I think one possibility to make a mid engined sport car would be to use some Audi`s engine (like a V8 from A8). The engine is mounted longtitudally as is the gearbox as opposite to most other FWD cars.

It`s just that the strongest engines like the 4.2 V8 was only available with quattro. My question is, are the gearboxes in quattro models a lot stronger and could a gearbox from a quattro model be modified so that only it could be used for a mid engines car?

The A6/100 has the engine mounted the same way. You may be more likely to find a 2wd manual box from one of these. Even a 6 speed!

The current A4 is transverse. But some of the earlier generations of A4/80 have the engine mounted longitudinally (sp?).

Renault and citroen have also used this layout on some of their front wheel drive cars.

use an A4 1.8t 20v turbo engine

bigger turbo n injectors 270bhp easy and a transverse box

The 1.8t motor is capable of producing 460 bhp, at the right tuners.

http://www.amdtechnik.com/product.details.cfm?ProductID=191&VariantID=116&ReferenceID=609

[Edited on 6/12/06 by jroberts]

The larger engines have quattro only as making a fwd transaxle capable of reliably running that torque is too expensive. Hence why the power is split 4 ways rather than just 2, as would be most useful to many on here! The other options are porsche boxes, and more racey stuff, such as Hewlands.

i'm going to use a audi 5 with the gearbox mounted in the back, and from what i've found out a number of porsche boxs are the just the same thing so you'd be safe enough with the 2wd box as they are over designed in to start with as for the V8 i know nothing

[Edited on 6/12/06 by goodall]

from what i remember ther is one particular 2wd box that was used in porsches and audi 200 i think. there is loads of info on lambo lounge but the site seems to have disapeared.

audi 5000, and porsche 944 are the same box

Best place on the net I've found for transaxle info is an America site called

www.gt40s.com

Wade through the "engine and transaxle" section.

This is an 016 from a 5000/500E 5 cylinder

Cheers

Fred W B

drive train


[Edited on 7/12/06 by Fred W B]

apparently the newer A4/A6's TDi's have a 6speed 2wd gearbox that can cope with 400bhp.

sounds good, but wouldn't the ratio's be wrong as they'd be quite close for the tdi and geared for lower revs?

Ned.

From what Porsche models are the gearboxes used? 911? What about the turning direction of the engine? In a mid engines car the gearbox is obviously behind the engine but in the rear engines 911 it`s in front. So does the gearbox need to be turned upside down?

hey all.

yep those usualy run upside down, that's good because you can mount the engine much lower also, point of gravity thing.

you can use almost all audi transaxle's an also all renualt transaxle's depending on power offcourse.

about the TDI ratio's If you where to build a light car, and have plenty of torque, you could end up with a fenomenal topspeed.

grtz Thomas

[Edited on 7/12/06 by thomas4age]

turn the box upside down or use one from a boxster?

Ned.

quote:

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sounds good, but wouldn't the ratio's be wrong as they'd be quite close for the tdi and geared for lower revs?

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From what I've read the only really useful Renault transaxle seems to be the UN1, the rest are usually too weak. Same goes for many of the audi jobbies, although when I say "too weak" I mean too weak to handle 400+ bhp reliably. This may not therefore be such a problem, but when I was looking, I needed something capable of 500+ bhp, and lbft. As said, many of the porsche boxes need turning upside down, except the boxster one which run as they "should", however, the earleir ones allow the engine to be mounted lower, giving a lower CoG, and many have LSD's as stock, although they are a LOT more expensive than the audi ones. One bloke reckoned he could blow up 34 audi transaxles, before he got to the cost of a rebuilt porsche one!

The ratios are geared differently for a lower reving diesel, but its actually favourable as it increases the gearing.

For example if the diesel does 30mph in 1st at 4000rpm then the petrol will do 45mph in 1st gear at 6000rpm.

That and they are designed to take the higher torque of a diesel engine.


As for the porsche box, the 911 is the favourite but it must be inverted and filled with an extra litre of oil...... they do work well though and if you get the right one take over 600ftlb reliably.

How much does a good Porsche or Audi transaxle cost? I've heard the G50 can cost over $5,000.

Yep that's true

very expensive those things. but when you take time to look around you'd be able to find an G50/50 for half of that in used order.
a G50/52 which has an LSD costs far more than that, and it's seems not as strong as the 50/50

UN1 will happily take some serious torque but very high revving engines and high speeds kill the overhung 5th gear part of the input shaft. it just breaks of. Bell has a conversionkit for this which is the buisnes.
A UN5 (traffic Van) is even stronger than a UN1 but has truck-like ratio's very popular in offroad hillclimb series, and near indestructable they feature a 4 planetary differential instead of a 2 piece one. maybe the stuff is exchangeble between the UN series, which could make a very nice replacement for the G50

grtz Thomas