KarlS

The 2003 GT3 Cup car splitter is 996.505.986.91 but I have no idea what the difference is.

Karl

Interesting. I just checked PET. From what I can see the calipers and rear rotors are all the same parts. The front rotors are slightly different, with the GT3 using 996.351.409.91 and 996.351.410.91 and the TT using the same part number but ending in 02 instead of 91.

I think I read somewhere that part numbers ending in 9x indicated Motorsports parts but I haven't confirmed this with anyone. Given they use the same calipers, the rotors must be the same size but maybe different in thickness or something small like that?

Karl

Loren,

Aren't the GT3 Mk 1 and the TT cast iron brakes the same?

Karl

Craig,

Thanks for the update. Any word on when the PSC's will be available in the stock GT3 sizes?

Karl

There is no load on the engine when heel toeing and the Motronic must recognize this. Try the same excercise without the tranny in neutral and see what happens.

Karl

This is a standard e-gas "feature". You can't left foot brake an e-gas car, including the TT, GT2, and GT3. I'm not sure of the logic, perhaps it is done for emissions purposes or for fuel mileage but they all work this way. That's why the Cup cars don't use e-gas.

Karl

I just installed a new set of calipers on my Cup car. After installation, I bled the brakes as usual, running about 24 ounces of fluid through the system to get all the air bubbles out and tapping on the calipers with a rubber mallet to force out the bubbles. My question is what else, if anything, should I do to make sure all the air is out of the system? I was thinking about maybe running a short session (4-5 laps) to heat things up and doing another bleed. But maybe that's overkill. What do you think?

Karl

Any place selling the supplements at a discount? I've been getting mine from MY Porsche but they charge list and aren't that quick on delivery. Plus once they sent me a supplement that was all in German and when I asked for a replacement, they charged me for it as well.

Karl

Gary,

Should be a warranty item but I wonder how an O2 sensor could go bad so soon? Did you get some bad gas?

Karl

Loren, I'm replacing not rebuilding the calipers, so I don't think any of this blurb applies. BTW, no one seems to stock these things. I called the 5 largest dealers I know of plus all the local guys and no one has a set of TT calipers in stock. FYI, Suncoast and Brumos gave me the best prices. Champion was the highest. Amazing how there can be so many different "list" prices for the same part.

Karl

Note that the factory would have you replace the socket head (they call 'em cheesehead) bolts that hold the caliper to the hub each time you remove them.  They come with a bit of goop on the threads to sort of lock them.  I have never done so myself....but, have used a bit of blue locktite.  Loren can quote you the torque settings.....important since you have steel bolts into aluminum hubs.

Yeah, I never replaced the caliper bolts on my 996 either and I had them off many times. However, I didn't use Locktite, I always used a copper anti-seaze paste. My understanding is that with steel into aluminum, w/o the anti-seaze you run the risk of the steel bolts bonding to the aluminum under high heat.

Fortunately, my Cup car has studs in place of these bolts for fast caliper changes during endurance races. So all I have to do is loosen a couple of nuts to take them off.

Thanks for the Snap-on tip.

Karl

I need to install new calipers on my Cup car. It uses the same calipers as the 996 TT. I've removed calipers before but not swapped them. I'm guessing there is an ABS connection to remove and the brake line. Any tips on the brake line, esp. how to keep brake fluid from going everywhere?

Karl

999 141 038 07 Torx Bolt (E12)

All seats EXCEPT the (RoW) GT3 seat use the same bolts.

Loren,

If I am reading PET correctly, wasn't that part number superceded by 999.141.039.07 in 2003? It appears to me this bolt is now used for all seats, including the GT3 buckets (XSE/XSF).

Karl

I can't remember for sure without looking but isn't there an overflow tube from the reservoir that runs down the frame on the driver side. I think it empties near the header/exhaust pipe. What is your coolant level at when hot? Is there any white residue around the reservoir cap?

Karl

Anyone know the spring rates on the Mk II GT3? I've heard 40 N/mm front and 90 N/mm rear but that doesn't sound right. The springs are H&R but there is no marking on them for the spring rate, just a PAG part number.

Karl

I rotate the tires from side to side at the end of every track day. Gives much more even wear. You'll still eventually cord them but they will last a lot longer. I've done this successfully with Pirelli P Zero C's and Hoosiers. I also do it with my slicks. These are all radial tires and I've never had a problem.

Karl

This is a common problem with the 1999 model. There is a TSB on it (I'm sure Loren can give you the number). The TSB calls for replacement of the coolant overflow tank and cap. There was a design issue with the first gen tanks that allowed the coolant to flow away from the sensor under heavy acceleration and trip the warning light. Mine used to always come on at the track but once I had the TSB done, I never had the problem again.

Karl

I just make sure I return my wrench to the same position it started when I began to loosen the screw. For example, for the inside screw, I usually have the wrench all the way up against the inside fender liner when I start to loosen the screw. I tighten back to the same position.

Karl

It can also be the e-gas programming. There was a good article on e-gas in a recent Pano. The e-gas is tied into the DME and is used to smooth the power delivery and control emissions. A friend of mine who has done extensive work on a dyno with e-gas 996's tells me the e-gas controller is slow to pick up when you accelerate from partial throttle unless you mash the gas. This is on purpose to both smooth the power delivery and control emissions.

However, in your case it doesn't sound like it is smoothing the power delivery but is making more jerky. If the problem doesn't appear to be the Variocam situation that Palting and Loren pointed out, have you dealer run a diagnostic on the e-gas controller.

Karl

I think Jeff means open the right rear bleed screw...

Thanks, now I get it, I thought there was some piece I was missing on my Motive PB. When I am doing a fluid replacement (as opposed to a bleed), I use the left front (closest) bleed screw to drain the reservoir down before refilling it (and the Motive) with new fluid. Not only does it drain a little quicker but you can eyeball the reservoir while you're draining. You can't see the reservoir from the right rear.

After I fill with the new fluid, I do the normal flush process starting with the right rear first.

Karl

If you are using a 'bug' Motive type pressure bleeder I open the RR screw when the pressure is on but the Motive tank is empty.  This will empty the reservoir like you are trying to do. Jeff

Jeff,

I have a Motive bleeder. What is the RR screw?

TIA,

Karl

Sure, David, I'll take a picture and post for you.

Karl

David,

I had the fire extinguisher mount in Don's picture, which is the R-2020. I had to modify it to work with the GT3 seats. I had to cut off the bracket that forms the leg of the "T" in Don's picture and drill some new holes to use it. If you will be a Summit Point this weekend, I can show you what I did. I don't have the car any more but the guy I bought it from will be there.

B-K has another model, the R-2030, that works with the R-9030 sub-belt bracket. This might be a solution for the GT3 seats. I think OG Racing sells B-K stuff and they will be at Summit this weekend as well, so you may want to talk to them. You might be able to go by their store in Manassas to test fit the brackets before buying them.

Karl

I had the BK fire extinguisher mount on manual seats as well. I'd suggest giving Brey Krause a call, they are quite helpful. Their website actually shows a different bracket than the one in Don's picture and states it works with non-power sliders.

Another option to consider would be to use some hose clamps to mount the extinguisher to the harness bar. I had a roll bar in my car which is thicker but the same thing should work for a harness bar. I got some large hose clamps and put a rubber gasket between the clamp and the car to avoid rattles. It worked fine and was in reach of the driver (which harnesses released, of course).

Karl

I got mine from Weissach They pedals have little rubber nubs that stick through the holes and give your feet extra traction on the pedals.

Karl