How High: RPMs on stock valve springs.
Apr 8, 2011, 08:50 AM
#1
How High: RPMs on stock valve springs.
Preface: I know the car doesn't make power up there...
I need/want some over-rev capability for autocross and with the shorter gearing in the evo and running shorter than stock tires I'm smacking my 7500 rpm rev limit even on small courses periodically. Its usually for only a couple sec, but that's 2 sec I could be revving higher. Also the rev limiter upsets the car, causing odd handling quarks when full throttle around a sweeper and all the sudden you lose acceleration.
Shifting to third is out of the question. Unless the course is long and open 3rd is slower and shifting 2-3-2 takes too much time. If I can safely hit 8500 without valve float for just a couple sec on the larger straights (if you can call an autocross straight large...) that would give me an extra 8-10mph capacity.
Valve springs, ASAIK, is against the rules in BSP.
I need/want some over-rev capability for autocross and with the shorter gearing in the evo and running shorter than stock tires I'm smacking my 7500 rpm rev limit even on small courses periodically. Its usually for only a couple sec, but that's 2 sec I could be revving higher. Also the rev limiter upsets the car, causing odd handling quarks when full throttle around a sweeper and all the sudden you lose acceleration.
Shifting to third is out of the question. Unless the course is long and open 3rd is slower and shifting 2-3-2 takes too much time. If I can safely hit 8500 without valve float for just a couple sec on the larger straights (if you can call an autocross straight large...) that would give me an extra 8-10mph capacity.
Valve springs, ASAIK, is against the rules in BSP.
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