Turbo Boost Creep Creeping T25 14B 16G [Merged]

[oldman]

I see no signs of "boost creep" in this thread, what I see are springs that are heavier than you think they are OR leaks on the signal line going to the wastegate.

Where are you getting the pressure source?

Do you have a MBC hooked up but turned all the way down?

Is the top fitting on the wastegate capped off or vented to the atmosphere?

 

[Zakrecony]

hi oldman theres no leaks onthat line and its comming from the compresor side of the turbo to the wg and the top is vented not capped and theres no boost controler just the spring the car shuld be running on the wg presurewhich the spring sets shuld be 6 psi but it does to like 13 it stops at 6 for few seconds then when i give the car more thrutle the boost goes up to like 13 and stayes there and i know the spring is 6 psi not 13

 

[bling5tatus]

holy mother of punctuation.

 

[Zakrecony]

hmm i think you are not to nice to people that english is their 2nd language at least i am trying i want to see you speaking somthing difrent

 

[oldman]

holy mother of punctuation.

Is your shift key broken again?

hmm i think you are not to nice to people that english is their 2nd language at least i am trying i want to see you speaking somthing difrent

We are more lenient when English isn't your first language but we still expect to see some effort, I think you can do much better with punctuations, use this opportunities like to improve your writing skills like I did, English was my second language as well. You should read some of my earlier posts.

hi oldman theres no leaks onthat line and its comming from the compresor side of the turbo to the wg and the top is vented not capped and theres no boost controler just the spring the car shuld be running on the wg presurewhich the spring sets shuld be 6 psi but it does to like 13 it stops at 6 for few seconds then when i give the car more thrutle the boost goes up to like 13 and stayes there and i know the spring is 6 psi not 13

Is there a reason you're so concerned about running 13psi?

 

[zippyshoe]

Hey guys i have a little problem with boost creeping on me, well heres the story.

I bought the car 95 Awd Talon its got few mods but here it is

6 bolt motorr
honed to .20
new 1g rods mounted on 2g pistons.
balance shafts eliminated, block and head were resurfaced
ported and polished head, 3 angle valve job was performed

new stainles steel 1mm oversized valves
new valve guides and seals,
new 3g non tick lifters and crower springs.
full fuel modes and dsm link

The turbo i am running is a SBR G50 it had an internal gate but i took that out and got an 38 MM Tail external and an new o2 housing with external dump. so i put the turbo on and start up the car no problem but when i went to test drive it i saw boost hitting like 15 psi so i changed the spring in the wastegate to a 6 psi one and went for test the car is still overboosting its hitting like 12-13 psi and i am using wastegate presure.. You guys think i am taking too mutch air in ### of the head work and the 2g exhaust mani cant handle it or maybe some other ideas

This isn't related to your higher-than-expected boost issue, but I noticed that you mentioned that you "took out" your internal wastegate. I was wondering if you sealed-shut the flapper opening? If not, this could increase the spool-up time for your turbo.

As No_Skillz mentioned, I wouldn't worry too much about trying to run these low boost levels. It appears that you have all the necessary mods to run boost levels more inline with this turbo.

 

[Zakrecony]

HI, the hole that was there inside the housing where the flapper was its open but the little hole where the arm for the flapper was is welded shut. I have just enough of this mitsu housing just ordered new t3 headers and new turbo enough of messing with this one , Thank you for all your help guys.


Hope the English is better on this one.

Oldman and yeah i don't want to run 20 psi all the time gas is expensive.

 

[Mr Peepers]

^ People with money

 

[Zakrecony]

Yep, wish i had some left.

 

[Mr Peepers]

Oldman and yeah i don't want to run 20 psi all the time gas is expensive.

You don't have to run 20 psi all the time... just don't boost. Gas mileage is up to your right foot. I don't see the point in a large turbo if you aren't going to take advantage of its efficiency at higher psi. I'm sure that T3 manifold and turbo could have bought a lot of gas

 

[oldman]

You don't have to run 20 psi all the time... just don't boost. Gas mileage is up to your right foot. I don't see the point in a large turbo if you aren't going to take advantage of its efficiency at higher psi. I'm sure that T3 manifold and turbo could have bought a lot of gas

He has a dual stage gas pedal, idle and WOT.

 

[Zakrecony]

I am sure it would , but do it ones do it right and i got a good deal on the new T3 turbo 400$ for a 57 trim can't complain.

Yeah oldman you got it.
One more thing, you guys think i shuld start thinking about rods, and pistons?

 

[blktalon3]

I was just wondering if a big enough boost leak at the compressor housing would make boost creep worse. I ported the exhaust housing after installing my exhaust be I'm still creeping bad. I did a boost leak check and found 2 big leaks, the compressor outlet elbow gasket and the o-ring that seals the compressor housing. I was just wondering if these 2 leaks may have been making the creeping worse. My turbo is still apart waiting for the o-ring so I haven't got to check it yet.
Thanks

 

[blktalon3]

Nevermind, I was confused.

 

[SLOWKID]

i got two question the first is about my boost gauge, when i shut my car off the gauge will go to and stay at 5 psi. what does this mean.


#2 i think i have really bad boost creep my boost gauge will go up to 30 psi as i give it gas i'm not sure what my boost is set i have the controller set as low as it goes what can i do to fix this


thanks for your time

 

[RedTurboEclipse]

What kind of boost gauge? Sounds like its being inaccurate aka broken.

What kind of boost controller? Sounds like an install problem.

 

[turbosax2]

What does the boost gauge read at idle?

 

[turboking15]

did you install the boost controller backwards or adjust it back wards?

 

[coeclipse12]

Hey every one,,,i'm joel,,,, i have a 91 talon converted to 92" ( don't like pop ups ) anyways,,, my question is this i have a newly rebuilt bottom end,,,new rings bearings mains, and that normal factory bttm end. and cleaned head with a evo III 16G...and i recently got the XS power sport FMIC and piping with the knock off tial bov.... No complaints with the fmic or piping,,,fixed a boost leak,,,i think my mbc is set to 10 psi and wot,, but in second and third it goes to 15 ( once to 17 psi) and the to 10psi and stays there till next gear and 5, 5.5 rpm's....boost creep as i have heard will go example from mbc set at 15 to 20psi when it's not supposed to,,, so is what i have boost spike,,, stock exhaust except muffler,,, i know i need exhaust and working on it but i'm poor... could that be the cause?

 

[oldman]

Howdy Joel, you have neither. Sounds like your MBC is set to 15-17psi and you're dropping off to 10psi due to more boost leaks.

BTW you might want to get a new keyboard, looks like your comma and period keys are stick making your post extremely hard and annoying to read.

 

[coeclipse12]

hey the boost controller was $ 19 with shipping from cimotorsports...I will do another boost leak or two... I read last night that u want to have the engine TDC and then move six teeth... ( didn't understand which way and y ) so I might try that and also read to unscrew the pcv valve to see if it's leaking boost??? I as going to try this also and more idea's ????? I'll post a pic of my boost leak tester...with the FMIC the boosts the best it has since may when I put the engine in after the rebuild... oh and for the hard reading and "sticking buttons" I use my ppc6700 PDA for the internet at work right now actually... and the buttons on my keyboard here and reg pc are different that's why there typo's sorry

 

[turbotalon1g]

Boost controller seems to be the problem.

 

[oldman]

hey the boost controller was $ 19 with shipping from cimotorsports...I will do another boost leak or two... I read last night that u want to have the engine TDC and then move six teeth... ( didn't understand which way and y ) so I might try that and also read to unscrew the pcv valve to see if it's leaking boost??? I as going to try this also and more idea's ????? I'll post a pic of my boost leak tester...with the FMIC the boosts the best it has since may when I put the engine in after the rebuild... oh and for the hard reading and "sticking buttons" I use my ppc6700 PDA for the internet at work right now actually... and the buttons on my keyboard here and reg pc are different that's why there typo's sorry

Then take your time posting it, we require our members to use proper grammar, spelling, punctuation, and capitalization in the tech sections, please do not make me ask you again.

Here is something I wrote while back on boost leak testing, do not mistaken boost leak test as something trivial, it is probably one of the most important subject for forced induction platforms. Setting your engine to about 30* ATDC (after TDC, always turn the crank CW and never CCW) is to avoid valve overlap (when intake and exhaust valves are both open at the same time resulting in pressure escaping through the combustion chamber out of the exhaust.). Make sure the conditions I listed is fully satisfied before you call the test complete.

1. Disable your mbc.

2. Turn your motor to 30* ATDC to avoid valve overlap.

3. Start your test at the TB elbow and focus on area behind the TB first.

4. Spray soapy water at TB gasket, BISS, TB shaft on both sides, IM gasket, injector insulators, brake booster, afpr and all vacuum lines/connections.

5. Open your oil cap and listen for leaks. (PCV, valve seals/guide, rings)

5. Listen to your tailpipe for leaks. (EGR, valve overlap, jumped timing, bent/unseated valves)

6. Once all leaks are fixed, move the tester back to the turbo inlet.

7. Spray down the compressor cover (known leak), BOV return/flange (DO NOT TAP YOUR BOV LINE FOR YOUR MBC!!!), IC end tank/fins and all connections. Re- test.

8. Note that you will leak air into the crankcase through the turbo seal but do not panic, this is normal during a static pressure test as long as there are no shaft play.

The desired test result from the begining of the LICP (bypassing turbo) is around 20psi (on boost gauge) with the compressor set at 30psi, while taking no less than 30 seconds to bleed down to 0.

As a reference, my last test on my 500 mile new engine, I was able to pressurize the system to 25psi, bled down to about 16psi (my 1G bov) in about 30seconds, then took about 3 mins to 6psi and just kinda lingered there for a while. It's not easy to do but the point is it's possible. My next goal is 30psi After motor break in and Dodge modding my BOV. A boost leak test is one of most pita but important regular maintenace task, the key is patience and endurance, have fun.

 

[SLOWKID]

I have a faze boost gauge and a turbo xs boost control. i have no set boost it just keeps going up. at idle it reads -10 or so like i said when i shut the car off the gauge will read 5 psi. i also think i'm hitting fuel cut because my boost will go past 30 psi if i step on it.

any ideas please help .

 

[Tsi_User]

First off, if your gauge is reading at 5psi when you car is off it's broken. Your vaccum sounds about right though. I would start with putting a new accurate boost gauge in its place, and then start messing with the MBC. If you are still getting crazy boost creep, try switching out your waste gate actuator (this is what was causing my boost creep).