Diablosport Forums

I recently purchased the Diablosport InTune and began running 93 Octane through it from the start. I've only used Shell and Exxon who from what I've read have quality gasoline. I waited to utilize the 93 Octane until I'd ran at least a tank through the engine. Last night I took the vehicle in for a dyno / tune and at this point it had been through over two and a half tanks of 93 so there should be next to no 89 anywhere in the tank.

Prior to the InTune I installed the following mods since I've had the vehicle: JBA Shorty Headers, Charger Air Intake Tube, K&N Air Filter, removed the resonators and installed Flowmaster American Thunder mufflers. Okay. So prior to the dyno I put the vehicle back to stock. I managed 353.21 HP and 394.87 TQ. Then we tuned to 93 with no adjustments. The numbers dropped to 350.52 and 391.42 respectively. This seemed odd as the 93 Octane Tune is advertised to boost numbers. With tinkering of timing and what not we got the vehicle up to 354.64 RWHP and 396.94 TQ. Now from what I've seen these are higher numbers than 100% stock but the gains, or lack thereof from a 93 Octane Tune confused both the tech and I.

I've come to a few possible conclusions but maybe someone can help me out here. Either the stock tune didn't take so the first run was faulty, the ECM learned the optimal flow of air so there were no gains from tuning to 93, the mods themselves just overcome the benefit of 93 Octane or the engine is knocking because Shell and Exxon still aren't good enough fuels and it is retarding itself. Any ideas? The Shells, Exxons and BPs in my area only have 93 Octane for premium.

my guess is you are running lean due to the headers, what was the AFR on the dyno?
Dynos are tools, gotta use them to see whats going on, as opposed to just measuring power.

I would be correct to assume that your car feels better, and is more fun to drive on the street with the tune, no?

It looks like it was a little lean, which lead to some Knock, which seems to follow what you found.
A quick log or two would have show how much knock was happening, and where, so it would have been easier to add some fuel there and get it dialed in...

mikel wrote:my guess is you are running lean due to the headers, what was the AFR on the dyno?
Dynos are tools, gotta use them to see whats going on, as opposed to just measuring power.

I would be correct to assume that your car feels better, and is more fun to drive on the street with the tune, no?

It looks like it was a little lean, which lead to some Knock, which seems to follow what you found.
A quick log or two would have show how much knock was happening, and where, so it would have been easier to add some fuel there and get it dialed in...

I'm at work so I can't view this log myself and the InTune doesn't let me do log playback. This is a log from one of the dyno runs, I think the 4th or 5th one. All of my charts are at home but the A/F ratio seemed pretty steady throughout all the tunes even the stock. He tried to raise it a bit but it didn't budge according to the dyno.

But to answer your question yes, the car does seem more fun to drive on the streets. At least seems to accelerate at a higher rate and seems to make a slight difference in the sound of the exhaust.

Attached another log of my ride home. I looked at the results of yesterday's Dyno and the AFR sat at around 12.5 from 2000-4500 RPMs and gradually tapered down to about 12% by 5500 RPMs.