Choosing the right canned DynoJet map

[PC_Hater]

The precision that EFI gives us leads to the notion that unless everything is 100% spot-on terrible things will happen to our motors.

Have a rummage through the old Microsoft HTT and search out any Dyno Runs on bikes with carburetors. My god! (Merde alors! For those that prefer not to blaspheme.) Runs acknowledged to be really good are all over the place on the AFR!

What do we conclude from this?

A softly tuned big motor is very very tolerant when it come the actual AFR.

I have been twiddling and tweaking DynoJet maps for my 88" with Andrews TW21G cams and Supertrapp 2:1 for some time. As far as I know the TW21 is the mildest aftermarket cam you can buy. I only went that route because my 1999 FLTRI was blessed with the poor quality ball-bearing cams. That's why I got the bike cheap. Adding power was not the objective. The Harley FL platform does not play nicely when given lots more power to cope with - it barely handles the standard power that Harley-Davidson chose to give it. 

My bike has the HD Stage 1 download. This was a major improvement but still not right. Hmm. Wallys Cycle World sold me a DynoJet PowerCommander III USB for a very good price thank you. But which map to use?

The bike was sort of OK with just the Stage 1 download but now I had the ability to twiddle and tweak to my hearts content I did.

There has always been a loud pinging rattle at low rpm with low throttle opening. Thrash it and there are no nasty noises and no problems. Being a cautious soul I looked at all of the DynoJet 2:1 options and always chose the lowest amount of additional fuel to create my "Conservative Map". The bike ran great apart from a definitely unpleasant clatter in the 1750rpm to 3000rpm range with a very light load. Whack the throttle open and no problems.

Hmmmmm. Much surfing lead to the possibility that the timing was a bit too advanced. HeadQuarters had a timing map for big-inch motors with a fair bit of timing retard. Hmmm. So I put the retard into my Conservative map. It wasn't perfect but a lot of clatter went away - and the motor ran a bit hotter.

Hmmm.

I had another rummage and because there are so many different DJ maps to choose from I decided on the Supertrapp 2:1 with Stage 1 download and 21 discs. I have 10 discs and the TW21G and the Stage 1 download. So I downloaded that.

Hmmmmm.
God awful clatter is effectively gone. Conclusion: not a timing problem but a lean problem.

The exhaust note changes with every different download I try,
The bike will go on a dyno soon, but meanwhile the lesson is this:-
Try the closest DJ maps for your bike. EFI has lead us to believe that unless the fueling is 100% accurate terrible things will happen. Not true.

If you are building a 'hot' bike none of the above is applicable. But for a nice bagger build the message is: "Don't Panic!"

[Don D]

Do the heat cycles and take it to a tuner, right away, that understands heat management and has the cell equipment to do that.

[PC_Hater]

Will do.
BUT the first class pain in the arse is the closed end cap on a Supertrapp system!
The bike will get done on a dyno with individual fueling and timing for each cylinder, but that waits for Supertrapp to reply with the part nos for the 2007-2008 downpipes with O2 bungs.
Plan A is to fit those downpipes and ride to the tuner so he can plug the sniffers into the downpipes and life is easy.

[CrazyRay]

PC, thanks for the info. I am gathering data for the eventual upgrade to my '99Rk. I have a question. I know you said you have done a lot of fiddling, but with the settings, how far from your "starting point" did actually end up with the pc III? Or, in other words, did the efi really need that much adjusting to justify a pc III, or do you think a DFO type device would have gotten you there easier? Or have you already adjusted it past the limits of a DFO?

CR

[PC_Hater]

CrazyRay
A DFO might well have been all that was needed. But I'm in the UK, so if the DFO isn't quite enough that is a shed load of money wasted... And the DFO doesn't let you change the timing, it allows you to ADD fuel only.

Because my TW21G and Supertrapp 2:1 with 10 discs and a closed end cap to keep the noise down isn't what you would call radical I suppose a DFO should work.
My Plan A is when rebore time comes to go straight to 95" or more, perhaps a DFO will work, but with the PCIII as long as you can find someone who knows what they are doing with a Dyno it WILL always be better than what a DFO can do.

But don't abandon the DFO just because a PCIII is more precise.
Look at the carb dyno runs and how the Air Fuel Ratio is all over the place yet they are still considered bikes that are tuned properly.
I'm the sort of old fart who likes things done 100% perfect. PCIII allows that, DFO doesn't.

I was twiddling and fiddling the PCIII more than I needed to.
The bike ran reasonably with the HD European ECU.
It ran better with the HD European Stage 1 download.
It runs very well with the Dynojet canned map for a Supertrapp 2:1 with 26 discs, a stage 1 ECU and HD cams. Mine has 10 discs and TW21Gs. The TW21 was making me unnecessarily paranoid.

If you do go to a PCIII, you MUST have each cylinder tuned individually for fueling and timing, otherwise you may as well have gone for the DFO and seat-of-the-pants.

[Don D]

It would not be hard to make a few end caps with soft copper that went up near the port and use bulkheads with compression fittings on the cap. Are there baffles to clear is that the issue?

[PC_Hater]

Dewey ( where's Hewey and Louey?)

I have drilled a hole in the closed end cap to allow the sniffer to be poked through it. But after 2 years the screws holding the endcap and the discs are rusted solid. Yes I did use a lot of copper slip grease! Still rusted solid.

Then we know that the sniffer has to be shoved through the system to be within 8" or so of the exhaust port. Having done one cylinder, you get to heave it all out and shove it through for the other cylinder. Tedious.

IMHO, no not IMHO 'cause Humble is not one of my virtues... ALL exhaust systems should now have a sniffer bung in the right place so DynoMan can just undo bung, plug in sniffer and GO!

[autoworker]

Hers's my 2 cents worth on your post.
HP numbers can be good with a lean tune.However there is a greater risk of engine damage due to heat and or detonation (broad term).
The exhaust can also contribute to heat and pinging if it doesn't breathe as well as the engine would like.
Finally a good tune  can and will make a world of difference in starting,warm up,response,rideability,and most of all engine smoothness.
The hp/tq numbers are only a part of a "good" tune.