GoodfellaFD3S

iTrader: (213)

I'm debating about swapping boost controllers, my profec b has been 'old reliable' since 2001. Thinking about a dual solenoid Blitz, if I decide to make some future dyno runs at 25+ psi, I don't want the controller to be holding me back. I poked around the net, did a search, went through Greddy's website with zero information. Looking for firsthand info if possible .

BLitzed33

I would think it would be fine, i use the type S, essentually the old style profec B with the three ***** and it worked fine....if I were to get another one it would be the apexi avc-r with the gear dependent boost control. If your profec decided to take a crap while tuning, I would have a manual boost controller handy

AnthonyNYC

iTrader: (3)

I just went through this a few months ago. The first question is what is your wastegate spring pressure. If you have a 15psi spring, then you should be able to go to 30psi. I found that my profec b would only double the wastegate spring pressure. There are ways to "rig" it but I did not want to. I had a 8-10 psi spring in my setup and with the boost controller on high boost on the highest setting, I could get no more than 20psi.

When I wanted to raise the boost, I upgraded the spring to a 20psi spring but would much rather run the 15psi spring. This way you can go up to at least 30psi. It was an PITA for me since I started with a manual boost controller. When I could not go past 20psi I thought it was because I had a manual boost controller. I then upgraded to the profec Type S (the new one that goes up to 42psi) and still could not go past 20psi.

So now I have a boost controller that can go to 42psi and it wont go past 20psi Someone mentioned to me that the boost controller would only double the spring pressure. I called a few Greddy distributors and they never heard of such a thing so now I thought my blow off valve was leaking and changed that like an idiot.

In the end I just got a new spring and now I can go up in boost using the boost controller. I got a 20psi spring since I wanted to go to 35psi. So far the most I went up to was roughly 27psi and made 580HP running really rich but everything in regards to the boost controller works as it should. Each notch increased boost and HP.

I created a spreadsheet of the "high settings" and wrote down the boost in the 12'o'clock position and each notch after that. I don't have it in front of me now but I think I was like 3 notches past the 12'o'clock position. Get your boost stable first since you can't really tune a car that has erratic boost, I should say it's harder....

I'm curious to know if anyone has a 10psi wastegate spring but able to bump up the boost to 30psi with an electronic boost controller.

Anthony

Hyper4mance2k

iTrader: (40)

i heard they're terrible above 1 psi and you should sell it to me for $40 shipped... but basically what Ant said seems to be true through my experiances...

GoodfellaFD3S

iTrader: (213)

lol, nice.

Anthony, thanks for the good info. I have a 12 psi spring, so based on that I should be able to see 24 psi, which realisticly is more than enough for a street car. I'll see how tuning goes and take it from there, thanks again

BLitzed33

I had a 10 lbs spring in mine and I could only get 25 lbs out of it...then I swapped a 22 lbs spring (S doubled up) and all I could get was 28 lbs but I ran out of turbo and it would just bleed down to 27 lbs...it did spike to 31 lbs when I added a MBC in addition to try to squeeze more boost, but it just kept bleeding down.

sk8world

iTrader: (5)

I am glad I read this, reminds me I had similar issues on my last tune. Know I need to fix before the next tune. Last time was Profec B almost all the way up on high boost setting and 22-23 psi max. This was on a 10psi spring.

Asleep

Nice information, Anthony.

I have the Profec B, Spec II. The digital one. I will be selling it for the Turbosmart electronic controller once the engine is broken in and holding steady boost above 20psi...and yes, Howard Coleman, the methanol injection is in.

I have hit 25psi on a 17 spring. But I had issues holding boost due to other issues, unrelated to the controller.

Two things:
1) backpressure (between the turbo and the exhaust ports)
2) the positive impact of higher WG spring pressure to spool up.

Backpressure influences how you build the boost and where it ends up. As well as the "curve" of the spool up when your WG spring is closer to the target boost. High backpressure is going to limit the boost target.

The closer the spring pressure to the goal pressure the faster the spool up. Rich, for you, I think you should be spooled to 20psi by 3800-4100 rpm. Then again you can't forget the size (and the path for the runner) of the WG orifice...how quickly it can dump the pressure. Small WG opening isn't as much of an issue at high boost if your spring pressure and the target boost have some "space" between them. Running a 25psi spring and trying to hit 26psi and a tiny WG opening might be an issue. But running a 20psi spring with the smae 26psi goal and a "small" opening might be okay. But if you want to run low boost then you better be able to dump out of the opening quickly...large opening is going to help here.

books

iTrader: (8)

Tony, For the boost challenged, please decribe this effect in quantative terms,

"Small WG opening isn't as much of an issue at high boost if your spring pressure and the target boost have some "space" between them. Running a 25psi spring and trying to hit 26psi and a tiny WG opening might be an issue."

25 psi to 26 psi seems to be an extreme case any other data?

CMonakar

I had a Greddy E-01 on my blue car. It has a start boost function that holds the gate shut until the 'start' boost value is reached. It has the same effect as using a stiffer spring on the boost curve, but you can fine tune it to prevent overshoot.

Lets get down to the basics on how an electronic boost controller works for a minute. It is just an electronically controlled duty valve. Even with the self-learn function enabled on the Greddy E-01 all it is doing is goal seeking for the ideal duty value to reach the target boost in the ‘learning’ mode. Once the learning function is turned off I believe that is the value the controller uses regardless of what boost you hit. Point being, the way it configures itself is intelligent, but it isn’t exactly adaptive once it is configured. The curve created by that duty value is then modified by the START and GAIN functions.

Asleep

Books (I forget you name...I tuned you many moons ago, right?),

Quantative or quantitative terms?

The extreme case was picked to illustrate the case where if you were trying to hit 26 psi, running a 25 psi spring might be "too close" for a small orifice runner pipe and wastegate. You could have spike issues...trying to dump too much via too small of an opening, too quickly.

My point is that you will get a better boost curve (spool up) with a higher psi spring, closer to your target levels. I think "double the spring" (or spring pressure = 1/2 target pressure) versus, say, spring pressure = 2/3 target pressure is going to show a faster spool up. The closer the spring pressure is to the target pressure, the steeper the boost build up curve (faster spool up).

The physical limitations still come into play and hence you are dependant on how much air you can move out of your wastegate. Properly sizing the components for the boost level you are going to run is important. Just like having the right backpressure is going to dictate how the system performs.

My testing was done with two 40+mm wastegate orifices (two different brands, Turbonetics and Turbosmart) running ~10, ~14, ~17 and ~20psi springs at up to mid-20's psi. Testing was done with two different manifolds. The spring that showed the best spool up curve was the 17psi spring when running target levels of boost of 18.5 and 21psi. The 20psi spring had too much spike (for the manifold I was running at the time) for a target of 21psi.

I do not have fully documented test results. FWIW.
Cheers,

Tony

books

iTrader: (8)

Tony,

Yes you tuned one of my cars years ago, I'm Dave. Should have used a spell check.

I actually forgot the reason I asked this. Perhaps the reason was this, since I know you've logged so much, I thought you may have more data points that indicated how the spool rate (in terms of rpms ) was quicker for a range of specific springs..much like you had listed 10, 14, 17, 20.

I do know that Chuck Westbrook had logged data which demonstrated the faster spool when he changed to a 10 psi spring from a 7 psi spring.

Asleep

Dave,

If I remember you're running the Gt35r now? Don't need to worry about spool on that turbo!

My Gt40r has been an educational experience for me. I ended up building a new custom manifold (hindsight being 20-20 I would have just purchased Sean's long tube with some mods...or Gotham Racing's) and a custom 3.5" DP just to get that turbo to spool quicker. I took forgranted the engine and the exhaust porting. Well, let's just say I wanted to do everything short of changing the engine ports. Hindsight, it is the most major variable and I should have started there.

I got my Gt40r down to hitting 20psi by 4220 in 3rd gear. That was the old ports. Don't know yet what happens with the new ones yet.

An interesting side note is that going from the Apexi FMIC to the Greddy 3-row INCREASED spool-up by ~200rpm! The reason for doing that upgrade was IAT increases at 18+ psi, seeing 10c increase during a 40-140 run. The 3-row hardly shows an change in IAT during the same type of run at neat the same ambient temperatures.

I have so much data in logs that I in the middle of project to develop a system to use some enterprise information technology tools to analyze it. Should be interesting in terms of results.

Back on topic (sorry) I would say that the "old school greddy profec B" is one of the "rocks" in terms of simplicity in use. I never had a boost control issue with one of these units (outside of bad install on a wg spring once.)

Tony