boost creep?

[mgroshong]

ok i have a stock turbo legacy, and all i have doen is a k&n air filter.

now i hooked up my wastegate directly to vacume, bypassing the boost solinoid.

i will see 7 lbs in the lower gears and 10 lbs in the higher gears.

but every once in awhile it will show 12-13ish, and it starts to hesitate more then is does normaly.... lol

is thw cold causing this much creep? it is in single digits here.

[Legacy777]

You're getting boost creep in the higher gears because of the higher engine load in the higher gears.

The cold weather is probably contributing. Does the 12-13 occur just as a one time spike here and there, or does it happen all the time when it's really cold?

[mgroshong]

all the time when it is cold, during the day it will run better but not what i think it should be as i still feel the damn hesitation.

but at night i don't even like to get on it, as i think something is wrong and i would hate to blow something up. also i don't think i have ever hit fuel cut.

that is unless the fuel cut is way different then say a dsm. when i hit fuel cut in my old dsm(bad wastegate = 26psi )

it poped violently and let you know pretty good it didn't like that.

does the stock boost solinoid bleed off air depending on the map sensor so it always stays at 9lbs or w/e stock is? or is it just like a set amount of bleed to raise it from the wastegate pressure?

i have a hks 3" dp i was going to put on in the spring along with my vf39.

well do you think if i put that on there and got rid of the cats it would free up the exhaust, or would that just creep worse?

sorry for the noob questions/responces. i'm not used to stock turbo cars besides the dsm. i work with building turbo kits all day, and the smallest turbo i use for mockup is a t67. and recently just got my hands on a s372 with a race cover... huge.

so this is totally new to me, but the car is so fun to drive when it runs good. i had planned on racing it out on the lakes this winter but the way things have been going i don't think that it going to work out.

[BXSS]

Boost cut on these feels just like DSM boost cut (I had a GVR4).
? the creeping as I had a stock & 3" TBE on my car when it was ej22t'd on actuator boost pressure (5psi) with no probs.

[Legacy777]

You'll know when you hit fuel cut. The car loses all power.

Yes the stock solenoid regulates how much boost the wastegate solenoid sees. It's better then a standard bleed setup.

I think you would probably creep worse with the larger exhaust.

Have you done all the routine maintenance stuff, plugs/wires, etc?

[mgroshong]

i have done plugs, but not wires, new knock sensor.

now i have noticed that the car runs way better during the daytime. my guess is it is warmer out and it doesn't creep up as much.

would puting my wrx tmic back on help this in anyway? maybe so that when it is at 12 lbs it is safer?

[mgroshong]

i just thought of this.

could a clogged cat cause the exhaust gas to push back agaist the wastegate flapper and cause it to not open? and if exhaust flows the path of least resistence then it would cause it to boost more to compensate for the pressure forcing back? correct?

now this is just a guess, but today i will put on my 3"dp and hook it back up to the stock exhaust. so basically just eliminating the cats out of the system.

lmk what you think

[Legacy777]

I'm not so sure that is your problem....but try it out.

[BXSS]

I think the opposite would happen with a clogged exhaust = slow / no boost.

Boost creep usually happens with large or no exhaust (wastegate atmo dump) & I could tell you first hand that a healthy car will not creep with a catless 3" TBE my car held a stable 5 psi when I wanted it to.

? the problem on your car but I'd guess the problem lies with the actuator somehow/someway.

[mgroshong]

ok well i put the dp on the other day and well it didn't fix anything.

then i put on my wrx tmic and WOW!!!!

it runs great now, so i'm guessing it just had hella hot intake temps. right?


it pulls harder then it has ever.

i'm running around 10-12lbs now, havn't hit boost cut yet...