ok guys my buddy needs some help.....he has a kenne bell supercharger on his V8 jeep grand cherokee 4.7L, he has bored it out to a 5.0L, put a set of cams in it, forged and ceramic coated pistons, H-beam rods, ported and polished heads....completely built engine.......his is running about 12-13psi with a meth injection dyno showed his air fuel ratio at 12.5 and he would like to lower it to 11.5 or so to get it to a safe ratio

does anyone know someone who can tune his truck?

It's not going to be easy, but you'll need to splice in something like an SMT-6, or an ARC1 to control the A/F ratio. A lot of the hemi guys with turbo's are using these units with good sucess. As far as I know the ARC1 is an easier unit to use and just controls the A/F, where as the SMT-6 can do a lot more, but it more complex to setup right. I have no experience myself. Coltsteele might have more of an insight, though I believe he just has a flashed pcm.

if it has an adjustable fuel pressure regualator maybe jump the pressure up a bit

Btw, where did he get the kenne bell for the 4.7L, I don't see it listed on their webpage, heck they still say the hemi blower is coming soon... from 2003. ;)

Btw, where did he get the kenne bell for the 4.7L, I don't see it listed on their webpage, heck they still say the hemi blower is coming soon... from 2003. ;)


it's a kenne bell 2.2

if it has an adjustable fuel pressure regualator maybe jump the pressure up a bit

he's running all the fuel he can, maybe look into more pressure......has a boost-a-pump for extra fuel......he's going to bump the meth shot a bit to get the computer to dump more

He doesn't have the option of adjusting fuel pressure if he's got a stock fuel system. The Mopars are all returnless systems. What is his current setup?

I'm running a 4.7 in a Dakota with a Vortech FMU with an 11:1 disc in it, 55lb Super 60 injectors, KRC tune on the PCM, a custom return system, Walbro pump, Aeromotive Adjustable regulator.

This setup has yielded the safest results on the A/F without dumping so much fuel in vacuum/part boost that you get the stuttering.

I've got a Split Sec VC2 talking to the MAP sensor to keep it from going nutts too.

Kenne Bell quit carrying the superchargers for the 4.7 a year or so ago because of all of the tuning issues with the units. There are only a couple of guys running the supercharger without issues.

as far as I know he has an ajustable fuel regulator, stock pump, upgraded injectors, kenne bell computer, and as much reflash on the stock computer(no tune, just flash) as he can, with a meth injection to help richen things up a bit....i will ask him tonight what all he has exactly

what is your A/F and how much boost are you running?

A/F is 11.0-12 spiking to 13 right at 6500rpm. So I'm bangin gears around 5800 rpms at the moment.

Boost is anywhere from 12psi to 17psi depending on what pulley I'm running.