Going from 87 to 93 tune.....

neonhomer · Post by **neonhomer** » Sun Dec 23, 2007 1:59 pm

Well, I was told I can get better mileage from using the 93 tune over the 87 tune. Question is, what is the procedure from going to the 87 to 93 tune. Obviously I need to run 93 octane gas (waiting until my tank is close to empty to fill it with 93), but do I need to wait for a period of time before going from the 87 tune to the 93 tune?

Should I completely uninstall the Predator when going between 87 and 93, or just go to the 93 tune?

Grumpy_Aero_Guy · Post by **Grumpy_Aero_Guy** » Mon Dec 24, 2007 12:13 am

I simply ran my tank down to about 7/8 empty, filled up with 93, loaded the 93 tune (from DS 87 tune) and had no problems.

After burning about a 1/4 tank of the 93, I filled up with 93 again, just to be sure.

Didn't notice ANY issues.

You can go straight from the 87 to the 93 tune. Your original back-up is still in the predator and will not be molested by switching from 1 Diablo tune to the other.

In my case, if there was a mileage improvement, it appears to be marginal with the 5.3 in my NBS Sierra --- of course, the 93 tune appears to have made my right foot a little consistently heavier for some reason...

With summer blend gas, it seemed like the mileage improved slightly more than with winter blend gas.

The performance improvement between the 87 and 93 tune, however, in my mind was very significant and palpable easily.

Enjoy!

neonhomer · Post by **neonhomer** » Wed Dec 26, 2007 12:13 pm

Fuel here is $2.99 a gallon for 87, and $3.19 (or so) for 93/premium... If the performance and mileage gains are not that much, then what's the good of going to the 93 tune then?

Post by **mikel** » Wed Dec 26, 2007 12:34 pm

The performance of the 93 tune will blow the 87 tune out of the water...gotta pay to play!

neonhomer · Post by **neonhomer** » Sat Jan 19, 2008 5:24 pm

Now to rehash a old thread.... Since I have my trims adjusted, when I go to the 93 tune, will I have to readjust the trims, or will they carry over to the 93 tune, and vice-versa?

Post by **06MonteSS** » Sat Jan 19, 2008 7:43 pm

on my model predator (U7191), when you switch tunes, it prompts you and tells you that you're changing to a different tune, and asks you if you want to "Reset All Parameters?"

if you select YES, it will wipe out all your previous adjustments... if you select NO, it applies your existing adjustments to the new tune you are installing.

01Z · Post by **01Z** » Sun Jan 20, 2008 11:00 am

06MonteSS wrote:if you select YES, it will wipe out all your previous adjustments... if you select NO, it applies your existing adjustments to the new tune you are installing.

Even if those adjustments conflict with the new tune?

1st6.0GTO · Post by **1st6.0GTO** » Sun Jan 20, 2008 3:12 pm

I'm kinda wondering the same thing, to a point. The thing I just thought of is my car says to put 93oct in it with a stock Pontiac tune, Right on the gas door. So if I am already running 93 stock then I'm starting to wonder if I modify the factory tune if I will see better timing numbers.
Sorry for the partial thread jack.

http://diablosport.com/index.php?name=P ... pic&t=5397

Post by **06MonteSS** » Mon Jan 21, 2008 9:33 am

yes... for example.. the default tune settings all have the adjustable parameters set at 0 - in the middle... if you made adjustments to your injector slope to -5%, and you install a different tune and choose to keep the previous adjustments, it will make that -5% adjustment to the injector slope setting of the new tune you are installing.

neonhomer · Post by **neonhomer** » Mon Jan 21, 2008 7:17 pm

My LTFT's were still around +0.7 or so with the new programming...

I did a couple of WOT runs, and got around a 870 or so on the downstream sensors....

Stevens07 · Post by **Stevens07** » Tue Jan 22, 2008 8:23 pm

Your not kidding when you say the 93 tune blows away the 87 tune. I just switched my Vmax back to the 87 tune, and it's night and day how the truck runs. I hope to get a mileage increase, or I'm going back to the 93 tune.

Steven

Post by **06MonteSS** » Wed Jan 23, 2008 9:36 am

neonhomer wrote:My LTFT's were still around +0.7 or so with the new programming...

I did a couple of WOT runs, and got around a 870 or so on the downstream sensors....

don't go by the O2 sensors at all...

just get your fueling dialed in via inj. slope adjustments so that you're average ltft's are at 0 to -2, then leave the PE settings alone at the 0 default setting and you'll be all set.

Post by **mikel** » Wed Jan 23, 2008 12:53 pm

Stevens07 wrote:Your not kidding when you say the 93 tune blows away the 87 tune. I just switched my Vmax back to the 87 tune, and it's night and day how the truck runs. I hope to get a mileage increase, or I'm going back to the 93 tune.

Steven

Mileage will likely stay about the same between the two tunes...

Thanks

Stevens07 · Post by **Stevens07** » Wed Jan 23, 2008 3:02 pm

I can't keep my foot out of the gas with the 93 tune..... so I'm sure I'll see an increase with the 87 lol

Seriously, both should yield better mileage?
Steven

Post by **mikel** » Wed Jan 23, 2008 3:13 pm

Stevens07 wrote: Seriously, both should yield better mileage?
Steven

Yes.