bkaskel23

Hey guys, i recently did the 82mm TB upgrade along with 550 injectors. The car already has a 77mm fixed pulley upgraded intercooler pump, split cooling, 3" intake and a tune.

After completing the TB and injectors upgrade the car would loose power when full throttle at about 5500 rpms. i just can't figure it out. it seems like the bypass valve is opening up but I'm not sure why that would be.

Anyone have a similar problem?

I have since done long tube headers, X pipe and cat delete, no change to the above issue.

Tavs

Solid you update the tune after the injectors and TB upgrade?

bkaskel23

The original tune was setup for the 82mm tb. Air fuel ratio is good.

C32owner

More likely what he was asking, is the car tuned to use the 550cc injectors? I guess you must have a tune loaded to use them as you say your afr's are good. So you know you are losing boost specifically? So you are monitoring boost. Could it be belt slip? Do you have a BWK installed to run the 77mm

bkaskel23

Yes, tune is setup for 550 injectors. No BWK installed. I don't hear the belt slip but not sure that I would be able to hear it.

C32owner

You can lift the front cover on top of the SC pulley and check under the cover for belt wear dust. If your belt is slipping should be quite a bit of dark dust sitting on the underside of the engine cover.

bkaskel23

Ok I'll check it out, belt is fairly new. Don't remember the brand but it's the green one most people are running . I don't notice belt slip at any other time, like off of a launch. I am not 100% that it's a boost issue . I don't have a way to monitor it. I have a scanner that does live feeds but can't figure out how to view boost on it.

BoostedAero

Information is power my friend

Without information, all you are going to get is opinions and speculations...

You need to log to find out what is going on

Get a ZT-2/nDASH combo and provide a log of boost, RPM, IAT,Timing and wide band AFR

With this information you will more than likely find the cause of the boost drop

Provide some logs for some help

cnterline

See above ^^^^^^ if you just had your S/c off your hoses going to the surge tanks could be loose or losing boost at that RPM ,ask me how I know,you need the data log set up otherwise your in the dark.