dirtygalant wrote:why would you do it with the throttle closed? whole point of the exercise is to see how much the cylinder can compress air and it's not going to get a great deal of air flowing through with the throttle shut.
Plugs in on the other cylinders is only going to slow the rpm down but you're going to end up with the same figure if you crank it over long enough.
Honestly why do a test with plugs in and throttle closed? it's just a half-assed way of doing the correct test and it's not going to give you accurate results, which at the end of the day is what you want..
It's like going to the dyno with your handbrake half on or your air con switched on.
Mate not everyone knows that you need to have wot when you are doing a compression test, i certainly didnt when i first started. I gave that example as a possibility why results can vary.
Using your example of dynos, even with the same branded dynos power results can vary as there are varying factors which will affect the results.
yeah mate I totally understand what you are saying, that there are variances due to the accuracy of the tester used, if WOT or not, plugs in plugs out whatever etc etc - I'm just saying that 130psi isn't the best figure out there, and would usually indicate that it's not a 100% healthy motor - I'm not saying the motor is absolutely screwed I'm just saying that being down on compression would have something to do with the power figures it's achieving. I would say you can assume it would easily make a few more hp if the compression was say 150-160psi across the board.
I noticed a definite drop in power from when I originally compression tested my motor when I first got the car, with 155psi across the board - and after two years of thrashing, 16psi+ on the TC06 it's down to 140 on one and 145 on the other three and an increase in oil consumption.
Mate if he said it wouldn't make any more then that after 1 hour, I would say you would be better off taking it somewhere else. You will get better results for your money in the long run. This just sounds more like lack of tuning. But be aware, you most likely won't make the same result having less boost. But you should make more then what you have.
)