Based on the few details you have provided, I'd guess the wastegate is a little loose or is leaking at pucks and bleeding off drive pressure. You should pull the inspection cover on the exhaust housing and look at the pucks to see how well they are machined and how good of a seal they are making. If you disconnect the wastegate actuator, you can lift the pucks up and see if soot is going by the pucks. During normal operation, the wastegate shouldn't open till 40psi or more so the pucks should be clean on the portion that overlaps the ported wastegate holes.

Did your turbo come with a spring actuator or a boost controlled diaphram setup like the stock turbo?

 

Definitely sound like a leak of some sort, either boost side, or exhaust side like Big Blue is saying. That turbo should be hitting hard by 1700 rpm, not 2300.

Have you talked to ED about this?

 

something sounds odd and off. Your only running 90 sized sticks? You should almost be able to run the stock turbo (I ran the HY35 for year that way). My truck running a single garrett 3782R (60mm inducer/72mm turbine) run 700-800 deg's, twins I'm 600-700 on flat ground empty and run 3-5psi of boost (70mph). My max egt's are 1200-1300 on a single. Start with boost leaks and also check to see if the wastegate is closed tight and is sealing.

 

Yes i have the spring actuated waste gate on this turbo. So mike how do you like that garrett ? any ups or downs?

 

The turbo barks lots when run as a single. It spools decently, as fast or faster than stock. The only real down is that its pricey. In a twins set-up its very nice secondary turbo. I've run three now, each abit different. I really like for twins. The GT3782R spools faster than the 3788R, buts not alot slower. My next twins project I'm gonna try a GT3582R as the secondary. I usually use the turbo for abit then I sell it off to try a different one out.

 

More fuel might help but seems like you've got an issue with drive pressures to me. Just like everyone else said.

 

I love my Garrett! Great upgrade for me. Sucked way to much air for my K&N filter.

 

They really work good in automatic trucks. My starts to spool around 1200-1300 rpm.

In twins, its a little slower, but once you get the primary to lite, they are very nice set-up. I've run both a GT3782R/GT3788R over a BTH-3B or S475 turbo. Very nice.