mchrono

Has anyone done it? Ive searched and cant find anyone who has. Ive seen some 997TT guys who have removed their center driveshaft, front diff, and front halfshafts and love the result. Also, R8 and Huracan owners do the same and never go back to AWD. Seems it's do-able on the 991TT (?):

Jean

The hardware will be the easy part, back in the day I have gone 2WD on two cars I have. You would need to go with some GT3 components for the front drivetrain as well.

But I am not sure the current generation electronics and systems will cope well with the change. Reprogramming might be a PITA.

I used to have weight savings of ~70-80kgs from this process and was worth it for a track-used car.

If you find out something please keep this forum updated!

Catorce

^ exactly.

Lazy 997TT owners simply remove the cardan shaft for instant 2WD action, but I have not yet seen a good solution that doesn't make the car freak out computer wise from loss of the front wheel data.

I am not sure you can program any of that out even with a PIWIS 2.

mchrono

It seems on the earlier cars, it was do-able, by pulling the center driveshaft, front diff, and front half shafts. The trick was to either break out the outer front axle ends or buy specially cut down ends, not only to keep everything together, but also so that the front wheel speed sensors still work.

The later cars have a computer controlled electromechanical clutch assembly along the front driveline, that apparently cannot just be disconnected without consequences.


I would love to see someone tackle this and create something along the lines of a GT2 from a 991 TTS!

ace37

I'd be interested if it was reasonably reversible. Is the transmission up for the torque?

I expect the software will be the part that makes or breaks this one. Doubtful it can be done without a fair bit of tricky software work.

GT2 ECU retrofit and retune to calibrate the motor/turbos maybe? Probably not something easy... thinking some serious software work and $10-20k worth of retrofit parts...

Where's the guy that made a MT GT3RS??

Unconscionable

I wouldn't do this without the hand of an experienced Porsche shop. Last thing anyone wants is a hormonal Porsche with a midlife crisis.

The electronics are so integral to the Turbo that I find it implausible that the solution is as simple as pulling the hardware.


But hey, someone else can be the guinea pig.

ace37

Is the ECU the same for a RWD 991.2 Carrera/CS, C4/4S, and a 991.2 TT/TTS?

Catorce

^I highly doubt it. That is not the way Porsche rolls. The TT has a tone of specific gear being the flagship, stuff that is not shared cross platform.

ipse dixit

It is not.

This is why RUF basically uses (I believe) a bored-out 997 ECU to do their RWD 991 Turbo S conversion.

Northquest

ace37

Northquest

So, if I understand this correctly - simplified - it can be divided into two:

1.) Hardware - detach the front drive
2.) Software - getting the electronics to accept the detachement of the front wheel drive by using a customizable ECU?

Do you know of a stand alone ECU that would readily be prepared for that?

Any one have an idea of what range this app., would amount to?

Randyc151

The only reason you'd want to do this is for weight savings, so it's more than just detaching the shaft and calling it a day. You'd be better off just buying a GT2RS like everybody else is doing these days.

miky360

I would assume the highest model Haltech or Motec is up for the challenge. About a 10k ECU iirc

AKSteve

With a 997, I thought you could just pull the emergency brake up one click to disengage the front wheels. I know this was an undocumented feature that worked on my C4S.