k3k0a

iTrader: (2)

i have a 04 wrx and ive searched over this forum and found that a lot of people have this problem... when im at wot my boost hits 18psi drops down to 10 goes to 14 then back to 10 then it holds at 14... i just bought the car a week ago and it came with this problem i hooked up the wastegate actuator straight to the turbo and it holds 7 psi all the way up... so i think something is wrong with the stock boost controller.... ive read all the posts about putting a mbc in and how its bad for the motor to up the boost... but i wanted to know if i put a mbc in just to hold the boost at stock which i think is 13-14 psi is it still bad for the motor? or for some reason does the ecu need the signal from the stock boost controller to run right? sorry so long this is my first wrx and i dont want to blow the motor if anyone can help id really appreciate it thanks in advance.

cbf246

iv heard of that happening with the stock boost solenoid. i have a mbc and it holds at 14.5 lbs, w/ ecu of course. ive had no codes/problems pop up. its hooked up just like you said. and i think stock boost is 13.7? apx. .08 kpa. if you plan on getting an ecu, go with an electronic boost controller so you dont have to get out of the car every time you wanna change the boost. good luck.

k3k0a

iTrader: (2)

sorry im kinda new to subaru's what do u mean by ecu? do i need another ecu to run a mbc?

cbf246

the ecu is what controls timing, fuel, etc. all modern day cars have an ecu, hence fuel injection and check engine lights. you dont need to change out the ecu if you add a boost controler, but it is a good idea. especially if you add TBE, intake, etc. as you add these onto the car, you start to add more power, more air, and more fuel. the stock ecu/computer can only handle so much before you need to upgrade. your spiking to 18psi is probably killing your head gaskets. there are many different ways you can go about this. you can get a piggyback, which uses your stock ecu and plugs between it and the wiring harness, or you can get a full stand alone, which fully replaces the stock ecu. right now id say, get your mbc and keep it at 14 psi or lower until you upgrade your ecu. hope this helps. good luck.

k3k0a

iTrader: (2)

thanks man, yeah i love this car but im not gonna spend too much money on it cuz im building my credit for an sti i wanted an evo but i live in hawaii and there is only one mitsu dealership here and they mark up the price to over 40k so thats out....the only mods im gonna get is just exhaust and a bov, then some cosmetic stuff like rims, etc. i just want this car to last... im running the turbo pressure straight to wastegate till i get a mbc.... i dont really need to go that fast to tell u the truth stock power is enough for me, thanks again for your help.

caseysrex

just telling ya if ya want the car to last then i wouldnt get a bov. it will kill your performance and make your car run like crap. if you really want power then get a cobb accessport a downpipe. that will cost you easily less than eight hundred and it will make your car run amazing! skip the mbc the cobb accessport is the BEST thing you can get for your rex. you can find one on ebay for less than five hundred for the version one. i am running this setup and it is the best. do not get a bov. stick with the stock.

Jake

iTrader: (2)

i agree u do not need the bov...will make ure car run rich=more sluggish and lower gas mileage

cbf246

^^true to an extent. an open air BOV with stock ecu is a no-no. but if he were to get the AP and get a pro-tune, then itd be ok.

k3k0a

iTrader: (2)

oh ok.... i used to have an eclipse and the stock bov suckd *** so i have an extra hks ssq and i didnt want it to go to waste.... too bad these cars cant be easily modded like a dsm but then again the stupid thing always had something wrong with it

cbf246

hahaha. i hear ya. my buddy has a dsm and has problems all the time. same with my rx7. its up to you weather you wanna put on the BOV of not. some people will say itll bog down the engine, but ive never had a problem with my HKS between shifts.

MO REX

iTrader: (2)

Since you don't want to mod the car or spend too much $ I'd suggest ditching the BOV, MBC and AP ideas.

There is something that needs to be fixed and your were on the right track origninally troubleshooting the WG. Since you know the WG is functioning the way it should you should verify that the restrictor is installed, all of the vac lines coming from the WG actuator, FBC, T and turbo outlet are on tight and are not leaking. If that all checks out try to find someone to lend you their FBC for a test run or try cleaning yours.

Since you bought the car used someone might have messed with the WG actuator arm. Try lengthening the arm http://www.scoobymods.com/forums/showthread.php?t=3654 . follow the directions but don't shorten the arm, make it longer.

k3k0a

iTrader: (2)

ok i think i know what you are talking about with a restrictor.... im looking but i cant find anything where exactly is it supposed to be? if i dont have it then where can i get it?

MO REX

iTrader: (2)

It's been a while but I believe its between the FBC and T. Not positive though. I'll look tomorrow and get back to you.

MO REX

iTrader: (2)

I checked my car and it is between the T and FSB. Here is a link that has some pic's of the pill (brass orifice), restrictor and how everything should be routed http://forums.nasioc.com/forums/show...estrictor+pill . Make sure to update this thread with your findings so the next guy can use it as a reference.

Good luck

k3k0a

iTrader: (2)

ok.... i checked and i have the brass restrictor between the "t" and the turbo pressure nipple and it still overboosts, but there is the hose from the "t" to the fbc supposed to have an adapter to make it bigger?? i saw on that that pic that you posted had a "3/16 mod" what is that? im gonna try and find another stock fbc and try it out