Boost higher in 3rd and 4th?

[Roc87]

I've replaced all rubber boost hoses and zip tied every connection, but in 1st and 2nd gear all I can get is 20# of boost. Once it shifts to 3rd it goes right up to 24# (Where I want it in 1st and 2nd) I have the alky coming on around 15#, using 100% denatured. The timing in the chip is 19.3* WOT, the rest of my combo is in sig. I've messed with the alky controls and it doesn't affect it. Headers have been off and welded, no leaks. Any ideas?

 

[Roc87]

TTT

 

[Roc87]

Anybody have any ideas?

 

[BM Computer Src]

The issue is with the boost controller. It sounds like you are using the stock one. I dont know why it does this, but I have seen the exact same issue in many other GN's, (2) of mine included.

However, in cars that have external wastegates, the problem has always been the bleeder valve. A good quality one will fix this. I know you can just run a manual bleeder valve with the stock stuff, but it's up to you if you really want to do that.

Another possibility is the length of the hoses (to the wastegate controls). I have tried locating a bleeder valve in the interior, and due to length of the hoses, the boost tends to fluctuate a lot. I have located them under the hood and had no fluctuation at all. I dont know if your hoses are very long, but you should have them as short as possible, even if it is only a few inches.

This is just been my experience, but I am no expert.
Hope this helps,
Bob

 

[Roc87]

Thanks Bob! I am using all stock stuff for the wastegate. I'll get a bleeder valve and put it under the hood.