all cylinders were 180-185. Seems a little high doesn't it?? At least they were all the same.

 

The gauge could be a little off but it is uniformity between cylinders that matters.

 

The only experience I have checking compression was when I did it for the first time on my 98 a few months ago. I use a lot of oil, so I decided to check mine. Five were 210, and one was about 205. Sounded high to me at the time, but I was told something similar to what 98sterlingmax said.

 

How did you go about testing your compression if you dont mind me asking..

Step By Step if you remember

-matt

 

Additionally, on high mileage engines, excessive combustion chamber deposits will increase compression ratio by decreasing the combustion chamber volume.

 

The fact that my compression is a bit high explains why using 96 octane helps me so much at the track. The advanced timing of the JWT ECU along with the little bit higher compression....

 

yeah I-30 that JWT ECU helped me alot too

 

Yup, those deposits increase octane requirements two ways, the first being the above mentioned increase in compression but even more of an effect is that the deposits create hot spots that cause preignition. In the case of our VQ's with the knock sensor, the engine should not ping. However the performance could be affected a bit because the ECU will retard the timing a little.

 

Not sure of any specifics you may be referring to, but it seemed fairly straitforward. It's been a while, but I think I just went by what some guys said here, my FSM, and my Chilton manual. Could I have done something wrong to cause high readings?