How to decrease boost

nigel77

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#1
Hello everyone,

Fresh engine with drift motion 3" downpipe and exhaust and aftermarket intercooler, drift motion modified oil pump, oil thermostat, cooler and filter relocator, now makes so much boost I get 12lbs at about 5000 rpms and hit fuel cut. Running stock turbo and wastegate, what is the easy way to lower (or control) boost? Can I change where the waste gate gets its hose pressure, or somehow modify the internals? What's the cheapest/best way to do this?https://solitaire.onl/ 9apps.ooo/ https://bluestacks.vip/
 
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suprarx7nut

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#3
Hello everyone,

Fresh engine with drift motion 3" downpipe and exhaust and aftermarket intercooler, drift motion modified oil pump, oil thermostat, cooler and filter relocator, now makes so much boost I get 12lbs at about 5000 rpms and hit fuel cut. Running stock turbo and wastegate, what is the easy way to lower (or control) boost? Can I change where the waste gate gets its hose pressure, or somehow modify the internals? What's the cheapest/best way to do this?
I'm surprised a CT26 can do that, but you need to either reduce exhaust flow or increase flow through the wastegate. You could install a weaker spring in the wastegate, but that really shouldn't be needed with a stock CT26.

Are you sure there's no boost controller installed currently? A picture of your turbo with the heatshield removed might help us here.

Get a boost controller?
Traditional boost controllers can only raise boost. To lower it you have to modify/correct the wastegate itself.
 

Zazzn

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#4
Yeah with free flowing exhaust you'll hit more boost.

You can either put a cat in to cause a restriction or b but a more restrictive intake. Boost controller wont help.
 

supranewbie

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#5
Yeah, misspelling. I was asking if OP has a boost controller. Got, not get.
Wondering how he knows he's at 12psi.

IIRC, Driftmotion sells various weight wastegate springs.
 

Zazzn

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#6
with a high flow intake and downpipe, I used to make 14-15 PSI uncontrollably, but if you are hitting 12 and boost cut, you most likely have a boost leak.
 

suprahero

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#7
I just came in here because I thought it was spam or a robot. Who wants to lower boost? I want all the boost...…..lol
 
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shipkiller

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#8
with a high flow intake and downpipe, I used to make 14-15 PSI uncontrollably, but if you are hitting 12 and boost cut, you most likely have a boost leak.
Just want to piggy back on this.

boost cut will be dependant on AFM reading (aka airflow CFM going through the MAF sensor).
As Zazzn said (because this is right), 14-15psi is about right on a 7m before fuel cut. However with 57trim and 550cc/lex with safc2 I could boost to 16-17psi before fuel cut. It was a VERY wild ride (The owner of perfecttuning is my witness).
Warning: never go this crazy with SAFC and altering fuel maps like that, because timing is also affected and my 7m eventually blew