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92410, Did compression check..have some questions.
Posted by skyler475, Dec-29-05 11:38 AM

I know this has probably been asked before, but i did a compression check today and i got 170 across all fours. I have been seeing that everyone else is getting close to 200psi from their motors, is my motor healthy enough for boost? How long will it last on 8-10psi?

Thanks,
Skyler

92416, RE: Did compression check..have some questions.
Posted by Blizare, Dec-29-05 01:26 PM

Your good to go. With no varience your motor is fairly healthy and well taken care of imo.

Boost it. Anything below 120-100psi is time for a rebuild. :thumbsup

How many miles are on it?

92441, RE: Did compression check..have some questions.
Posted by skyler475, Dec-30-05 03:38 AM

It has prolly 120k..the speedo stopped working at 116.

92447, RE: Did compression check..have some questions.
Posted by Blizare, Dec-30-05 04:49 AM

Yea man, I'd say your definately good to go.

92485, RE: Did compression check..have some questions.
Posted by HadesOmega, Dec-31-05 11:29 PM

thats ok you engine is starting to wear highest compression you should have is 215psi. But like they said if there isn't much variance your fine.

Did you do it warm?

92504, RE: Did compression check..have some questions.
Posted by l6u9k6e9, Jan-02-06 08:31 AM

does it matter if it is done warm? also i have 8.0:1 compression, how much lower is mine going to be than stock... i did my compression test cold and they were all at like 140ish i think, i really dont remember.

92513, RE: Did compression check..have some questions.
Posted by Blizare, Jan-03-06 09:14 AM

Originally posted by l6u9k6e9
does it matter if it is done warm? also i have 8.0:1 compression, how much lower is mine going to be than stock... i did my compression test cold and they were all at like 140ish i think, i really dont remember.

It makes a difference cause the pistons will expand when at operating temp causeing the "RIGHT" compression figure your looking for. At 8.0:1 your prolly looking at 15 psi less or so. Stock motor new being 200psi per cyl.

92509, RE: Did compression check..have some questions.
Posted by Aggression, Jan-03-06 02:25 AM

Originally posted by skyler475
How long will it last on 8-10psi? Thanks, Skyler

Is it a stock bottom end your running this amount of boost on?

92510, RE: Did compression check..have some questions.
Posted by BlackMagic, Jan-03-06 03:03 AM

my guess is that it is a stock bottom end otherwise he'd be saying "how long will it last with 20+psi?" haha. But yea it all depends, some people's last 2 months, some 2 years, depends on tuning and taking care of your motor. 8psi is a safe boost to run daily on a stock bottom end intercooled. 10psi is the maximum and I would only use if you were going out to race or something. Of course some people do run 10psi daily, but it's just a risk you don't need to take

92701, RE: Did compression check..have some questions.
Posted by sike, Jan-12-06 04:09 PM

Warm, I have 175-180's across the board with 8.8:1 compression..