Very common question around here. To get the best bang for your buck you want to do the exhaust, air cleaner, and a tune all at the same time. As you’ve probably heard before, an engine is essentially an air pump, so your improved air cleaner is getting more air in, and the better exhaust is getting it back out. Now you need to adjust the air fuel ratios to take advantage of the changes.

If you care about maintaining your powertrain warranty your only option on the tuner is Screamin Eagle because anything aftermarket will void the warranty. But it’s EPA compliant so your gains will be marginal.

So your choices are 1) wait on all of it until your two year probation is up, 2) do it all now and say screw it to the warranty, or 3) do the exhaust and the intake and the SE tuner now, then spend money again in 2 years and buy an aftermarket tuner to take full advantage of your situation……. 🤷🏼‍♂️

 

The stock head pipe with the cat removed has been a proven winner. I know folks with 128 builds with the stock de-catted header and the torque curves look great. And its the most cost effective.

 

Was there a Tune after de-cat? or just stock tune. I know the is very little back pressure with the stock muffler and baffle removal is about a 10 minute job. Just wondering what the gains might be with baffle / cat removal and a higher volume air cleaner.

 

Comprehensive tune afterwards.

I definitely would not do baffle removal. The bike will sound like shit (at least they do to me anyways) and is not what you wanna do for more power. I'd buy new internals from Fullsac or just buy a performance oriented set of mufflers.

 

Your M8 likes the Stock Header and loves good back pressure....unless the heat is killing you, the Stocker is not all that bad

 

ok cool, thank you!

 

Save yourself some issues. decide as a package what header /mufflers/tuner and Cam you want.
For the best results those must work together.

 

I did a stage 2 with torque cam, have the screamin eagle tuner, wide band O2, Rinehart headers and klock work mufflers on a 23 rgs. Am more then happy with power, wont win any races, lol. But passing on highway is very nice.. For info I weigh around 275 and if I have my daughter or wife does not matter bike goes. Anything over 2k rpms and it pulls decent till redline.

 

A good friend of mine has a "21 RG with the 114 that he bought new...he wanted and needed more power,but wanted to retain his warranty so he had a local HD dealer do the S.E. stage 2 upgrade complete with tune and surprisingly it performs well...check with your local dealer(s) because some offer really good discounts.

 

I put in the Star Racing 30-30 cam, adjustable push rods, s&s lifters. Kept the stock header, Reinhart slip ons, pv4 tuner. Great torque to get these heavy beasts moving. DIY. HD adjustable pushrods.

 

The stock header with or with out the CAT does a good job with most Stage 2 work depending on the mufflers chosen .
The term back pressure gets used but it more about flow and heat routing.
If you open it up to much no amount of tuning will fix it.

 

I have the Bassani 2x2 header on my 2023 and 2024. I had a gutted stock header for a while and it sounded raspy and had lots of crappy decel noises (not a pleasant type of decel gurgle). The 2x2 has a better collection chamber design and the crossover outlet has a louver that sticks far into the collector to direct some more flow to the left muffler. That louver also does some magic to the airflow to help with the reversion that you can get by just gutting the stock head pipe. I think that is the back pressure thing people always talk about. The stock header is engineered to prevent this with the cat, but not when you hollow it out. The 2x2 was engineered to fix that problem.