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Greddy Profec B spec II settings for 18psi on stock twins

17K views 51 replies 18 participants last post by  Ludalee  
#1 · (Edited)
Please give me your Greddy Profec B spec II settings for 18psi on stock twins

Hey
I was wondering if anybody could help me out in giving me their settings for 18psi on the stock twins? I can not quite get the Gain-Start boost-Set boost levels correct. Please help me out in telling me what works for you to get me pointed in the right direction. ANY help would be appreciated. For my car mods, see my signature if you think that is necassary...
 
#2 ·
The gain feature basically controls the air pressure going to the wastegate.

As your turbo is building boost, the boost pressure going into the motor rises parallel to the boost pressure being picked up by the wastegate. Now what this does is make the wastegate creep open before you hit your desired boost pressure, therefore the turbo spools slower because that wastegate is creeping air away from the turbo. What the start gain feature does, is make the wastegate read a smaller amount of boost pressure so it does not creep open as much or at least slower UNTIL it hits the boost it is set to.

Follow me?

As you turn your gain up and down your changing how much pressure is being read by the wastegate therefore changing when the wastegate opens up.

I can't help you with the settings since i do not own an EBC, but i can at least tell you the concepts behind them

Jimmy
 
#3 ·
Thanks for the tips... I kind of understand the function of the features, I just can't get them set correctly. If anybody has any settings that get a solid 18psi and 15psi and was willing to share them with me, THAT WOULD BE AWESOME!
 
#4 ·
Does anybody know if you are supposed to set the start boost higher or lower than the set boost? It just doesn't seem right that I have the boost controller with the set boost around 70% and I am only getting around 16psi...
 
#6 ·
I've experienced this 1000 times. I hate that boost controller. Not that its the boost controller, its just a big pita to function and set. Although, once you get it right, the HI LO features are nice.

Check for boost leeks. Also, do you have a stock clutch in there? maybe its slipping a little bit(like mine did and I could only get 16 psi and I had 0 boost leeks)
 
#7 ·
No, I have the TRD clutch installed so there isn't any slippage... Do you have your settings to let me copy? I wish somebody would post up some settings for me. I also wish that all I had to do was turn it to a PSI setting and be done like some other boost controllers... Hopefully I will get this thing figured out soon...
 
#8 ·
This is a very popular boost controller, I can't believe that nobody has any setting that they are willing to share with me.
 
#15 · (Edited)
Someone else's settings may not be of much use to you. Your car will react different to the settings than another car. Someone else's settings for 18psi may get you less than 18 or more than 18.

The best way to go about tuning with the Spec II is to start with everything at zero. Then adjust the first setting, set boost. Then work from there on gain, and finally start boost. Trying to adjust them all at the same time is going to get you no where. I've had 2 before.

This is assuming you have your hoses and solenoid plumbed correctly.

I use an HKS EVC1 now and like it so much more than either of my Profecs. It's just one knob to turn boost up or turn it down. You might want to look into it if the spec II is frustrating you so much.

Are you boosting normal with the profec off? I mean as if the controller is not there at all. With the unit off, you should be boosting stock. If you haven't done that yet, start there.
 
#13 ·
they suck, that's why noone has settings to share....i basically gave mine away because it was such a pita.....
i had my start boost at around 55 and my set boost around 60.....
agreed. It is the biggest pain in the ass boost controller made. I'll never buy one again

I actually hated it so much, I sold it for a mbc and the mbc out preformed it countless times!
 
#10 ·
I'll look tonight on mine and tell you. I can't remember what the percentage was. I just went out and redline third gear, pull over and adjust it until I got what was exactly 18psi on my gauge. I'm assuming you have a boost gauge right?
 
#16 ·
Yeah, I realize that someone else's setting won't be exact, but I was just looking to get a starting point to work off of. I just want to see if I am on track at all..

I do have a boost gauge, so I am good there. I just didn't know if the start boost was supposed to be above or below the set boost. Gain I have pretty well set at about 12% it seems to hold pretty steady. I haven't had a whole lot of time to play with it yet, it just seemed odd that I was turning it up so much to only get 16psi.

As far as when the boost controller is off, I can't remember but I think I am getting somewhere between 11-14 psi, I will have to check again though.
 
#17 · (Edited)
IIRC if your start boost is set too close to your set boost, you will overboost.

The start boost is a control of the wastegate. If you roll up your windows and listen to the solenoid, you can hear it when it starts working. It makes an audible clicking noise you will be able to hear through the firewall. If you have start boost at zero, the solenoid will start clicking really early before peak boost. This is how it works with no controller at all. The wastegate starts opening before you hit peak boost. When you turn the start boost up, you will notice you hear the clicking of the solenoid start later. This means that the solenoid is holding teh wastegate shut longer. This can help you spool up a little quicker because you're not bleeding off exhaust gas as early. BUT, if you set the start boost too close to set boost you will have overboosting problems because the wastegate will not open early enough. Let's say you have set boost at 2 bar. If your start boost is set at 1Bar, you will hear the solenoid start clicking and opening the wastegate at 1 bar. But let's say you set the start boost to 2 bar. The wastegate won't start opening until 2bar, but by that time it's too late and you will overshoot your target boost regardless of what your set boost or gain are set to. Follow me?

That's why I said start with everything at zero and work your way from left to right on the settings. Adjust set boost first with everything at zero and find your target boost level desired. Then move on to the gain. If you have too much gain, you'll spike. If you don't have enough gain, your boost will fall off at higher RPM. So find a happy medium without spiking and without boost tapering off. Once you have set boost and gain where you want them and you're hitting your target boost level, then you can adjust the start boost and keep the wastegate closed as long as you can to promote quicker spool without getting too close to set boost and overboosting. Or if your boost is coming on too quick is causing you to lose traction, you can turn the start boost down lower as well... I found that worked for me once. I had the start boost set as high as I could without overboosting but I was frying the tires when boost hit hard. I turned down the start boost to allow the wastegate to open earlier and allow boost to build slower and it helped me hold traction better in low gears.

Make sense?

It was confusing to me at first and I had all kinds of problems with overboost, boost spiking, boost falling off back to stock, etc. Once you get a good grasp of how each function actually works with your turbo and wastegate, you'll find it's alot easier to manage and you can find your target boost alot easier. But if you are impatient and want something easier, you can try an EVC1. I recommended it because it's really a fool proof EBC assuming it's plumbed correctly. There's a knob to turn boost up or down. No gain, no start boost.

HTH

If you haven't thoroughly reviewed the manual, it would be a good idea to do so before you try again. Just incase you don't have it, here's a link to it.

http://www.greddy.com/img/PHP/products/pdf/682.pdf
 
#18 ·
Thank you very much Socalguy!!! I will definitely try that next time I am able to get the car out. It has been pretty ugly around here lately. Looks like I will get my chance this weekend though. I will report back with my results and settings in case other people end up wanting a starting point and/or comparison setting.
 
#26 ·
Just watch for the cops because you are going to have to push the car. :) I really like my profec B II. I think people just give up on it too quick. If there is a local shop you could always take it up to them and let them throw your car on the dyno while you are there that helps alot.
Image
 
#19 ·
Cool... No problem. Hope it goes well for you. Double check your hose plumbing to make sure your problem isn't there as well.

Also, make sure you're using the correct port on the solenoid and not the one meant for an external gate. Refer to the manual if need be to confirm.

It should boost consistently once you get it figured out.
 
#25 ·
hah, i have an original profec b and have had 0 probelms wiht it..other than it doesnt go high enough..but for my stockers its fine.. sorry i couldnt help any.
 
#31 ·
#33 ·
As already stated, someone else's settings for 16 and 18psi are not necessarily going to make 16 and 18psi on your car.

There's enough information in this thread for you to be able to find your own settings.

What is your car doing exactly? Give some details on how your profec is acting and maybe I can help point you in the write direction of adjustments you can make.
 
#35 ·
I figure I get some settings n then go from there. Its not like its AEM or anything thats everybodys setting is different. Theres alot of cops where I live so cant drive like a maniac for each setting. Dyno is out of the question. So if members would post up thier numbers and compare would be great.