Ok so I have a boosted LS teg with a basic setup:

Turbonetics T3/T4 57 trim turbo, log manifold, 38mm Tial WG, HKS BOV, 3" inch downpipe, DSM 450's, etc.

I fixed all my boost leaks using a DIY tester. Keep in mind that I also have a 10psi spring in the WG. Problem is the car won't boost past 5psi. It's on a phearable basemap and I want to fix this problem before I go to get it tuned.

I have my WG vacuum connected to the turbo compressor.



Can this be the problem? Are there better vacuum sources?

Any help will be greatly appreciated!

 

does it hesitate at all? do you know if you are getting a good afr? if you are hesitating it wont build boost.

have you used that spring before?

I wouldnt boost on a basemap

 

How are u measuring boost? Sure about that spring?

 

what color is the spring? Is it the large or small one?

 

First thing id try is to pull that "filter" off. I ran a mesh screen+ small piece of cloth and it wouldnt flow enough air to make over 4psi. Took it off and the problem went away. Got a real filter soon after, which you should do too since it appears you have plenty of space

If thats not the case, does it hit a rev limiter at 5psi or will it pull through the entire rev range at 5psi?

 

This ^

Also, are you running a dedicated line to your boost gauge? I just finished installing a vac distribution block so everything has dedicated lines now and noticed my boost gauge went from reading 8 psi to 13 psi.

 

The car hits boost, then it goes for a little bit but around 5700rpm the needle starts to fluctuate up and down and doesn't feel like it wants to go anymore.

It's the large yellow spring. I had the small yellow spring before and it was hardly boosting anything. With the big yellow one, it only goes 5psi -.- What if i use both?

I'm running mesh only. I ran it without filter and no change. I want to get a actual filter but there's actually not much space. I'll figure something out though.

I'm pretty sure it's not the boost gauge because it definitely doesn't feel like 10psi. There is no wheel spin or anything. So in your situation, you were running 13psi the whole time but it was only reading 8psi?

 

Yes sir. After hooking up the vac block, my tune had to be touched up due to the fpr having a dedicated line, my boost gauge read accurate with what neptune was seeing, and my bov was popping off louder/stronger. My vac lines were a mess before, teed and split, all fighting for vacuum amongst themselves.

You could also try capping the line from the comp housing and running your boost reference line from further up the charge pipe or intake manifold.

 

Ya I might try that. I'm getting my car tuned tomorrow so hopefully everything goes well!

 

No body else noticed he's using a basemap? Get it tuned before you have more problems than not boosting past 5lbs.

 

Oh snap! Good eye on the guessmap, dawg!

Edit:

It's good that you're getting properly tuned, but I don't advise going to hit the dyno until you've figured out your problem. And you should def run a dedicated line for the fpr before tuning so that your fuel map doesn't change as mine did. You go there with problems and you're wasting time and money.