Profec B Spec 2

[kilmer420]

Quote, originally posted by whizbang18T »
i set one up on my buddie's car (fwd sr20det) ... the instructions on the evo forums confuse me. anyhow, now that i know how it works - there's really not much to it.
how i did it ...

1) change the units to psi as documented in the manual.
2) turn off the boost controller
3) do a test run to see max psi - this is max boost set by the wastegate only. make note of it.
4) determine % increase for desired boost.

say wastegate boost is 10psi, and your desired boost is 14.5psi.


dB = desired Boost
wB = wastegate Boost

((dB-wB)/wB)*100 = %

in our case:
((14.5-10)/10)*100 = 45%

5) SET = 45% in this case
6) GAIN = do not touch yet ... leave @ 0% for now
7) SET GAIN (aka START BOOST) = dB - 4psi ... 10.5psi for this scenario

 WARNING = dB + 1psi ... 15.5psi in this case
9) LIMITER = 4%
10) go for a test run. you will notice that the boost doesn't build smoothly. this is where u adjust the GAIN. bump up the GAIN by 5% increments. then retest after each increment. if it starts to overshoot your desired boost, then you've gone too high. back it down 1% at a time 'til it no longer overshoots desired boost.

that's it ... pretty simple

how do u know what your desired boost should be? learn to read a compressor map

NOTE: if your max boost @ SET is higher/lower than desired, adjust as necessary ... it's not dead-on accurate


Here is some info I found on another forum (SRT) that should help you out:

Definitions and things you need to know before you start:

SET This is how you set the boost pressure. Rather than setting it in psi or kPa, the Greddy unit allows you to adjust it as a percentage value, from 0% (greddy unit essentially turned off) to 100% (greddy unit will set the boost as high as it can). This setup demands a certain amount of trial-and-error to properly configure it since you have to make adjustments, then drive under WOT (Wide Open Throttle) and see what the maximum boost pressure achieved was throughout the entire RPM range. SET SHOULD BE SET TO A CONSERVATIVE VALUE WHEN BEGINNING TO TUNE YOUR GREDDY UNIT. 30% SEEMS TO BE A CONSERVATIVE SETTING BASED ON MY TESTING AND BASED ON OTHER REPORTED NUMBERS FROM EVO OWNERS AND TAKING INTO CONSIDERATION THE LINK BETWEEN SET AND GAIN (see GAIN below).

GAIN is defined in the manual as the value to adjust the "boost consistency". You don't really need to know exactly what that means. You should set GAIN to 0 when beginning, and you will then test the car under WOT while paying attention to the boost pressure. If the boost goes up and then falls off at higher RPM, you will want to increase the GAIN by a conservative amount (5% should be relatively conservative to begin with, then when you want to fine-tune it, you can go down to intervals of 1%). When you increase the GAIN value, the corresponding boost that you will go up to will be higher even if you leave the SET value alone. GAIN SHOULD BE SET TO 0 WHEN BEGINNING TO TUNE YOUR GREDDY UNIT.

START BOOST (also known as SET GAIN because that is what is displayed on the unit when adjusting this setting) is the lowest boost that the Greddy unit will begin increasing the boost from under WOT. You want this to be as close to the SET value as possible, since you want to keep as close to your desired boost as possible. However, setting it too close to the SET value will cause the boost to spike. You should set this to a conservative setting when beginning to tune your Greddy unit. Then you can fine-tune it later to get it as close to the SET value as possible without causing the boost to spike. Fortunately, you can set this in psi or kPa, thankfully Greddy didn't decide to let this be adjustable in % like the SET value. START BOOST SHOULD BE SET TO YOUR DESIRED BOOST PRESSURE MINUS 4 PSI (about 28 kPa).

WARNING is the maximum boost that you do not want to exceed. Fortunately, you can also set this in psi or kPa like the START BOOST value. When the boost exceeds the WARNING level, it will kick in the LIMITER, which decreases the boost a certain amount that you can set. WARNING SHOULD BE SET TO YOUR DESIRED BOOST PRESSURE PLUS 1 PSI (about 7 kPa).

LIMITER is the boost percentage that the Greddy unit will lower to when the WARNING boost pressure is hit. LIMITER SHOULD BE SET TO YOUR SET VALUE MINUS 4%.

PEAK is the peak boost value that the unit has seen since the last time it was cleared. To clear it, go to the peak boost display, and hold down the set knob until the unit beeps and "---" is displayed. IT IS A GOOD IDEA TO CLEAR THIS BEFORE YOU BEGIN JUST IN CASE YOUR UNIT HAS A HIGH BOOST ALREADY RECORDED.

LAST BOOST shows you the last boost that was recorded every time the accelerator is released for 3 seconds. TURN LAST BOOST ON BECAUSE IT IS A GOOD DIAGNOSTIC TOOL WHEN TUNING YOUR UNIT.

Keep in mind that when displaying in kPa, it does not show it technically in kPa, but rather misleadingly in bars, which Greddy inconveniently tries to justify by sticking x100 kPa next to the display. Therefore, 100 kPa will be displayed as 1.00 x100 kPa. Psi will also unfortunately be displayed in psi x10 so that 19 psi will show as 190, adding to the confusion.

Another very important thing to keep in mind is that when you first power on your car or the Greddy unit, WARNING will be set to 14.5 psi (100kPa, or 1 bar) until you interact with the Greddy unit by pressing any button. This "feature" is not documented in the manual.

Also keep in mind that atmospheric conditions affect the operation of your boost controller. When it is hot, you will get different results than when it is cold. One possible way of solving this issue is tuning your Greddy unit under the "Lo" mode for when it is relatively cold, and under the "High" mode for when it is relatively hot. Unfortunately, two modes are hardly enough for somebody that needs to account for very different summer and winter climates, and also for more aggressive settings for when increased performance is desired.

The maximum boost that you will see is also not consistent throughout the gears, which adds even more to the confusion. Unfortunately, if you've already increased your start boost to the maximum setting that doesn't give you surging, then there seems to be no way to get around this variance in boost pressure from low to high gears. I don't know if this is a limitation of the greddy unit specifically, or if it's something inherent to electronic boost controllers in general. The only two things that you can do to compensate is the following:

1. Set it to the "safest" of the settings that does not trip your limiter. To do this, tune the unit to your desired boost pressure in fifth gear.

2. Tune the "Lo" and "Hi" settings corresponding to having the boost maximized during the low gears and during the high gears. This would require you to manually hit the button to switch to the "Hi" setting when you shift to third gear or whatever you started tuning your "Hi" setting at. This is why Greddy makes the wireless remote switch that straps to your steering wheel to switch between "Hi" and "Lo" settings.

The following steps should be taken in exactly this order, taking into consideration all of the previous information:
1. Change boost pressure units to psi if so desired (see manual).
2. Set WARNING to your desired boost pressure plus 1 psi (about 7 kPa) (see above).
3. Set START BOOST (SET GAIN) to your desired boost pressure minus 4 psi (about 28 kPa)(see above).
4. Clear PEAK boost value (see above).
5. Set LAST BOOST to ON (see above).
6. Set GAIN to 0 (see above).
7. Set SET to 30% (see above).
8. Set LIMITER to SET minus 4% (26% if you followed #7).
9. Test for boost falloff at high rpm. You should probably do this in a wide open area with no other cars nearby and preferably no cops. It is also good to have somebody in the car with you that can watch the gauge while you concentrate on not wrecking your car. If there is no boost falloff, then go to #10. If there is boost falloff, then increase the GAIN by 5% and test again. Keep in mind that when you increase the GAIN value, the corresponding boost that you will go up to will be higher even if you leave the SET value alone. Repeat until the boost pressure does not decrease, or until you feel surging. If you feel surging and the boost pressure still decreases (not sure if this is possible) then decrease to the last level that you did not feel surging at.
10. Increase SET by 2% and adjust LIMITER accordingly, then test again. Keep increasing by 2% until desired boost level is obtained.
11. Increase START BOOST (SET GAIN) by 1 increment and test until surging is felt or the WARNING level is hit and the display turns red, then decrease to the previous setting.

Once you have followed these steps, you will have roughly tuned your unit. To fine-tune it, repeat steps 9 and 10 except this time only increase or decrease by 1 increment.

Here are some number that some of the people on the board are using.
I would start from the base and work from there. Every car will be different.

Low setting is at 15 psi, with no dropoff. with the 12-15psi W/G spring.
LO--
Set Boost: 30%
Gain: 20 psi
Set Gain: 23 psi

High setting is set at 18 and has about a 2 psi drop off. Unless you are completely in it, there is compressor surge when shifting within your low RPM range. So this setting is really completely useless for normal street driving.
HI--
Set Boost: 45%
Gain: 20 psi
Set Gain: 38 psi


Adding the in the end for Big turbo guys with Wastegates that have a top and bottom nipple.

If you are running the profec B spec II EBC then your line setup will be as follows:
On the solenoid - make sure that you have "nipples" couming out of COM & NC port. Also make sure those are in tight - as any leaks would screw everything up. Then, run a line from the compressor side of the turbo to the bottom part of the wastegate.
Measure how much line you need to go from the TOP of the wastegate to the COM port. Run that line & hook everything up. Then find a good place to "T"-into the first line that we run & put a plastic T in it. & from that nipple run a line over to the NC port on your solenoid.
Recap - COmpressor to bottom of the wastegate - also tinto this line & take it to NC port. Then run a line from COM to the TOP of the wastegate. & you're all done.

Wastegate is being closed shut by the spring inside of it. You run a line from the turbo compressor to the bottom of the wastegate. As the turbo builds pressure so will the pressure on the underside of the wastegate increase. This will push up on the spring & open up the wastegate. Now, it is obvious that any leaks in this line would result in no pressure buildup on the bottom of the wastegate so it would never open. Causing your boost to keep rising.... So, - when you T into this line it goes to the NC port (Normally Closed). So, no leaks would develop. Now, top of the wastegate is open to atmosphere. BUT - with profec - when the solenoid activates - it will open the port from NC to the COM (com goes to NC & NO - & when one is open the other is closed). SO, what is going on now is that you're sending pressure from the turbo to the upper part of the wastegate as well & this will press down together with the spring to keep the wastegate shut. So, boost keeps rising. Once desided boost is achieved - the solenoid will start closing a bit - shutting off the pressure going to the top part of the wastegate & causing the wastegate to start opening. ALso, every time you're sending pressure to the upper part of the wastegate - you're also decreasing pressure to the bottom part of it. & vice versa. /

[whizbang18T]

thx

[mj6234]

FYI, here are my settings for my .86 GT28RS with 10psi WG.

Low boost (16psi)

Set - 37%
Set boost - 0.85 kPa
Gain 19%

High boost (19psi)
Set 45%
Set boost - 1.20 kPa
Gain 19%

[elitedübs]

how do you convert kpa to psi? sorry guys

[mj6234]

100 kPa = 14.5psi = 1 bar

[GTi30R]

dont know what my waste gate spring is....it was opening at 9 psi when the ebc was off....

Low boost settings (daily) = 20psi
Gain = 18%
Set Gain = 180
Set = 39%

High boost....we will see tomorrow at the track

[kilmer420]

100 kPa = 14.5psi = 1 bar

it's 14.7 but I won't nit pick, it's close enough  


and 9psi is about .6 bar

[mj6234]

Na, it's 14.5. Google around and look. Here is one page.

http://www.convert-me.com/en/convert/pressure

[kilmer420]

I did...and that's why I said I won't argue...but atmospheric pressure is 14.7

http://www.pumpworld.com/Absolute%20Pressure.htm

[Don®]

I did...and that's why I said I won't argue...but atmospheric pressure is 14.7

http://www.pumpworld.com/Absolute%20Pressure.htm

14.69595...To be exact  :face:

[mj6234]

I think 1 atm > 1 bar (just slightly) in terms of absolute pressure.

[27psiBOOM]

Excelent and simpe write up!!!  :bowrofl:

I just bought a Profec B for a friend, it's waiting to be installed.

Should I have bought the Profec Type S EBC???  :3deek3:

[BillyT]

The percentage that you change on the boost controller in no way relates to a percentage of increase over your wastegate spring.

You are adjusting the duty cycle of the valve that regulates the boost signal to the wastegate, and that is all.

If this forumula held true, at 100% duty dycle, you would only see 20 pounds.  If you set your boost controller to 100%, thinking you are only going to see 20 pounds, you are in for a big surprise, no matter what wastegate spring you have.

FWIW, I have a 20 pound spring, and run 50% to see 35 pounds of boost(gain at 10%(default).  Per that formula, I should only be at 30 pounds, or running 75% duty cycle.

Not trying to bust anyones balls, just trying to add to the knowledge base.

discuss...

[mj6234]

Billy is exactly right. I have a 10psi spring. 45% = 19psi.

[BillyT]

Lets use 20 pounds on a 9 pound spring as an example

(20-9)/9)*100 gets you 122%

Let me add, that from where I am standing, 45% with a 10 pound spring, will yield the same peak boost as 45% with a 20 pound spring.*  The stiffer spring will give you better boost control at higher pressure(better spool, sharper boost curve more conssitant pressure), with the trade off being always having to run more boost.  The softer spring will let you run less boost as you feel, but at the expense of consistant boost regulation at higher pressures, and a more relaxed boost curve, taking longer to reach the same peak boost

So what wastegate spring is right for you?  Always pick the spring that is the least amount of boost you can live with day to day.  If you feel like you have to run a 10 pound spring, run a 10 pound spring.  But if you plan on running 17 pounds every day anyway, try to get as close to a 17 pound spring as you can. You will be better off because of it.

*This looks to be wrong, but I don't know why.  More on it as I find it out.  but the rest of the info in there regarding the pros and cons of different wastegate spring pressures is spot on.

[whizbang18T]

The percentage that you change on the boost controller in no way relates to a percentage of increase over your wastegate spring.

You are adjusting the duty cycle of the valve that regulates the boost signal to the wastegate, and that is all.

 :notworthy:

[BillyT]

Let me add, that from where I am standing, 45% with a 10 pound spring, will yield the same peak boost as 45% with a 20 pound spring.*  

*This looks to be wrong, but I don't know why.  More on it as I find it out.  but the rest of the info in there regarding the pros and cons of different wastegate spring pressures is spot on.

Okay, was thinking about this on my drive to get my Tahoe reg. renewed.  I was definitely wrong there.

And Luis, it isn't like that.  It is a pretty common misconception that you are  setting boost at a certain percentage of the wastgate pressure with the Spec 2.  You aren't the first, and probably won't be the last.

I guess the bottom line of all of this is that the only way to really set the Spec 2 is to start with the duty cycle at 0%, and go up from there, maybe 5% at a time, till you find the boost you want.  I haven't had a chance to mess with the gain or anything yet, but so far am pretty happy with this boost controller.  Coming from a the old Profec B, I thought I would have all kinds of problems setting the boost where I wanted it, a la the old Profec A, but this was not the case.  Pretty straight forward, once you learn where all the buttons take you.

[mj6234]

I dunno Billy, you might be closer than you think. I set mine to 10% set originally, and it boosted very little over 10psi. I kept going up, and I had to get to 25% or so before it made any significant boost over 11psi.

[BillyT]

My low boost is set at 15%, and I see about 23-24 pounds.

Think of each spring as a different level, the higher the level(stiffer spring) you start at, the less duty cycle you need to run x amount of boost.

The lower the level(softer spring) you start on, the more duty cycle you need to see that same amount.

[tim18t]

My low boost is set at 15%, and I see about 23-24 pounds.

Think of each spring as a different level, the higher the level(stiffer spring) you start at, the less duty cycle you need to run x amount of boost.

The lower the level(softer spring) you start on, the more duty cycle you need to see that same amount.

exactly right, i installed two of these in the same day on identicle srt4's, only exception was one had an aftermarket wastegate. the settings were completely differnt for the two cars. the oem wastegate needed much more duty cycle to get the desired boost level.

[elitedübs]

what do you guys mean by duty cycle? like what setting is that on the profec...

[BillyT]

Duty cycle is the frequency that the boost control valve opens and closes.  When I say boost control valve, think N75.  The stock N75 valve works this same way.  

At 15% duty cycle, the valve is closed for 15% of a certain unit of time, and open for  the other 85% of that time.  As the duty cycle increases, the amount of time that the valve is open decreases and you get more boost.  At 100% duty cycle, the valve stays closed, and the turbo will make as much boost as it is physically capable of making.

This is the main boost adjustment setting on the Profec B Spec 2.  If you don't feel comfortable with this type of adjustment, you can always get a Profec Type S, and just dial the knobs to the boost you want.  But rest assured that you are making the same exact type of adjustment to the boost control valve, you just aren't seeing the numbers.

[elitedübs]

oh ok, thanks for clarifing. i have the profec b spec 2. with my gt28r i had my duty cycle set at 72% for high boost 23psi. does that seem right?

[tim18t]

oh ok, thanks for clarifing. i have the profec b spec 2. with my gt28r i had my duty cycle set at 72% for high boost 23psi. does that seem right?

its going to be differnt on literally every set-up.

[BillyT]

when you turn the boost controller off, how much boost do you get?

[Steve_Soeder]

ok i noticed you said you didnt have time to play with the gain feature yet...
i ditched my spec 2 for an mbc, but thats besides the point...

soooo... i ran a 1.1bar spring setup and to get 20psi i had to set my dutycylce to 35%... i used the default gain of 10% and for some reason i felt something was missing... prior to the spec 2 install, with the mbc i was seeing boost much quicker....
so i turned the gain down to 0% and i got my "on/off" feeling back...
once boost hit, it was neck snapping, thats just what i like tho...
for a nice smooth transition into boost bring your gain up and drop your start boost down to about 2psi before your desired boost level...

for example: 35%  duty cycle for 20psi, gain set at 20%, start boost setup at 18.5psi... power is really smooth, not very violent...

thats my expereince with the "gain" feature that i hate so much.

[27psiBOOM]

this is great info, I was playing with the profec B today and let me let you it's a nice piece.

But I still don't get the start boost setting yet, does it means that the boost will be controlled by the EBC from THAT point?

[Steve_Soeder]

this is great info, I was playing with the profec B today and let me let you it's a nice piece.

But I still don't get the start boost setting yet, does it means that the boost will be controlled by the EBC from THAT point?

Well the start boost is a feature for gradual opening of the wastegate...
if your dutycycle is set to say 35%...
well that 35% results in 20psi(on my setup)...
well your start boost will determine when your wastegate starts to open up...
if you set your start boost at 16psi, the wastegate will slowly open starting at 16psi, and slowly bring on 20psi...
if you set your start boost at 23psi, then the result will be a spike... you will hit 23psi, then drop to 20psi(your duty cycle setting).

your start boost is exactly that... where your wastegate starts to serve its purpose (diverting gases around the turbine to regulate boost pressure).

i always set my start boost .5 psi under my desired boost... so if my desired boost was 20psi (35% DC), then my gate would start to crack open at 19.5psi...

[elitedübs]

when you turn the boost controller off, how much boost do you get?

with the R i never tried it. but the hose going from the ebc to the wg actuator broke and i would spike 25psi.

 now i'm running an RS. with the ebc out of the loop (hose from charge pipe to wg actuator) i can only get 4psi and with the ebc in place i can't boost more then 18-19psi. and thats with the duty cycle from 70% to 100%.... wg srping to weak?

[BillyT]

 now i'm running an RS. with the ebc out of the loop (hose from charge pipe to wg actuator) i can only get 4psi and with the ebc in place i can't boost more then 18-19psi. and thats with the duty cycle from 70% to 100%.... wg srping to weak?

yup...  it's not too easy to find those actuators with stiffer springs, either...

it's possible that even at 100% duty cycle, the spring in the acuator is so weak that it can't even hold the flapper shut.  The pressure in the manifold is just way too much for a 4 psi spring.