ok... this isnt down load... .this problem is up top... under Wide open Throttle.

the leanness @ 2500 is fine. I am not worried aobut that as I am not under boost or WOT at that point.

 

Could this be caused by the wrong size of tires on the car? and the hesitation is the VDC kicking in?

225/40R18 in front, and 255/35R18 in back. Both fronts and backs are on Rota P45R 18x9.5 +33

 

Honestly dude it sounds like a tune issue. I know lots of people with that kit and tuning it wasn't easy (the included tune is so sh!tty it has to be tossed out) but in the end tuned from the ground up by a capable tuner everything is fine.

 

Would the grounding wire kit be messing with the MAF? etc. Sorry Just trying to check everything. Ive had it tuned twice, by 2 capable tuners.

 

The simple fact it always happens at 2500rpm tells me it's probably not the MAF... because the MAF has no idea what RPM the engine is at nor could it care one bit..the only thing it sees is engine load. did they tweak the MAF table at all? I still think it's tune or fuel system.

 

nope, won't hurt it.

 

Could it be an issue with the cam switching?

 

K, So need some feedback, Ive thought about things, and narrowed it down.

The Placement of the MAF in the piping is about 4 inches away from a bend in the pipe. and its 2 inches away from the BOV... So as soon as I switch a gear, the BOV opens and closes, which creates disturbance in the air flow which the MAF doesnt have the resolution to see..

Now if I am to close up the MAF plcement, and weld in a new MAF bung about 7 inches further up towards the TB. Would I need a retune for that?

Also what gauges of tire is the wire from the MAF? I am going to have to extend the plug so that it reaches the new MAF placement.

 

OR relocate the BOV farther down where the turbo meets the IC. I have seen couple of people do that with the turbonetics kit.

 

Momentum's kit is pretty tight hahaha, plus the MAF would still be within 4 inches of the bend.

 

ooooh great.... you better off redoing the charge pipe design, and relocating the BOV just to make sure you don't run into issues in future... god top mounted ST kits are PIA. lol

 

Relocated MAF Sensor closer to the TB.

No change

 

Not surprised that it made no difference. If the location of the MAF sensor was really the culprit, your issues would be common amongst Momentum kit owners.

Did you ever check your spark plug gap???

 

No, I double and triple checked with my mech, he gapped them all to 30.

for **** sakes lol. haha.

NOW the hesitation @ 2500 is REALLY bad if I am at anything other then WOT. lol

 

What? Take them out and measure them yourself. SMH.

Just because he said he did doesn't mean he actually did. Stuff happens. Pulling spark plugs is so simple. And if you don't already have a spark plug gapper you should buy one.

Also when you see the plugs you can usually tell what's going on in the combustion chamber.
Don't be a lazy-***, that's how cars get ruined.

 

I still think it's probably a fuel system resonance based on the simple fact it happens only at a certain RPM.

 

First I've heard of issues with this kit. +1 to the tune. Who did the tune and how much time was spent on it?

When my tune sucked my car would stumble at times, stall at times, and just over all felt like crap.

After my last tune the car went from being a little sissy likes to act up car to a turn key off the dealership lot OEM car.

 

Im usless I JUST learned how to do my own brakes lol.
Last time I took a spark plug out... well, I cross threaded the plug and well... Here is a few pics lol.
Needless to say, Blew the engine after a plug blew off inside lol.
This was in 2007

 

That sucks, but just because you fell down and broke your leg doesn't mean you should never try running again!
Just make sure you start the threading with your hand on the extension, hasn't failed me yet. If it gets hard to thread even the slightest amount it's already starting to cross.

Besides, it's quite possible previous owner cross threaded that hole already and you just followed the groove.

Regardless you should get your plugs checked any time there's an issue.

Could be a fuel resonance issue. Str8's car had that... But he was running haltech. If I recall it went away when he went pro efi... Or maybe that was only the cam issues.

Does it seem like this? (Kudos to str8 for putting it up on the net for everyone)
http://www.youtube.com/watch?v=5ASOcDuDsqY

 

i had an issue, put in 3 dampers (new CJ rails plus a Marren) and its gone.

could be the same issue or not. no telling without having the car running 100% otherwise