Wastegate question please help

[gokartmar27]

Hi i have a 02 wrx but when im racing sometimes it happen at around 80 or 100 my car will literally jerk like a stall out or something? could the wastegate be the problem? i am pushing high boost or what could be the problem. I have all supporting mods for what im about to do to it, 720cc injectors, hks bov, 20g turbo, apexi full exhaust up and down pipe + performance cat, stage 4 clutch, walbro fuel pump, forged rods and pistons. But before I install all that i wanna know what the problem could be please help I am new to the forum and i hope people are mature on here and dont act like the kids on xceedspeed. Could it be my wastegate im pushin 21 psi so im thinkin about gettn a turbo internal wastegate for a 20g. But that still doesnt solve my problem, i have a high stakes race in a few days so i need help asap. Thanks guys... oh p.s. i just read that fuel cut could be the problem if so what should i do about this, will the walbro fix that if installed?

[MainFrame]

No.. insufficient wastegate spring pressure will cause you not to be able to hit target boost, not at all what you're describing.


What do you mean you're thinking about getting an internal wastegate for a 20g? Do you mean the 20g you are planning on buying doesn't already come with an internally gated turbine housing? AFIK all aftermarket stock location turbos come with internally gated turbine housings.

Also, the HKS SSQV BOV you're getting is known to leak, it's going to give you problems. The stock BPV will function much better than that HKS unit.



For what it's worth, the symptoms you are describing sound like boost cut to me. That would be something to talk to your tuner about.. often times they don't really tune for 5th gear, which will see higher loads, and in turn higher boost than the car is actually tuned for. I'm assuming you're not getting any CEL when the car bucks?

[MainFrame]

oh p.s. i just read that fuel cut could be the problem if so what should i do about this, will the walbro fix that if installed?

No, a fuel pump upgrade would only help with starvation, not fuel cut. Fuel cut would once again be a tuning issue.

[MainFrame]

Post up a log.. we need to compare the boost targets in your map to your relative manifold pressure to see if you're actually over boosting or if there is something else going on..

[gokartmar27]

i bought an ebay 20g turbo, i kno not the best thing to do, direct bolt on, and i dont have a tuner me and my friend were just messin with my aem tru-boost. im buying a tial external wastegate. And my hks bov has givin me no problems at all btw. And what is CEL?

[MainFrame]

i bought an ebay 20g turbo, i kno not the best thing to do, direct bolt on, and i dont have a tuner me and my friend were just messin with my aem tru-boost. im buying a tial external wastegate. And my hks bov has givin me no problems at all btw. And what is CEL?

Okay... well eBay turbos are junk, raising the boost without tuning will blow your engine, you cannot run an EWG without tuning, and you have no way of knowing if your BOV is leaking without logging or at the very least performing a boost leak test.

If you don't have a tuner, how were you planning on scaling your injectors?


CEL = check engine light

[Anub1s]

Wow....

[UEDan]

I have all supporting mods for what im about to do to it

Sounds like assume you are still running the stock setup?
If so:

i am pushing high boost

+

im pushin 21 psi

=YES! WAY TO MUCH ****ING BOOST

i have a high stakes race in a few days so i need help asap. Thanks guys...

You seem to enjoy wasting money. Just quit the race, get your car properly tuned..... scratch that just give me the money =)
MainFrame is 1000% right. He is honestly just trying to save your engine.

[gokartmar27]

im gunna take it to a tuner thanks guys and we figured the problem it was my coils, my car is not stock i just didnt give a **** about the turbo

[poly_poly-man]

You need engine management to do what you're describing. Assuming that you're on stock everything except an MBC right now (that's what it sounds like, if you could be more clear about this it would help), then yes, you are definitely hitting boost cut. 21psi is alright for a short peak on these turbos, but I should advise you that you cannot hold this to redline - for a small turbo like stock, EBC is a necessity for maximizing power, so that you can taper your curves properly.

TL;DR: tune your car!