Mid engine prototype with S2 mechanics

[Steyn_b]

Look for KRB homemade monster on youtube.

[jade]

Just saw a VW Van 5 cyl diesel, not up on my models but that was rear engine 4X4 what system are they using ?

[AudiPortugal]

I need to refer that this project is a build between friends, and budget is barely enough to make a Audi s2 swap, so stuff like "audi r8 swaps" is impossible.
Also, we really want the 5 cylinder scream.

Between us we have access to CNC Mills, CNC plasma cutters, tube benders, at zero cost, but it must be us to do the work, and we don't mind to work a lot to make it.

Thanks to everyone helping out!

Mid engine means that unless you go rear drive, you'll have to get a transfer box and prop shaft to put drive to the front. (...)

Yes, for sure it is going to be a bit complicated.
Right now we think the best way to get AWD and good weight distribution is to make a system similar to the Nissan GTR, but reversed. Engine near rear axle and gearbox near the front axle connected with a main drive shaft. The main differential coupled right after the gearbox, with a drive shaft going to the back differential. The front differential is coupled to the main differential.

Any thoughts/suggestions on this?

No idea of the mounting face but you could look into a 911 4 wheel drive system.

Isn't a 911 nearly a front engine AWD car "rotated 180º"? At least to my understanding.
The engine is behind the rear axle.

Motorgeek thread on the subject with a lot of thoughts/suggestions. (..)

Thanks for the thread!
How was it done on that Audi? Are those all specially made parts or some standard quattro parts "bolted differently"?
Also, seems to me that the center of gravity on that Audi will be a bit high, or am I interpreting the drawing wrong? Seems like the engine needs to be put higher for the rear drive shaft to pass under it.

Gearing would be wrong but possibly use a transverse box on the back with the normal drive shaft outputs feeding propshafts to front and rear diffs. If seen this being used on homemade rock crawlers and off road buggies.

That idea is interesting, but wouldn't that require to mount the engine transversely?
Also, what would be the cost of one of those transverse gearbox (with a suitable differential) able to handle a 500-600hp 5pot?

Look for KRB homemade monster on youtube.

Very interesting project! It's not mid engine, but the gearbox they used made me curious after reading this (look at the first two comments)

http://www.speedhunters.com/2011/07/car_spotlight_gt_gt_krb_audi/

What would be the cost a gearbox like that?

Also, can a standard S2 gearbox with a dogbox gear kit, be able to handle 500-600hp and be reliable and dependable to competition?

[DJones]

Isn't a 911 nearly a front engine AWD car "rotated 180º"? At least to my understanding.
The engine is behind the rear axle.

Only trying to help, ignor it makes no difference to me......

[AudiPortugal]

Only trying to help, ignor it makes no difference to me......

I'm sorry, I didn't meant to be or sound harsh. English is not my first language, so I try to keep the sentences short and direct. Sincerely thank you for your help

[DJones]

I'm sorry, I didn't meant to be or sound harsh. English is not my first language, so I try to keep the sentences short and direct. Sincerely thank you for your help

Don't be silly no problem at all, you speak much better English than I do any other language....

I love quattro and always have and think I have a pretty good mechanical understanding of how things work.

I am also lucky enough to have a 911 which knocks out circa 650bhp, it's handling is unbelievable, while the front can often go light the grip from the rear when booting it is staggering, progressive oversteer the lot none of this widow maker stuff you read of..

Anyway best of luck with your project, just wish I had the time.....

[AudiPortugal]

Don't be silly no problem at all, you speak much better English than I do any other language....

I love quattro and always have and think I have a pretty good mechanical understanding of how things work.

I am also lucky enough to have a 911 which knocks out circa 650bhp, it's handling is unbelievable, while the front can often go light the grip from the rear when booting it is staggering, progressive oversteer the lot none of this widow maker stuff you read of..

Anyway best of luck with your project, just wish I had the time.....

Nice ride you have!
Thank you, appreciated.

[Val]

http://iedeiblog.com/2011/02/16/group-s-and-the-secret-audi-prototype/

[andy10v]

How was it done on that Audi? Are those all specially made parts or some standard quattro parts "bolted differently"?

That is a factory prototype , so a lot of custom stuff. Info about the car in the link Val posted.

[Error404]

Looks to me like it had two transmissions one driven from either end of the crank, like the new 4wd Ferrari.

[martinws]

Get bambridge to make something up to fit a box to the harmonic damper and you are sorted.

[driftin jo]

Get bambridge to make something up to fit a box to the harmonic damper and you are sorted.

If you tried to drive off the harmonic damper it would sheer of the end of the crank
instantaneously. That end of the crank is too small to drive anything more than the cams, alternator and stuff off.
The only way to do this would be to make a new crank with the front the same as
the back with a proper flange to bolt a flywheel to.

[G60Rallye]

Easiest way to do it would be to keep the engine in the front and use a skyline gearbox. You could then move the engine all the way back behind the front axle if you wanted and have a stand alone front diff. This would basically give you the same set up as the KRB quattro. Andrew Gallachers spaceframed focus is also the same but using cosworth running gear.

[Steyn_b]

The gearbox is from sellholm.

[Mcstiff]

Looks to me like it had two transmissions one driven from either end of the crank, like the new 4wd Ferrari.

Not enough room for that. If you look where the "front" (nrst to flywheel) diff/drive flanges should be, it looks like they came up with a single output driven by what would have been the front pinion. No need for a front diff but the "front" drive shaft is still useful. You can see the prop shaft running under the bellhousing. Up front it looks like they used a gear box to get things rotating the correct direction.

Something that I considered in the past for a mid-engined 4x4 was using a FWD engine and transmission turned sideways for front and rear outputs. Of course, for going slowly offroad having the additional reduction of the FWD final drive is desired but could be an issue for going fast onroad. Also, you'd have to make sure everything was spinning on the correct direction. I'd use one of the new 07k I5s from a rabbit or jetta and, maybe, DSG