Boost 2.5 WRX Hawk 1.55 BAR
 

Hi, I have a car with MDX321T, RCM Headers, Forged 2.5 SCDB, AVCS, RCM Induction kit, currently on TMIC with standard mapped ecu but getting mapped on FMIC on 6th May. Power was v420/420 on Toyo Sport headers at 1.4 bar, however turbo always wants to go past that and gives fuel cut, wastegate open etc, even with a !Removed! on ignition to reduce temps due to FMIC. Do you guys think it will run at 1.55/1.6 bar to reduce the overshoot on standard ecu? p.s the overshoot happens more with RCM headers. Is syveccs only option?

yes you can run 1.55/1.6 on a standard ECU - the overshoot should also be cured with wastegate settings unless you have a 1.6 bar spring in the wastegate?

syvecs it, ecu will be struggling to cope at that level

Mines running 1.7 bar on stock ecu, on a Owen Development SC42HTA
No issues,
2003 uk sti

Should run 1.5 no problem, to go above you need a JDM Spec C MAP sensor to allow you the extra headroom.

Sure syvecs is better no doubt,
but a decent mapper should have you running 1.5 no problem.

It's not the boost level thats the issue.

What is the issue then ?
As it's almost same spec as i have with zero issues,

RCM Headers,
HDI Frountmount
AVCS, RCM Induction,
3 ports solenoid SWRD
Mapped on ECUtek by A.Forrest,

Although mines is a Stock 2.0

Forged 2.5 single avcs heads, decat and sc46. Main issues were around the ecu not being able to keep up with the 46 even on low boost.

Must be that extra 500cc.

smurfy, whilst your car runs well on the stock ecu - you would almost certainly see an improvement in torque/hp figures if you went aftermarket ecu.

Syvecs is an excellent option, you can also look at simtek/alcatec depending on what your tuner is happy to work with.

Absolutely I agree car most cars will work BETTER on aftermarket ECU for sure.

As I say mine runs well no issues so I have no real need for it,

The above however doesn't seem to be working very well at all by the sounds of it,

I was pointing out that it is possible to have it working correctly at that level on stock ecu without the issues he has.

At least is is in my case,

i'd totally agree with you there, no reason an MD321 shouldn't be peeling your face off all day every day on the stock ECU once it's all setup!

Not that I wouldn't bite anyones hand off for a Syvecs,

It just seems overkill for my needs

You got a boost graph of the 1.7 bar on stock ecu?

Nope sorry,

Thats going by my gauge in car and what Andy F says,

Im actually just learning how to use rom raider,
So if i have my cable at the weekend
could i use that to get a boost graph ?

Or is that all gained during a Dyno run

yes you can log engine speed, throttle position sensor, gear, vehicle speed and manifold relative pressure (DIRECT) psi and you should see how much boost your making in each gear and at how much throttle.

at 1.7 bar your probably on the upper limit of what the standard MAP sensor can give you so your fuel cut limit will be tight or off entirely.

Had to find a JDM spec C map sensor or andy wouldnt go past 1.5

He did say it wouldn't read correctly on the log tho as he scaled it or sumthing would that be right,

i go by gauge in car anyway

yes that's right, you have to rescale everything in the car as even with the 3 bar map sensor from the spec C the ECU has trouble addressing a value higher than 24. By shifting the scale of the MAP sensor the car reads a different ambient pressure (so you can shift what the car thinks is 14.7 to be higher or lower) - this will give you sufficient headroom to manage the boost in the ECU as well as allowing for proper fuel cut to work.

I get you,

Would be able to work it out if i manage to log it correctly,

Yea, that's why Andy wouldn't go higher without the map sensor, wanted to keep all the stock safety features.

yupyup - difference between doing it right and just doing it :) you can work out actual boost value by comparing what your boost is reading with the engine off vs what your reading at peak load.

Thanks again mate
I hope to have that cable this weekend :)