Boost Problem....plz help!!

[cb3016]

Ok so i recently put in a new slowboy boost controller...and now my PSI goes off the charts. I'v checked all of my hoses and everythin seems to be fine. My old boost controller did this too so thats why i got the new boost controller, but now i'm doubting it was ever the boost controller to begin with. Anyone ever have this problem before? does anyone have any ideas what it could be?

Boost gage is out of wack?


please help i want to get his fixed before the turbo comitts suicide.

-CB

 

[psychlow]

You probably have it routed wrong. The boost source should go into the open top side of the T, while the wastegate should be connected to the bottom of the T.

 

[oldman]

now my PSI goes off the charts.

All out boost = Boost shot straight up immediately.
Boost creep = Hitting lower setting first, then creeps up as rpm increases.

Which do you have? Please fill out your profile so we don't waste 10 more posts just trying to figure out what car you drive with what mods.

 

[cb3016]

There ya go boss, nothin much, just problem came outta no where.

 

[oldman]

So do you have all out boost or boost creep? Bypass the mbc and test run, post back results.

 

[cb3016]

Full out boost, my guage only goes to 20 psi and it well passes it, i'v been drivin light on the gas pedal to keep the psi around 5-10.

wont bypassing the MBC make it go full out boost anyways? i'm probably wrong in that one, i'll give it a try.

 

[azkikr10]

could your wastegate be stuck closed?

 

[oldman]

wont bypassing the MBC make it go full out boost anyways? i'm probably wrong in that one, i'll give it a try.

No. Bypassing the mbc will result in boosting at actuator spring rating of about 10psi. Can you also explain how the mbc is hooked up?

 

[cb3016]

waste gate could be stuck closed i suppose, know how to check that?

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in this image the pipe goin down is connected to the waste Gate Actuator, and the lefty is connected to the T fitting.

I thought maybe SB was designed diff so i tried it both ways and nothing, i'v adjusted the bolt many ways and nothing has yet come of it.

Here is the low down i'v what i have done before the problem occured...

I Installed This:

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and before driving it I lowered my then HKS MBC 1/4 turn to go from 9PSI to what should have been approx 8.25-8.50 PSI.

Immediatly the problem went, I tried re adjusting the controller but it didn't do anything. Thought maybe the plastic HKS controller had busted, so i NEXT DAY AIRED the SB boost controller, any still not workin.

The more I think about it the more i think it is probably the waste gate actuator... but the closest i'v ever worked to the turbo was porting the exhuast manifold and doin the first HKS MBC.

 

[cb3016]

oh yes and i will have to bypass MBC tomorrow, need to buy long enough tubing. I'll let ya know how that works out.

 

[azkikr10]

I don't have first hand experience checking to see if a wastgate works or not, but you would need to hook an air compressor directly to your wastgate, turn the regulator down to about 15psi (although it should open up around 10depending on the wastegate) and see if the wastegate opens. Old man correct me if I'm wrong.

 

[oldman]

I don't have first hand experience checking to see if a wastgate works or not, but you would need to hook an air compressor directly to your wastgate, turn the regulator down to about 15psi (although it should open up around 10depending on the wastegate) and see if the wastegate opens. Old man correct me if I'm wrong.

That would be the next thing to do if he's still getting all out boost after bypassing the mbc by connecting the pressure source directly to the actuator.

 

[cb3016]

bypassed the MBC and ran @ 9 PSI roughly.

I run 15 PSI with the SB controller and i have like 1 thread in so it should almost have no PSI. I think their boost controller is really ment for cars that can saftley run that amount cuz its set to its min.

guess i'm goin off without a MBC for a bit.

thx for the tips. I appreciate it.

 

[oldman]

I run 15 PSI with the SB controller and i have like 1 thread in so it should almost have no PSI. I think their boost controller is really ment for cars that can saftley run that amount cuz its set to its min.

A properly functioning ball/spring type mbc should allow you to boost at the actuator spring rating when adjusted all the way out. The fact that it doesn't means either the spring is too long, wrong tension or the actuator pressure relief hole is too big. I suggest calling SBR and get a replacement.

 

[cb3016]

I took apart the MBC from SBR and the spring was being held down by the rim of the aluminum box for the spring to push through, stuck a paper clip in it and moved it over now i'm back in good shape, sadly the problem was that simple.