360 Transaxle strength and best ratios?

[MikkiJayne]

Hey guys,

I'm building a project based around an Audi V8, and I'd like to use a 360 transaxle and torque tube setup for it, but having read a bunch of threads on here I'm a little concerned about the strength of it

The engine produces 260bhp / 250lb/ft in stock form, and probably won't remain stock for long, and the VW Corrado it's going in weighs about 1200Kg. Will any of the transaxles hold up to this?

Looking at the haynes manual it seems that the B200K has the best ratios, but I've read that its not the strongest? Something like the Getrag setup would be ok, but way too ambitious at this stage. Budget is limited so I can't afford to splash out on any mega-priced race setups. If the Volvo setup isn't going to work then I'll have to investigate Porsche options, but thats too predictable

Pic for clicks:





Tia, Mikki x

[Ronnie]

Don't go with the Volvo 300 set up for a hot V8, it's really not up to the job.

You mentioned Porsche already, Alfa 75 had transaxle too, as well as the Jeep Wrangler - sure there must be others too!

[kaos]

porsche is goign to be your best bet espesially a 925, as its based ona VW van anyway.

[pistonpen paultje]

Isn't the 968/928 a V8 transaxle? That should handle the power perfectly

[filthyjohn]

Surely there's a 2wd audi box that's up to the job. My 2.8 100 wagon was FWD and I couldn't break that transaxle.

[MikkiJayne]

Thanks guys. Sounds like the Volvo setup is not the way to go, which is a shame

The problem with the Porsche setups is that they mostly use Audi boxes which have a bellhousing on them. I don't have space under the car for a bellhousing at the back, nor will that type of box clear the rear suspension setup I have. The Volvo is the exact right shape
The Alfa 75 would be nice, but its too rare, and also has a bellhousing.

I think I may have to end up making something like the 760 Getrag one on 300power.com.

Thanks,

Mikki x

[Ronnie]

Hybrid prop/torque tube sounds like a god bet then. No reason you couldn't use the clutch end of a 360 transmission and bolt on another type of transaxle on the back. Just need to throw some cash at an engineering shop, or be a good fabricator to make up a hybrid prop/torque tube assembly.

People always mention the Porsche 928 in these discussions. Manual 928's were really quite rare, and I'm sure there's a demand for them for modding standard auto 928's. They're undoubtedly going to be hard to source, and expensive. I would be more interested in a 944 turbo transaxle. These will probably be easier to get hold of and will certainly be able to take the kind of power you have in mind. That said, I have no idea whether there were any upgrades on the 944 turbo transmission - a non-turbo 944 one might well be up to the job.

Sounds like an interesting project, please keep us posted whatever you eventually go for.

[jtbo]

There is always Corvette transaxle, but don't know price and availability for such.

[mac]

Mornin' all,

Have to agree that the 300 transaxle is probably not a good choice for long term reliability with power much over 200bhp.

There would be no problem with the M47R g/box but I can see two other weak points. The drive quill to input shaft splined connector at the tranmission end of the torque tube (known to be marginal even with stock 360 power). The other problem is likely to be the diff - the plain bush planet gears won't take punishment. (obviously if you only travel in a straight line and never spin one wheel more than another it wouldn't be an issue - but who does that!!). The diff carrier probably hasn't got enough meat to beef up the planets brgs. c/w and pinion should be fine - as should be the main diff brgs.

I'm not sure how the actual diff casing would respond to really high power/torque (but a bracing frame could be fabricated to solve that).

At least one regular here is intending to modify a 300 diff case to take a limslip which would certainly solve the planet issues - so there is hope.

All in all though, in your case there are probably more reliable routes to follow.

Best of luck anyway!

Mac.

[jtbo]

There is at least two around 300hp 300 series cars in finnish Volvo forum, both eat gearboxes, differentials seem to hold bit better if welded, but shaft between differential and gearbox is known to fail, gearbox main shaft that is inside gearbox etc etc I can't even remember what all failures there has been which I have read.

Usage is of course what destroys parts, but let's face it who is building such power for only gently cruising and high speed runs with flying starts?

Corvette option could be of course pretty tight squeeze:


Alfa GTV6 had also transaxle, but those are rare cars today and many of them needs parts too so not first choice.

Best bet seem to be that one picks a suitable box, mounts it to differential chosen to do the job with some custom fabrication, hard to find easy way out in this one.

Several ways to do it, but at end of day it always will cost undefined amount of euros close to same in every option. Using Volvo bits might be cheapest to get it run, but then replacing parts almost every time one floors it, is going to cost something too