Hello I have a gsr with typeR piston and just want to know, when you have a compression test done what nubers would be good, I ask because I had my motor rebuilt just 4 monthss ago and my test came back 140 (give or take a point) on every cyl. that is very low compared to a gsr ( 240 -230 ) and that piston has even less compression than the typeR. I have the usdm typeR, please if you have any number on this please post.

 

You should be around 240ish or so. Make sure you perform the test properly, with a warmed up engine and the throttle wide open.

 

Great advice. The first time I did a compression test the engine wasn't warmed up and the numbers were all over the place. After warming it up, all the numbers came back within spec.

 

we did it warmed with a wot, I had just drove 30 mins and then did it.so 240 is the number than. by chance do you know what kind of power im missing out on due to 140 across the board?

 

You're missing out on a lot. Piston rings could be bad ... I'd start there since you had them replaced (hopefully they were replaced when the new pistons went in). Valve seals, valves, etc. Do a leakdown test if you can. That will help narrow things down to the upper or lower half of the engine. Either way, it sounds like you're looking at a tear down and parts replacement no matter what.

 

Definitely do a leakdown test. Also, try another compression test, but drop a spoonful of oil down into the cylinder before you insert the compression tester. If the numbers jump, it's your rings.