Originally Posted by iclick

IED's and their variants (XIED's, etc.) work only in closed-loop mode, so they will not alter dyno numbers (peak HP and TQ) at all. Accordingly, they make no adjustments outside that range once you enter open-loop, which is above ~85kpa or 50-60% throttle and ~3500-4500 rpm (depending on year-model). They also may prompt the ECM to throw codes if they alter the closed-loop area too much, i.e. outside the limitations of the O2 sensors (~14.4:1), but AFAIK these are historical codes that won't prompt the check-engine light to illuminate, revealing themselves only if checked. Can anyone verify this?

IED's will cool the engine down a bit at idle and in the cruise-range by lowering the AFR, how much depending on the variant that you buy, but in the tests I've made on my bike by experimenting with two different tuners (PCV-AT and PV) this doesn't translate into a meaningful improvement. They also may increase part-throttle response, but gas mileage will take a dive when AFR decreases this much.

Other than that they do nothing, and if you plan on moving beyond stock to a full-Stage 1 or greater you will need a real tuner, or as a minimum the much-maligned (rightly so, IMO) and overpriced HD "Stage 1 download." Despite claims that they are not recommended for Stage 1 applications (including AC), I think they may work acceptably on some models. On others the open-loop area will run unacceptably lean, just as they would without IED's or a tuner installed.

I'm not putting IED's down, as I do think they have a market niche with value for some riders, but I think potential buyers should realize their limitations before jumping into a purchase. Again, if you want some cooling and part-throttle-response improvements and don't aspire to changes beyond a muffler swap these can help a bit in the two areas mentioned. If I'm missing any other aspect of operation they aid I'd appreciate any info.

Originally Posted by jjnoble

You're off track here, no one asked about any of that.

iclick, do you secretly work for fuel moto?

Originally Posted by mikedanben

Bought the XIED's love them on my softail. they keep the motor cooler and let you drive in a gear and "lug" rather than always shifting down gears at lower speeds. Yes, if you twist it beyond 1/4 you will want the air cleaner upgraded. I did that and it helped. But then i added the commander. Now I have all three (stock pipes) and love it. I will not take my XIED's off and it will be the first thing that I buy when I get a street glide someday. I live the low end fuel at the bottom of the gears.
Peace.
Jim

Originally Posted by frog13

Really, he is not off track and is just being very informative, hard to dispute anything he said. It's fundamentally wrong for someone to come on here and try to convince people the XIEDs are the cure all and you'll never need a tuner until you do engine work, just like it's wrong for guys to come on here and say you always need a tuner. The forum is to become informed and make intelligent decisions. You have to filter out all the crap and do good research, a lot of what is said on the forum is true, a lot is not. I can't put down XIEDs, I have no data to back my claim if I did, but the info here was pretty much common knowledge if you do your homework. Lots of guys add them at the same time as pipes and air cleaners then say how great their bike runs. Many times I have experienced seeing people add pipes to their bikes, actually lose power, but the extra noise gives the impression it is running stronger. Must be right? It's louder. Me, personally, I like to make sure my bike is running at absolute peak, not just good enough, so I will invest in a tuner and have it tuned. If you're happy with how your bike runs and don't care that it might run better and you don't want to pay to find out, then that is good for you, too. This XIED, tuner, dealer flash fight will go on for a long, long time .....

Originally Posted by iclick

IED's and their variants (XIED's, etc.) work only in closed-loop mode, so they will not alter dyno numbers (peak HP and TQ) at all. Accordingly, they make no adjustments outside that range once you enter open-loop, which is above ~85kpa or 50-60% throttle and ~3500-4500 rpm (depending on year-model). They also may prompt the ECM to throw codes if they alter the closed-loop area too much, i.e. outside the limitations of the O2 sensors (~14.4:1), but AFAIK these are historical codes that won't prompt the check-engine light to illuminate, revealing themselves only if checked. Can anyone verify this?

IED's will cool the engine down a bit at idle and in the cruise-range by lowering the AFR, how much depending on the variant that you buy, but in the tests I've made on my bike by experimenting with two different tuners (PCV-AT and PV) this doesn't translate into a meaningful improvement. They also may increase part-throttle response, but gas mileage will take a dive when AFR decreases this much. Have you ever used them?

Other than that they do nothing, and if you plan on moving beyond stock to a full-Stage 1 or greater you will need a real tuner, or as a minimum the much-maligned (rightly so, IMO) and overpriced HD "Stage 1 download." Despite claims that they are not recommended for Stage 1 applications (including AC), I think they may work acceptably on some models. On others the open-loop area will run unacceptably lean, just as they would without IED's or a tuner installed.

I'm not putting IED's down, as I do think they have a market niche with value for some riders, but I think potential buyers should realize their limitations before jumping into a purchase. Again, if you want some cooling and part-throttle-response improvements and don't aspire to changes beyond a muffler swap these can help a bit in the two areas mentioned. If I'm missing any other aspect of operation they aid I'd appreciate any info.

Originally Posted by jjnoble

Yes, he is off track. This is not an Xied/Tuner debate. The question was and I qoute: "My question is if I add a stage one air cleaner will my xied's still keep it running as it is now. I'm thinking of going with the Fuel Moto billet air cleaner."