Does Air/Engine temp affect mixture ?

[Moved On / My Own Choice]

Originally Posted by obiwan

Your explanation of Turbos makes sense ... would a Supercharger do the same? Which one would be more effective? I know some EFI cars have superchargers, Mercs etc., which boost a somewhat lower capacity engine. Although I don't recall ever seeing a supecharged motorcycle engine. Might not be practical.

Turbos and Superchargers do the same thing, via different means.

Turbos (and I'm oversimplifying for illustration) use a turbine (almost like a pinwheel) which is driven by exhaust gas flow to drive the "fan" which creates air pressure and forces additional air into the intake tract/combustion chamber.

Superchargers do the same thing, but instead of exhaust gas flow they are belt or chain driven. This IN THEORY removes all or some of the turbo lag (i.e. Turbos must "spool up" and start spinning before they can give boost, supposedly superchargers do not need that). I say IN THEORY because the motor still has to spin to produce the boost, and that can feel an awful lot like turbo lag (just for a shorter duration, and less often).

Originally Posted by obiwan

Because the EFI will always try and maintain stoich values the only way to induce more fuel (= more power without becoming too rich) is to induct more (denser) air.

Think we're on the same wavelength now ...

By George I think he's got it.

But there are lots of mays to induce more air.

Remove restriction points (in the intake and/or exhaust) and or jam more in (turbo/supercharge).

K

[mark883]

I betcha that later in the hot day, the FI map is trying to run the thing as lean as possible for emmisions, but early in the day on a cold start engine, the FI map has things richened up to a more ideal mixture from a power standpoint.

Granted, power will be down in the hot air, regardless of mixture, but I'm betting the map there is less than ideal, from a power standpoint.

Also does anyone know if the XL FI will drop a cylinder firing if it needs to cool off? I thought the newer BTs will do this if they get too hot, instead of richening the mixture. I think I read that in Enthusiast, in their FI explanation issue.

FI is great, but a lot depends on the mapping. I've heard some complaining about the new 96" in Electraglides w/ lower fairing being pretty toasty.

[Screw Loose Dan]

My understanding is that the Sporty EFI system is the same exact systems as the new BT's with O2 sensors. They use the same ECM's from what I've been told as well. So, my guess would be anything that applies to the BT's EFI system carries over to the XL's.

[Krayven Sumhead]

My '03 Ultra has the Delphi FI. Don't know if the new sporties are still using the Delphi system. There is an 'ambient air temp ' sensor that possibly could be going bad, but if it were the bike would throw a code. I suppose the sensor could be intermittently bad, but doubtful. There are a lot of variables. Check for loose connections (loose or corroded connections don't throw codes) and then go back to the 'stealer' and have it checked. A manual will give you all the information you need also.

[sportin_2007]

Obiwan,

Did you ever get your remap done, and if so...what map did you use? I've been riding the crap outta mine and twisting it WOT is cool. Now I need more power. I nailed it yesterday in great temps, and the front wheel was really close to coming up, but not quite yet. Maybe once I add another 10 HP with the stage 2, I will start to see that happen on roll on.

[obiwan]

Originally Posted by sportin_2007

Obiwan,

Did you ever get your remap done, and if so...what map did you use? I've been riding the crap outta mine and twisting it WOT is cool. Now I need more power. I nailed it yesterday in great temps, and the front wheel was really close to coming up, but not quite yet. Maybe once I add another 10 HP with the stage 2, I will start to see that happen on roll on.

G'day Sportin'

No I didn't. The dealer wouldn't entertain any downloads, in spite of the part number you gave me. They kept spouting they were waiting for a HD sanctioned map for this country. Prolly just BS to get me to buy a SERT.

In the end I just went with a K&N filter and the new Cobra fueler with the O2 connectors (Fi2000r-02). It's great, haven't been able to get it on a dyno yet and not sure if I really need to.

Now I'm looking at maybe fitting the RSR air/fuel gauge which will tell me if I'm rich or lean on the fly. Might be better for real world riding rather than the WOT readings from a dyno. I'll keep you posted.

Your bike seems to be going from strength to strength. Glad you are still enjoying it. Look forward to some pics or videos when you finally get some air under that front wheel !!