Boost issue?

[chevellejoe]

How steady should my boost be? I’m just curious if it’s normal for the boost to jump around at full throttle. I’m trying to set the car up at about 25psi. Looking at the power logger, the boost builds up till about 4400rpm where it maxes out but it will jump around from 23 to 26. It’s not creeping up, it's jumping up and down. It’s a TE44 turbo with a heavy duty actuator and stock configuration actuator lines.

 

[TurboDave]

Does your gauge also show this jumping?

 

[chevellejoe]

I dont have a gauge yet. The 3 bar map is new.

 

[jasjamz]

Post the log you may have another problem causing that.

 

[TurboDave]

You want to run 25# of boost without a mechanical gauge to verify/backup the map.?????

Please do not do that.

 

[chevellejoe]

I will post a log up this when i make a clean full pass week.

 

[jasjamz]

What octane race fuel? Do you have alky injection?
If you are using pump gas only, that is the problem.

 

[Nick Micale]

My guess would be it is a wastegate problem?

A HD WG is good to about 25 psi. What I have experienced on dyno runs is the WG will open for a moment, or fluctuate quickly.

We have solved this issue by using an external spring for additional pressure on the puck.

 

[TurboBob]

a flaky transmission 3rd gear switch might show a similar symptom.

B

 

[chevellejoe]

here is a powerlogger file. I am running pump gas 93 with alky. As you can see the boost is all over the place. I dont feel it but you can see it on the log.

 

[chevellejoe]

And for those that cant see the file, it goes from about 21psi to peek at 28psi

 

[TurboDave]

Try turning on "light" or "medium" filtering, on the F3 page in PL.

 

[TurboBob]

is the MAP sensor installation stock?

The Powerlogger reads all voltages referenced to engine ground, the stock MAP sensor wiring uses the instrument panel (body) ground.

If the MAP sensor wiring is stock, the noise may be improved by changing the +5 and ground feeds to the sensor to use the TPS wiring.

Bob

 

[chevellejoe]

Thanks. Changing the PL to light definitely helped. And yes all wiring is stock. I will look into changing the input voltage and ground around.

BTW I do have an issue with noise in the wiring. Not sure if the issues are connected but I have static on the radio that started two months ago. If I hit the brakes the static will go away for a little. It’s really annoying. I have gone over all the grounds in the engine bay and tried a spare antenna with no luck.