A 35R is significantly larger than a 30R, and flows a lot more air. I think it has everything to do with the 38mm wastegate. I've personally never heard of anyone with a 35R and a 44mm unit ever complain of boost creep, but I have heard of it quite a bit on 38mm units.

 

its not that much bigger and the fact I was able to hold 5 psi leads me to believe that the wastegate should be able to keep up

who else have you heard complain of creep with a 38mm?

 

A 35R is significantly larger than a 30R, this common sense. The 35R is going to flow a lot more air than a 30R, expecially when you are in the 20-30 psi range. I have heard of a lot of complaints coming directly from the Honda community on this issue.

 

i was told by my tuner that boost creep by like 2-3 psi is normal with bigger turbos 35r ect...

 

I have boost creep with a 38mm Tial WG running an AMS 37R..
I have boost set at 18psi because it creeps to 21psi at redline which is what I want to run consistently...
I just got tuned for it like that and the car works OK.

 

yea same here i have my boost controller set to 28 psi and it creeps to 30.5 psi to redline but my car is mapped all the way to 33 psi of boost.

 

at 20psi the 35r is only flowing around 50 lbs/min. its not that much bigger when run at low boost


plus, smaller turbos/ hotsides are more prone to boost creep, so shouldn't i be creeping with an apparently much smaller 30r?

 

my is dump, also a 3076R and 35R is two different turbo. It's way bigger.

wow 37R on a 38mm WG, that's just crazy. i thought AMS quote was "we design it right the first time so no boost creep" ??


this is what i found from Turbosmart website.
TRUE OR FALSE

*The more powerful the engine, the bigger the
wastegate you need.*

False. This is one of the more popular misconceptions. A wastegate is possibly the only component in your whole engine package that can actually be made smaller as you increase your boost/horsepower output. Use this simple guide:

Big Turbo/Low Boost = Bigger Wastegate
Big Turbo/High Boost = Smaller Wastegate
Small Turbo/High Boost = Smaller Wastegate
Small Turbo/Low Boost = Bigger Wastegate

Wastegates don’t operate in high temperatures.

False. Contrary to the popular belief, external wastegates are usually mounted at the hottest part of the exhaust. It’s the place where all the exhaust gases meet, creating extra heat. This, combined with the late combustion of unburnt fuel (due to rich mixtures, retarded timing and high octane fuels) significantly raises the exhaust temperature.

Larger wastegate valve diameter = better flow.

True – sort of. While the valve diameter is without a doubt an important part of the flow rate, equally important, but often misunderstood, is the importance of the flow path. When comparing wastegates with similar valve size, it is important to have a balanced body/valve/spring combination that is designed to work together to allow for maximum boost control. All Turbosmart wastegates are designed with this in mind.

 

i have a problem like this myself im using the hks evc 5 i thought it was/is the bc but my case is mmmuuuccchhh more serous than what ive heard so far i have an ams 35r kit w/38mm wg and with all my settings set to just wg pressure and a large green spring (13.5psi) it will build nicely but by 4500rpm i will creep till i shift and the highest peak ive got so far is about 34-35psi and fyi iv only put about 4k on this turbo
So anyone with any info please chime in, my next step will be to take it to my tuner and have the problem fixed

 

^^^ damn and i thought my boost creep was bad.

 

hehehe...I am pretty sure that AMS never ran as little boost as I did so they never experienced my problem. A couple weeks after I asked them about it I saw they added a disclaimer on their site stating that the Tial 38mm may creep up to 22-23psi which may out of the realm of pump-gas.
I tried to fit a bigger WG but there was no space for it.

I say try the bigger WG. It should work.

 

yeah that's what i'm thinking of doing. But i car barely see under 28psi when race season start. I wonders bigger WG would spool faster also? i saw on google somewhere. Buschur never run any of his kit smaller than 44mm WG

 

That is not that bad of boost creep. Put a bigger gate on it or change the position of the wastegate.

 

thanks Ron.

 

post pics of your manifold

also, try a 3rd gear pull with no wastegate on what so ever (big hole and loud) to see how much boost you get with no wastegate at all