Car falling on it's face at WOT

[JackFlash]

I just had my 09 challenger 5.7 dyno tuned yesterday after installing some shorty headers. The problem we are having is, we think it is pulling timing when it shifts. The car sputters out the exhaust and then basically falls on its face. It takes a second or so to get back into the swing of things after the shift. This only happens at WOT. The tuner doesn't seem to know what to do to fix this issue, so I thought I would see if anyone here has had this problem and hopefully find a fix.

Thanks in advance!

[Cruisin1966]

Yup, I can see that in all my logs for my 09 SuperBee. From a dead stop, the timing drops 10 or more degrees, and at shift points it drops more than I think it should as well.

[JackFlash]

Nobody has any ideas or solutions? I have discovered since I wrote the original post that this not only happens at WOT, but at partial throttle as well. Just not as noticeable. The guy that did the tune has contacted Diablo, so he says, to see if he can find an answer. If not I will go back to the canned tune, it's that bad. There has got to be somebody out there that knows how to tune this 5.7 so it will run right!

[Cruisin1966]

It's not just the 5.7's either. Some of the 6.1's (mine) are like that as well.

[mikel]

Well, if it feels worse than the canned tune then it is not right, make sure he started with the canned tune to make your custom tune.

FWIW, shorty headers should not really require custom tuning.

[JackFlash]

He did start with a canned tune. I had the 91cai, canned tune in the car when put it on the dyno. It has a bunch more power now with the new tune, but it is pulling huge amounts of timing at the shift points, and he doesn’t know what to do to get it to pull hard through the shift and not sputter and fall on its face. I am tuning the car because I want to squeeze as much hp out of the thing as possible. He said he has contacted Johan, so we will see what happens.

[Cruisin1966]

Same with me, started with the canned 93 CAI tune (running Husky 94 fuel) and still seeing the same timing drop from a dead stop and at the shift points.

[JackFlash]

Got her fixed. Johan wrote my tuner back with a few ideas after looking at the tune, but in the end, we needed to change the Dwell timing to get good smooth shifts. Now it is pulling hard and shifting like it should.

[Cruisin1966]

Congrats!

[JackFlash]

Congrats!

Thanks...Hope you get yours figure out.

[Cruisin1966]

Congrats!

Thanks...Hope you get yours figure out.

As do I.

[broadfca]

Congrats!

Thanks...Hope you get yours figure out.

As do I.

OK, just ordered a Moe's Ported TB (85mm) to see if it helps the bogging problem. I'll keep you posted. There has to be a solution to this bogging BS.

[Lymzilla]

What 'timing' PID are we monitoring here (need category and exact name)? I'm curious because I've always tested WOT shifts for ST and LT knock, rpm, and mph... but I've never monitored 'timing' before and I'd like to see if I'm "pulling lots of timing during WOT shifts" too.

I have a 2007 Charger Daytona running '93oct w/ CAI' tune. It pulls very nice. My mods are C&L CAI, 185 degree thermstat, JBA shorties, JBA high-flow cats, FlowMaster Super 44s, Blastin' Bobs 6db resos, Predator (of course). 'Free-flowin' makes a big difference, and the MDS drone is almost non-existant.

[JackFlash]

Sorry, I can't answer your question. I am working with a custom dyno tune, and not a canned tune, so the guy tuning the car would have to answer your question. What he told me is that it is pulling way too much dwell timing, designed in by dodge to help save the transmission by lessoning the toque when the car shifts. The predator canned tunes worked great with no problems on my car, but with the added HP and TQ of the custom tune, the timing issue was very noticeable. It’s not like going into limp mode, but a stutter out the exhaust and lack of power at the shift points. We have it running great now.