ian

Well I have been having some boost issues with my car, one is that I seem to get different boost levels with the same boost dialed into the EBC... and the the 2nd issue which could be have some relation to the first was that my boost would dither and not hold a constant PSI, I dial 15 psi in, and I see 14 to 15.5 psi right as boost builds.....

And while talking about what it might be I think I have narrowed it down to the BOV.

So I'll post soon as to if this was the issue or not, but i'm going to adjust mine to have a bit more resistance to pressure (just adding a few shims)....

But that could be the problem right?

As for the first issue, it may be the lines running to my wastegate, or it may be my Fuzzy Logic EBC (greddy profec A).....

Danno

Had this problem with the AVC-R as well and the datalog of the boost-curve showed a sine-wave. The solution was to increase the feedback speed to make the sine-wave fluctuate faster with less of a swing in each direction.

ian

I'm going to mess around with the EBC as well, but the Fuzy logic of the Profec A might be one of limiting factors there, Greddy did just replace it with the E-01 and the Profec A did have a bad reputation....

The other reason I think its the BOV is because of the sounds coming from under the hood it sounds like the BOV is letting go in short little bursts.....

evil 944t

Danno, How do you increase the feedback speed?

keith

Hey Ian - how did the DYNO go?

toddk911

Would there be any other place then the stock banjo bolt, to tap wastegate line into??? For better readings, efficiency, etc.

Anyone experimented???

ian

todd,

Well, on my EBC I'm tapped in at the banjo bolt, but thats not for readings, thats for the air to actuate the wastegate as it is manipulated by the EBC. The readings for the boost level are coming from the intake manifold. The EBC is supposed to make up the difference and keep a constant boost level at the intake manifold.

I'm still having some dithering issues, but it got a little better with some shims on the BOV, i'm checking the vac lines next, and then its on to my greddy profec A....

ian

Keith,

Dyno went ok, I learned I was very rich, and that my 02 readings are off by a good deal, but then I could not dial in the boost. I'm still trying to track things down, I'm going to try a few things, and hopefully should have the car ready to roll by this weekend when I go to VIR....

But if you want to drive the car at some point this week just let me know.... I have 15psi dialed in fairly well....

fast951

Ian,

If you don't get your boost under control by the weekend. You might want to use a manual BC for the DE.

ian

John,

that might not be a bad idea, thankfully i'm not over boosting, I was loosing boost when the car got hot on the dyno, and there is a little bit of boost creep at the higher rpms in 4th gear. But I know the greddy is adjustable so i'll see if I can't nip the boost creep off, and see if I can't nail down the dithering...

toddk911

How do you shim the BOV???

And what exactly will the do??

ian

I can shim my BOV valve because its an aftermarket unit, and it will add more resistance making it take more pressure to open it. The Vac line on the top does the rest....

toddk911

Oh ok. So it can't be done on stock BOV I guess.

Found this today:

"Those of you running turbochargers, listen up! Many stock (and even tuning shop) configurations use a port on the compressor housing to provide a pressure reference to the wastegate. What this ends up meaning is that the wastegate sees a pressure signal that's a little higher than pressure at the intake manifold because of the pressure drop through the intercooler and its plumbing. By simply capping the compressor fitting and moving the wastegate signal line to the intake manifold, you can pick up a few more pounds of turbo boost and enjoy more responsive boost control."

AlexE

Ian I have the same setup as you with the PRofec A controller........... I ended up using the home depot version ........... It works just dandy.

1 full turn 2 psi. Lock and go.

I gave up on the profec A. I used it on my stock turbo and I would constantly get 'boost creep' it would not hold 15 psi....... it would surge from 9- 17 psi.... no matter what I did.

Finally finished installing my Vitesse 2 kit in the car.........and the flippen thing "profec A" would make me overboost like it was going out of style. So I threw in a fitting from my compressor..........

As much as I am dying to do a 40 psi 'glory run' ...........I told John that he could leave the country on his trip before I dial it up.........he doesnt want to be hit with any pieces of block or stray pistons..........

fast951

Thank you Alex. I'm hoping you can resist the temptation to run 40psi boost, at least till I'm over the Atlantic

So, how does she drive?