Rush 2 in.slip ons

[bobl]

I have a 2008 flstc. I put Rush slip-ons on. And it is running good. That’s all I put on. Had It dyno and came out good. I pulled the plugs out. The rear one look great but the front turned out a little on the white side. Thinking of replacing the stock filter with a k&n. You think it will run to rich? Let me know;

[tommyglide]

Hey bobl, it certainly won't be running too rich, too lean maybe. DId they do an afr reading for you when they dynoed the bike and what were the readings? There has been lots of debate about whether a stage 1 (mufflers and intake) needs a factory download or other fuel enrichment but the general consensus is no, however the target afr for the ecm is still 14.7 to 1. Good for fuel economy, good for heat, good for pinging etc.

[cntrhub]

I believe some emission A/Fratios are cruising at 17:1. That is crisp lean. And I think cars also may run that cruise range until the throttle is applied and then it is back to WOT the throttle and you can see an A/Fratio down to 11:1 A/Fratio and that is flat on the floorboard fat rich.

So when you bring up the map change because you change a muffler that is still quiet and an air cleaner that just caused the same even to happen a tad quicker, where did you need to raise the A/F if she is just as clogged as she started out?

[bobl]

I just ran across my dyno paper. And the air/fuel is reading at startup around 14.6 1200 rpm. at 2400 it goes to 13.7 stays there all the way though. The tec. Said I need to just leave it has is. What do you all think

[cntrhub]

It doesn't get any better. 14.6 is lean/mean just about if you are going to nitpick a 10th either way. You want that much lean on the low speed, yes.

Running steady up 13.7 is 12.1 could only get fatter and send the power off as to cools the pressure down. So, that is more or less pretty mean running.

It is back to you to say, yes it stumbles, no it lifts the front wheel I am sorta scared to throttle up or it is a slug and the guy cannot goose it any better is I bet that bike runs awful sweet.

[frisco-rigid]

Ooh boy


Ok, I set-up my motors to run anywhere in the 13's but even a wee richer off idle..

Off idle, taking off, is a very common place for detonation/pinging cuz you're putting the motor under the most load of the day..
Add a healthy honey a hot day and a grade you almost invite a ping or 2..

That's why it was always advised to be a wee fat off idle..
It is easier for us with carbs to make those fine adjustments..

If you choose to leave it be you will prob be ok, keep your R's high and don't lug..

[bobl]

Thanks for all the advice. I think that I will take your suggestions and just leave well enough alone.

[mstngjoe]

Here's a before/after dyno sheet of my '07 FXSTC. The only change was the Rush 2.0 slip-ons. Note that the a/f ratio was virtually identical before & after the muffler installation. So.....either the ECM made the adjustment or one wasn't necessary.