Hello,
I understand that an EFI bike needs to be tuned. I sorta-kinda understand that you need a "tuner" to do so (please correct me if I'm wrong). With this tuner you can either upload a "map" or tweak the settings on a computer. I'm having a hard time with why you can't simply change the "map" already built in to your bike. I'm also not clear if the different tuners out there perform the same job, albeit differently, or I should be looking at one type specifically.

I've got a 2008 FXDB (96 in.) with Hi-flow air filter and V&H pipes.

Here's my dilema. I damaged a piston and cylinder and need to replace. I was going to buy stock, but S&S has a big bore kit that looks interesting and would take it up to 106 in. I know I have to "remap" the bike. The guy at the HD dealership recommended a TTS MasterTune and then they would tune the bike on their dyno for $440. Add the $400+ for the tuner and it's outta the budget.

So any recommendations? Are the "auto-tune" tuners reliable? Can I get away without the dyno tune? I've read a ton of posts and I'm getting data overload. Also a lot of the threads are a few years old and I know a lot has happened in the last few years regarding EFI, technology and HD engines in general.

Thanks for your time and help and sorry for the long-winded post.

 

TTS or Powervision, smart way to go.

 

I'd go with what the guy tuning it recommends. The term Auto-Tune is kind of a poor description for most every tuning device, there is no such thing as a true auto tune. Most flash base or ecm replacement tuners still need some interaction to get the tune correct. If you're only just addressing the AFR, you're only performing a fraction of the tune.

 

The ECM doesn't know anything other than what it's programmed with. It is unaware that the displacement has gone from 96"s to 106"s, and the compression from 9.1:1 to 10:1.
When it left the factory, it had an emissions legal tune, designed for a restrictive exhaust, and lean enough to make the EPA/DOT happy. The job of the tuning device is to allow the tuner access to the ~ 3 dozen tables in the ECM, to correctly re-calibrate for the increased displacement and compression, providing you with the best running bike possible.

 

@rigidthumperrigidthumper: In your answer, when you say "to allow the tuner access", "tuner" refers to the guy doing the tuning, correct?
If so, you're recommending a dyno tune, not auto-tune? Any recommendations as to what tuner device? Sorry if I'm being thick. I want to get the bike running the best it can but also within budgetary constraints.

 

Couple things to note.. Ecms are calibrated to a build. If you significantly change anything that changes air flow into the motor, you will need to retune the ECM.. Flash tuners like TTS and power vision simply supply an interface to allow tables in the ECM to be changed. Some have utilities that help with the changes.. On your bike, the ECM also has narrow band 02 sensors that can be used for tuning manually but you are really better off going to a tuning shop to have the job done as they should use wide band 02 sensors. Another thing to point out is that doing a bore kit by itself will like bump the compression to a point where it is too high and hard to tune. It's a good idea to change the cam at the same time which really blows your budget..

 

My suggestion is always to consider the tuning phase of any build as important as the performance parts you are using.
In other words there is little gain to making changes to the airflow through the engine , including exhaust, cams, heads, etc without properly recalibrating the EFI for the changes.
The question comes up all too frequently asking if it is necessary to dyno tune.
I say if you want to know what the $$ spent actually got you and peace of mind your baby is properly tuned for best running, take it to a reputable tuner and use whatever tuning device he prefers.
The difference between a built engine performance and a properly recalibrated built engine is noticeable to say the least.
Your bike and money, just sayin'
Bob

 

Yellowbird. The DR is a little different than other areas of the site. We have no advertising here.

Please don't advertise or suggest vendors in this area. Talking about them is one thing but giving phone numbers and such is against the rules in this area.

Thanks

-Wiz




Edit: Wiz, Sorry! Was trying to be helpful. Had no idea I was doing wrong.

Thank you for letting me know.


YB

 

Forums tuner locater found here :https://www.hdforums.com/forum/ignit...p-locator.html