So I got tuned on Friday night to come up with 575whp on pump 93 and 100% methanol. The tuner (and i) agreed to stop tuning because it seems there is something choking up. Notice in the graph how the power dips at 7200 rpms. This was at 34psi


The tuner feels its my Turbo XS catback that is choking me up. Opinions?

Mods:
Built 2.0 (8.5:1 CR)
ETS Equal Length 6262 (.82 a/r)
Magnus SMIM
Boomba 75mm TB
Turbo XS Exhaust
GSC S3
Buschur Dual Valve Springs/ Retainers
Labonte meth
Sparktech non-cdi

 

Stock head?

 

yes stock head.

 

Bobby i cant see it being the exhaust because my megan stealth catback has a resonator and a huge muffler maybe that magnus Intake manifold is doing something or maybe a bad sensor somewhere?

 

intake mani/throttle body combo

 

also what valve springs do you have in there looks like valve float almost

 

I always though float resulted in a huge dip in the graph.

 

it looks pretty much like that those are pretty big dips probably 50whp worth of dipping wish we could see the whole graph tho

 

updated in original post

 

fixed

 

those definitly shouldnt be floating must be something else or those springs are shot hmm boost leak?

 

I would've guessed ignition issues, but you've got the sparktech unit. What plugs/gap?
What did a/f do above 7k?
How was your timing in the top end? I'd try reducing boost a couple psi and adding a degree or two of timing to see if that helps above 7k.

Marshall

 

i think the timing is either off a tooth or the cams are not what they should be. it seems like the motor is choking for air.

 

Hmm....choking you say huh? Does the car feel like it's just kinda...i dunno missing something? I can say that a nasty boost leak at my TB robbed me of close to 50whp and made the car feel like it was ...well....missing something. I had to break down the UICP/LICP into two different sections and really do a thorough boost leak check to find out it was at the TB. My suggestion is to try that. If you do a THOROUGH boost leak check then if nothing else you've done your car a solid by ridding it of any possibilities.

 

we did a boost leak test...had a minor one but fixed it. Not sure of the AFRs or timing but the plugs were gapped at 24 and we then gapped them down to 21. Misfiring is not the issue. Also, the car did not pull any timing during the pull.