For those of you with this boost controller, what were your final settings? I know there should be some differences, depending on everyone's ambient temp/etc., but we should be in the same ballpark.

For me i think I set the duty cycle to ~40%, gain is at 0%, with the target boost being 10 psi.

What I notice is that with the electronic boost gauge, it always picks up a higher psi peak boost than what the mechanical guage shows, and I suspect that it's because the electronic guage can read the pressure changes a lot faster than a mech. guage....so while the boost may hold around 9.7 psi, the peak will show more like 10.4 or 10.5 psi.

This makes it a little harder to tune, because you can't rely on the peak boost to tell you what psi you're sustaining before and after the transition unless you're watching the readout. If the car has been doing this always, then I'd be hurting my performance by tuning so that peak boost is set at 10 psi, which means my actual sustained boost would be more like 9.5 or so.

Then again, if this IS normal, then I should tune for a higher peak of 10.5 or 10.6, so that my sustained would be a 10 psi before and after transition.

To rephrase my main question, for those of you with electronic boost gauges and a peak recording function: is it normal for these cars to have a very slight spike? A spike small enough and fast enough that couldn't be picked up by a mechanical guage?

BTW, i just did a few WOT runs with the gauge off (which means i should have a max boost of 7 psi). The peak I recorded was 7.5 psi.

Anyway, thanks for reading!

 

Yes, I noticed that higher peaks were recorded with my Defi than eyeballing my cheapo mechanical boost gauge.

BTW, I don't get more than 0.25 psi of overshoot on boost spool. If the "gain" control adjusts wastegate response, I would turn it up. Careful though, as this may have an effect on overall boost levels.

Sorry, I have the old school Profec B with three *****, a boost select switch and a power button....

 

Wait a sec now....it's true that turning up the gain would increase wastegate response, but it also increases the chance of a spike. (It should be like your Sharp ****, right?)

I turned gain down all the way to 0% to make sure that I wasn't getting any spikes from having it set to high. Boost response right now is pretty good...I actually can't tell that it's slower than stock, if it's slower at all. I'll play with gain once I'm sure I've got the boost duty cycle set the way i want it. (FWIW, I think i can set it up to about 5% without any spiking)

You say you've never gotten more than 0.25 overboost on spool? I'm already seeing 0.5 psi with the controller off....you're still looking at a defi guage though right? Not an electronic readout?

 

hahaha, you did start a thread on it. sorry, for post whoreing

 

hehe
make sure you let me know what YOUR settings end up being!!

 

If the gain acts like the "balance" control on mine, turning it toward sharp (raising the gain?) will actually REDUCE spiking and overboosting. The only problem is if you turn it up too much, the wastegate will cycle too rapidly and you will get unstable boost.

Actually, I've never verified boost behavior at lower gears with the Profec off. I can tell you that in 3rd or 4th, it builds boost more slowly off and it stops right at 7 psi. Of course, even with the gauge and peak/hold, it might not be capturing that instantaneous spike. I really wouldn't worry about it. Just as long as you're not spiking more than 0.5 psi or so, just set it and go.

 

I think you're right...I didn't even make a note that I was in 2nd gear when getting this 0.5 overboost. I recall doing a run in 3rd that didn't do that, but I'll need to do more runs to double-check.

Damn, these WOT runs are killing my fuel economy!! lol

I'll post again when I finalize my settings...

 

please do....this crap is annoying is hell to figure out.

 

Correct me if I'm wrong, but if I set my start boost to 9.5 psi and the turbos never reach 9.5 psi, the Profec B will not do anything at all. True or False.

 

lol, i thought there was a thread on this a couple weeks ago. this boost controller is confusing as hell. i don't have mine tuned yet either.

 

When boost spikes, LOWER the gain. When boost FALLS or RISES as rpm's rise .....RAISE the gain setting. Raising the gain to much WILL up your overall boost levels so keep an eye on that.

 

Ralph....dunno man, but if you think it's true then set your start boost a little lower then and try it out.

my start boost is set to 9.5 right now, but since the weather's been getting quite a bit colder i may have to bring it down a little because i'm overshooting the boost a little bit.

It's not my gain, since that's set to 0.

anyway, aiming for ~10 psi.....my setting is about 35% duty cycle. I'll probably lower my start gain to 9 psi and see how that works.

 

I should start with my situation. I put a boost gauge in my car. I saw 11+ psi and it spiked to 14.9 psi. I got the Profec B and did an acceleration run with it turned off. I saw 7.0 psi. Then I turned it on with settings I got from this web site 35% duty 2 gain and start boost of 9.5 and saw 9.5 psi. A couple days later we went out to a low traveled road and did a bunch of accelerations to fine tune the settings. After several runs I never saw boost higher than about 6.7. The pattern was something like 5-3-7 at best. Also the drop and surge when the pre spool and second turbo kick in was a lot more pronounced. The reason I asked about the start boost setting is because if the controller does nothing below that setting, it has nothing to do with my problem. After I posted my question I hooked the stock lines back up and got a tiny bit higher but very similar boost pattern. At this point I don’t think it is the controller.

 

on my B II i have 11-35%-98-130-99% hold at 10.5 peak at 11.8

 

Profec B II = overboosting and cause me to spike to 22psi when it was set for 13psi, which caused me to blow the motor.

 

oo0o0oops what were your settings

 

.

 

I did the same, but that's just because I forgot it was on. 24.7 psi. Didn't blow the motor.

I've yet to figure out how to use the damn thing. I'm just on the spring (15 psi) and would like to use it to see if I can improve response at all.

 

if you tweak it right you will, Ive got a nice response time spools much quicker then stock

 

Bump this thread

Just installed mine and want to set up this nitemare LOL

Want stock levels on LO boost and 14 psi on hi boost. How should i set it up

Help

Scott

 

So, do you guys have any advice for me since I have the profec still in the box? I am running my set up sequentially. Should I go nonsequential? I looked up the poor man's nonsequential set up but a few pics did not load so I think I will just install the boost controller as is. What do yall think?

 

Leave it seq. i have mine set up now and it pulls like an ox

Scott

 

The attached file is based on my experience with the Profec on a single turbo. Use at your own risk.

 

I bought an rx7 with the profec b spec-II already innstalled and i dont have the usermanual, cound somebody copy it so i can download it or send it to my mail adress: thomas_m_cool50@hotmail.com

Thanks

 

Did you try their website?