i just did a compression test on my b16b boosted for like 2000 miles. #1 135, 2- 145, 3- 145, 4- 150 those sound low especially when a buddy of mine has 9:1 and his come up at 180....

 

that does sound low, did you do the test with the engine at WOT ?

 

thats average 90 is low

 

is there anyway to calculate compression ratio from a compression test?

 

you said you have a b16b correct...ok your compression test should show numbers closer to 210. 135 is way off the mark for a b16b...way off

 

Try a different gauge. Gauges can be off quite a bit and cause wierd readings like this. Maybe try using your buddy's gauge that read 180psi on his 9:1 engine.

 

thats REALLY bad

on a 10.8 compression motor, you should be putting between 200-300 depending on which gauge u use

 

They are all within 10 - 15 % of each other sounds like the gauge is bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg_type_r93 &raquo;</TD></TR><TR><TD CLASS="quote">thats average 90 is low</TD></TR></TABLE>

for a 10.8 compression motor, thats not average

try a different gauge and make sure you follow this testing method-

1) make sure car is at operating temp
2) remove ECU fuse
3) some people say remove intake for better results
4) press gas petal all the way down
5) turn motor over 4 times
6) read result

repeat for other cylinders