Okay, this question has probably been asked quite a bit but is there anything to be concerned with raising the drive idle with a tuner? My truck was running the stock 525 rpms in drive idle, which is seemingly too low, and it idled a little rough, with some noise occasionaly.

I raised up my idle 100rpms from 525rpms and is now at 625rpms on my X3 and the truck is running a lot smoother at stops and rolling starts. I've also noticed there seems to be a less hesitation from a stop. Only bad thing I would imagine possible from raising the idle up is that a bits a little bit would be burning a tad bit more gas. Aside from that, I love the deep throaty sound the truck gives off now that its idling higher, before it seemed like it was sipping on gas. I've heard Troyer sets his right around 600 rpms with his tunes which is pretty close to what I'm running now, but I've seen others raise it up to around 750rpms.

Question is, how high is too high to set the drive idle, and what did you guys set yours too?

 

Personally, I'd try setting my idle as low as possible. (Smooth idle, no hesitation on acceleration).

The reason for this is twofold:
An interesting thing I've noticed with my truck is that it does not "creep" in idle with the brake off. It's actually a bother when I'm trying to back up the last few inches to my trailer hitch. I have to tap the accelerator and then quickly step on the brake.

Just my opinion - Your mileage may vary.

- Jack

 

As I told you in the other thread, mine is at about 750. It will creep from a stop, which I actually like and use. We have a lot of stop signs and heavy traffic. So I let it creep as the traffic moves forward. I think the reason the tuners say to set it high is so you can flash start from a standstill without stumbling. This is when racing. Just a guess. I would not want mine any lower than where Bill has it, about 750.

 

Mine seems to be about 500 when the engine is all warmed up - and I did not change the settings Bill put into it. (However, one of my points in my custom tune requests was that I'd like to save on gas). No hesitation on acceleration from idle though.

The "creep" IS sort of useful, isn't it? My car does that.

- Jack

 

Well it wouldn't make sense to have a higher idle for racing, because when you race from a dig you usually preload the powertrain for a launch. For a rolling start that wouldn't make a difference either since it's in gear.

Just my perception though



I know when you have a really mean cam you need a higher idle so your engine doesn't die out but I haven't seen any F150's here with massive cams so that's sort of irrelevant.

 

I have been told that with the drive by wire that we have, you are better off not preloading like we were used to. That you are better off falshing it all at once. I don't race it, so have no idea if this is true or not.

 

one thing about a low idle: occasionally i've noticed that my power steering isnt quite as effective when it idles really low(its set on 600 rpm or so, and i can barely notice it). im running a level 3 canned tune waiting on bill's custom tunes. the next time i re-load a tune, im gonna bump it up to about 650.