What does this boost pattern suggest? Car has downpipe/chopped airbox, otherwise stock, 62k miles

thanks guys

edit: I should be a little more specific, it goes to ~7psi past transition and stays there till redline

 

Clogged mid pipe?

R.K.

 

A clogged mid pipe??

 

What I meant is a clogged cat in the mid pipe.

R.K.

 

clogged cat is one possibility. and also it sounds like turbo control valve is not opening. Things that can cuase this are

1-loose vaccume hose that go to pressure chamber and vacuume chanber.
2-bad one-way check valve for the pressure chamber.
3-solenoid

if you don't have smoke or noise then turbo should be okay. please check all the vacuume hose not only by visual check but actually pull them to see they are tightly connected.

Good luck

Yuke
Long Beach, CA
日本車世界一！
がんばって直してやー

 

Sounds sorta like your precontrol and wastegate solenoids are mixed up. Try switching them and see how it goes. Those 2 solenoids are the ones just under and in front of the intake manifold. You can see them behind the little vacuum box.

I had a 10-6-6 boost pattern before, and I switched the solenoids and it fixed it right up.

 

"switched" solenoids? to my knowledge me nor anyone has done anything with the vacuum lines ever, except the check valve from the y pipe to the pressure chamber near the charge pipe had busted in two, i replaced that and got SOME boost past transition but still low

elaborate further? the vacuum connections are changed? the solenoid plugs are changed? I pulled the codes and only one exists, for the purge valve, it shouldn't cause any problems like this

 

If your wastegate and precontrol solenoids plugs are switched, it wont show any code still.

From the factory, there should be a white dot to show the plug with its corresponding solenoid. Even though mine were installed correctly according to the matching dots, I still had a 10-6-6 boost pattern. I switched the plugs, and ended up with a 10-8-10 pattern. So it was wrong from the factory to begin with.

Having a boost pattern of 10-6-6 is usually the result of switched solenoid plugs. You can give it a shot and try switching the plugs. If it doesn't fix it, then just switch it back.

 

Solenoids were switched! I bet it happened when the dealership did the recalls!

YOU ARE THE ******* MAN, now i'm getting 10-8-10!!!

*MUCH* better, tires rip free at the top of 1st now, running 3" downpipe and chopped airbox, oh man i'm so happy.... soooo much work into this car the past few weeks with oil leaks, clutch, etc etc etc.... and it all pays off!@#

Should I add a catback now (is it worth the gain?) or any other items besides engine management that make good gains yet still safe? (I have aluminum AST already)

 

Glad to be of help.

Right now you got a dp and chopped box, so I'd say you're good for a catback exhaust. After that, you may need an ecu if you plan to push it past stock boost.

 

does a catback add enough power to warrant it's cost? Also, one thing I enjoy about it's current setup is the TAME QUIET "stock" like sound, i'm not a big fan of opened up exhaust rotaries as all i've heard are VERY loud and high pitched, what gains are in it for me and what exhaust would I like? (i'm looking for deep sound, nothing raspy and civil under light throttle, loud and mean sounding under WOT is fine)