Stock GM tune Vs 87 Tune

[VenturaI]

Totally stock 07 Avalanche 5.3, 7194 9R08.

I've been running the 87 tune for over 3 months now, LTFT's good. Taking the truck in for service, so the other day I went back to the stock tune. I imediately notice more low Rpm torque. WOT, not sure I can tell any difference. The stock tune also edges out the 87 tune by about 1 mpg.

What's up, I don't understand? My guess is that the stock tune is running more timing at partial throttle than the 87 tune? Predator only changes WOT timing correct, maybe modifying the stock tune would be the best solution?

Thanks

[gundog]

I would be interested in knowing what is actually changed form the stock tune in the 87 tune. However with my 2007 Yukon, I believe I get better mileage with the 87 tune.

[VenturaI]

Yea, comparing gas mileage is very difficult. When I first installed my 87 tune I thought I was doing a little better on gas, but looking back I think my driving style slowed up because I wanted to see a gain. I drive the same 20 mile (one way) highway route every day, when I went back to the stock tune I picked up about 1 mpg, same temperatures, same tank of gas.

As far as the low Rpm power, while monitoring KR on the stock GM tune I will see 1 degree of knock now and then when under high load, like lugging up a hill. The Predator 87 tune never did show any knock under the same condition. The stock tune just feels a little stronger. I don't see any knock with either tune under WOT, and I don't notice any difference between the two.

Has anyone had good results modifying GM's stock tune? Not sure what I would change other than getting the LTFT's correct and try to bump up the timing some while monitoring knock.

[mikel]

Everything thats changed in the diablo tune is changed in the 87 tune, but the 87tune gets a little less timing generally...

[VenturaI]

Timing at partial throttle would be one of the parameters that is modified in the 87 tune then?

[KDIXER]

i have an '09 Silverado 5.3 6l80E 4wd. I ran WOT logs with the 87 octane tune and and then I restored factory tune and logged the same parameters on the same stretch of road. The diablo 87 octane tune had 1.5 to 2 degrees less timing than the factory tune in all RPM ranges at WOT.

I also noticed that 0-60mph times were a tiny bit faster with my 3rd log which was the factory tune with the LTF's dialed in. Which required a -5% adjustment. I did the 3rd log to dial in my PE which will require a -4% Low rpm's and -10% high rpm's.

I am still debating if I am going to sell this thing or not. I am not completely sold on the performance gains from it. I will do a WOT log with the PE dialed in to see the 0-60 time.

I would like to see a WOT .csv file if anyone has one showing vehicle speed to compare 0-60 times. Silverado of course.

[VenturaI]

On my 07 5.3 Avalanche I ended up with the same thing on the factory tune, -5 on the slope, this was on a 40 degree day. I'm not 100% sure the diablo 87 tune is stronger than the gm factory tune, right now I'm giving the edge to the stock gm tune. I do like the ability to modify the factory tune, would be much better to be able to make transmission adjustments.

Could you tell any difference after adjusting the PE?

[KDIXER]

I have not really driven it enough yet. I plan on doing another WOT log this evening to see what it looks like. But to me, if it does not improve my 0-60 time, then there is no need to hang on to this tool. 0-60 is not a big deal to me but it is the only benchmark test I can do to see if I have gained anything.

[KDIXER]

I could not see any benefit after adjusting PE. I restored my factory tune and plan to sell the predator.

[aviraled2002]

I have a diablew tune on mine right now, I can tell you that it did improve my throttle response and the overall driveability of the truck. I also gained about 1.5-2 mpgs out of it. just my 2 centavos...

[mikel]

Timing at partial throttle would be one of the parameters that is modified in the 87 tune then?

No...

[gump2388]

u cant always go from a 0-60 run. the new stuff dont get going good until 60. even at a raceing look u shouldnt look at it like that. hows the driveabilty vs stock. theres alot more things to consider than stupid 0-60

[KDIXER]

theres alot more things to consider than stupid 0-60

I agree but the bottom line is I want a noticable difference. And when I could tell no difference, I started comparing 0-60 times.

I just really do not understand the tuning of this truck. I know it has plenty of power, it just bogs itself down. I honestly think it pulls harder from a redlight at steady 3/4 throttle than if you drop the hammer from a stand still. It is hard to explain but it seems to put you in the seat more.