Truckcustumizers is awesome! Ordered mine from there and was to my door in 2 days. The intake I just ordered took a couple days longer but there was a weekend in there. Good to deal with.

 

Hey thank's a lot !!

 

Thank' Captain

 

Well I hold a degree in Shade Tree Machanicin' (un-accredited) for almost 30 years and I can tell you that even back in the day when we'd advance timing by just turning the distributor a bit, if you did so and not stepped up in octane, you'd knock and ping like hell, especially when towing.
But you go ahead and run that new SC on a performance tune with 87 octane fuel AGAINST the documentation of the manufacturer of said tuner.
Let us know how you make out...

 

ehehehehe

 

I was an ASE certified mechanic for many years. Ive been wrenching and building high performance engines for *OVER* 35 years

Its call detonation (or pre-ignition) and its because of the increased load, but advancing the timing to the point of causing detonation, then feeding it premium fuel, will not increase performance.

If the tune advances my timing, then yes, I will need premium fuel to prevent the detonation, but that in its self, will not increase performance.

Regards,

-Chris

 

Mine is bigger than yours. is that what we are doing here?

Just get your tuner and run basic 87 oct gas with the perforamnce tune if you think you know it all. But wait, manufacturer reccomends 89oct for sole reason of pre-detionation that I have personally seen happen on a few Hemi engines that have run 87oct on stock form tune, so make sure you run min. of 89oct.

My mustang lost 12rwhp ON THE DYNO when we pulled 2degrees of timing out. Then we added 2 degrees over stock and gained 14rwhp. So, for 4degrees of timing, there was 26rwhp difference and you think advancing the timing does nothing? I had 93oct premium in for that session and knock started at about 6degrees advancement and so did power loss, where as before with 91oct, the pre-det had begun at just 3degrees of advancement and there was power I could not obtain due to lower grade gasoline.

Besides, 93oct burns much cleaner than 87 or 89 and for that reason, I want 93oct in my ride.

 

Well, I'm neither an engineer or a mechanic but, I did stay at a Holiday Inn Express last year. Just havin' a little fun guys.

Here's a layman's theory as to why my mileage increased by almost 1.5MPG with 91 Perf Tune and 93 Octane over 87 Tune and 87 Octane... With my current tune, I might apply 20-30% TP to get my moose to climb a 25% grade with ease. With 87 Octane and 87 tune I'd have to apply 50-60% TP to get the same MPH to climb the same grade. I believe the engine is working so much harder with 87 octane to accomplish the same result and, it's much less efficient burning of the available fuel thus my mileage suffers.

Feel free to tell me where I going wrong with my theory. (see my sig line...)

(I guess this isn't as "on-topic" as I thought because the initial discussions was using 87 octane with a 91 Perf tune and KR (pre-detonation))

 

My recent testing with the SC shows some interesting results. I have been running the 87 tune with 87 octane (yes, even at 4700 feet altitude, still needed 87 to prevent knock) for nearly a year. Here we get 85 octane as the low grade, but I heard the truck ping uphill with the 87 tune...hence me buying "mid-grade". No real mpg change from stock but drivability much improved. The truck is much more responsive. It won't spin the tires (yet), but it's a 4.7 and I have a locker in the rear (very good for snowy days).

I switched to the 91 tune and 91 octane last week on a trip back from Las Vegas and can tell you I am getting 1-2 mpg better now, even in the city?!. I had the SC datalogging on my Vegas trip and noticed the truck would only pull about 11-12* advance when at 100% load going uphill on the 87 tune. With the 91 tune, it would pull 23* advance at 100% going uphill. I also noticed the ignition advance stayed high longer than with the 87 tune. On the 87 tune I could see 45* advance, but that was around 50% load. Once the throttle started opening for hills the advance fell off fairly quick. On the 91 tune, I could still see 30* or more advance even up into the 70+% loads. I also noticed fuel flow was slightly lower but I do not remember specifics. Wish I'd had my laptop plugged in to record the data now... The ignition advance seems to be the key to me. I give two thumbs up to the 91 tune.
MDSBigPapa, I agree. I thought my truck was working harder going uphill on the 87 tune also.

 

Timing Adv on 91 tune other than stock hemi ram.