Took out the green (weak) tial sport spring and installed 1 bar blue spring. However, no difference in boost. Had a little over ten pounds with green spring and same with blue?? Checked all the hoses to wastegate and turbo piping. No found leaks. What's the deal. Any help would be appreciated.

 

What kind of turbo kit?

 

It's a butt turbo (non sts). garrett turbo tial sportwastegate. It seems to be getting boost creep for some reason.

 

First you said you weren't getting the boost numbers, now it's creeping If it's creeping you need to either turn the boost up or get a bigger wastegate. The Tial gate has two ports, you can use a press regulator hooked up from the pressure port to the port on the top of the gate to allow you to run more boost.

 

I thought creep was when the wastegate was opening below max boost levels and bleeding off boost prematurely? NO?

 

Boost creep is when boost levels creep past the waste gate setting, very bad for the engine. This happens because the wastegate is opened all the way and there is still too much exhaust that spins the turbo faster. The fix is to get a bigger wastegate that will flow more exhaust around the turbo.

What you are seeing is not hitting your boost numbers. You may be creating too much back pressure and blowing your wastegate open prematurly. That's wny SMOKNZ suggested adding a hose to the top of the wastegate. It will help hold it closed.

 

MN Thanks for the info. ok i have the hose coming form the boost side of the turbo......tee ing- one to the bottom of the gate and one through the manual boost controller and into the top of the gate. Controller wide open.(screwed all the way out) Still it only makes about 11 pounds of boost. Is it possible that the t4 can only produce 11 #'s. As for back pressure, I have pacesetter lt's and 3" all the way back to the turbo...no cats! any good ideas??

 

Which garret turbo are you running?

 

That's a good question I think it's hemorphadite! Someone built it and stuck it in the car for me. I can only tell you the wheel sizes and a/r's. Maybe you can tell me. inducer wheel is 64mm ar 1.05 or close to that over 1. something The turbine wheel is small only aobut 54 mm with and ar of .61 ..got any ideas?

 

That seems like an awful big A/R for the turbine for a rear mount. It's quite possible that thats all it can make. You may need to get a smaller turbine housing to spin the compressor faster. From what I understood from the STS rear mount kits they run smaller A/R on the turbine because they claim that the hot exhaust has cooled down some by the time it reaches the back of the car. Something to consider.

 

I have a turbo guy who has access to all the turbo parts. We'll try and put a smaller hot section wheel and smaller opens. Hopefully that will accelerate the gases and spin the wheel even faster. I'll let ya know Thanks
Jay

 

http://www.tialsport.com/documents/w3_tial_38_sp.pdf