HiWind

great update Jack! Not sure if you've owned a C2 before but I'm sure you've driven a few .. I guess the feel of the C2 is just a bit (tail happy) scary at first post C4
but as you say you can tone it down by softening the rear sway if its adjustable or stiffening the front etc.. and I guess you'll adjust to the feel quickly.

jack.pe

Hey, no it's definitely lacking in rear end grip.. even for a C2. I had it set up to kill understeer on the C4 so it makes sense that now it's a little too tail happy. Am going to play with ARB's in first instance as they are all set on soft and need to be set on hard, front and back as too much roll. The rear then needs more camber, I had the car set up quite high at the back to put the weight on the front so lowering the rear will help too..
I know just stiffening the front ARb would make the balance better but i think it's actually a problem of rear end grip so want to try and sort it from than angle rather than reducing grip at the front end by just stiffening that ARB..

kos11-12

Hi Jack,
Great vid ! As usual, you are nearly there, I hope the improvement will be with in the geo..
can't wait to hear,
good luck !

kos11-12

I guess, a lower rear tire pressure could help a little bit as well.

ManuFromParis

If I'm not mistaken, the PDAS stays locked until you brake, but letting the throttle go should not unlock it.
To be confirmed.

ras62

You've made so many changes Jack that rather than guess I would say its time for 1. Corner weighting 2. Geo by a reputable specialist. Corner weight is critical, it could be going down the road like a three legged stool!

jack.pe

Yes but unlike a traditional mechanical LSD the PDAS will not activate the diff if slowing down, only if it detects slip under power

kos11-12

n1ne11

Hi Jack

Great video and great work. Admiring you'r will to go for a C2 setup on your C4. I would If I had the means and if it would pass MoT. Someone please correct me but no chance you pass swiss MoT with that setup/ or not get insurance issues.

I will observe your detailed analysis after a new C2 setup and will decide then what to do. Value is a bitch too, may be easier to sell and buy a C2 as long as I didn't spend too much money on the C4.

BTW of course your C2 setup will not behave nicely now, just setup your car to Cup or RS geometry/bars and it should run just fine. All the mods done to negate understeer will now induce too much oversteer. Not an engineer but seems pretty straightforward to me.

Keep up the good work & videos.

kos11-12

jack.pe

I have tone honest I'm not good enough a driver at this stage to be able to tell you how good it is. I can say it is working.. and there is no reason it would not be as good as a mechanical activated one, except under deceleration where it wont work..

Hey, thanks for the kind words. I doubt it would pass the swiss MOT if they knew. But would they check to see if the front gearbox and driveshafts are still in place? knowing the Swiss maybe they would!!

Ghia

Hi Jack.

I watched your videos with interest.

As you've already found out, you can't fit 964 C2 output flanges into a 964 C4 gearbox because of the diff. It uses different length output shafts.

The reason that you've broken the CV joint is simple, they're not strong enough. The 964 C4 is designed to spread the load through all four wheels, not just two. Porsche fitted larger CV joints and driveshafts to the 2WD version of the car for this reason. You've just found out what Porsche did.

There is good news though...

I am using a 964 C4 gearbox in a different project and as I'll be putting around 450bhp/450ftlbs through mine, I had to upgrade to 108mm CV joints (that's 964 C2 size).

The good news is that Porsche produced a 964 C4 Turbo-look and in the process, produced 108mm output flanges for the 964 C4 gearbox (yes... the odd length ones).

What's even better is that they're not silly money. I bought a pair direct from Porsche earlier this year for my gearbox.

PM me if you need some part numbers or text me on 07989 333437







Mike Ghia

HiWind

^^ wow Mike great post thanks!!

FlyingDutchman

Is that locking collar available for purchase? Any pics of it?

jack.pe