factory tune vs. 87 octane&diablo tune

[squall8158]

I have a 2004 Silverado with the 5.3L. Predator U7193. I took my truck into the shop to get some work done a returned my truck back to stock. had to wait a few days for things to come in so i was driving around town and highway in stock form for a few days. I was getting 16mpg in town and 19-22 on the highway. So i tried to make all my tranny changes with the factory stock tune setting but i cannot get the rev limiter to push past 5,900rpms and i have it set so that at WOT it shifts at like 45mph and its like 6,100rpms or so. so that pissed me off cause it wont shift unless i let off the gas. So i installed diablo tune. am running premium 91 fuel and at best am getting 14mpg in town and 16-18 on the highway. i did a log today and i am suppose to adjust my slope -1% so i dont see me getting those mpg back. also way less torqe on bottom end from a dead stop. its very frustrating. should i try the 87 tune and see what i get? cause i know that the Diablo tune timing is way high. thank you much.
Mike

[squall8158]

?????

[mikel]

sounds like you need to lower the WOT MPH shift point, and let it use the rpm only, works well.

[squall8158]

any idea of how much i should turn the WOT MPH shift point to? cause like i said 5,900 rpms and it limits out even thou i have the rev limiter +700. is it just because the factory stock tune wont allow higher then 5,900? thanks

[remowil55]

Squall8151, i feel you pain, i lost about 5 mpg the day i hooked up my predator to my truck, never have got it back and have got no help from DiabloSport. No matter what tune i put in it the DIC in the instrument panel always says "reduced engine power". Have burnt up one tranny so far, and when i put in the 93 octane tune or the sport tune my truck runs like a slug. I just about to the point of taking my truck to the chevy dealer and having them program the stock tune back in, and do the gear change for me. Which my predator can't do without putting incorrect information to get the tire size right. Sorry you having these problems, i hope you get better help from these people than i have.