I am currently running on a T25, with a 3'' downpipe, cat, and piping w/ an N1 apexi exhaust. I have an Apexi mechanical boost gauge with an Apexi electronic boost controller. After getting that installed i set the boost at about 9psi and the car ran fine with minimal boost spikes; unfortunately, about a week later my boost gauge is reading over 14lbs and the car starts to backfire after fast acceleration. I turned the setting of the boost controller off and the car is still running the same. Can anyone help me solve this problem???

 

your wastegate may be stiking shut haveing something to do with the install of the boost controler also could be a bov problem if you dont have a bov get one as it may fix the problem but even if it doesnt you need one any way but you pry allready have a bov

 

Yes I do have a BOV and it's a GReddy Type S. But for some reason it doesn't open up like it's suppose to. When i lightly feather off the gas pedal the valve would open but when i just quickly take my foot off the gas then you would just here this fluttering noise coming out of the intake.

 

you should definatly check your waste gate... you might need a new one... and for the boost controler you said it still did it when the boost controller was off so it might not be that... oh and for the flutering, and the BOV not closing or opening fast is because you need to tighten the spring thats in the BOV... but dont tighten it too much or it will be too hard to open.
I think im right but just make sure with someone who knows.

 

Fixed the problem dude. Thanks. The line to the wastegate had a crack and i replaced it with a new one. But as for the BOV shouldn't tightening make it harder for the BOV to open?? However, I've tried having it very soft as well and it still does the same thing. Well, lemme know if you can find out what the problem is but thanks again. I appreciate it.

 

Just to let you know the fluttering noise is called compressor surge. this is a very $hitty thing. this is what will kill your turbo in less than 5000 miles if it happens too much. check all of your vacuum lines. it sounds like that would make it happen. if they are old just replace them. it only costs a couple of dollars. if the wastegate doesn't see the boos it wont open. if you have a leak it will raise up the boost. remember that a wastegate only opens under it's stock boost rating. all a boost controller does is restrict the amount of boost that gets to the actuator. if you loose some of your boost through a leak it will not open properly.

GOOD LUCK

 

Yeah thanks, i'll look into that. But I might just get a new BOV. I bought mine used off of ebay from japan so maybe the springs might have been changed because my stock BOV was opening up fine until i installed the GReddy Type S one. I'll prolly pick up an HKS since i have an HKS S Type FMIC. But should i put back on the stock one for now when running 9psi??

 

Sounds like boost creep to me. Wastegate issue. I take it you are internally gated? Sounds like it's sticking.

 

Now is there a way to fix that problem with the wastegate because my boost is already spiking. So to fix it from creeping I would have to increase the boost duty and if so i'll be way over 1 bar. whatdya think??

 

no, creep happens when your wastegate cannot get rid of "waste" fast enough, therefore increasing your boost. So, remove the waste more efficiently and you wont have a problem (I.E. dump it, use an external wg,etc.)

 

Does this happen with all SR20 internal wastegate or is it just mine that's deffected? And if so should i get another one?

 

it can happen to any turbo my friend. DSM'ers go through it too.