JonMortensen

I have a 7.25" (18cm) 2 disk button clutch on my T56 and the QuarterMaster throwout bearing setup was VERY finicky. There were numerous warnings about setting it wrong and damaging the pressure plate or the hydraulic bearing itself. I had to do a bunch of measuring and then set up a pedal stop so that the bearing didn't travel too far. Maybe you did all of that too, but the way you described had me a bit worried that you might have skipped a step or two, or maybe it doesn't matter as much with the particular throwout bearing you have, but thought you might benefit from a heads up.

Thanks. Right now I have no rear wing, just a 250mm spoiler, and a big 150mm plywood splitter in front. Vented hood and no inner fenderwells so it should suck air out the sides. It's actually an autocross car, but once I get a few seasons behind the wheel and figure this thing out a little better I'll do track days and hopefully it will have a nice big wing by then. Have mixed feelings on Richard's idea there. I agree that trying to seal the sides to the ground has risks, but I think you could run a contoured underside without the fences or big tunnels and still do better than flat bottom. Flat bottom is just something that they came up with to slow the cars down. If you look at what time attack cars are doing, some of them are running huge tunnels and going really fast. The thing that scares me about aero is trying to find the limit with whatever modification you make. I was watching an interview with a race driver and he was saying something to the effect of: "The car runs out of mechanical grip and feels like it's at the limit, but then if you just go faster the aero starts working enough to get you around the corner." I'm hoping my aero kicks in at a low enough speed that I don't have to cross that too fast for mechanical grip but too slow for aero grip threshold like he described...

Been lurking on this thread for a while, now I have a few questions to ask. Looking at doing a flat bottom on my Z as well. Was discussing it on another forum and people seemed to think the grade of aluminum was pretty important. They were saying use a 6061 or better. 6061 would run about $500US, but 7075 was actually a lot cheaper, so that was the way I was planning to go. What did you use, how has it worked out? Also see you did a front diffuser with the flat bottom, like a GTP car. Did you try without the front diffuser first, and did adding the front diffuser make any noticeable improvement?