Can anyone shed some light on the meaning of the 'Custom Changes' option when installing a PPE tune? There are four options to choose from: 1. No Timing Added. 2. No Fuel Added. 3. No RPM Increase. 4. No De-Fueling. I'm not sure what to choose and what outcomes result from these parameters. Anyone?

Thanks in advance to everyone. This site is amazingly helpful.

IMO only screw with the de-fuel. I told mine not to de-fuel when shifting.

I wouldnt mess with any of it IMO!!

ttt... I have the same question, maybe someone will see it and be able to give an answer. No offence to the other posters but we got progammers so the we can mess with our trucks

I know what your saying, but I have never messed with mine. I don't know if I would change any of those settings out of fear I would royally screw something up.

I messed with mine a littlke when I firsy got it, trying to increase MPG's. So in the settings it asked "No Fuel Added" and I said yes. I figured if its not dumping more fuel in I would save. Well I left it like that for about 10 miles, cause crusing down the hiyway going up and down hills, the truck was doing a lot of down shifting from 6th to 5th, as if it has a lot less power. I changed it back to add fuel and the problem went away and haven't messed with it since. By the way this was all done on a level 2 tune.

...thanks for all the replies. I'm just tryin' to figure this gadget out.

Can anyone shed some light on the meaning of the 'Custom Changes' option when installing a PPE tune? There are four options to choose from: 1. No Timing Added. 2. No Fuel Added. 3. No RPM Increase. 4. No De-Fueling. I'm not sure what to choose and what outcomes result from these parameters. Anyone?

I am not a tuning expert but maybe I can help a little.

Tuners make more torque and HP resulting in better efficiency by changing parameters such as fuel injection timing, injecting additional fuel, increasing the factory rev limiter along with others including increasing boost pressures.

That being said, if you are just looking for a little more power for a daily driver don't mess with any of the "Custom Changes." If you restrict the tuner from changing timing or fuel you might as well sell the tuner and run stock IMHO.

If you are racing or pulling you can risk your tranny and turn off the de-fuel. The de-fuel cycle, which is intended to prolong transmission life by not shifting under full power, will put more power to the ground during shifts.

You could limit the RPM to the stock limit if you want to be very conservative, however there is not much risk associated using the PPE parameters for rev limiting IMO. Increased RPM allows the tuner manufacturers to claim higher HP gains. HP is a function of engine speed (RPM) and torque, so by increasing the RPM at a given torque, they can claim more HP increase.

Thanks for your reply...I appreciate your thoughts. 3 outta 4 are starting to make sense to me. As far as you know, does allowing PPE to alter injection timing carry a similar moderate risk for engine damage as allowing for slightly higher RPM's? Thanks in advance.

The stock injection timing takes many things into consideration one of which is to get the cleanest burn possible while making reasonable power for emissions certifications.

Again my limited understanding is: By advancing timing, much more power can be made even with the the same amount of fuel being injected. The advanced timing increases combustion temperature which increases power but also increases NOX and CO emissions. Risk of damage to the engine is small on the lower levels, as you turn things up more you take more risk of damage to components such as pistons. You indicate running level 2, from what I've been able to determine that is fairly conservative tune for all parameters.

Don't know if you noticed this line in the tuner instructions (page 14 referring to the Custom Changes)? "Note: We recommend not modifing these settings if you want maximum performance and fuel economy. (Exception when stacking the PPE Xcelerator)"

Dale-

Thanks you very much for all your discussion.

If it helps at all...and i dont know if yours is the same way....but on my PPE tuner NO meant YES and YES meant NO.

So say on level 6 it would say NO defuel as the default setting. If i changed that to YES, then it turned off my defuel...

I had the same question when I first got mine,so to answer my confusion I called them.The guy I talked to at PPE said when that screen shows up to just hit yes and move on.

heres an email from ppe:

Here is a bit of info on the Custom Changes menu:

PPE Tunes include all three Timing, Fuel, and RPM. There are some circumstances that might require one of these to be turned off.

Timing added – improves power output by increasing timing (not used when spraying nitros oxide)
Fuel added – improves power by delivering more fuel (more fuel equals more horsepower)
RPM increase – increases engine rpm under load
De-Fueling – reduces full engine power to the transmission during gear changes (this is only adjustable with the Hot+2ET programmer)


I hope this info helps out.

Best Regards,
-Eric Sempson
Sales / Dealer Development
Pacific Performance Engineering303 N Placentia AveFullerton, CA 92831　
Office: (714) 985-4825 x100Fax: (714) 985-9907www.ppediesel.com (http://www.ppediesel.com/)