I plan on putting some Firebrand or V&H Slip Ons on sometime. One mechanic at my harley dealer told me I wouldnt need to tune it up because the ECM will allow for one aftermarket. I could either do slip ons or a different air filter. I called Revzilla and they said the same thing...other harley dealers said you MIGHT need a tune up and others said youre going to need a tune up. So which is it?

 

Always tune it IMO. If nothing more than to get rid of the crappy lean HD stock tune.

 

Need to? Usually not, but you don't need shoe laces to wear shoes either.

Is it going to make a difference?

Huge.

Tuning the bike is probably the biggest power gainer. Since you already have the intake, better breathing mufflers will help as well. (I'm researching this but with the 'tommy gun' style 2-1-2 exhaust the LRS has, with different mufflers you may get about 95% the power a new 2-1 exhaust would make. Course it's heavier)


I plan on having mine Dyno tuned locally since there is a top notch tuner here. Cost about the same as a tuner like a Power Vision.

From what I've come across in my research you should be able to toss on the slip-ons and be Ok, but if you tuned it as well you would get a lot more out of them and your bike would run better with them. I recall some mention of things running hotter with slip -ons and no tune, but don't quote me on that. So basically, yeah you can but you're going to want to tune it sometime in the near future.

 

I couldnt of asked for a better answer. Thanks buddy.

 

I have a 2016 FXDLS, from new the dealer installed screaming eagle slip ons, decatted the headers and removed the exhaust flapper valve from the top muffler, they installed a stage one tune via SERT and I couldn't be happier with how the bike runs and sounds, it now has 32,000 klm's with no problems.
When mine was in for a service they gave me a loan bike which was a stock FXDLS with the same screaming eagle slip ons but stock tune and I was able to compare the difference which was night and day, mine definitely was stronger in acceleration throughout the rev range and the Motor just feels better and more responsive.
I suppose a proper dyno tune would probably gain more HP but I don't need it the bike is plenty fast enough as it is and I'm happy to leave it alone and just ride and enjoy it.

 

If all your going to do is change the slip ons, then you do not need to tune. Will run the same as before. However, if you want better performance, then yes, will need to buy a tuner and tune it. Do not have the dealership do the tune as can only tune it to factory specs (ie lean). Actually, not sure if the dealership can sell the SERT now with the new regs.

Now if you change the air filter (K&N) as well, then will need to tune it as will run very lean as more air will be coming in.

If your planning to do slip ons first, then do air filter at a later date, then would save your money and wait to tune it after you purchase your intake.

Or you can buy a tuner from places like Fuel Moto and they will install a canned map that is pretty close to where you want to be without having to run it on a dyno.

 

Glad I could help.

Do the LR-S not come factory with a K&N filter? Their website shows the replacement filter as a K&N but I can't find if it's the same thing. Figure I should check that before hitting a dyno tuner.



Also if any of you guys with slip ons have any Dyno charts I would love to see them.





And FYI, sometimes the dealers will have a Dyno shoot out challenge where you can have it on the dyno for free (not tuned, just shows you what you have). Did it last year about this time of year.

 

You will still need a tuner of some sort. Be it Moco or aftermarket. I’d find out what your tuner prefers and see if they’ll make a package deal.

I bought a PV when I got my LRS. Luckily Horsepower Inc tunes with it as well as some others. I’ll be taking mine their for tuning after I get done with my engine upgrades. Should have my throttle body from them this week, fingers crossed!

 

The LRS has the k&n heavy breather as standard from factory, I think the SERT tunes have changed since when I got mine to suit the new epa restrictions.

 

All that’s available from HD is the crappy street tuner which is epa friendly which equals useless lean.