When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I was hoping someone who has used both the Harley tuner and then an FP3 or PV Tuner could tell us if they actually could feel a difference in how the bike ran with the different tuners...?
Here's the fuel table from the H-D Street Tuner for an M8 Heritage Softail Stage I or II (I did not look at others but they will be identical or very similar).
I compared it to the posted FP3 fuel table below:
Green is 1% difference or less. Basically no difference.
Blue is when the FP3 is richer by the percent shown (lower Air Fuel Ratio (AFR) is richer so a negative change percent is richer)
Yellow is when the FP3 is leaner by the percent shown.
One difference to note is the 20 MAP column where the fuel enrichment helps prevent decel popping.
The other is the 80 and 85 MAP columns above 1500 rpm. This takes the engine out of closed loop O2 sensor control and enrichens the mixture at a smaller throttle opening (sooner) than H-D does. When you open the throttle, Manifold Absolute Pressure (MAP) goes up to a max of 100 kPa which is typical atmospheric pressure.
I'm surprised in the typical operating range the two tuners are so close. Same goes for WOT at all RPMs. Makes me wonder if I should get an SE tuner just to try it out without too much risk? I just did slip-ons and the stock high flow AC, but maybe there is something to gain even with SE?
So what your saying is the Harley Tuner and the FP3 pretty much provide the same state of tune, correct?
The point is that the H-D Street Tuner is not too lean.
The FP3 advantage comes in tuning non-Harley engine components and non-Harley exhaust. The H-D tuner is limited to tuning H-D Screamin' Eagle Stage Builds or very similar aftermarket parts.
The H-D auto tuning module with wide-band O2 sensors can adapt to a wider range of components. The best situation with any tuner is to have the bike tuned on a Dyno.
Both my wife and my bikes are 103ci TC
Hers with fp3
Mine with dynojet
Hers, even thi I programmed it for no decell pop. Still pops
Mine I dowloaded a map programmed for no decell pop. Does not
So I think that even tho motors may be identified as same, will not respond the same to inputs after market tuners try to provide.
So not all tuners, even when programmed for similar performance tables will not generate similar results.
Both my wife and my bikes are 103ci TC Hers with fp3
Mine with dynojet Hers, even thi I programmed it for no decell pop. Still pops
Mine I dowloaded a map programmed for no decell pop. Does not
So I think that even tho motors may be identified as same, will not respond the same to inputs after market tuners try to provide.
So not all tuners, even when programmed for similar performance tables will not generate similar results.
If you contact V&H, there's a good chance they can provide a map to alleviate that issue.
So I think that even tho motors may be identified as same, will not respond the same to inputs after market tuners try to provide.
So not all tuners, even when programmed for similar performance tables will not generate similar results.
Yup, that is why a dyno-tune helps in many situations.
The target command tables like fuel, spark, warm-up etc. are usually never changed. What is gained from dynamometer or road tuning is measured volumetric efficiency (VE) for your engine, cam, intake, and exhaust combination.
The VE table is used to "dial in" the calculated air mass flow through the engine and then, using the Air Fuel Ratio target, the fuel injector command is determined.
A download tune uses typical or estimated values for VE, usually pretty good, sometimes not so good. Hence, the difference between bikes.
When you are cruising around, the engine is in closed loop control and the Oxygen (O2) sensors are used to compute fueling so the bike adapts and VE accuracy is less important. During acceleration transients or heavy engine loading, the ECU switches to open loop and is totally dependant on the VE tables being correct. Open loop is needed because the O2 sensors can not deal with the needed rich fuel mixture or the rapidly changing conditions in the engine. The ECU can do the required calutations fast enough using the VE tables and ignoring the O2 sensors for the moment.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
