thomas.rousseau

Jaime,

I actually think that your test did not heat up the VC at all. Since it requires hardly any torque at all to spin the front wheels up in the air, the front wheel will spin with the same speed as the rear which produces no heat in the VC. What you need to do is to in some way put resistance on the front wheels. Then heat will be produced and hopefully you will have another result when you put the car on the ground.
The VC oil needs to be 160C warm....quite a lot.
However the test you did anyway verifies that your VC is not destroyed!

ttAmerica RoadsterAWD

Well, thinking of past activity, Most of us have seen that 993tt going circles on an icebed (see previous post). Maybe it's fair to say that once the fluid is hot enough, it will behave like an AWD.

In the name of experimentation, I'm going to drive my car around tomorrow for about 30-40minutes, lift the rear just enough to clear the rear tires, since I live in a culdesac that has a down hill slope, I'm hoping it will not strain too much. I'll see if I can induce a front wheel crawl. Anybody have any thoughts on this before I try? Am I out of my mind??

Jaime

Kevin

Per the factory manual, try to check the car on a 4 wheel dyno.. They say at no more than 5 mph.. It also says that it takes only 20-45 seconds to heat the VC up.. There is going to be friction taking place in the coupler.. Rub your hands together, then multiply that by the RPM of your engine, thus the 160 degrees.. Anyway they say to put the car in neutral at then hit the emergency brake. The front should drag down vs free wheel.. It list a graph.. You can also see the info on the PS2 tester..

viperbob

Wow this got busy.

Thomas - I removed everything from the transaxle forward. No new speed sensors are require. It does require the installation of a factory shifter box. I actually have full directions on removing and installing everything in my kit. As Jean said, you have to change your suspension a little to cope. You will get a lot less understeer. What I meant about liking the change was the car is a razor without the 4wd. No more turn ins with a will it turn in now, push a little more or not, etc,etc. Oh and the kit is not permanent. It can be reversed. I took mine out and reinstalled the 4wd system when I sold it. It is totally transformable. It becomes more difficult if you go into the transaxle and remove the VC.

Greg - DJ had a C4S. As I mentioned, more horsepower makes it WORSE. DJ had 300ish. 400 is OK, get to 500 and you will find that you are fighting the car all the time....

AndyT

bob can you email the infor on your kit please. i am planning on next winter tearing out all the 4wd poop and modding the gearbox with a LSD and 86ing the viscous coupler. Hey I thought you needed to modify the ABS gears on the front spndles ? No ? 45 teeth verses 48 or something to that extent. cheers andy

K24madness

I think these cars have **** for traction!!! I have the gaurd LSD (thanks Bob) yet the cars still fights for traction 1-3rd gears. I would have expected the AWD would allow you to just mash the peddle and point it and go. I have to feather the gas until I am well into 3rd. I have checked the VC and it is in working order. I have disconnected to test and the problem gets worse. It may be time for some 315's in the rear with 265's in the front.

viperbob

In a sense Andy, you are correct about the gear needing to be replaced for the ABS. The ABS teeth on the TT are an integral part of the front drive axle. When you remove the axle, you reinstall the standard C2 ABS wheel with a gigantic bolt and a standard axle nut. No mods to anything else on the upright are required.

Can you send me your outside email address?

Rob 97 993c2

just curious, how does the 996TT awd work? same as the 993tt? Does the 996tt also struggle with the x50, or higher hp? Does it toast the coupler?

Kevin

The 996TT does not have the VC in the tranny. It is a direct drive input shaft that runs to the front diff which contains the torque transfer plates/coupler..

fc-racer

I find this very hard to believe unless you're running M+S tires for street use. I ran a RUF Turbo R in an auto-x with Bridgestone S02 street tires and it had no problem hooking up coming out of corners full throttle in 2nd and 3rd gear. Even in 1st gear, it had great traction. This same car pulled 11.9 @ 128mph in the quarter mile so the power is there.

You either have really, really bad tires or something is seriously wrong with your AWD or car setup. There is no way you should be having traction difficulties in 3rd gear on a decent road with decent tires. It would be interesting to do a wheel torque calcuation to see how much power can be put down in our cars. With the gear and final drive ratios known and the torque output known, we can calculate how much troque we can put down. We can then extrapolate from that what the theoretical max would be in each gear. I know that my stock 408hp car can deploy every single horse in 1st gear on a decent road.

ttAmerica RoadsterAWD

Well, I went ahead and lifted the rear wheels with a wheel jack. turned on the car, went into 1st gear and eased out the clutch. No movement whatsoever! Guess it's shot. I contacted this wrench which said there may be some sort of mechanical coupler. He's going to look into it and maybe I can totally delete this Bul****-coupler (viscous-coupler).

Jaime

Acropora

w/o 4wd most definitely would have a tree trunk planted in the front bumper right now...

thomas.rousseau

Strange. It worked before but maybe it can't deliver any serious amount of torque to the front.
How long did you let it spin. MAybe it takes a while. I remember a test in a Swedish car magazine where they ended up beside the road with a Carrera C4. They tried to get up on the road again and it took them about a minute of serious wheelspin before anything happended in the front. And this was on a new car....that's why I'm a bit sceptic to this concept.

/Thomas

K24madness

Not sure what to say. I have been through 3 sets of tires with the pirelli's being the worst. The latest set has been the best. If I roll on in thrid they will spin. The worst is second and first is still a problem. I think it may have to do with how the power hits. I am sure there is nothing wrong with the car as we have been through it very throughly. I am considering going to the AVC-R boost controller to bring the boost in more slowly. I would be willing to sacrific some midrange torque for traction. With that controller I can vary boost by gears and RPM's

Good times for the RUF. Was that full interior and spare tire? I know RUF uses the K16's for there turbos. Maybe its the way the power comes on.

JJayB

I had this discussion several years ago with Jeff Zwart on how effective the 993tt all wheel drive was.
FYI he's won Pike Peak numerous times driving Porsches. He was 20 seconds faster with his 400 hp 993 than his 480 hp GT 2. So I guess it works in racing conditons for him. I like it, and I've had several close encounters that the all wheel has helped on the track. Drive a early 911 turbo with 400 hp, see how fast your adrenalin turns brown. I've read that 25% of the 996 GT2's have been crashed or totaled. I guess thats the effect of having 65% of the rear weight behind the axel and no electronic helpers. For those seeking all out power, eliminating 150 lbs goes a long way towards that goal just keep it pointed straight.