Evo III Boost Problem

[BMWHATR]

Well i just installed an intake pipe couple days ago and a GReddy Profec B boost controller. The thing is the boost controller is set to 0 and @ 6-7k RPm's i get about 14.5psi WTF. It slowly gets there. at one point i got 107kpa(15.5psi or so) I am running stock fuel pump and stock injectors. Could it be that my wastegate is not big enf or something like that?

 

[DSMvroom]

your problem is you have an evoIII and probably didn't take enough precautionary measures to prevent boost creep from happening.

I don't know what kind of spring you have in your wastegate actuator but if I had to make a random guess I'd say 10psi (I literally pulled that number out of thin air so noone spam me for it). My point is that you will have to make at least a minimum boost pressure of the wastegate spring's specification. This is all assuming that all your hardware is hooked up properly. Add to that, it is an evoIII and your free flowing exhaust = boost creep.

I am probably wrong though.

 

[v2ner]

EVO IIIs are notorious for doin that. if you have the Profec B down than have Adam port the shit out of the ex. manifold. have Adam and his friend Cosmo look at the Profec B to be sure it's working correctly too since he runs one on his EVO 8. happened to me too so we ported the ex. manifold and i switched to a MBC....which worked alot better

 

[BMWHATR]

EVO IIIs are notorious for doin that. if you have the Profec B down than have Adam port the shit out of the ex. manifold. have Adam and his friend Cosmo look at the Profec B to be sure it's working correctly too since he runs one on his EVO 8. happened to me too so we ported the ex. manifold and i switched to a MBC....which worked alot better

Well i am FWD so i will spin on 1st (witch I do a lot more now cuz of the boost creep)



This is what it does: it starts out all fine @ 3-4k rpm it boosts 9psi like it should. As soon as i pass 4k it jumps to 9.5-10psi (slowly) but when I pass 5k its just starts to go from 10psi to 15.5 (15.5-9psi by the time I am @ 6.5krpm) Usually I back off by the time it comes close to reaching that. I don't freaking know what to do and I don't want to spend a lot of money trying to fix it.

I will try to unhook my boost controller and put the vacuum line back on. Just to see if the problem in boost controller.

 

[ZmanIV]

Have you done any supporting fuel mods?
Why would you set the boost controller to 0?
Did you port the EVO like it said to in the tech articles?
Are you following the perscribed upgrade formula?
Does the forge BOV vent to the atmosphers? Im not sure.
Have you updated your profile?
Do you have a K&N filter?
Did you expect to just bolt up a large turbo and exhaust system and have a huge performance increase?
I'm still new to all of this but I do know that any turbocharger will only give good results when all supporting mods are done. Or else you risk the chance of running extremely lean and burning up your motor.
Follow the upgrade list on this site, RRE or Buschur Racing and you won't regret it.

 

[truwarrior]

Mine creep to 20 psi, had to get fuel mods...consider yourself lucky your only getting 15psi.

 

[oldman]

The thing is the boost controller is set to 0 and @ 6-7k RPm's i get about 14.5psi WTF.

Just turn your boost up to 14-15psi and you'll be find, 14.5psi isn't much of a creep really.

 

[Spoolin4Ever]

Make sure the MBC is hooked up right. I have seen people have the 2 tubes reversed. Switched them and it worked fine.

 

[BMWHATR]

Took out the boost controler today and still the same problem

 

[Nanan]

The boost controle isnt the problem... You need to port the hell out of your turbo wastegate area and the wastegate area of the O2 housing. From the factory evo3's have a rather crappy wastegate port design, air at high velocity skips over the wg hole and goes down to the turbine.

 

[oldman]

Evo3 porting specifically for boost creep purposes.