Hey guys, I recently attempted to turn the boost up on my setup as its nearing the end of the season and why not lets get brave, its tuned safely for into the range Im trying to achieve. Ive had no problems running the car @ 16-17psi for 2 years, but when I turned the manual boost controller counterclockwise half a turn, the boost goes to about 21psi but begins to "flutter" the gauge from 19-22psi, doesnt feel steady and almost feels slower.

It is an nxs manual controller, with the bottom port being fed by the nipple right off the compressor housing, and a short line to the 38mm wastegate.

Ive had this setup for 2-3 years now so I am actually unsure of the spring rating that is in the wastegate, as its an ebay mini unit I dont think spring color is going to get me anywhere, but I believe it may be a 10-11psi spring.

Where would you guys start with diagnosing how I can put a steady 22psi out. To weak of spring, bov set to soft or boost controller possibly needs to be disassembled and cleaned?

Appreciate the help

 

Maybe you are at the efficiency limit of your turb?

 

It starts with the wastegate spring itself. Change that, and you get steady boost. The Manual Boost controller doesn't "Max out", its the spring in the wastegate that limits high boost stability.

http://www.boostcontroller.com/display_page.php?i=22

Just because a turbo is maxxed in efficiency, doesn't mean you can't make the turbo utilize more boost pressure.

 

Would a few well sized fender washers shim it enough to get a few more psi? as Im not sure I can find springs for this wastegate

The turbo is a t3/t04b s trim .60/.63

 

Have no idea. I haven't used an eBay gate for anything.

S-trim t04b S-3s are pretty closed to maxxed out anyway at 22-25psi at the surge limit

 

I would be very happy if I could get it to hold steady @ 22-23psi

Are the washers a trick in a pinch anyone uses to get a little more out of tial 35/38mm's? I really only want to try a few more psi at the track, Im happy with 16psi on the street

 

No. Ever since TiAL included ALL of their springs in their kits, its no longer a "quick" option or fix because all the springs are there.

Remember, these springs recoil tension can only take so much, so you're at a gamble with eBay knock-off versions. They could use a spring with terrible tension strength.

So give your "shim" trick a shot, and watch your foot on the accelerator as you test it out. You're asking a lot out of this turbocharger at a PR of 2.55 (which is about 22-23psi) and you're over 48lbs/min when this turbo can't support that, so don't get your hopes up.

 

Ok maybe I will just let it be and stick with 18psi.

Is there any chance this could just be the bov not sealing? Im not hearing the typical noise it makes when it releases, but maybe its just slightly leaking under high boost? Its a high quality made in america piece, but I simply installed it right out of the box with no changes to the adjustment on that

 

Its possible, but not likely. If it were leaking, it would have leaked well before 18psi. The possibility of that happening is more if you don't have the right spring based upon vacuum, not just positive boost pressure.

Tightening the bov may help, but also may cause issues with it being overtightened if you're not careful, by not opening to vent pressure consistently and to prevent any compressor reversion.

Good luck. It may be simply time for another turbocharger in your future.