leaking compressor housing

[esahuque]

I had an enthalpy tuned ECU with a SAFC and on the dyno i put down 300hp at 12.5 psi. that's about what i expected out of my t3/t4 50 trim .48 a/r with 8.6:1 pistons. knowing that I could get more power if i had more control over my timing I went ahead and fitted my S14 with a Nistune s13 ecu using my cross over harness from my enthalpy tune. While i was waiting to get tuned i redid some of my IC piping and re-clocked my turbo. Set up a basic tune to start with and hit the dyno with high hopes of getting 315hp or so out of 12.5 psi and maybe 350-360hp out of 17psi. well that wasn't the story, at 12.5 psi i put down 244hp and at 17psi i put down 286hp WTF. we couldn't squeeze out any more power. Even though boost came on quick and held throughout the RPM range only dropping about .5 psi at red-line, i went home and did a boost leak test anyway. come to find out the compressor house was leaking at 4psi right where it meets the back plate. must have happened when i clocked it. I took it apart and put a bead of red RTV around it and let it sit over night. I did another boost leak test and it held up to 25psi. I'm about to pay MORE money to get back on the dyno and tweak the tune some more hoping for more power. does anyone think that was the only problem, turbo become inefficient do to it working harder. or should i look elsewhere. oh and i did a compression test and its freshly built with 170psi across the board.

[WDRacing]

It could have been the turbo, but it would have to be horribly inefficient to lose that much power. When doing the dyno pulls did the AFR remain constant and around 11.5 or so? Did the motor rev smoothly?

What are you doing for timing retard? You could be pulling to much timing now.

WD

[esahuque]

It could have been the turbo, but it would have to be horribly inefficient to lose that much power. When doing the dyno pulls did the AFR remain constant and around 11.5 or so? Did the motor rev smoothly?

What are you doing for timing retard? You could be pulling to much timing now.

WD

yeah my afr's where between 11.4 to 11.6 and the the motor reved very smoothly, it sounded great. it sounded so good that i was shocked when i saw the numbers. timing is controlled by Nistune. for 12.5 psi I'm logging about 20* timing and at 17 psi about 16* timing. we adjusted timing till torque dropped and then backed it off a few *. no knock was detected throughout the whole process. I hope it was in the turbo but whats got me is if the turbo was over working that much, wouldn't the boost fall off more at higher RPM's?

[WDRacing]

The TO4E is a big compressor.

[esahuque]

The TO4E is a big compressor.

Agreed! well i guess the only way to find out is to put it back on the dyno and see if sealing up the housing made a difference or not. I just didn't want to shell out more money just walk away disappointed AGAIN!

[esahuque]

850.00 in the whole and im putting down 50-60 less hp the with my 400.00 enthalpy tune. make my stomach turn