[BoostedDb7]

Why does my pro-fec b 2 spike when i set gain to 25 and set gain above 0.75. It used to run perfect at these settings 11 psi (330 whp).

gain 25
set gain .90
set 75%

at wot @4.5k I used to feel a strong sudden surge of boost. All of a sudden it starts spiking one day, so I take it to get retuned and my tuner sets it to

gain 10
set gain .35
set 37%

at these settings I still push 11 psi (335 whp), but now its not a sudden surge of boost, its more like a gradual build up. I asked my tuner and he said I have a boost leak at my BOV which is a greddy type s.
Could this be true? has anyone ever had this happen before?

Or could my boost controller be broken or something. If i try to increse boost at my controller I'll spike all day, but with the settings low it seams to work fine, but not instant boost as it did before.
I think Iam over do for a vavle adjustment, could this be a cause?

Anyone familar with a pro-fec b 2 on with a sc-61 please give me your input of tunning.
Thanks

 

[DeadLock23]

internal gate or external?

the greddy ebc is a bit tricky to tune, you need to play with the settings. I had one and replaced it with a blitz.

I think there is a setting that controls how fast boost comes on, maybe its too high, so by the time the gate reacts you have too much boost already.

 

[BoostedDb7]

I have an external turbonetics 38mm WG. Do you favor the blitz over the greddy?

 

[DeadLock23]

I have an external turbonetics 38mm WG. Do you favor the blitz over the greddy?

I am biased because I have the blitz, but I have had the greddy as well, for about a few weeks. I couldnt get it to work properly, you might find some of my old posts about it. I thougt it was my internal gate or a leak in the G1 DSM BOV that I had at that time, but I can not say for sure. Some people have better experience with them, although I think non will have as flat a boost curve as mine is with the blitz EBC, mainly because it uses a dual solenoid design to control boost (DSBC) "Dual Solenoid Boost Controller"

The US version is also called the Spec R. It is pricey, but I think its worth it.

 

[vitamin_d]

I have the Greddy Profec b spec2 EBC. I have encountered many tuners who don't know how to operate this EBC when it actually is pretty easy once you get use to it. Here are the settings and what they do:

SET = Desired Boost level displayed in a % (psi)
GAIN = Wastegate sensitivity displayed in %
START BOOST (set gain) = Psi when wastegate will begin opening

Trouble shooting:

Spiking is caused by the gain and/or start boost being too high. When boost spike occurs, first step is to lower the start boost. This is usually the culprit because the wastegate is completely closed until the desired psi set is reach. That means if it is set to 9psi, the turbo will be at full spool until 9psi! That doesn't leave a lot of room for control when 11psi is just right around the corner.

once you got the start boost set low, if you are still spiking then your gain is too high. Other symptoms of the gain being too high is boost creep. Just the opposite, if the gain is too low the boost pressure will fall off as RPMs increase. Use that as your guidelines when playing with the gain to get stable boost pressure.

To me, if it is taking you longer to reach 11psi than normal then it sounds like your start boost is too low. Keep in mind though that you need to find out if you have boost leak first before you begin dicking with the settings on the boost controller.

Hope this helped.

 

[DeadLock23]

very good info Darell, thanks for stopping by

 

[vitamin_d]

pipe leak test

well, you can do what i did on my old eclipse gsx take a pvc coupler big enough to fit over your turbo inlet and a pvc cap that will fit in that coupler and put a tire stem in the cap by drilling a hole through it. put it all together and clamp it on your turbo and put air to it (like from a tire fill station or a compresser if you have one.) then listen for leaks. after about 20 psi it will probably pop off though so be carful and have some one watch the gauge so it doesent get too high.

Here's the one I made.

I pressurized the system to about 15-20psi and then used soap water to check for leaks.