JT76

Besides changing the ratio to 4.9 or whateve4r on the predator , dont you have to change the tire revoloutions per mile or something cause we just de tuned my friends car and we need to change the speedo back for 4.10's and it isnt working....what do you set it to? .................................................. .........also with just the "factory HP tune" (not canned diablo tune) you can run 87 octane right?

mself52

dont mess with the revs per mile that wont change b/c of gears that is if you have tires that are bigger diameter then stock....for gears just change the gear ratio to 4.09 if you have 4.10's and you will be fine and speedo will be correct

mself52

and to your other question that is correct with the tune from the predator if you dont advance the timing then you still use 87 octane but TRUST me use 93 octane and advance the timeing 10% and you will not be disapointed....

JT76

dude something must be messed up then cause i changed the gear ratio and its not working

mself52

well do you have the correct size tires in the rear of your car and are you sure you got 4.10 gears?

JT76

yeah i had the speedo and everything correct and i took the diablo tune off the car and as a result all the parameters were reset so i just need to adjust it but it isnt working, should i try to reset it and try again? maybe its just a glitch

mself52

sure try that and here is the rev per mile should be
for 245/45/17 its 809.9 revs per mile and for
275/40/17 its 810.6 rev per mile and make sure gear ratio is 4.09 and not 4.9

JT76

its still not working[:@][:@][:@][:@][:@] any other suggestions? I just go to change it to "4.09" and install the tune, take it down the street and i will be going at about 30 and it will say im doin 50! WTF!!!!!!!!!!!!

mself52

what do you have someone following you or what? how do you know how fast you are going without your speedo? if your revs per mile are correct and your gear ratio is correct and speedo is still off then i dunno man... reset the **** back to factory....unplug the battery for 15 mins hook it back up and try again... if that dont work i dont know what to tell you sept maybe something is wrong with the speedo

JT76

alright heres something bizzare.......i went and re- installed the factory "backup" tune and unpluged the battery etc. and then i re- installed the canned Diablo tune, just for the hell of it, and the gear ratio worked fine! I then tried to install the "factory HP" tune and selected the option to "save parameters" thinking it would hold over from the diablo tune, but to no avail. The gear ratio will not change to 4.10 under the "factory HP" tune only under the Canned "diablo" tune.....what now?[:@][:@]..................the diablo tune sucks so i DO NOT want that!