Preserved from CalaisTurbo. Original authors and dates are shown; archived members are not current Holdcom accounts.
I konw 0 about compression so I thought I'd turn to you trusty experts (he he) on here for some guidance. I'm looking at buying a VLCT. The current owner said he had the compression reduced and got 109 from each cylinder when tested.
Is that bad?
Would more boost be the reason to drop compression like that or is there another advantage?
What is the standard compression for a RB30ET?
Cheers - Brett.
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109 is crap, but it's very odd if you got that for all 6 cylinders. He's immediately dodgy if he's trying to pass that off as a healthy motor. I think mine scored 150+ when I did it.
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Stock compression for the ET is 166psi on a hot engine (memory)
however its not the really the psi you should be looking at. Variations between cylinders is the best to go off in your case - all cylinders should be within 5psi give or take of each other.
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109 accross the bord to me sounds like its been a non-turbo than added a de comp plate
but im not big on know diffrences between non turbo and turbo compressions
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I've put a 1.6mm copper gasket on factory VLT and am reading 120psi, the thing runs great. The only thing is to get the same performance you need more boost and fuel.
As long as its similar on all cylindars it shouldn't be too much of a problem.
Check the vin and engine numbers and make sure its factory turbo.
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And make sure that the compression test is being done correctly...
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unplug the coil too or it will fryyyy
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Found out the car had been in a major ass ender. Also had structural rust. So I obviously passed on that one. Thanks for the info tho. I'll use it next time.
Cheers -Brett.
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