Well, really my engine would be a serious 3500 to 7500+ RPM combo - however, I only twist it to 6500 RPM. The reason is that I set up my combination with hydraulic rollers, which I did on purpose because I wanted a maintenance free set up and because I do not want to ever break anything. I screwed around working on my 302 combination for years wrenching on it all the time pushing it to it's limits. Therefore, I wanted to build a mill that would give me the big power I wanted without breaking, blowing head gaskets, etc... By setting my engine up like I did I've never had any of the shortcomings of the 302 with this kind of power.
So, I do not get the full potential out of my combination like I could with a solid roller set-up, but so what. It's reliable, it doesn't ever break, and it is still capable of running mid-10's with just 10 lbs of boost and assuredly 9's with 15-18 lbs of boost. Exactly what I wanted. It makes enough power any ways for a 90% street driven car.
But, to answer your question, no - I haven't done better than a 10.9 because of my clutch. The original clutch I used after building the combination was a 10.5" RAM long style. Same thing as the diaphragm HP900, but in a long style configuration. Rated for about 500 HP. It was fine on the street with street tires, but as soon as I put it on the track on slicks it started slipping from the first pass. With my clutch slipping and turning horrible 60 ft's (only like 1.7's and 1.8's) I still went 10.9 @ 126+ MPH. After nine passes the clutch went bye-bye.
After that I went to a sintered iron 11" pro stock clutch, which I had clearance issues with and it would not fully engage (the fork hits the back of the bell housing). I have the parts to correct this problem, but in TWO YEARS now haven't done it. I've just been too busy in life unfortunately for one and the other is just not wanting to mess with it. The later because the engine is shoe horned into the car with its monster 2" primary headers and I literally have to pull the motor to get the headers out of the way and the bell housing off. However, this winter I will be doing it and planned to be ready to rock for spring. Once spring comes I have to get with Lidio (Alternative Auto, he tunes it) and retune the car again, do a couple odds and ends myself with it, and then hit the track.
My set-up's:
STREET
92-94 octane
10 lbs of boost
Already gone 10.9 with a slipping clutch on this tune
But, I fully expect it will go 10.5 to 10.6 with the new
clutch working properly.
RACE
C16 Race Fuel
18 lbs of boost
It's definitely going 9's!
(if I can hook that is)
