I have a 2003 5.4v8 I'll be towing a 7000lbs trailor. when I program my computer what shift point rpm's should I change to for the 93 octane I also understand I will need to increase the Rev limiter by 100 rpms above the shift piont. I dont want to end up hurting the motor. I can raise or lower the rpms by 100-500 at shift pionts same with Rev limiter.

 

The Hypertech III should have a tow-preferred setting on it. Use the pre-set program without making any changes; all the calculations for rpm and shift points should already be on the program.

 

jpdadeo thanks for the help this is new to me.

 

where would you find that preset option i.e. what buttons do I need to push to find it?

 

I think he,s talking about using the preset 87octane or 93 octane settings and not ajusting the rev limiter and shift points if you do ajust them that only applies when you are WO throttle anyway normal driving you computer works off one of those preset settings from Hypertech mine is a dual fuel when you plug it in it should ask you what octane setting you want then do you want to change rev limiter or shift points .

 

Ok so maybe I went about it wrong, I think I will go back and just do the performance tune and leave the other stuff be?! It didnt seem like a big gain the way I did it and when you drop to a lower gear the truck bogs a little.

 

one thing you do need to keep in mind if you do ajust the shift points you must ajust the rev limiter atleast 100rpms adove your shift point rpms now it wont let you ajust rev limiter for each shift point so before you plug it in figure out your shift point rpms and ajust your rev 100 above all the sift pionts thier directions are lacking info in this area I called Hypertech they said for towing they would only change the first two shift pionts to no more than 300 rpm and raise the rev limiter to 400 but they said try the preset 93 octane first. if you did not change your rev limiter when you plug it back in and it reads codes from your truck I bet you will get a code 1270 the 1200 codes are rev limiter you hit it these motor's tach out at 5500rpm your computer will trip the code at 4900-5200 depends but clear it. and start watching your tach dont get above 5000

 

I tried again last night just used the 93 octane and adjusted shift firmness only! WOW what a difference! This truck is like a rocket ship, thanks for your help!!!

 

anytime glad I could help

 

I have a 99 scab with the 4.6 and a 5 spd When i instaled the hypertech 93 octane the engine would ping around 3800 rpm So I changed to 87 and the pinging stopped. the power still comes on at 3000- feels like a rocket But i guess the question i have is how safe are these things will it kill my engine?

 

I have a 99 scab with the 4.6 and a 5 spd When i instaled the hypertech 93 octane the engine would ping around 3800 rpm So I changed to 87 and the pinging stopped. the power still comes on at 3000- feels like a rocket But i guess the question i have is how safe are these things... will it kill my engine?

 

Did you have 93-octane in the tank when it pinged?

 

jpedadeo is right if you dont have 93 octane it will ping and if the gas in your area is not good. some stations have better gas than others I have run into that here we have a new flying J its bad to water in the gas

 

I cant get 93 here but the box said "premium" so i had 91 w/oct boost must not have taken into consideration the 25 gal tank with oct boost for a 16 gallon import gas tank.......

 

MAF104 91-octane should work just fine without octane-boast. Depending on where you live (east cost / west coast) the quality of gas varies greatly but a good 91-octane should work without pinging.