I had a compression test done before my dyno tune last week and here were the results :

Cyl 1 - 190
Cyl 2 - 190
Cyl 3 - 176
Cyl 4 - 174


Isn't the normal range 165? What's your opinion on these results? The tuner was a bit wary because they seemed higher than average.


BTW, the car has 120k miles.

 

might just be a high reading gauge, is it a stock motor with stock cams?

 

don't worry so much about the values but the consistency between readings. Max difference between cylinders should be 14psi. Ur a little above that by only by a bit. With numbers that high u prob have an 8. Was the engine hot or cold? Search and you'll find a bunch of threads interpreting comp test results.

I say don't worry about the numbers themselves because various brands of compression testers will read differently according to calibration etc...

 

Yep, stock motor and cams.

 

Interesting.... Yes, I have an 8 and the engine was still hot. I did some searching around and found some various things. Like I mentioned earlier, the tuner was a bit wary on those readings and tuned w/ lower-ish boost (22psi) and low timing.
Now I'm thinking we had some more room to kick it up a notch and make more power.

 

I wouldn't be too concerned with those numbers, if the motor runs fine and doesnt burn oil you're good to go. If you want you could do the test again with a different gauge and also do a wet test.

 

So this was with a warm motor? whats the altitude where you are? Was the throttle wide open? did u put oil in the cylinders when doing this test?

Ive done a lot of comp. tests in the past, but really, all youre looking at is if you should rebuild soon or not. if it runs good and the you tuner knows how to tune, it shouldnt really matter (not much you can do about it anyways)