Diablosport Forums

Hi all,

We have a customer with a 2006 Charger Hemi that purchased the U7135 programmer. We downloaded the newest release software per the website as the Programmer asked for an update. He installed the Performance Tune and really liked the Transmission feel but "felt" no power increase. We ran the car on our Dyno just to check things out and here is what we have come up against.

The car made similar power as previous runs before but was running about 14 on the A/F at WOT instead of the 12.5 it did in the past. We said lets add more fuel (added 5%), it then went to 15 on the A/F scale at WOT. We added 15% to see what would happen and the same 15 A/F readings occurred. We were concerned so we took out the performance tune and went back to stock, ran the car and A/F showed 12.3 at WOT.

Put the Performance tune back in and the same thing happened, Car was running at 15 A/F under WOT.

Took the Performance tune out and put in the 91 octane CAI tune and the car picked up power (basically 11 hp over stock) and the A/F ran at 12.5 at WOT.

Is there a chance the Performance tune in this newest release was a little messed up? What do you recommend?

Let me know if you need any files, I have them all saved.

Thanks, Don
Idaho Speed Center

Don, this is a strange one.
So far, feedback on the SRT8s has been nothing short of phenominal.
We see gains of 25-30rwhp on stock cars, and have had reports of up to a full .5 second reductions in 1/4 mile times.

Now, I'm guessing this car is not stock...does it have an aftermarket cam? Heads?
You say it ran 12.5:1 with the stock tune....that would be the leanest SRT8 we have ever seen, as all of the stock vehicles we tested on were in the 10.5:1 range at WOT.
This leads me to believe that this car has some modification that takes it beyond what the canned tunes are designed for.

Let me know.

Thanks

Hi Mike, Yes we are baffled as well. Here is a list of items:

K&N Cold Air Intake
1" Throttle body spacer
Random Technology Hi Flow Cats
Magnaflow Cat Back exhaust
JBA Headers

This is the A/F reading from the very first run when he got the car after 1100 miles. (12/16/2006)
s RPM x1000 hp ft-lbs Air/Fuel
2.00 44.02 115.59 14.92
3.00 167.69 293.58 14.80
4.00 258.48 339.39 12.55
5.00 295.70 310.62 12.21
--------- --------- --------- --------- ---------
MAX: 9.09 5.00 295.70 339.39 14.92
MIN: 1.68 2.00 44.02 115.59 12.21

So it seems the car has run lean from the beginning. He is concerned because he plans on going with a Cam and Heads in the future and wants to make sure the Diablo will handle getting enough fuel for him.

Thanks, Don

Im assuming the A/F numbers below 4000rpm are at part throttle...did you only run the car to 5K rpm?
The SRT8s tend to peak around 6000, higher with mods.
Also, are these the A/F numbers from before he installed the headers?
If so, again this is an oddball of a Hemi, as we have seen like 30 cars here and not one of them got out of the 10:1 range in stock form.
I will have a new revision ou soon that will include a fix for the WOT fuel adjustment, as it was not working properly in 8r14.
Try this rev. once released and add like 15-20% more fuel and let me know how it turns out, should be perfect.

Once he does the Heads and Cam, he will NEED a custom tune from a CMR dealer to get the most out of the new parts.

Thanks

that's not an SRT8,

I see, I was mistaken, but that does not change much, as the 5.7s were still really rich in stock form.

Thanks

Idahospeeddon, did you ever get to the bottom of this dilema? Which tune did you end up running, or did you get a CMR tune?