Lack of engine decel..

[Nemesis]

I recently installed the Arrow PCM and noticed a significant change in off throttle engine braking.. Where as previously when I let off the gas, the engine would start engine braking, not it just seems to coast, with the RPM's slowly dropping... Has anyone else experienced this or know what is causing it?

[darbgnik]

Just a guess, but maybe adding fuel to create the decel burble might reduce engine braking?? Only a guess though....

[supersnake]

Is your car stock? Have no answer for the engine braking, But what other things did you notice after the install. Just got mine yesterday and haven't installed yet.

[Nine Ball]

I haven't noticed it, because I only use my brakes to purposely slow down.

[Dman]

I haven't noticed it, because I only use my brakes to purposely slow down.

Yea, sorry, me too, just a good habit that is too engrained. But, with the Arrow I do let off in gear when cruising around, to just hear the popping, silly, but it sounds so cool, makes me laugh everytime. But I can't compare to before, I don't "jake brake" my cars.

[Malu59RT]

The lack of engine braking is in fact from the Arrow PCM. As someone else suggested, adding fuel in decel to create the pop is the culprit.

[Nemesis]

I haven't noticed it, because I only use my brakes to purposely slow down.

Oh you don't just compression brake to a stop?

[ViperPete]

I like to downshift to 1st when around 50 to slow down fast!











No not really.... Cant wait to get my PCM... maybe for my birthday!

[Steve M]

Just a guess, but maybe adding fuel to create the decel burble might reduce engine braking?? Only a guess though....

This is the issue right here...you can use HPTuners to enable/disable DFCO (deceleration fuel cutoff). I've played with it on my Gen 4, and I can get it to pop at any engine RPM and vehicle speed, but you lose engine braking because of it.

People bitched about the decel burble not being there with the Gen 4 Mopar PCM, but they didn't realize that this is the byproduct of having it, and why it is only active below about 1,500 RPMs or so in the stock calibration. You don't get something for nothing in this world.

[JonB ~ PartsRack]

this is the issue right here...you can use hptuners to enable/disable dfco (deceleration fuel cutoff). I've played with it on my gen 4, and i can get it to pop at any engine rpm and vehicle speed, but you lose engine braking because of it.

people bitched about the decel burble not being there with the gen 4 mopar pcm, but they didn't realize that this is the byproduct of having it, and why it is only active below about 1,500 rpms or so in the stock calibration. You don't get something for nothing in this world.

exactly!

[ViperPete]

Id rather the car coast better... But that's just me.

[rlhay2]

Once upon a time...in a world where carburetors where still in widespread use, we would turn up the idle screws on bikes/cars so that you could never "dead throttle" it into a corner.

The lack of engine braking is a good thing. Brake pads are relatively inexpensive.

[TrackAire]

Which system shoots more flames out the exhaust tips??

[Steve M]

Which system shoots more flames out the exhaust tips??

The one without cats.

[LmeaViper]

lol..awesome

[ViperDog]

I don't want the popping but that's something that can be easily tuned out?

[Steve M]

I don't want the popping but that's something that can be easily tuned out?

With the Arrow PCM, it is what it is...I don't think they are doing custom calibrations at this point. It is something that is easy to tune out though.

[TrackAire]

The one without cats.

Understood, not running cats now. Which would would shoot more flames, the program with the decel popping (the new Arrow update) or the original Mopar pcm? Or does the popping have nothing to do with the amount of flames exiting the side pipes?

[Steve M]

Well, considering the Mopar PCM cuts all fuel (that's what DFCO does), the Arrow update should shoot more flames. The exhaust popping is the unburned fuel igniting in the exhaust...cats arrest those flames, so if they aren't there, they'll just keep on going out the back (or sides in the case of the Viper).