My 03 IS300 has been supercharged with a powerdyne bd11a at 7 psi and controlled by an e-manage for about 12k miles over ~4 years.

Lexus did a compression and leakdown test on my car. Here are the results ...

Compression/leakdown percentage
#1) 140/22
#2) 145/20
#3) 155/15
#4) 155/15
#5) 150/17
#6) 155/15

From my little knowledge on the subject, the compression looks ok because the span is only 15 psi which keeps it with ~10% (15 psi) variation from a rough average of ~150psi. What makes me worried is that I read that a stock engine should be putting about 190 psi, but then again, this test was done at ~5000' ASL (above sea level) and an unknown engine temperature.

Now the leakdown ... shouldn't it be down in the 5-10% range?

Thanks for the insight!

 

the leakdown numbers look pretty high. Did you check to see where it was leaking from and do you burn oil?

 

no burning oil ... and the Lexus techs didn't go too in depth with the test. The more I think about it, they probably didn't get the engine up to normal operating temperature before doing the tests.