Ok Im stumped...PLEASE HELP!!

[sinceregtp]

Looking for Help on this one guys!!

Trying to figure why 2 cars with similiar modifications have such a difference in boost. I will say the car in blue is a top swap on a GT while the car in red is a GTP.

My GTP Has new Wires beldon and plugs (104) thermo (180) SSAUTO Headers, Straight Pipe no cat? cleaned the MAF BBV is good, New fuel filter. No misfires..
Both cars have:
Headers, FWI, 3.4 Pulley. Long blocks are totally stock. We have about 13 degrees with the top swap car that has more compression and only 7 degrees of timing due to KR with the GTP. Trying to figure out why I have a 2 psi difference at 6K rpm's using the same pulley. For now we are going to do a 3.6 pulley and lower the boost on the GTP. Hopefully it will take some timing then. A/F's are both 11.5 on both cars.
Here is a link to the DYNO

Note: There are no cats on the GTP. The top swap car still has a cat.
The I am sure the hp difference is because of the timing difference.
What could caust the High boost and KR on My GTP?
Please advise.

[sinceregtp]

Ok..sooo No one wants to take a crack at finding the solution to the gtp boost/kr issues? NO ONE? BlueGTP? Blowfish? no one has any insight to help with this one huh?

[matt5112]

Could be a million and one things causing your KR but for sure, different engines will do different things, different blowers will produce different amounts of boost.

[Bio248]

the cars a different. even with the same exact build specs both cars will perform differently. there isnt a good answer to this question.

[blueguy]

Exactly...you can't assume that car 1 with mods A, B, and C will make the same amount of power on car 2 with mods A, B, and C. There are all sorts of things to factor in, wearing parts, transmission shape for each car.

[sinceregtp]

Thanks for the response..I guess the real issue we are trying to get to the bottom of is what could be causing my GTP to run with such high boost and 4* kr after timing has been cut to 7* all supporting mods have been made I know there could be a lot of variables but im looking for the MOST likely suspect as money IZ an issue..MAF is cleaned, bbv closed, new fuel filter plugs(104) Wires (beldon 7m) thermo (180) Headers and cat removed? Could it be valve float? Injectors? What can i do and would a 3.6 even be worth it? Would like at least a 3.5
Thanks forum BIO,BLUE and the rest of my forum family for the help!

[Bio248]

a 3.6 is worth it. a pound or two of boost doesnt make the difference, its the timing that is key on mild builds. high boost could be a number of things, but usually ends up being a clog in the system somewhere.

[sinceregtp]

Ok Bio..I will drop to a 3.6 till I figure it out..someone else mentioned could be a Lim issue and i think i have a small leak there that may have grown since i have. Been flooring it to dyno and wideband it..so I will start there and keep u posted..again well done and thanks guys!

[sinceregtp]

Ok guys, new symptom! I put racing fuel to check false knock did another scan with my tuner and 0 KR Intact we were able to increase spark timing by 1 over stock and still no knock..so my question to you guys now is what could cause this? Since I'm pretty sure its prob not restriction of air..or am I wrong on that?

Now I'm just gonna mix racing fuel with 93 until we can figure this out!

Please give suggestions
Thanks