ECM upgrade needed for slip ons only? - Page 2 : V-Twin Forum: Harley Davidson Forums

BlockHead96 · 07-22-2008, 12:04 PM

Then my bike must be "extra" lean as it's a Cali bike! All I am doing is freeing up the exhaust with a free flow pipe. So, the ECM notices the difference in back pressure and leans out according?

bacon225 · 07-24-2008, 09:40 AM

Quote:

Originally Posted by BlockHead96

Then my bike must be "extra" lean as it's a Cali bike! All I am doing is freeing up the exhaust with a free flow pipe. So, the ECM notices the difference in back pressure and leans out according?

Yep in a way it does not respond to back pressure but you have the right idea.
If you are OK with the lean running it will be OK to just put on the slipons. The air cleaner would be a different story the stock ECU can't make up for pips and and air cleaner with out some help.

ceraaa42 · 07-24-2008, 11:04 PM

When I got my 08 Ultra I just put on the Rush slipons with 2" baffles. It was fine, right up to the point the right one turned yellow from being too lean. It was fine the summer months, then in the fall when the air got cooler and heavier it became leaner and "taa daa" yellow. Glad it didn't hurt the engine as Harley probably wouldn't have covered it since it wasn't thier fault.

Some get away with it, some don't.

Chris

FatBobRob · 07-25-2008, 02:27 AM

C'mon already! can i do this? can i do that? Stop being a p#ssy and do it right!!!! My buddy told me he didn't want to touch anythig because he was afraid it would void his warranty and he figured he let the dealer fix all the heat related issues. Run the bike that hot/lean for 2 years and i bet many motors will probably have excessve wear and will probably fail a year or 2 out of warranty. ok.......The narrow band 02 sensors will compensate for freer flowing mufflers.......but,The motor is too lean from the factory anyway.Do yourself a favor and get some type of enrichening device and free flowing air filter. You will enjoy your bike much more because it will have more power and won't fry your balls. See if you can access the article by Joe Minton in a recent issue of American Rider magazine and see his take on this

08fxdlscoot · 07-26-2008, 10:27 PM

Without adding the AC upgrade, you should be fine. With the tight perameters the 02's work within, just adding pipes alone should be OK and the o2's will compensate. I would just keep an eye out for decel pop, which shouldn't happen. If it does, then maybe try installing the IED's or Xied's from Nightrider.

jwh2573 · 07-30-2008, 06:58 AM

bacon225 is absolutley right. Any mod that brings in more air is going to make the bike more lean in an already lean setting. Reducing the restrictions in a exhaust system or installing high flow air cleaners will do this. You may also find that after these types of changes your bike may still not pop on decell. The only true way of telling how your bike is running is to have it put on a dyno and gas anylizer to determing your proper settings. A less expensive way is to monitor your changes by installing a brand new set of plugs, pulling them out every 500 miles and checking them to see how they are burning. You may not be able to be extremley precise doing it like this but you can determine if it's way to lean or way to rich this way. I would recommend monitoring the plugs for couple thousand miles just to make sure. You can google for a spark plug burn chart and compare your results.

Chief101 · 08-04-2008, 07:48 PM

For what its worth, I ran my bike about 6 months with SEII slipons only. Had the normal decel popping, oil temp didnt change a lot, plugs still ran white. But, it ran ok and I didnt have any issues.
I then decided to go with the HD "race" download and HD/SE A/C. Very pleased with the difference, but it ran hotter, so I went with the PCIII. Very satisfied with the end results.
All the while, the shop manager at my dealer assured me that with the pipes ALONE, there wouldnt be a problem, and I never encountered one. Mines a '06. Newer bikes may be different.