while i was at work, i looked up (on alldata) the stock compression on a 98 gsr and it said that they run about 270. does that sound right? that seems pretty high for a car thats supposed to have compression of about 10.5-6? my compression is off, but according to the alldata, its says its WAY off. any help is appreciated.

 

sounds high. most people with ITR's hit around 220-240(high end)... never seen anybody above that on a stock R... and they have 10.6:1.

 

thats way off.

 

270 is incorrect.
Also when doing a compression test the results have very little to do with the engine comp. ratio. I could have a 12 to 1 engine with a cam with tons of overlap and other variables that need to be considered and have the same readings as a motor with 10 to 1. A compression test is to inform you if everything is sealing correctly (rings,valves) and to see if you are getting uniform amount throughout the cylinders. also many people perform the test wrong, 5 cranks only.

to answer your question on a stock GSR expect 190 and up for a excellent reading if all cylinders are close in range your all good.

 

Compression on a gsr engine is 10.1.