Help with PCIII

[RocketCowboy]

I have TOR and cat bypass and K&N, with the PCIII I am getting 28 mpg and don't ride that hard. I am also having problems with idle not returning after throttle shutoff sometimes. I need a good map that will give decent mpg , I don't care about optimizing power as it has more than enough for me with any tune. I like the PCIII for the elimination of the popping on decell, but other than that it is way too gas thirsty now.........what should I do to get back to decent mpg, 28 sucks!

[vonbonds]

I am wondering if all PCIII maps are created from the 20050 as a base which is for a stock pipe with cat setup. It seems all maps, even the zero map (no motifications) destroys fuel economy. I have seen other motorcycle boards and haven't seen them complain about fuel effeciency the way we do with our beloved Rockets. I have been slowly adjusting my PCIII map from the base of the zero map. Right now I am at -5 on all settings except for 0 RPM so I can keep the bike from farting. I get between 28-30mpg with this setup. I will keep incrementing it slowly until I get to about 32mpg then quit. I don't want to make the bike so lean it will hurt the motor.

[RocketCowboy]

Thanks Vonbonds

I guess most of the PCIII users are mostly looking at max HP. I thought you were going to take your PC off and sell it? I would think we could use it to get rid of the popping and still maintain decent mpg. If we get close to stock mpg I wouldn't think it would run too lean or the stock set up would be too lean??

[vonbonds]

By the way I have the TORS + catbypass + stock air filter.

[vonbonds]

The popping on decel was driving me nuts so I put it back on. I am just hoping to get to 30mpg.

[straightline]

I have map 20055
Stock air cleaner
Mad dog exhaust with empty cat(put cat back on-too loud with bypass)

I run zero map and get anywhere from 28mpg when I run hard and 38mpg when I ride with my HD pals(ultra conservative riding)

With the O2 bypass no popping on decel and it runs great.

If the map is too rich you will have problems with the idle being too low. If you run it too lean it seems to idle faster(idle wont come down when you shut throttle off)

I have talked to Dynojet to no avail. I will keep it on till something better comes along.

[miketango]

I am ready to pull the trigger on a PC III. I have a few questions. I have MadDogs, Cat bypass and K&N filter. Has any one had their bike put on a dyno to tune the PC III? I have some popping and it seems like it leans out when the throttle is closed. What do you all think who have this set up? The sound that I am talking about is when you rev the motor and let off it seems like fuel is cut off completely. Not much sound just air. At times it can sound like the baffels are loose. I have checked every thing and all is tight. I think a PC III would correct this. I think all of the Rockets make this sound but they come so quiet that it isn't as noticable. I hope that my rambling makes sense.

Mark

[Toystoretom]

RocketCowboy said:

I am also having problems with idle not returning after throttle shutoff sometimes.

Go to Triumph tune 20054 and use that with the PC III. I don't know what Triumph tune you are running but I use this and it helps the bike to idle down quite a bit. It won't help your gas mileage.

My theory on the popping is this: If you have some sort of aftermarket silencers or TORs you are hearing popping that was there all along (with the stock mufflers) during decel. The stock mufflers are so quiet it covers the popping up. If you listen closely and focus on it... you can hear it.

The crank is so heavy that when you close the throttle the engine doesn't drop rpm's very quickly, and you notice this in the lack of engine braking during decel with the throttle closed. Because of this the engine is able to draw a substantial amount of air past the throttle plates and the ECM cuts fuel delivery. Now you have a lot of oxygen with a little leftover fuel hitting your very hot headers and you get some explosions in there... ie popping. The PC III adds fuel during decel so you get combustion in the cylinders so not much oxygen hits the pipes, so no popping. Triumph possibly leans it out to keep the air clean (let the cat deal with unburnt hydrocarbons) but the good folks at PC III don't care and they shoot some fuel in there.

Maybe... if the Tuneboy program ever gets up and running you could just add some fuel during decel to kill the popping and leave the rest of the curve alone to keep the gas mileage.

[miketango]

So has anyone had the PC III tuned on a dyno?

Mark