1999 4.8 silverado

[2nsane]

1999 Chevy Silverado 4.8 Z71 4wd
OK I have not purchased the Preditor YET!
couple questions.
I have a intake and a Boarla XR1 Muffler

I am looking for the best possable MPG and TRQ if HP is a gain thats awesome.

With the above mods what kind of performance increase and MPG increase can I see on the three differnt tunes that the Pred offers?

[06MonteSS]

well... first let's start with the 3 tunes... which are actually only 2.... heh...

Diablo/Performance Tune - for trucks, it's made for 91 octane gas... so, you must use at least 91 octane gas in your truck if you want to use this tune. This tune offers the best performance due to the higher increase in timing/spark advance (and other parameters) of the other tunes.

(if you run 93 octane gas exclusively in your truck, then the tune can be tweaked more via a custom tune to take advantage of that - yielding even more power)


87 Octane Tune - as it states, this tune is made for 87 octane gas, if that's what you run... still an improvement over stock due to timing increases and a bunch of other tweaks, but not as much performance as the Diablo/Performance Tune for 91+ octane...

and the THIRD tune that you're thinking about, the Factory HP Tune - is only a copy of your stock/original GM tune - this tune is the same exact tune that came in your truck from the day you bought it... this tune is used if you do not want any of the diablo performance tweaks/enhancements of their tunes, and you just want to make adjustments to your stock/original tune.


so, having straightened that out...

on the BEST tune, the Diablo/Performance Tune for 91 octane gas, your gains would be about 25 hp and 35 lb.ft. of torque... depending on the quality of gas you use, your altitude of your location, etc etc, as that all comes into play. crappy gas = more KR, which results in more timing being pulled, which = less power... etc etc...

and obviously, the 87 octane tune would have less power, due to less timing and lower amounts of tweaks on other areas as well because of the lower octane gas being used...

[2nsane]

would those numbers be at the wheels or fly? and what kind of MPG's do you see? 90% of my driving is freeway 70mph with the cruise set driving 60 miles a day. See lev, using Shell 87. my main goal is to pick up a little power yes, but mostly some extra MPG's.
my buddy has a dyno at his shop so we will be able to see real numbers after he sets it up for me. just wondering before I splurge.

Dan

[05Z71]

Stay away from the Shell gasoline! Don't know where you are, but your best bet is BP/Amoco, Exxon/Mobil, or Sunoco. Shell has detergents in it that will T-TOTALLY fuck your shit!

As far as performance, I jumped up around 25-30 hp at the rear wheels with my set up, but throttle response is more of what you will feel. As far as economy, I went from 18-19 on the highway to anywhere from 22-24 on the highway. That is setting my cruise at 65-70, mainly flat surface, sea level, and a shit load of humidity. I live on the Texas coast so high temps and humidity are a regular occurence around here.

[06MonteSS]

yeah.. no shell gas...

and if you're only using 87 octane, you're not gonna get those numbers anyway... won't get THAT much more power with only the 87 tune and 87 octane gas...

the diablo performance tune and 91/93 octane gas is where it's at...

[2nsane]

Stay away from the Shell gasoline! Don't know where you are, but your best bet is BP/Amoco, Exxon/Mobil, or Sunoco. Shell has detergents in it that will T-TOTALLY fuck your shit!
.

No Sunoco or BP around these parts, we have shit gas like AM/PM and other places that charge you just to use your debit card, or Chevron and shell. there are a couple 76 stations.
its shitty cali gas. untill I can get stationed out of this shit state I am stuck here.

[08Silverado]

76 stations use to be amoco, not sure if they still are.

[05Z71]

Run the Chevron

[pheonix311]

I agree run the chevron. if you dont your going to be replacing shit you didnt know existed