First let me start with the setup.
LS/VTEC 84mm
Neukin A/C manifold
3inch from downpipe back
Turbosmart wastegate 38mm (Open dumptube) 10.5psi spring
Greddy Profec Spec 2 EBC


I got some serious boost creep from 7500 rpms on. The wastegate is the same from my old setup and was holding 10.5 PSI no problem. I was wondering if anyone else with a related setup as mine was experiencing the same problem. i tried disconnecting the top hose from the wastegate to see if that would solve the prob but it didn't. I guess I'll have to run the wastegate straight off the turbo alone to see if it holds. No matter if I turn the boost controller off it still doesn't help. Also in my old setup my dumptube was routed back into the exhaust stream. I was wondering if that could be the problem with this setup. Maybe the exhaust gases coming out the wastegate needs to be routed back into the exhaust to aid in evacuation. Any help would be appreciated!

 

you might need a larger wastegate

 

smells like you need a 44mm tial i had similar issues with my gt35r and a tial 38mm gate. i upsized to the 44 and the problem was solved.

 

44 is the answer

 

44mm tial wastegate

 

Also try running your vac source off the turbo if not already doing so.

 

Thanks guys. I think I need a larger wastegate also. I hooked the wastegate directly up to the turbo minus the boost controller and the same results. So I guess larger wastgate it is!

 

what size turbo?

there are plenty of people that run neukin manifolds with 38mm wastegates that dont creep. Try disconnecting your boost controller and run straight off the wastegate spring and see if it still creeps.

 

Have you tried turning the gain down on the boost controller?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dunkd &raquo;</TD></TR><TR><TD CLASS="quote">what size turbo?

there are plenty of people that run neukin manifolds with 38mm wastegates that dont creep. Try disconnecting your boost controller and run straight off the wastegate spring and see if it still creeps.</TD></TR></TABLE> Yes I tried. Posted that right above yours. It's an SC61. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">Have you tried turning the gain down on the boost controller?</TD></TR></TABLE> Everything is set to the lowest setting. I tried turning the gain up also with the same results. I tried it with the boost controller turned off. I also tried it witht the boost controller disconnected.

 

on a car that i recently tuned the customer had a 9lb spring in the gate (38mm ramhorn manifold with a 44mm wastegate welded on) the car was seeing 15 psi.

we put a Neukin ramhorn manifold in the car and put a 12 lb spring in the gate and the car was seeing roughly 14-15 psi.

get a 44mm

 

Thanks. That's the same symtoms I have. I have the 10.5 spring in and seeing 18psi. I can hear the wastgate open the whole time and it holds 11psi, but as soon as I hit past 7500 the boost just starts rising fast. So I guess I have to find a good deal on a 44mm.

 

Vi