Wompa164

iTrader: (4)

Hi everyone,

I just got back from my tuning session at Gotham with Steve Kan (he's the man, didn't you know?) and the car felt great, aside from one issue: boost creeeeep.

I was really surprised when he told me I was getting creep. Sure enough after checking out the boost gauge and watching it, I was getting creep from 13psi to 16-17psi running only on wastegate spring pressure (boost controller was disconnected).

I'm running the A-Spec GT35R kit, 44mm TiaL wastegate dumped to atmosphere, and full 3" exhaust with no restrictions. Ideas are that the wastegate positioning is sub-optimal and causing the creep. This issue worries me quite a bit because I lost my last motor due to creep (different reason though, my wastegate hose split) so I'm kind of paranoid. Everything got tuned out well to account for the creep, but I'm wondering about other possible reasons.

Does anyone have any suggestions or advice from their 35R kits? Are you experiencing creep? I'm extra worried because the weather is like 85*f out today, I don't know how bad the creep will get when it gets cold again (even though it won't be for a while). Also, I'm running both the wastegate pressure source and the boost controller solenoid pressure source to the nipples on the left side of the UIM. I know this is suboptimal because there is quite a bit of pressure travel from the compressor outlet to the UIM. I think I'm going to have the 120*elbow that sits directly after the compressor outlet tapped for a vacuum fitting. Is there anything else I can check? Loose fittings on the wastegate?



Thanks everyone!

S3DF

Did he point out where is it leaking?

Wompa164

iTrader: (4)

What leaking are you talking about?

classicauto

iTrader: (3)

Change the pressure source location and you'll be fine.

2psi of creep is about the same as what's being lost between the turbo and the UIM, so it adds up.

Switch over to directly after the compressor outlet and I'd put 10 bucks on it going away.

cewrx7r1

iTrader: (2)

The wastegate and solenoid pressure source should always see pressure from the turbo regardless what the TB does. Not after the TB.
Best place is after the IC and before TB.

I have a short runner A-Spect GT35R 1.06 T3 kit. It originally had a 7lb spring.
Now it has the 10lb spring. It never has had boost creep.

Your installation is bad. Nothing wrong with the kit.

Wompa164

iTrader: (4)

That's what I thought! Thanks for the advice Chuck

I'm off to get my compressor elbow tapped and fitted, I'll report back with results after I reroute the vacuum lines!

Sarusanj

iTrader: (9)

All this and no dyno #'s thrown in just for the heck of it?

PandazRx-7

iTrader: (18)

I have an A-spec 500R, 1.06, wastegate re-routed, 3" DP. Steve tuned mine in January and said it was creeping to 17psi on the dyno. On the street, it was more like 19-22psi depending on temps... I had the wastegate boost source from the UIM and switched to turbo compressor and now I hold steady at 17psi. Still a problem though since I'm supposed to have a 13psi spring...

twokrx7

iTrader: (1)

I've run them all over the intake track including the UIM and no creep ... the UIM nipple connection is not your issue.

G's 3rd Gen

iTrader: (11)

What kind of dyno #'s did you see w/ that set-up.. Thanks

silverTRD

iTrader: (37)

did you talk to sean about it?

cewrx7r1

iTrader: (2)

The kit design is fine, no need to hassel Sean.
Most likely installation or operator errors!
You see it all the time on these forums.

sk8world

iTrader: (5)

HA! I have the same issue on my 4094 kit and called-left several messages with no call backs.. Great products... shitty service.....

I am going to swap gates (50mm) and go 4inch exhaust..

DriftDreamzSS

iTrader: (4)

Im getting creep on my 35r kit, not the aspec kit tho. I have both my pressure sources at the uim and using a profec type S. I have a Tial 44mm with the 11.6lb spring and I get creep to 16lbs before I let off on low boost setting. High boost is way out of control and with the controller off I only creep past 14 on cold days. Im pretty sure if i put a vacuum fitting right after the compressor it should help out.

t04tii

I've seen those turbos creep also. I think its more of too much compressor mated to too small a turbine wheel for a rotary, unless you're going to build an exhaust manifold around boost control( main flow going to the wastegate, with a big wastegate( 50+))

cewrx7r1

iTrader: (2)

His WG goes to atmosphere.

My A-Spec GT35R T3 1.06 dumps into the DP which impedes flow and I never have any creep.

Wompa164

iTrader: (4)

You also have a T3 exhaust housing. Mine is a T4 1.00.

DMoneyRX-7

iTrader: (2)

I have your setup (A Spec T4 1.00a/r GT35R) except my WG is routed to the DP, and I don't experience creep. My vac source is from the compressor housing. I think once your creep will be fixed now that you did this.

IRPerformance

iTrader: (41)

I bet it has to do with the installation of the tuner is making excuses for another problem. The wastegate is plenty big for that turbo. On my 35R kit I noticed that I had much better wastegate response if I sourced the boost from near the compressor housing rather than the uim. Also, I have had nothing but problems with the profec b spec 2. Granted I had an early one, but it would never maintain consistent boost. FYI, Sean was out for a few days so they are very backed up. Took me awhile to get a hold of him myself.

ICE_Pilot

I have a GT35/40. 1.06 AR. 50mm waste gate plumed back into the exhaust system. I have a 10psi spring & control boost with a greddy profec BspecII, It holds 1.1bar solid or around 16psi. No spike or creep. WG opens at around 12-13psi with boost controller.

Same solid boost at 20psi on the 2nd boost setting. My boost gauge and controller are both plumed into the runners, Or uim or plenum. What ever you call it. The controller solenoid sees the WG pressure so as to open the gate to what I set it too.

I know alot of people give me crap for my power figers on this turbo so ill understand if you dont belive my boost setup.

cewrx7r1

iTrader: (2)

If we do not hear of the fix and what caused the problem (realistic) then we will assume it is another case OPERATOR ERROR which includes installtion.