browning4x4

just curious if any of the 98+ guys running the 784's has played with any of the programmers(banks etc..) for power or fuel mileage ? what have yall noticed?

Tsaani97xj

Don't believe a programmer does anything beyond monitoring on our XJs. Only way to do any programming is with a piggy back as far as I know.

salad

+1

Only "chips" for the 4.0L are basically biasing an input signal like MAP. Gonna need more mods to do anything interesting...


BTW 99+ is 784s. 1998 and prior fit 703s

XJwonders

I installed 784's on my model year 99 but it was manufactured 12/98. Lol

salad

Be quiet lol. You know damn well the difference between build date and model year :P

XJwonders

haha indeed

98REDXJ2

i have 784s in my 98. got them cheap and used plug adapters

browning4x4

so no one has really played with the super chips or banks OB2 port options along with the 784's? was looking to see the differences made when the programming modes were switched from say towing to eco or eco to power/performance. im guessing there isnt alot guys look at doing other then the bigger tires and crazy lifts. curious if there was more to pull out of the 4.0. seeing the 2 spray patterns has me curious at what other things could make use run a little more efficient.

salad

There's nothing to do really. The 4.0 was so out of tuning that it was discontinued... It's not some derated engine.

Unless you tear into one of these engines and increase compression, force induction, or increase displacement it's a game of spend $600 for 3 HP at 4000 RPM.