OK most of you know my list of mod's
now the problem is the engine has more than im getting at WOT the cars is slightly less powerful than if i lift my foot off the gas a touch this causes problems because im running an auto the tranny is set to shift at a specific RPM at WOT
now i have to lift my foot off a bit it short shifts on me and i lose time. Ive played with my tune changing timing back and forth playing with fuel curve nothing works the plugs are good the fuel filters new mass air is clean i cant figure this out now that i have 4.10s this is way more noticable anything i changed on the tune i put back to diablo original after. could this be mass air?or injectors? im stumped i know the car needs a dyno tune but im only in town for a few days then im heading back up north for work.

Im going insane trying to figure this gremlin out so any help or insight is apreciated

well heres a list of mods for those who dont know

4.10 FRPP gears
BBK OR X pipe
Flowmaster CAT BACK
BBK U/D pullies
BBK 70mm TB
Diablosport Predator
Ported upper intake plenum
Intake and TB spacers
BBK CAI

thants all i can remember

thanx guys!!!

 

Bump................13 views and still no insight need some expert advise here!

 

go manuals *shrug* sorry, no good with autos

 

tranny's good its the engine thats not quite doing as it should and its minor thats what pisses me off the most i can handle big problems its the little stuff that bugs me

 

Sounds like the T.P.S. is not set up properly to me.

 

OK with my stock TB it did the same thing but only mildly with the new TB its more prominent so how do you set up the TPS?

 

Im totally not getting what you are saying.
Are you saying the car should have more at WOT? or do you realize your getting more power if you let off a bit?
OR......the car wont shift properly at WOT?

I see you have a BBK TB.....Do you usally smash on the trottle? like HARD.
Those BBK TB's have weak throttle linkages the what I mean is they bend very easy. If it is bent you would open your throttle all the way and look inside at the flow plate it wont be sitting 100% at 90* it will go farther so it screws up your WOT runs.
This has been noticed on my TB and StealthGT's TB aswell they are known for it.
Hope this helps man.
Keith.

 

Yea the car has less at WOT than it does if i back off the throttle aprox 1/4" theres a sweet spot. now the Auto tranny has 2 shift perameters WOT shift and part throttle shift WOT is set at 6K now part throttle shift is set to factory so if i have to let off the gas a bit to make the car pull harder the tranny short shifts.... i dont know if this makes sense to anybody else
But i didnt know about the BBK linkage being weak thanx boys!

 

I know what you're talking about though I don't know the cure. I doubt it's a TPS setting issue. More likely it's an airflow and/or turbulence issue. Perhaps with the throttle plate just so you're actually getting higher quality airflow into the plenum than you would at WOT.

Maybe it's a velocity issue: the narrowed passage gives higher airflow speed into the manifold than the bigger diameter at WOT. You said the factory 65mm TB did the same thing but to a lesser extent...might make sense if the smaller diameter actually had better flow rates at WOT than the 70mm unit does...

It'd be interesting to get a manifold and TB on a flow bench and profile the flow for throttle angles from 50% to 100%.

 

well thats a good theory but yea how do i cure it? maybe my CAI is giving me grief? i should throw the stocker back on and see what that does ill have to adapt the end to fit the 70mm unit