T28 Spool issue.

[midnightprod]

Hellow fellow DSMers, i did my research on T28 late spool, i hit boost at 3800, 4k rpms. and it spikes up to 17psi, i have the stock WG set at 12psi no MBC. here are mods

catback, highflowcat, dp, stock o2 housing stock exahust mani, turbo is unported.

-i check for boost leaks, nothing so far. what could it be?, my goal is 280awhp. any suggestions appreciated.

 

[delta448]

Check for any exhaust mani leaks, missing mani studs, broken or stripped turbo bolts and obvious signs of failed exhaust mani or turbo gaskets. Then when that checks out ok, pull the O2 housing and check for cracks in the wastegate area, bent or damaged turbine blades. If that still looks good then start looking at the wastegate actuator, and test the pressure at which it opens the flapper.

 

[pboglio]

All good suggestions. Running a can of seafoam thru the intake system via the pcv port on the intake manifold will show any exhaust leak near the head/manifold/turbine housing area. Then I'd do a complete intake leak check via pressurizing the intake thru the compressor inlet with an adapter etc.

That high of a slow spool I've only seen with a wastegate valve hanging open but you'd need to start systematically checking: intake leaks, exhaust leaks, wastegate actuator, boost control, etc. You check those your going to find the problem.

 

[midnightprod]

thank you, im goign to try the can of seafoam, , pboglio, u had a t28 before?

 

[pboglio]

Yeah, I owned a T28 for 8 years, right when they first came out in 2001. I pulled some nice h.p. out of it but it took alot of bolt ons to do it. I moved on to the EVOIII 16g and haven't looked back.