Hey guys, with over 1500 miles on my new street ported motor I figured its about time to see how this thing does . And I was sadly disappointed today when I tried.
I ofcourse let the car completly warm up and hold idle, but when I got out on on the road and reached operating temp I tried boosting. I can watch the guage nail 8psi+ and have it only feel like 2-3psi. Its not holding boost. I do have a S5 turbo/manifold, and I am a bit concerned about the waste gate. I can "feather" it into boosting, nail 8psi and have it feel like 8psi, but it dosent happen all the time. I would love to take it to PIR but with it acting like this I dont know what I can do.

Wastegate? Turbo? Vacume leak (Only 4 vacume lines... checked all of them)? What could cause this?

 

hmm... That sucks man. What are you taking it to, RPM wise?

So what exactly happens at WOT? It spikes to 8psi+ (what RPM?) then it drops? Or it SAYS 8psi and feels really slow...?

I guess give a little bit more "hard data" if you can...

 

I can run it to 7k without thinking about it. Still feels like 2-3psi but says 8.
If i just floor it and WOT it, I can spike 15psi and drop it to 10, still feels like 2-3 psi.
It can say 5-12psi and still feel dog *** slow. I will really pay attention tommorow and give a better idea of whats happening. Anything I should look for?

 

yeah..not enough fuel

 

Not enought? I some how doubt that. At 8psi with the 680 secondaries, I should have no problems except running rich. Chris at pinapple racing said so and judge ito who ran a TO4E on the same port/fuel setup had no fuel problems.
If I go from a stop, 1st I hit 8psi, 2nd my rear end slides out at 10psi, 3rd at 10psi I am shoved far back into my seat and holding on for dear life, lol. I dont want to try 4th.

I noticed it only happens when I try to boost when I am normaly driving, I step on the gas and the boost guage starts to climb, and the car hesitates and eventualy hits and holds boost. If I do not get it to hold, the boost starts to fall off. Goes from 8 down to 5 down to 2-3 and fluctuates.

 

could have been fuel..cars that do not "feel" right at WOT usually run lean...

 

I should not be feeling fuel issues from 1-5psi like I am, heck I can feel it all the way to 12psi. I may be running too rich, who knows? I will try to get my friend to bring over his wideband.

 

I see if you slowly bring the power up, it seems to come on full, so the fuel is there.
Since the mechanical gauge is hitting 8.5 the waste gate is good.
Any CEL codes?
Is the tach acting normal?
Maybe weak signal/connector at the CAS.
Maybe weak signal /connector from the TPS or AFM.

 

did you double check the wastegate arm? make sure its attached with the clip? that can cause spuratic boost or no boost. Intercooler plumbing all tight? where is your boost gauge tapped into? are your only fuel system mods the 680's? and i am assuming fcd. that seems like it might be iffy, but just my opinion. how bout ignition timing? to retarded could make it feel slow as ****. just some suggestions, oh yeah plugs and wires in good shape with solid connections? compression test on the engine? im running jspec stock @12psi and if feels damn quick right now!