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four27
10-03-2002, 11:24 AM
I have a 94 GSR with 98k miles. compression is 192 to 199 with engine warm and throttle open. Leak down is 2% per cylinder. The shop manual says compression new should be 270 psi. Minimum acceptable is 140. My question is how do these nunmbers look and how much power am I losing being at about 200 pounds versus 270? this car is now used in SCCA road racing so I need all the power I can get. anyone got good idea how much more power the higher compression will provide.????

Dom Pirinchinci
10-03-2002, 07:44 PM
I don't have a GSR manual in front of me, and you do, but that 270 must be a typo. That's alot, and a range of 140-270 is WAY too big. I can think of two (non Honda) engines with 9.9:1 factory compression ratios that, when built right and broke in right, never see above 205 psi hot when cranked at 600 rpm on dyno. If your leakdown is 2% hot, I wouldn't worry about it.