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[aftaylor]

I was told by a vendor in Daytona that Harley's throttle by wire will only give you 30% power until 3500 rpm is reached. I have a power commander V, of course he was seelling a Thunder Max tuner and said the Thundermax would eliminate the harley settings and the 30% power setting until 3500 rpm, but the Power Commander did not. I didn't buy it and was just wondering if this 30% power was true? My bike is a little hard to get rolling and it does seem to need at least 3500 rpm at take off.

[Steve Cole]

The factory HD ECM can be reprogrammed to work just fine. The stock programming does limit somethings in the lower gears but that doesn't mean you need to replace the whole ECM. It just means you need to use a programming system that will take care of it for you. A PC-V will not do it for you.

[xsdbs]

Harley's throttle by wire will only give you 30% power until 3500 rpm is reached.
My bike is a little hard to get rolling and it does seem to need at least 3500 rpm at take off.

I believe the vendor was talking about "30% throttle", instead of 30% power".
The throttle by wire isn't "directly controlled" like a cable operated throttle.
If you "crack" the throttle wide open, a cable throttle is opened 100% immediately.
A throttle by wire system "rolls on" the throttle, allowing the engine to build RPMs as the throttle continues to open to 100%.
This "throttle lag" can be modifed within the ECM by a programmer (race tuner, tts, powervision, etc), but not by a "piggyback" module (powercommander, fuelpak, etc)
Harley's 6 speed tranny has "taller/faster" first gear(9.5 to 1) than the previous 5 speed tranny(10 to 1), which is why it's a little hard to get rolling.
Both things seemed "odd" to me at first, but now I'm just "used to it".

[glens]

The throttle by wire isn't "directly controlled" like a cable operated throttle.
If you "crack" the throttle wide open, a cable throttle is opened 100% immediately.
A throttle by wire system "rolls on" the throttle, allowing the engine to build RPMs as the throttle continues to open to 100%.

Somewhat akin to the way a CV carb works as compared to having the throttle cable directly driving the slide.

Believe it or not, V&H makes a "throttle pak" which plugs in between the throttle body and wiring harness and is marketed as a way to get rid of the "lag" in throttle response.  Believe it or not, some folks actually use them...

[2006ULTRA]

I'm curious about this 30% throttle limitation.  I just ordered a TMax because my throttle response is horrible with my Pro Tuner.  I just decided I didn't want to mess with the pro tuner after working with a TMax on a friends bike.  Plus my brother in law has a built 113 in a 08 SG and his throttle response in unexplainably responsive with his TMax.  That's what sold me.

Tell me more about the difference between my setup and a Tmax in regards to what happens with 30% throttle to 3500 rpm?

[glens]

Going to a TMax to address throttle progressivity is quite a bit overboard.  If your SEPST won't help you, get yourself a TTS kit instead.  It can address your issues and is less than half the price.

[2006ULTRA]

I didn't just do it for the throttle response but that was the the last deciding factor.

I do like the auto tune feature and also like the fact that I can load 5 maps and switch them without a computer.  I'm sure eventually I will settle with one map and just leave it alone.

I realize my Pro Tuner is very capable but I like the software in the TMax WAY better.  So much easier to use and understand.

I got a good deal on the TMax through Cat Eye Customs.  It is still expensive but not double the TTS.

[aftaylor]

Thanks everyone for your replies. My plan right now is to take the bike to Kendell Johnsons and have it mapped and dyno'd. I talked with Zac up there and he said installing the V&H Throttle pak will remove the hesitation, so that's what I plan on doing. I just bought the wrong tuner from the very beginning. I'll reply when it's completed. It's definitely something to think about and research before you buy a tuner, live and learn.

[grc]

First thought I have is, whoever that guy was in Daytona (I'm guessing Zipper's), he is about as FOS as can be.  Just one more in a long line of vendors who think the truth is something to be ignored or avoided, and all is fair in the pursuit of sales.  

Do a search, or just follow this link  
http://www.cvoharley.com/smf/index.php?topic=39937.msg617082#msg617082
and you will find that the stock Harley ETC torque smoothing strategy has the throttle plate pretty much caught up with the grip rotation by 2500 rpm.  Look at the table in that linked thread and you'll see that the 30% figure is achieved by 1500 rpm, not 3500 rpm as represented by the guy selling the T-Max.

While I can see where the strategy employed by Harley could be considered excessively conservative, I don't know that I'd just automatically eliminate the entire thing.  Considering all the bottom end failures that occurred prior to the incorporation of this torque smoothing strategy, I'm firmly convinced Harley did this to electronically enforce a "No Lugging" policy to protect their engines from ham fisted riders.  

Anyhow, it would make a lot more sense if someone wants to modify this response curve to do so with a proper tuning solution and the stock Delphi ECM.  Removing the highly capable and reliable stock ECM and replacing it with one that is much less sophisticated doesn't seem like a great idea to me.  And the fact that the folks selling it are using misrepresentations to do so would just make me even less likely to buy their product.


Jerry

[aftaylor]

Thank you Jerry for replying. Is the Master Tune the stock ECM? I hate to be an idiot, but I am. If that's the case, then the bike could be tuned using the stock ECM from the very beginning?

[grc]

Thank you Jerry for replying. Is the Master Tune the stock ECM? I hate to be an idiot, but I am. If that's the case, then the bike could be tuned using the stock ECM from the very beginning?

The MasterTune product is an aftermarket tuning solution that consists of a communications module (VCI) and computer software package that allows you to change the settings in the stock ECM.  This is one of several methods out there for modifying the stock settings (and the best in my opinion).  Due to emission regulations and other issues, the dealer can't just go into the stock ECM settings and change stuff (it's locked out).  They have to use a tuning package of some sort just like everyone else.  There are many products offered that will modify how the bike runs, from simple add-on boxes like those offered by various exhaust system companies to more sophisticated add-on boxes like the Power Commander, all the way to complete replacements for the stock ECM.  It was much simpler (and cheaper) back in the carb days.  But a properly tuned EFI system is so much better than any carburetor I'd never want to go back.

Since you have already invested in the PCV, it will probably be less expensive to just go with the Throttle Pak to address your concerns with throttle response versus changing to a TTS MasterTune.  But maybe not, if you can sell the PCV to someone else.  You might want to ask the guy at Kendall Johnson about that approach.


Jerry

[glens]

I'll add that, to answer your question, yes, you can tune the bike with the stock ECM using the TTS kit.  That's to say that you use what the ECM has to say about things to get the ECM set up so that it's "happy".  When it is, the engine will run very well.

Sell the PC-V is what I'd recommend.  It can't do nearly what the TTS will allow you to do.  Plus you'll free the space on your bike back up and get rid of the extra point of failure down the road.