Diablo Tune V/S 91 Octane

[Jlencioni]

What is the performance difference between the Diablo tune and the 91 octane tune?
I have a 2009 Corvette LS-3 and want to load the best performing tune.

[BlackZ71Silverado]

I don't have a Vette but I know for my Silverado, the "Diablo Tune" is for use with 91-93 octane fuel. I would think it's the same with every other vehicle because the timing advance is set for the higher octane rating.

[06MonteSS]

for the vettes, the Diablo Tune is made for 93 octane gas or higher... it has more timing/spark advance than the 91 octane tune does, and give a little better performance for the higher octane fuel used in the car...

and yes BlackZ71 - the Diablo Tune for trucks is made for 91 octane... but the car tunes are different - they have 91 and 93 octane specific tunes...

[Jlencioni]

Thanks for the information as I wanted a tune with a better shift and spark curve.

I just finished installing Kooks long tube headers and high flow cats along with a Callaway cold air intake so I wanted to start with a more aggressive tune. I know the fuel slope will have to be enriched considerably so I will start at 8% and check the lift. I think I will end up around 10% with the changes.

[smokestack]

Thanks for the information as I wanted a tune with a better shift and spark curve.

I just finished installing Kooks long tube headers and high flow cats along with a Callaway cold air intake so I wanted to start with a more aggressive tune. I know the fuel slope will have to be enriched considerably so I will start at 8% and check the lift. I think I will end up around 10% with the changes.

For you a custom tune will work tons better.

[06MonteSS]

Thanks for the information as I wanted a tune with a better shift and spark curve.

I just finished installing Kooks long tube headers and high flow cats along with a Callaway cold air intake so I wanted to start with a more aggressive tune. I know the fuel slope will have to be enriched considerably so I will start at 8% and check the lift. I think I will end up around 10% with the changes.

For you a custom tune will work tons better.

yes, definitely! ^ ^ ^

that much change to the injector slope setting for the fueling is not good...

you will make it too rich by adjusting the injector slope that much - and the car will feel like a slug - the MAF sensor tables need to be adjusted instead...

and why start with an adjustment BEFORE you even do a log?? don't make blind changes - do a steady driving data log FIRST... AFTER you have gotten about 100 miles put on the tune - because the fuel trims need time/miles put on in order to get relearned and settle in before the data will be correct/accurate...

you will definitely want to get a custom tune done for your predator/car/mods... but, it's up to you man...

with a custom tune for your car/mods, you'd gain even better/quicker throttle response and acceleration, stronger/harder pull, and usually even a little better mileage too... if you're interested in a custom tune, let me know, I can hook you up...

[Jlencioni]

I already had run log before making the fuel slope change and the lift indicated a 9% increase over the 3% I had installed. You are correct I do not have the programming tools to access MAF table program in the ECU to properly develop a tune myself I only wanted to get it close enough to drive without hurting anything. I thought 11% was excessive so I installed a 6% as a test and created a log and it was too lean so I now have the slope set to 10% and everything is happy as far as error codes but I would not call this tune a keeper.

I am going to take it to a shop and placed on the dyno to get a custom tune for the modifications as soon as I find one I feel comfortable with.

If you have a shop you would recommend in the Kansas City Are please provide it to me.

I very much appreciate your comments and advise.

[06MonteSS]

10% is too much... I wouldn't set it any more than 5%... doesn't matter what your average ltft's read at this point.. the 5% setting is still better than stock, and won't be too much as to negatively affect the vehicle's performance - it will still be better than it was...

I'm not sure about any diablosport CMR custom tuner dyno shops in Kansas City... but I know I can get you dialed in all via email....

if you want to look for possible diablo tuners in your area, use the dealer locator to find a few and give them a call...

[Jlencioni]

Thanks I will make a few calls.

I was getting low cat efficiency and lean engine error codes when I had the slope set at 6 % and those have gone away since I increased the slope to 10 % are you sure I should change back to 5 %?

I know the MAF and VE tables are not correct since the changes and that is what is causing the wild slope readings so I really want to make sure the folks I go to really understand the complexity of the tune and take the time to do it correctly.

Just a little history I installed the headers first and the 5 % was fine and the car really responded but since I installed the Callaway cold air it pushed the MAF off the charts. Your diagnosis is right on and correlates with all the research I have made.

Thanks again.

[06MonteSS]

You're getting those trouble codes because of the headers... Those codes need to be disabled in the tune file when adding long tube headers, removing cats, etc...

[rowdync]

I am running the 91 octane tune on a '05 vette. Just put an LG long tube header with high flow cats on it and now I get a P0171 (bank 1 too lean) code. What is the best or easiest fix for this? Any suggestions.

[06MonteSS]

need to get a custom tune done in order to get the fueling adjusted correctly and to disable the necessary trouble codes...