Well although I am putting down some nice numbers (417 whp/ 360 ft lbs), I seem to have an issue - lag...

If I start a 3rd gear pull at 2700, I don't see 27psi until 4900 rpm, so clearly there is something wrong. I don't have any boost leaks and I don't believe I have any exhaust leaks. What else could be causing the boost to hit so slowly (using an MBC) ? I also have a FP 18# wga installed....I have heard that others are hitting full boost by 3900....

FWIW, a friend used to always say that my stock 9 turbo was lazy (it did not hit as early as it should either), so I am wondering if I have an engine issue....TIA

UPDATE : SHOULD ANYONE ELSE EXPERIENCE THESE SYMPTOMS - CHECK YOUR WGA....AFTER PRELIMINARY ADJUSTMENT I AM SEEING 30 PSI BY 4100....THE CAR AND TURBO ARE UNREAL....THANKS TO ALL THAT HELPED POINT ME IN THE RIGHT DIRECTION.

 

Says in your sig that you have a GM 3 port BCS, why are you using the MBC? How is the preload on your wga? Can you slide the arm on and off with ease?

 

After switching the turbo I just hooked up the MBC for ease. My plan is to re-connect the GM BCS.

The WGA was on too loose and I tightened it this AM but have not logged the car yet. That said, I'd be surprised if it was a loose arm as the spring is the 18#. My boost to 18psi takes until ~4300 rpm (starting WOT at 2700 in 3rd gear).

Thanks

 

You would be surprised what a loose wga arm will do to spool. I'm sure it will not cure your issue totally but it is a start. I have mine cranked down. You should not be able to just slip it on and off by hand.

You have an Evo IX, who tuned it? Messing with my MIVEC map, I was able to hit 28psi at 3.5k on a stock turbo. The BBK should be pretty close (I would guess by 3.8k should be full boost).

 

I would almost bet money it is the WGA. Put the OEM WGA back on there, I hit 25psi at ~3800 and was able to hold boost just fine and make plenty of power.

 

You should have to pull the WGA arm over the nubbin. It should require some effort on your part if it is preloaded properly. If it is loose and easy to put over, it's not preloaded properly and will certainly effect spool quite drastically.

 

wastegate or you having issues with your flapper.

 

Well I am wrong ....Adjusted the WGA arm and am now hitting 30 psi at 4100 rpm (when started from 2750)....Car feels unreal and still has plenty of tuning power left....Currently I am at 440 whp / 368 ft-lbs according to VDR - easily 50 - 70 more hp than my stock 9 turbo.

 

Did you use the same WGA on the stock 9 turbo? You are saying that the car felt lzy with teh stock turbo.

 

Woohoo! Go BBK go!

 

Problem fixed (bad FP WGA).....I am hitting 30 psi by 3900 - 4100 depending on when I go WOT in 3rd gear....The car currently is at 450 whp on VDR and has more in it....I am at zero knock and may try increasing the boost even more....Hopefully when I install the cams I could get close to 475 whp on VDR....

 

Cool!

 

Start messing with your MIVEC now. You might be able to spool couple hundred rpms quicker. I went from spooling 24.5psi at 3.5k to 28psi at 3.5k with just mivec settings.

 

How did you determine it was a bad FP actuator? Good job fixing though and updating!

 

The arm does not move smoothly or extend fully on a consistent basis (when driven by controlled pressure - aka compressor)....I bought the wga used and got burned....

Boostedwrx - Aaron is tuning my car...are you running an MBC?