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[Indenial]

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This is the best explaination I've seen for an idiot to understand the tuners.


For all the people that don't quite understand why you need a Race Tuner (SERT) or Power Commander (PCIII USB) for your Harley please read this. This was not written by Harley (who makes the SERT-Race Tuner). I favor the Race Tuner but will concede that the PCIII is also a good piece of equipment. But PLEEEEEEEEEEEEEASE...Don't use the HD download


Why EFI Vehicles Need To Be Tuned
The need for "re-mapping" a fuel injected bike only arises when internal and/or
external engine components are replaced with non stock components, i.e. air
cleaners and exhaust systems. When components are changed on an engine to
any non stock or "performance" part you alter the way that engine moves air in
and out, thus altering the Volumetric Efficiency. If the V.E. is altered the stock
ECM fuel settings continue to deliver fuel at a base-line rate unaware that the air
delivery has changed. With the fuel delivery unchanged and the fact that this
engine is receiving more air there is a lean condition created that will most likely
cause engine damage due to higher heat levels in the combustion chamber. A VTwin
engine is just that, two separate cylinders in a "V" configuration which
generally speaking will cause these cylinders to flow air at a different efficiency
rate. This effect is mostly caused by a non tuned exhaust system that flows air at
different rates from front to rear thus changing the volumetric efficiency.
With the advancements and complexity of today's fuel injection systems
simplicity is not necessarily advantageous. The need to compensate for fuel
delivery to a modified engine ideally would be performed by the original engineer
or programmer of the ECM since they would be the one most knowledgeable on
this system. Since this avenue is not available to the average consumer, a
method of putting a "Band-Aid" type programmer (HD Download) to compensate
for the modifications is the easiest solution, however it is not necessarily the best.
Installing a "Band-Aid" on a system with this complexity can sometimes create a
whole new realm of problems that the original engineers could not have
anticipated.
The Dyno Jet Power Commander unit with it's 126 fuel adjustment cells and 126
spark timing cells offer simplicity that cannot always compensate for the high
demands of a modified V-Twin engine. Especially when the cylinders have a
different V.E. rate, this also offers a "Band-Aid" solution at best.
The H-D EFI Race Tuner Kit offers 220 Volumetric Efficiency adjustment cells for
each cylinder along with an Air Fuel Ratio (AFR) adjustment table that has an
additional 120 cells for a total of 560 fuel adjustment cells. There are also 220
cells for each cylinder to compensate for spark timing, fuel enrichment cells for
cold start and cranking enrichment for easier starting. With these extra tables and
cell adjustments there are over 1000 adjustments that can be made. Also
consider the advantages with having the ability to set your idle mixture as well as
idle speed and having access to your own rev limiter which is adjustable from
4000 to 7500 RPM.
 

[dlaws01]

    Huh? What?

[RickC]

Reads like an advert for the SERT, doesn't it?

[Deuce Bigelow]

Reads like an advert for the SERT, doesn't it?

It's more like an ad for the PCIII..........

[RickC]

It's more like an ad for the PCIII..........

Yeah, that's what I meant! I think I'm starting to show early signs of OldTimers Syndrome!

[BMF-110]

Sounds like a description of an apple versus an orange, Makes perfectly good sense and having been around both, I agree!!!  For me the proof is always in the pudding, I already know,send me an employment application for either one I'm getting bored this winter already.

[Indenial]

Thanks for the comments. Let's me know what is real and what is not.

[gremlush]

I don't understand how we lived without fuel inj. and cell phones. I must be old ,because I remember talking into a 'can' that had a string attached to it,for the 'other' can. Getting fuel into your hog was easy , Mikuni 'round' slide {44mm} . Daniel Boone  {Fess Parker} 

[Hoist!]

I don't understand how we lived without fuel inj. and cell phones. I must be old ,because I remember talking into a 'can' that had a string attached to it,for the 'other' can. Getting fuel into your hog was easy , Mikuni 'round' slide {44mm} . Daniel Boone  {Fess Parker} 

Daniel (Fess) was a proud American and use a Super D Dewey!!!

Hoist!

[Trapperdog]

I met Fess Parker back in the early 70's at the grand opening of Mariots Great America theme Park in Santa Clara Ca. Right nice guy. He let my infant son place a ring on a bottle to win a HUGE stuffed animal.

[sportygordy]

O.K. I give, who wrote the excerpt  

[Deuce Bigelow]

O.K. I give, who wrote the excerpt  

Dyno Jet, explaining why you NEED a PCIII tuner........

read it again slowly..

[grc]

Dyno Jet, explaining why you NEED a PCIII tuner........

read it again slowly..

Read it again, even slower.   Why would Dyno Jet bad mouth their own product while extolling the virtues of the SERT?
--------------------------------------------------------
"The Dyno Jet Power Commander unit with it's 126 fuel adjustment cells and 126
spark timing cells offer simplicity that cannot always compensate for the high
demands of a modified V-Twin engine. Especially when the cylinders have a
different V.E. rate, this also offers a "Band-Aid" solution at best.

The H-D EFI Race Tuner Kit offers 220 Volumetric Efficiency adjustment cells for
each cylinder along with an Air Fuel Ratio (AFR) adjustment table that has an
additional 120 cells for a total of 560 fuel adjustment cells. There are also 220
cells for each cylinder to compensate for spark timing, fuel enrichment cells for
cold start and cranking enrichment for easier starting. With these extra tables and
cell adjustments there are over 1000 adjustments that can be made. Also
consider the advantages with having the ability to set your idle mixture as well as
idle speed and having access to your own rev limiter which is adjustable from
4000 to 7500 RPM."
------------------------------------------------------
I forget where I originally read this, but it was at least a couple years back and it was a pitch explaining why the SERT was a better choice than the PCIII, at least in this person's opinion.  In my opinion, he is probably correct if someone wants or needs access to all those additional tables that a PC can't access.  For those who don't want or need to fine tune the warm-up tables, the idle speed, etc. the PC still offers less complexity which results in less expense both for the hardware and for dyno time.  And the PC is still able to be removed without a trace, unlike the SERT, which eases the minds of those worried about the cheap bast#@ds at H-D trying to void their warranty.

Unless someone just enjoys poking around in lots of tables, the best advice is still to find a good tuner first and then let him steer you to the device he recommends.  As time goes by the good tuners will probably learn and be more comfortable with multiple choices, but there are still many who are "experts" with only one particular device.

Jerry

[Deuce Bigelow]

Damm.....LOL

you're right!


I really do need to read slower!

[Steve Cole]

I forget where I originally read this, but it was at least a couple years back and it was a pitch explaining why the SERT was a better choice than the PCIII, at least in this person's opinion.  In my opinion, he is probably correct if someone wants or needs access to all those additional tables that a PC can't access.  For those who don't want or need to fine tune the warm-up tables, the idle speed, etc. the PC still offers less complexity which results in less expense both for the hardware and for dyno time.  And the PC is still able to be removed without a trace, unlike the SERT, which eases the minds of those worried about the cheap bast#@ds at H-D trying to void their warranty.

Unless someone just enjoys poking around in lots of tables, the best advice is still to find a good tuner first and then let him steer you to the device he recommends.  As time goes by the good tuners will probably learn and be more comfortable with multiple choices, but there are still many who are "experts" with only one particular device.

Jerry

Why would you think that to be able to do a better job makes it harder? Just because features are there, that does not mean it needs to be used. The extra feature set when not used make it as easy to use as a PC to use.

[grc]

Why would you think that to be able to do a better job makes it harder? Just because features are there, that does not mean it needs to be used. The extra feature set when not used make it as easy to use as a PC to use.

I don't think that's what I said Steve.

"For those who don't want or need to fine tune the warm-up tables, the idle speed, etc. the PC still offers less complexity which results in less expense both for the hardware and for dyno time.  And the PC is still able to be removed without a trace, unlike the SERT, which eases the minds of those worried about the cheap bast#@ds at H-D trying to void their warranty."

Even without getting involved in all the other parameters, a SERT tune will require more dyno time than a similar tune with a PC.  This has been attested to by many tuners and members on this site, and is reflected in the charges of those I know who tune with both devices.  So if someone is interested in conserving resources ($$) more than they are interested in owning some extra capabilities that they may never need or use, in my opinion the PC may be all they will ever need.  I have no personal axe to grind or financial interest in any of those choices, btw.

Jerry

[mvent]

I have to agree with Gremlush, been riding for years with carbs and thought my bikes ran great using 42 Mikunis leaned out a bit, 3 jets and an air screw, now I have FI tuned with SERT and it seems necessary to tune every 250 RPM and throttle position or my bike CAN'T be running or tuned properly 

[Steve Cole]

You do not have to tune it every 250 RPM but if you want to you can. The PC just adds on top of what is already in the factory tune. A SERT only shows you the factory tune and allows you to change what you want. IF you want to do it like a PC you can, if you want to tune it and use all the functions you can. Anyone that thinks its harder to do than a PC has not used it most likely. Look the PC works but this BS of the SERT being harder to use than a PC is just that...... BS.

To make a PC like tune with SERT just go to the AFR table and move it high and lower this will richen or lean the mixture same as a PC does. To change the Spark go to the spark tables for the front or rear cylinder and add or subtract spark just the same as you would a PC. Done simple and just as easy to use as a PC with no extra parts or wiring on the bike.

Now if you want to step up and do it better you also have all the controls to do that as well, but Like I said before you do not have to use them all.

[dmnrdn]

I don't understand how we lived without fuel inj. and cell phones. I must be old ,because I remember talking into a 'can' that had a string attached to it,for the 'other' can. Getting fuel into your hog was easy , Mikuni 'round' slide {44mm} . Daniel Boone  {Fess Parker} 

Feeler gauge, static timing, maybe a timing light but a good ear.  Brings back memories of the good old days.  Almost as good as a good donut hole.

PS.  We need to see if we can get a donut icon for Dewey

[mvent]

Steve, I agree, I don't really think you need to tune every 250 rpm, that was tongue in cheek , and my opinion of using the SERT, is once you get into actually using it, it's really straight forward and changes can be made easier than with a timing light or screwdriver, data logging is a great feature for feedback also. I'm jealous I can't V-Tune like the new bikes using your new system !!!
Mike 

[Hoist!]

Feeler gauge, static timing, maybe a timing light but a good ear.  Brings back memories of the good old days.  Almost as good as a good donut hole.

PS.  We need to see if we can get a donut icon for Dewey

Ain't nuthin wrong with that dm! Been doing my carb bikes like that for years! Still do! And I think Vern's ears have a built-in timing light in them! But we ain't doing that with a Race Tuner on an EFI bike though!

Hoist!

[dmnrdn]

Ain't nuthin wrong with that dm! Been doing my carb bikes like that for years! Still do! And I think Vern's ears have a built-in timing light in them! But we ain't doing that with a Race Tuner on an EFI bike though!

Hoist!

Hoist,  that is one I  have not heard before.   Good one.