2G Slow Spool B16G Turbo 4500+ RPM

[1slowhatch]

Just installed a used Big16G OEM Mits turbo. No free play, spins freely. I ported the stock 2g manifold, 02 housing, turbine housing, etc. I have done a boost test, double checked exhaust leaks, new gaskets, etc. The turbo makes good boost around 4500rpm (15psi) in my car. I am at 4500 ft elevation. I was expecting spool to be much closer to 3500ish RPM.

I did some testing today. I've read that a bad WG actuator can cause problems. I tried shimming it away with washers under the mounts (to insure the flapper is closed) and it made no difference. With no boost controller hooked up, I only get around 8 psi. With the controller maxed out, I get a 17 psi spike, falls to 15 or so.

Does it sound like a bad wastegate actuator? What else could be causing the slow spool? I have stock exhaust less the rear most muffler.

 

[b00zt3d spyd3r]

Mine spools at about 4500 rpms too... I thought it should spool at 3-3500

 

[Maroon4g]

I had the same problem with a 14b upgrade with a ported 16g o2 housing, and I had a NXS Manuel Boost Controller. Come to find out that with a MBC there is actually a calculation based on what type of Wastegate spring you need and how much boost your can to make (Safely). I had a 20 psi wastegate spring with a MBC, but after my calculation I had to buy a stock 16g wastegate with about 11-12 psi spring in it. I installed it, and problem solved .

 

[1slowhatch]

I'm not sure that is the problem. Mine spools exactly the same with or without the MBC installed. Also, nobody has addressed my elevation.. 4500 ft (with air density usually 6500+ summer). Also, I'm seeing full boost (19-20 psi) by 4500 rpm. It starts building boost at 3k or so on the highway. Obviously 1st gear spools later than 3rd or overdrive. I believe it is just more noticeable because the car is an auto with a stock, tight converter.

 

[b00zt3d spyd3r]

I have a nxs mbc also maybe that the issue