MBC problem?

[VegasTiff]

s14sr20det
t28 turbo
FMIC

Bought a ISIS Manual Boost controller...the crappy looking plastic one. It has 4 ports, 2 of which are blocked off. Inlet port is going to the wastegate. Other port is going across the engine to a welded on nipple on the cold pipe. This was the exact setup that I had with the stock boost controller aside from the 3rd tube running into the intake.

Stock my car would hit max boost at 2.5-3k maybe less.

Just got the car tuned on e85 with all the supporting fuel mods. We were trying to get the controller to hit 15psi, and the car now hits 10psi by 3k and seems to stay at 10psi until about 5k. 5-6.5k pulls hard at 15psi. It does this in all gears.

Is there something wrong with my boost controller setup? or Is the boost controller just bad?

[VegasTiff]

Could it be a problem with my timing? I took it to a mechanic for tuning and I know the timing has to be advanced some for e85. So could it also be a timing issue with the tune?

PS: No boost or Vac leaks. All have been tested. And im using Power FC

[Croustibat]

You said it was tuned for e85 ... how was it tuned if timing was not set ?!?

Yes, timing changes a lot with e85, it is not just an offset. More advance before and after peak VE efficiency, even more @ WOT because it does not det and timing is pulled on regular gas maps to prevent that (dont put more than needed though, it is useless and will only produce higher EGTs), and not a lot more at peak VE but still a bit more.

If you dont know how to tune, let someone who knows do it ... and get an EGT sensor and gauge if you dont have one. E85 does not det but it can produce very high EGTs that will melt your engine. Using pump gas does not have that problem, as it makes det before.

edit: I hope you are not running standard injectors too, e85 requires high fuel flow delivery, you cant achieve correct fueling with them when boosting 1bar and using e85.

[VegasTiff]

Like I said before all fuel mods have been done. 550cc injectors(STI Injectors),walbro 255, z32 filter. Injector duty is not maxed. The car was not tuned by my me, but my mechanic whom has tuned many cars on e85. The car was just tuned on the street for now though, and I will be putting it on the dyno in the next week or so. Dont have an egt sensor or gauge, just the powerFC(Which displays coolant temp), AEM wideband, and boost gauge. I will look into getting an egt sensor for saftey though.

[!Zar!]

Are 550cc injectors even enough for e85?

[VegasTiff]

Most people go with 1000cc injectors when running e85 simply for the fact that you can just turn the boost up and retune when your ready to upgrade. With a t28 at 15psi the injectors would be at like 50-60% duty. I thought it was just more cost effective to get some STI injectors($120), but also keeping with the reliability of having a stock injector, yet still be able to push 15psi on e85. I will check my powerFC controller next time I push it, but I know they are not at 100% yet. The car pulls hard as heck when it hits 15psi, and it wants to pull past the redline baaaaaad. Steady AFR of 12.5 at full throttle the whole rpm band.

[rcdad123]

it could be the tune. if you don`t have enough exhaust pressure to push 15 psi, no matter how high you set the MBC, it won`t reach 15 psi. you might have to advance the ignition timing a couple of degrees at the rpm you want the boost to come on.