Boost Surging...

[Boozshey]

So I noticed today that when I am in 6th and I step on the gas a little to pass my boost jumps to 6psi then drops to 0 then back to 6psi then back to 0. I found that odd, so then I dropped down to 5th gear and tried the same thing. The same thing happened. So I dropped it down to 4th gear and bamn, full boost.

Other than belt slip, which I am running a stock pulley, what could cause that to happen?

 

[zporta]

Throttle calibration could be off?

 

[Boozshey]

Ill call my tuner and find out what's going on...

 

[GT500RedStripe]

I had the same thing and my tuner (Jon Lund) fixed it.

 

[armycook1981]

hey boozshey thought you got rid of the motor...

 

[Boozshey]

I did, and put in an Aluminum one...

Now I have the snake bite kit on it...

‪Building Boost on the Dyno... Still 2psi short.‬‏ - YouTube

 

[armycook1981]

what were your 1/8th mile times ?

 

[Boozshey]

Horrible.. Last night I ran a 7.6 but the car was bogging on launch. 1.76 60'. With the old motor at 525 I ran a 7.3 with a 1.6 60ft.

Just go tuned today so next week I will see what I do.

 

[blackshelby]

Throttle calibration could be off?

If anything is off its probably the MAF transfer fucntion in the tune.
The boost guage works in conjuction with/off the airflow the MAF sensor signal sends to ECU.

 

[zporta]

So the throttle calibration has nothing to do with air flow? Last time I checked you have to give it gas for the TB to open up, and doesn't the throttle cal have to do with the sensitivity of the tb opening? Hence giving the blower air and creating boost?

 

[blackshelby]

So the throttle calibration has nothing to do with air flow? Last time I checked you have to give it gas for the TB to open up, and doesn't the throttle cal have to do with the sensitivity of the tb opening? Hence giving the blower air and creating boost?

The throttle body doesnt know what gear it's in.

Its all about airflow. All airflow and load calaculations come off from the MAF meter. Its needs to be accurate.
The MAF sensor/meter is the heart of the system. When the transfer function is wrong in the tune.... so will everything else.(it controls all, every calcualtion behind it depends on it)