Help with T-28 Killer

[SilverMitsu]

Having trouble with my killer.

Current Mods: Intake, BOV, UICP, 3in turboback catless, SAFC, 560cc injectors, 180 fuel pump, HKS EVC IV BC...

Problem: High boost setting is 19psi, low setting is 10psi. The turbo wont boost past 10psi, I even tried upping my low boost, tried switching to high boost, nothing. If I stomp it 100% throttle from a roll, it will peg 10psi and hold with no creep, spike, dips, NOTHING. It pegs 10 and holds it solid no matter what I set it to. I sent an email to turbochargers.com and they said its not the turbo, its my EVC IV...I dont believe that because I was using the EVC IV with the t-25 and it adjusted boost levels fine. I've checked, and checked, and re-checked EVERYTHING, hoses, clamps, couplers, did a boost leak test with NOTHING...

I checked the wastegate actuator and the spring is in working order. It doesnt free flap around like a broken wastegate however, I'm not sure if it supposed to have play if I twist it. The arm has no play in upward downward motion, but I can wiggle it about a quarter turn...thus far, I'm thinking its the wastegate.... Any ideas fellas?

 

[sapki]

sounds like a wastegate actuator. get that out and check for knicks, and any noticalbe problems.

 

[Mr96GSX408]

You should try not connecting the EVC at all. Hook up the wastegate line to the turbo as if it was like stock. Then see if boost rises above 10. It should be at the default boost limit of your wastegate. Kinda wierd, my T28 Killer (ported) has it's lowest boost at 14psi, can't go any lower.

A probable answer is that you probably hooked up your boost controller backwards?
But you should be weary of a leak somewhere. You might be overboosting your turbo and not know it because of a leak elsewhere...

 

[Budget90GST]

A quick check is to disconnect the wastegate vacuum line then gently raise the throttle until close to redline while keeping an eye on the boost. Make sure to let the throttle go if boost goes higher than what your fuel system can handle (under 20 psi is fine for testing purposes). Be very careful cause if it's your boost controller, then this check will let you boost as high as the turbo will allow or fuel cut, which is not too good. Again, do this at your own risk. Good luck!

 

[hellotbone]

Sounds like your wastegate isn't sealing you should have some preload on the arm when the gate is closed. As stated above if you unhook any boost reference from the WG actuator and give it an easy run boost should rise like crazy that means the turbo is fine and the boost controller isn't if the boost still doesn't rise with the WG boost source unhooked then look into the WG its self hanging up.