Setting and tuning the Greddy Profec B Spec-II boost controller is straightforward. Compared to other electronic boost controllers (EBC), the Spec 2 uses a relatively simple interface and set of controls. I have had excellent results on my 3000GT VR-4 with my Greddy, and I have tuned several other modified 3/S using this EBC. The boost response, boost curve, and falloff are all as good or better I’ve seen with more expensive boost controllers like the Blitz DSBC, the AVC-R, and the HKS boost controllers. Plus, it has all the basic features you’d want in a controller: 2 different boost settings, a warning alarm, a peak boost display, the option to read in psi or kPa (kilopascals), and intuitive buttons for making adjustments on the fly.
When tuning the Profec EBC, there are 3 important settings to understand:
1) Set: This sets the duty cycle of the solenoid and the base setting for your peak boost
2) Gain: This modifies the “set” to help your car hold more boost to redline and prevent fall-off
3) Set Gain: This sets the pressure at which the solenoid begins to control boost
First, you’re going to adjust the set. Decide now what your target boost is. Let’s say you want to run .9 kPa, which is equivalent to 13.5 psi (this is a safe starting point for a 3000GT). Take your car out and do some full-throttle pulls. Start raising the set until you see .8kPa on the Profec B display (or the equivalent pressure on your boost gauge). I suggest starting at about 20% and working up from there. Of course, if you see that you’re running too much boost, let off the throttle immediately and turn down the set.Next, you’re going to adjust the gain. Gain percentages are generally very low. I’ve used a single-digit gain on each Profec B I’ve tuned. I’ve also experimented with very high gain settings and lower set numbers. There was no advantage. Take your car out and do some more full-throttle pulls. Slowly raise the gain. Going back to our example, you should be shooting for a very tiny spike—perhaps .1 kPa at the most—and then a good hold of .9 kPa. Experiment a little bit and find the number that corresponds to the smallest boost spike and the least amount of fall-off. On my car, I use a gain of 5-6%.
Finally, you’re going to adjust your set gain. It can get a little tricky here because the set gain can affect how the gain and set numbers that you have interact with each other. But don’t worry, you just need to find a balance. Turn your set gain until it is just below your desired peak boost. Let’s go back to our example. For a target boost of .9 kPa, you might turn the set gain to .85kPa.
Once you do that, you might find that you’re spiking a little. No big deal—just turn down your gain. If that fixes it, great. If not, try changing the set by a few percentage points. At this point in tuning the Profec EBC there’s always a little back and forth, a little fiddling with and adjustment of all 3 settings.
Some Profec B Spec II boost controllers behave oddly when they’re set to display in psi. I always have mine display in kPa, and I suggest you do the same. Psi is easy to read, but’s good to learn how to read a new unit of pressure.
Finally, please be sure that you know what boost is safe for your car before doing any tuning. I advise everyone to get a datalogger of some kind and monitor knock, o2 voltage, and timing.
on January 24, 2007 at 5:43 pm The Pansy Patrol - Info for the 3000GT / Stealth Community wrote:
[...] Electronic vs. Mechanical Boost Control:An “EBC” (like the Greddy Profec B Spec-II) is typically $300-400 and often reports boost pressure on the face of the unit. This is not as easy to read as a boost gauge, but “warning” features can help you keep track of it. If you like tinkering, aren’t afraid of electrical wiring, and have the money to spend, an EBC may be for you. An “MBC” can cost $20-40, and is perfectly adequate if less adjustable. They are simple to install, simple to adjust, and cost almost nothing. The MBC will be more inclined to let boost fall as engine speed increases, but it’s still much better than factory boost control. [...]
on May 29, 2007 at 10:15 pm David wrote:
just thought i’d say this is a great help. ty for the post
on August 19, 2007 at 11:03 am sammage wrote:
FYI, the problem with Greddy Profec B Sepc IIs behaving oddly when displaying in kPa is a software gltich. I think around 2005-2006 Greddy fixed this glitch in the Profecs going forward.
on August 19, 2007 at 11:04 am sammage wrote:
Oops, meatn when displaying in psi.
on August 19, 2007 at 11:44 am Clint wrote:
Thanks for the info Sammage. Got a link to this info? The erratic behavior in psi mode always struck me as something simple that Greddy could fix. I’m glad to hear they did.
Clint
on August 19, 2007 at 10:11 pm sammage wrote:
Clint, searched around, couldn’t find anything on it …I remember a DSM friend of mine having the same problem with his Profec. Couldn’t hurt to email Greddy, it might be just a simple firmware fix.
Sam
on August 19, 2007 at 10:20 pm Clint wrote:
I was searching around earlier today after I read your comments. Couldn’t find anything either. So long as it’s fixed.
Clint
on August 20, 2007 at 1:46 pm sammage wrote:
Agreed. Thanks to this article when I decide to retire my MBC I’ll probably get the Profec, seems to be a great unit for the price.
on May 27, 2008 at 9:51 am Greddy EBC help - 3000GT/Stealth International Message Center wrote:
[...] Greddy EBC help Assuming you get it routed correctly, take a look here: The Pansy Patrol » Greddy Profec B Spec-II: Tuning Tips for 3/S owners __________________ 2002 WJ — 1994 VR-4 — 1993 ZJ –Canon Rebel [...]
on June 10, 2008 at 9:07 am Tom wrote:
I have been playing with the settings, is it possible that the stock BOV will cause boost surges and hesitation?
on June 17, 2008 at 10:44 pm greddy prof b - 3000GT/Stealth International Message Center wrote:
[...] check for boost leaks while you’re at it. And if in doubt in dialing in the correct settings- The Pansy Patrol » Greddy Profec B Spec-II: Tuning Tips for 3/S owners Mike __________________ If you got a 96 stealth wing you want to sell please PM [...]
on June 25, 2008 at 4:02 pm Who has base settings for a greddy profec B spec II with my mods? - 3000GT/Stealth International Message Center wrote:
[...] Who has base settings for a greddy profec B spec II with my mods? The Pansy Patrol » Greddy Profec B Spec-II: Tuning Tips for 3/S owners __________________ If you got a 96 stealth wing you want to sell please PM [...]
on June 28, 2008 at 1:48 pm Greddy porfec B spec 2...What is everyones settings and mods??? - Page 2 - 3000GT/Stealth International Message Center wrote:
[...] to no spike. Do all of your testing in 3rd gear. Read these 2 things and go out and try it again. The Pansy Patrol » Greddy Profec B Spec-II: Tuning Tips for 3/S owners http://www.alamomotorsports.com/gred…EC_B_SPEC2.pdf __________________ 92 Stealth RT/TT BPU [...]
on July 17, 2008 at 12:05 pm Help a Noob With This Whole Turbo Thing.. - 3000GT/Stealth International Message Center wrote:
[...] Help a Noob With This Whole Turbo Thing.. The Pansy Patrol » Greddy Profec B Spec-II: Tuning Tips for 3/S owners For starters your gain is WAY too high. That link will tell you all you need to know! [...]
on October 24, 2008 at 7:12 am question about Greddy Profec EBC - 3000GT/Stealth International Message Center wrote:
[...] question about Greddy Profec EBC The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners __________________ 94 VR-4: 11.8 @ 116, 17psi, pump, 13Ts p.s. buy my [...]
on February 8, 2009 at 10:18 pm Greddy Profec B Spec II Install Options? - 3000GT/Stealth International Message Center wrote:
[...] Re: Greddy Profec B Spec II Install Options? Just making sure you’ve seen this one too! The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners [...]
on May 6, 2009 at 6:11 pm Issues with a Greddy Profec B II Please Help - 3000GT/Stealth International Message Center wrote:
[...] here http://greddy.com/img/PHP/products/pdf/682.pdf What are your settings? Have you seen this? The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners __________________ 1994 3000GT VR-4: 11.8 @ 116, 2008 Season NEPA SoloII NM 2nd Place, 3Si Nov [...]
on June 1, 2009 at 10:25 pm Greddy Profec B -Spec2 "Comments Please" Likes and Dislikes - 3000GT/Stealth International Message Center wrote:
[...] and it seemed to change my max boost. not sure what that was about. but i followed clints advice on The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners and it works great. __________________ “Change we can believe in” I’ve got a whole pocket full [...]
on June 30, 2009 at 10:18 am Kien wrote:
hey, i have the same boost controller in my skyline r33 and i wanted to run 14psi but dont know the settings. can you please help me out.
on November 12, 2009 at 2:59 pm Boost Conroller headache - 3000GT/Stealth International Message Center wrote:
[...] as has Clint (struggly) - and he’s gone one further and actually written a how-to on his website. The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners Best of luck with whichever direction you choose. //Ryan __________________ [...]
on March 14, 2010 at 4:20 pm Greddy profec B spec II - 3000GT/Stealth International Message Center wrote:
[...] Greddy profec B spec II I’m not from your area but i read this and it helped me greatly! The Pansy Patrol Greddy Profec B Spec-II: Tuning Tips for 3/S owners __________________ 1991 3000GT VRFOUR http://www.facebook.com/bhodgin WTB: Krank Vent System, [...]