V8's and tuning, and 2WD gearbox for power.

[S@.]

Hiya,
New here as you can see, hopefully i foudn the right place to be. I would just like some basic advice to start with, im a long way off spending the money but would like to get the early design done around something a bit more specific.

I am building myself a RWD mid engine track car.

I was going to use my existing engine a 4-pot 2L turbo and mount it to a audi FWD box perhaps, currently making 350hp that i was going to uprate to around 4-430hp or so. but im aware without spending silly money that is its limit. and also pushing the engine fairly hard.

So what im now pondering, is that I seem to be able to find entire cars(A8) for about 2-2.5k with a V8 4.2L all day every day, pop a couple of turbo's on to get the car handling setup, on std internals/management, so im thinking (without knowing engine specifics) that 450hp shouldnt be too much out the question, and then to look into uprating the internals and management as needed to boost it a bit more to around 600 or there abouts depending on what the chassis/box/engine will take.

So I'm wondering what specific year car/engine you'd reccomend on a "realistic" budget that would be best suited to the project. (ie strongest/lightest that would need least modification to take good power)

And also what gearbox you'd reccomend as being the strongest most suitable gearbox for high power 2wd application.. if any are at all suitable that is. what sort of power it will take etc before breaking up..

Any links to tuning you guy's have done on these engines, or anything at all relevant greatly appreceated. I will try to find some time to do some searching on here over the next week or so.

Cheers!
Stu.

[adamss24]

Hi, i suggest you look on ebay for an rs4 2.7 bi turbo engine + running gear includding key, clocks and ECU.

[S@.]

Hmm. just had a quick look on google etc, the engine doesn't seem to be all that capable of what i'm after? or am i missing something? with only 2.7l i'm guessing the figures of up to around 400hp are about right though. perhaps the box may be of use to me, i will investigate that.
all input appreceated :)

[adamss24]

The 2.7 is higly tunned as it come from the Cosworth factory. There is a massive weight difference between the 4.2l and the 2.7 and the v8 wont make the power you looking for unless turbocharged or supercharged. Also, the electrics are simpler on the 2.7, the gearbox is a 6 speed manual and it wont need many internals replacing as its been done allready ! Get a twin turbocharger kit from states and a racing clutch on that box and you will see 500 ponnys. The gearbox wont take much more. If you want a trouble free reliability, get a UR quattro rear diff and propshaft as they bulletproof, the factory rs4 isnt as strong as the old turbo one...Failling that, look for an rs6 v8 bi turbo engine and gearbox and be preppared to spend big money to get it running right ! The current Pikes Peaks hill climbing record holder is running a rs6 lump and running gear with a quaife seqvential g-box and its running about 1000Bhp on race fuel. The engineers from Quaife said that the box wont take much more than 600 Bhp though to cope with the standing starts and the engine had to be restrained at produccing less than 1000Nm ! It has a full carbon fibre shell wich resembles an audi tt shape and its british built with german components...Its running a stand alone engine management though and the engine is heavily modded... They used s8 running gear and the propshaft snapped at 475 Bhp.http://www.fibre-lyte.co.uk/cf/TT%20Hill%20Climb%20Car/TT1.html .There was a full review in PVW few years ago and i remember reading the spec and not believing what they done to overcome the problems....There is also an s4 estate in germany wich runs a highly modded 2.7 engine with MTM gearbox wich runs 240 Mph ! It does have about 600 brakes with a propane/methanol injection, custom turbochargers and a few more goodies...It had a full review in the PVW a few months ago ! That is a sick car....I f that still not enough to satisfy ur appetite, look for www.dahlbackracing.com on the net or you tube and see the projects 2.1L engines with 600-900 Bhp ! They have tunned a few sub 10 sec. quarter mile cars, a few sick s2, couple of s4 and a few rs4 as well none with less than 700 Bhp....There is a golf mk4 wich ****** all over a ferrari on a drag race you should see on youtube !http://www.youtube.com/watch?v=xS8yMhC7cY8&NR=1 How a 970+ s4 2.7 biturbo sounds ? Enough to feed your appetite ?

[S@.]

The trouble is, I can make 450 easily(i would just need to add a bigger turbo tbh and its there pretty much) on my current engine if i am willing to push the engine hard. and it is probably lighter again then the 2.7 due to it being only 4-pot. The point is i dont want an engine at the top end of its capabilities at this stage.

I'm not 100% convinced a small engine is the way forwards.

Is it not just that the space limitations in the engine bay of the 4.2 have stopped most of you guys thinking about adding turbos?? so the 2.7 is the more common route?
this is a custom project and there will be plenty of room and I will be designing the manifolds etc myself so can make them fit. around half a bar should see 4-450 easy

thoughts?

[alecmartin19]

i am doing a similar thing and i already have the car and the engine. i need a gearbox to bolt onto the 4.2 v8 i have from the a8. i've heard rumours that the box from an a6 diesel will bolt on and cope with the standard power and torque. if so then what else do i need to modify on the box and the engine to get it to work, bearing in mind my engine is from an automatic. not sure if this makes a difference to the flywheel!