http://gdcars.com/images/gallery/gdt70/Pic2_800.jpg" alt="" />
<img src="http://gdcars.com/images/gallery/gdt70/Pic3_800.jpg" alt="" />

<small>[ April 25, 2002, 03:38 AM: Message edited by: Miraz ]</small>

Pro Stock John

iTrader: (34)

I am going to move this thread into the HYBRID section. Look at threads going back to the beginning, user 'Toyjet' has a Porsche with an LS1 conversion.

Miraz

Thanks...I'm familar with toyjet conversion.

One small problem - in the porsche the engine is behind the wheels - in my car it's in front, so I get 6 reverse gears and 1 forward!

The solution seems to be to modify the breathers and mount the gearbox upside-down - but as I said the Porsche gearboxes with 6-speed and LSD are getting expensive - if the T56 gearbox that I have bolted to my LS1 at the moment could be used then it would make a lot more sense.

Wonder if any of transmission techies will wander into the hybrids section <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Pro Stock John

iTrader: (34)

I reopened the original thread let's have both run to see if you can get help.

70 LS1

iTrader: (1)

I know this is an auto, but it gives you an idea of how the C5s are put together.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1823300980

jeromio

Someone here posted a link to a ream of info on the C5 including the transaxle. From my vague memory, the auto is done quite a bit differently than the manual. The manual has the flywheel/clutch in a bellhousing directly aft of the motor and a shaft running back to the gearbox.

There was also something unique about the way the diff was placed in relation to the gearbox. Can't recall what.

It depends on the dimensions and the chassis you're shooting for. It would obviously be cheaper/easier to go T56, but the length might get extreme.

The Ultima uses an LS1, but they mate it to a Porsche transaxle. Seems like they would've used the C5 unit if they could've. They do list out that unit pretty high (incl. clutch, adapter, shafts, etc.) at around $6500 - yikes ( http://www.ultimacars.com/home_pricing_ordering.htm ). The packaging of the Porsche unit just makes it much easier since the gearbox ends up being behind the diff (relative to the flywheel). With the C5 unit, you'd end up with a seriously cab forward chassis with a loooong back end.

<img src="http://www.ultimacars.com/images/gallery/engineshot-1.jpg" alt="" />
That is an impressive-*** car BTW...

70 LS1

iTrader: (1)

Don't quote me on this, but I am pretty sure the C5 transaxle is a T56 with a differential mounted where the tailhousing would be. If this is the case, you should be able to bolt a camaro bellhousing up to it and make it work for you.

Miraz

Interesting pic of the Ultima LS1 installation, I was wondering how they managed to fit the cats into the exhaust system in such a confined space.

The subaru boxes just won't take the torque - it looks like I'm heading back towards the Porsche or Audi solution.

The car is based on the old Lola T70 racecar.

Miraz

<small>[ April 29, 2002, 01:49 AM: Message edited by: Miraz ]</small>

RacerX

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jeromio:
<strong>There was also something unique about the way the diff was placed in relation to the gearbox. Can't recall what.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I think it's that the pinion is on top rather than on the bottom.

98c1500

Yes, the ring/pinion can be flipped in Porsche transaxles. In fact, some of the 914s used 911 transaxles, and thats mid-engine vs. rear-engine. And as for your question about the C5 trans setup, the R&P is considerably further away from the flywheel in one than that of a Porsche trans, so the Porsche setup would allow for a more compact installation, check out the FAQ for the Mosler Engineering MT900, they go over that.

98c1500

of course length would be an issue, but i can see the LS1 being mated directly to the 4L60E, as for the T56, it IS basically a standard mt mated directly to a unique differential, but the T56 has a housing different from that of the non-transaxle cars, as the shift linkage goes directly into it via the rear bellhousing, an engine would kinda get in the way of that hehe

TX_Silverado

I dont kno if ur talkin puttin one in a FIero or some other car...but The guy with the most mid-engined LS1 exp i know is ArchieV8.com or something like that...he just finished a LS1 in a fiero along with one other guy

LS171Malibu

From looking at my tranny, and memory of a c-5 t-56, I can give you this input. The tail shaft housing on mine is where the differential is located on the vette. On the f-bod the tail shaft housing is where the shifter is located. This will not work...but maybe a viper trans with a f-bod bell housing and a vette diff case???

Derek 357i

iTrader: (1)

Great to see someone else "thinking outside the box." I looked into this for a Ferrari 333sp Replica project I had considered and these are some of the issues I noted. Note: I am pulling this from memory, my notes are not with me.

1. From the tip of the input shaft to the stub axle centerline is 30".
2. Selector shaft is on the front of the trans case just above the input shaft. (Linkage might be a bitch)
3. Input shaft length is something like 8", though I think it has standard # and size splines.
4. Custom bellhousing almost guaranteed to be required.
5. Gears don't hang out the *** end of your car.
6. You would be looking at a pretty cab forward car, like someone else suggested.
7. With the custom work required, cost savings would probably disappear quickly.

This is all I can think of for now. If you do it, send pics derekbkisler@galesburg.net

98c1500

something i have actually been contemplating is doing something similar to the C5 trans/diff setup but using a Muncie/Saginaw/BW trans mated to a quickchange housing. since the gear selectors are on the outside of the trans, i dont see why a cable shift linkage couldnt be fabricated, and though it would be greater distance from input shaft to the hub centerline, it would less than a C5 auto trans/diff unit, and would provide 4 forward gears. plus we're talkin a quickchange, so imagine the possibilities. i was actually thinking about this for a Corvair.