MrBonus

iTrader: (4)

Since I've added my Profec, I've experienced strange boost fluctuations. I get it dialed in perfectly and, after a short period of time, I experience a large loss of boost at the initial spool up at around 3000 RPMs.

My boost will spike to 19 PSI, then drop off to 9-10 PSI (I'll receive a WARNING even thought the warning setting is far above the seen boost), then build up to 18-19 PSI again.

Now, I've pinpointed a way around the issue. Every time I start the car up, I have to adjust my WARNING. It doesn't matter if I lower it from 22 to 20 PSI or raise it to 25... Just as long as I change it. If I DON'T change my WARNING limit, I'll have the problem described above. Otherwise, the car will hold boost with only very mild fluctuation at ramp up.

What's wrong with my Profec?

Quickshift

iTrader: (4)

What are your current setting with it?

MrBonus

iTrader: (4)

Duty Cycle: 66%
Gain: 2%
Rise: 17 PSI

cdavy

iTrader: (1)

You are not alone... Mine does the same thing. I had to turn the gain down to like 4-5 to stop the spikes. I had the SAME issue with the warning feature that will reduce boost at a given level. I set the warning as high as possible and set it to not reduce boost as my initial workaround.

After I had the dyno flash installed the situation was more noticeable as spool was faster. Al at Dyno flash told me to set the gain lower and it would stop the boost spikes. He was correct.

My guess is that the spikes were hitting and causing the warning to activate prematurely. I have not tried to use the warning feature since making the gain adjustments but I bet it would now work... I will make those changes and let you know.

I think this boost controller might not be that good… It does work now, but…. Any comments on the quality of this device? I had used the older fuzzy logic boost controller in another car and it was a POS.. This one seemed simple to use.

Quickshift

iTrader: (4)

Are you sure you connected up the lines correctly to the wastegate and turbo nipple beneath the turbo and that the NO and Com connection are the ones used on the solinoid . I am running 62 duty cycle 17% gain 1.20 start boost 20% limiter 1.45 boost max before limiter run around 20 psi to 19.5 stay pretty smooth.

MrBonus

iTrader: (4)

I've tried it with Gain settings from 0 to 20. Same issue once I shut off/restart the car regardless.

cdavy

iTrader: (1)

I guess your gain is already down... Your start boot might be to close tot he max boost setting.

Could be a combination of things that are affecting your cars boost curve. Your car might be pulling timing causing your boost to be unstable. Not sure if that makes total sense, but my boost controller is MUCH easier to adjust since the Dyno flash.

JaMa

According to a friend of a friend who works for Trust in Brunei, this is an undocumented feature of the Profec B spec 2. Even if you set your warning to 25psi, it is going to be 1 bar when initiated until you interact with it. So, I end up having to press one of the buttons when I get in to drive and I no longer have the issue.

I guess Greddy dosent want you hopping in and driving without knowing where your boost is set.

J

cdavy

iTrader: (1)

For what it's worth, my car hits 20PSI @ 47% duty. It seemed lower than other folks on this forum, but it works for me. If you have an intake you can hear the boost fluctuation under full throttle very easily. I adjusted my gain lower and lower until it stopped.

cdavy

iTrader: (1)

Would have been nice to document that... It makes sense and now I understand why it would do that and then stop after I goofed with it... Thanks for that info… I figured that the controller might have been defective or a POS… I just never have had time to call Greddy.

Quickshift

iTrader: (4)

What other mods do you have on your car cdavy, cause like a turboback exhaust will require a little higher duty cycle also intake will do it too.

cdavy

iTrader: (1)

I have an RMR turbo back (dp/exhaust), RMR intake, RMR induction pipe, UR highflow cat, walboro pump, SAFC, dynoflash and other stuff like an oil catch can and grounding kit...

Depending upon the temp it ranges from 47 - 53 % to maintain 20-21 PSI.

MrBonus

iTrader: (4)

Interesting.

This would explain my issue. I'll have to pass it on to my friends with the Spec II.

I greatly appreciate your input.

JaMa

Personally I find this socalled "feature" quite irritating. I have owned about 5 electronic boost controllers in my day and none of them have needed this kind of babysitting. On the other hand, this Unit works really well otherwise.

J

MrBonus

iTrader: (4)

Yeah, no kidding. I have no complaints about the way it holds boost.

I just have to remember to play with it before doing any highway runs.