Well, the Vortech is installed beautifully, but I'm only making 300 rwhp. The tuner did not do a baseline dyno. In addition to the SS box, I'm running the J&S Safeguard timing for knock retard. A NA run with the supercharger pulley removed, but piping still in place resulted in 217 rwhp. I know for a fact that the car didn't come in there with 217 rwhp, because I just ran a 14.1 at 99 mph two weeks before. The only common factor between the Vortech and NA run is that the J&S was hooked up for both runs. I will have them bypass or disconnect the J&S to see if it is pulling timing even though we're telling it not too. My EGTs are around 1400, so timing is not out of the question. Also, I had him do a compression and leak down with the following results:

cylinder 1: 200 22%
cylinder 2: 195 22% (intake valve)
cylinder 3: 195 22%
cylinder 4: 189 18% (intake valve)
cylinder 5: 204 9%
cylinder 6: 195 28%

I may want to address the valve problem first anyway, but I need to know if the J&S is bad out the box. The loss in Vortech power could be from the leaking valves, but doesn't explain 217 rwhp in stock form. I'll keep you guys informed.

 

Those are very high leakdown numbers if the test was done correctly.

 

I believe they are correct, but would these numbers rob me of 30 boosted rwhp?

 

With 18-28% leakage that loss of hp is very believeable. On my turbo 1300cc motorcycle good leakdown values are more like 1-2%. What are acceptable compression numbers for that engine?

 

thats way too much leakdown in my opinion.. I had 25% leakdown in the front two cylinders, and for that, infinity replaced my shortblock....

 

B1kg35,

Don't you mean long block? How did you present them with this problem?

 

Leak down tests should be performed after a bad compression test. There are to many things that can change a leak down test. Cam timing, lack of oil on the rings. My first test would be to check the blow bye in the block bye starting the engine and seeing if any smoke is coming out of the oil fill. and a better test would be to plug the EGR valve. If you think you have bad valves seats or a burnt valve or valves, The easy check would be pull the upper plenum and check for mass reversion in the intake runners. Bad, would be a dark brown color in the runners. How many miles are on your car? Think positive!! Im sure its something simple. Pasta

 

The car has 74k miles.

 

I would have a hard time thinking you have bad valves seats or guides. This is a simple thing I would like you to try. It will not cost you much, but could save you a lot of money.
I will assume your install was done right. Was it? OK this can happen sometime in your climate. I would like you to change your oil and when you go to fill it, try 3 quarts of 5-30 and 2 quarts of transmission fluid. The trans fluid will clean out every bit of trash in your engine.
My guess is you might have a ring land, that has some deposit's. No big deal. Just drive your car normal for a few days and then dump your oil and fill it with your normal brand.
Your ring seal is where you need it most with your mods. Understanding that at this late date with an upgrade, could be as simple as a sticky ring land. What do you have to loose?
Remember just drive your car around simple and get it warmed up real good and then change the oil. You will be surprised on what your oil looks like when you change it.
Simple is good. Pasta

 

Thanks, Pasta.

 

Now that I think about it, I changed out the Crawford myself and the intake runners on the lower plenum were clean as a whistle. Also, I was there when they were finishing up the leakdown. The engine wasn't as hot as it should've been considering how heat can affect the characteristics of metal. I think I'll let them just tune the car and get a second opinion on the leakdown.

 

My G35 factory manual shows that standard compression is 185psi and the min is 142. Allowable variation between cylinders is 14. Your values are well within these except for one cylinder with a 15 lb variation. That sounds pretty typical for an engine with 74K. I would have the leakdown repeated by someone else before tearing into the engine.

 

Thanks, Gary. You beat my dealership in responding to Nissan specs.