5.7 Tuning Issues

[kwazydave 0]

I have a 09 challenger RT Auto and I cant seem to get a tune that has consistent afr numbers. Whenever the tuners get close, they will make a minor change at one end of the rpm range and the whole rpm will change. I have had two tuners attempt to get a good tune and neither can explain why it does that and have not come up a tune that is close to correct. As an example I had it at a tuner/dyno and after 13 tunes the best one he could come up with runs 14.0 afr at 2800 rpms and goes rich to 10's and low 11's afr, up to around 6000 where it leans to 12.3 afr by 6200. Both tuners have had the same issues. A minor change at one part of the rpm will change the whole range, sometimes by a major amount. Are there any tuners out there that have any ideas? Mods to the car include, 392 cam with springs, stock 6.1 headers, homemade 2.5 in exhaust with 1 set of magnaflow mufflers, homemade, legmaker style, cold air intake with air temp sensor moved near the air filter, 3200 rpm stall converter, blue top solenoids in transmission. I use a predator for tuning and I have a wide band to keep an eye on the air fuel. Does anybody have any ideas? I have been fighting this for a long time.

[Cam 157]

If you're looking at your lower rpm band at part throttle it'll always try and maintain stoic. But if we're talking WOT for these readings it's in the tune. Also it sounds like you might be out of injector up top. Another standard question is who's tuning it.

[kwazydave 0]

yeah I am talking about wot readings. And yes it would appear to be in the tune but that is where the problem is. Changes in the tune do not show logical changes in afr readings. Johan has tried his hand at it, as well as a local shop call Sharadon. Both have given up and say they have no explanation. I don't think it is running out of injector because certain tunes have shown low 10's afr at 6200rpm. Changes with the predator do not reflect logical changes either. One tune was exceptionally so I leaned it by 20% in all ranges. It showed richer when I tested it.

[Cam 157]

Hum, you sure your wide band is money?. Also are you confirming injector pulse width with the change in AF?

[El Diablo 73]

The two different tuners that have tried to tune it, are they email tuning it or in person ?

[kwazydave 0]

yeah i think the wide band is correct. It matches the one at the dyno. Yes the injector pulse width changes, It follows what the afr is showing pretty closely. One tuner was email tuning and the other was in person.

[Cam 157]

Have you tried a new map sensor to see if that helps?

[Speedy 255]

Just a guess but maybe the home made CAI and home made exhaust are allowing air in where it shouldn't? What do the fuel trims look like just cruising around?

[kwazydave 0]

i have not tried a new map sensor. I am not sure what to look for as far as fuel trims go. What would be considered normal?

[HighHorseman 11]

Email me a copy of your stock tune and full mods list to [email protected], if I can get it then I'll charge you, if I can't it's usually a mechanical issue. If they are changing airflow tables at the same time then that can be the cause for air/fuel jumping around since they are tied to each other although they shouldn't be. Plus there are hidden max' sand min's in the factory computer where you will head in one direction, hit a limit and the tune will go into a default setting and shoot way off.

[kwazydave 0]

how much would you charge? What sort of mechanical issues could it be, because Johan also said it could be mechanical.

[1FST4DR 85]

Any codes at all?

Maybe check your 02 sensor on your A/F guage.. If the car is running well you might be chasing a ghost. IE bad 02 sensors or guage.

[kwazydave 0]

I dont get any codes. Driveability is fine it is just wot that seems to be tough to get dialed. My a/f gauge matched the one at the dyno shop so I feel confident that mine is correct. When I data log, the injector pulse width gets longer in the areas when I see lower afr numbers

[HemiSam 191]

you need a proper tuner changing cams on vvt

HS

[kwazydave 0]

i thought i had a proper tuner. How does one know who is a proper tuner until after they pay many dollars to find out?

[Hemi57 54]

AJ Berge aka Hemituner

or

Mike Doban aka OSTMike

[R/TWildChild 16]

i thought i had a proper tuner. How does one know who is a proper tuner until after they pay many dollars to find out?

Johan really isn't the greatest IMO for tuning aggressive mods. Get with Josh@HHP; AJ HemiTuner; or Mike@OST