Harley Davidson Street Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hi,

I wanted to know that is it compulsory to tune my bike if I have added a slip on exhaust (V & H Hi Output) and upgraded my air filter (K & N Air Filter).

I know obviously it is better/suggested to tune if the intake has been changed.

My question is that, what if i don't tune and ride my bike with these add on's. Will it create any problems to my bike ? and if it does create problems, what are the potential problems am looking at ?

i have a 2017 street 750.
 

Attachments

·
Administrator
"Loose Nut" from Houston, Texas
Joined
·
494 Posts
All motorcycles come from the factory running lean (more air to fuel ratio) to assist in meeting the emissions requirements. When you free up the exhaust and especially the intake, you are making the bike run leaner. Tge leaner an engine, the hotter, temperature wise, it runs. A hot engine are bad on engine internals, valves, bearings, etc, and will prematurely cause engine failure. Unfortunately, this is a case that if you play, you pay. With all that said, YES, have the bike tuned to your upgrades to ensure the longevity of the engine.
 

·
Registered
Joined
·
11 Posts
I installed only the exhaust at first. And went for a couple of weeks. Then I got a full pack 3 and a KN filter. and I installed a filter and a special card from Vance. The effect is very different in operation. and the engine control became sharper and the sound became even more pleasant.
 

·
Registered
Joined
·
294 Posts
Yes your bike will run, but it will not perform as good as it could and in the worse case scenario you are causing problems for later down the line.
Having said that - if you ride it with a new / different exhaust and air filter YOU will likely not notice anything is running not as it should be because the sensors in the exhaust will likely make fine adjustments so that the bike does run as good as it can.
However, as Lesblank has stated the engine will be running very lean and damage will likely result over time and as aveator-vv has also stated - the bike DOES run better when tuned.
The thing anyone needs to consider before adding aftermarket parts is 'am I prepared to do what needs to be done to get the benefit from these parts?' and factor that into the cost of buying them. An exhaust or air filter does not get fitted to change the sound of the bike - they change (improve) the way the bike performs when correctly fitted.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
This question of yours has been on my mind for a while. How do you plan on getting the bike tuned in India? My dealership does not offer tuning at all. They just offer Screamin' Eagle parts without tuning. And they won't let me fit aftermarket tuners saying it would void the warranty.

Here in Kochi Showroom (Kerala) they were ready to do the tuning. Am not sure about the warranty. Coz my warranty period is already over. The service guy told me, if i buy the Fuel Pack they will do it for me. I ended up not doing as it was costing 45k+ here. so am running on stock air filter now.
 

·
Registered
Joined
·
55 Posts
@Ogbob so I have a full V&H stage 1 on my Street Rod, I noticed that when running the FP3 tune with Hi-Output Slip-On and Stock Intake Filter the tune gave me much more power and lowered the number of backfire pops I had substantially, when I upgraded to the K&N high flow intake filter, coupled with the same exhaust and same exact tune map I am getting much more backfiring now. I am guessing I need to do a few sessions with the auto-tune feature to really fine-tune the AFR on the map and help eliminate the backfire.
 

·
Super Moderator
2016 Harley-Davidson Street 750 in Sunglo Velocity Red
Joined
·
781 Posts
You might try using a map with the Hi-Output Slip-On and free flowing intake filter. That will probably solve most of your problems. If you aren't thoroughly pleased with such a map, then go to auto-tune.

That being said I didn't find a stock map for my TAB exhaust and K&N high flow filter. V&H would have been happy to tell me what to use, but I just guessed poorly and went straight to auto-tune after that.
 

·
Registered
Joined
·
55 Posts
So update numero uno amigos!!

I ran two 30-40 minute auto-tune sessions yesterday evening and have noticed that the backfire pop has almost completely gone away.

Something to note, on my way home, I stopped and started the bike it was already up to temp by this point and my idle was low for some reason, upon starting the bike it was idling between 1100-1350 and just felt a little sluggish only at idle, this lasted about 5-7 seconds and then it went back up to what felt like normal operation. RPM at 1300-1500

Will take it out for a spin today and not do anything with FP3 just see how the ride and engine operation is.

So far so good as I think the idle issue was a one-off - will keep you all posted after my ride today.
 

·
Administrator
"Loose Nut" from Houston, Texas
Joined
·
494 Posts
Some folks like load exhaust. It's a personal choice. Like why are bikes different colors? Why different bars? Why chrome rather than all painted? Why different seats? While I might not agree with what someone thinks looks great on their bike, I'm all for personalized changes, as long as it doesn't affect the bikes safety.
 

·
Super Moderator
2016 Harley-Davidson Street 750 in Sunglo Velocity Red
Joined
·
781 Posts
Your Road King has 114ci displacement. These bikes have 30ci or 45ci displacement. There's a lot to be said for trying to squeeze a few more horsepower out of these little bikes.

@Lesblank is correct that it's a personal thing. I don't really like or want a particularly loud bike. I'm not a believer in "Loud pipes save lives" or anything like that. There's probably a quieter option than the TAB performance exhaust that I have on my bike, like maybe the V&H pipe with the quiet baffles. I just went the cheapest route to get some more power.
 

·
Registered
Joined
·
81 Posts
Since buying my 2016 750 with 3900 miles, I've been messaging with a friend of mine that works at an HD dealership. I bought the bike with a Two Brothers muffler. I checked the air filter. It's showing dirt on the outside. My friend says I'm ok with just the muffler. But, adding the Screaming' Eagle or K&N filter, I should get it tuned. I have a K&N on the way.
I will have the dealership, District Harley-Davidson, install and set up the HD tuner. I have experience with Dynojet's PowerCommander V and AutoTune. The HD tuner is cheaper and simpler for me.
See Les's post for why a tune package in the first place.
 

·
Registered
Joined
·
14 Posts
Compulsory? That's a yes and no...
Yes:
1. Factory takes years to develop a smooth transition of throttle apply. Each component has a formula. It is not guess work.
2. The air flow has changed. That means to match both intake and exhaust and the pulse factor change between this subtle change.
3. You modified from formula, so you now have to rematch back to what once was a smooth transition of driveability. That means to change the air to fuel ratio for those modifications. The pulse out the faster flowing exhaust might pull out fresh fuel and lean the engine out and a loss of power at the lower end. The stock muffler sort of helped the grunt at the bottom. Now you lost some. Thus the retune back to a slight rich to gain the torque back.

No:
a. That extra flow at the larger pleat opening is going to let in a lot more micron sizes to score the pistons and cylinder walls. There goes the hours lost on line compression. For example, line up all those score marks together and look at that air gap caused by all those lines.
b. What happens next is more a speed event change; than more air entering the chamber. Take the intake vacuum sensor and watch it stop at bottom dead center (BDC) having the vacuum stop as if the engine is turned off. The next stroke up is pre-calc'd so the ECM knows how fast that suck entered and the vac changed that fuel setting to an all day ride if you ran no muffler, no air cleaner.
c. You are safe to run cross country, flat out if you want and no tune from stock needed.

"I'm really confused."
Not anymore, right? Want to save those hours down the road? Cut the replacement intervals by half. If say the manual says to change the air filter at 15k you cut it in half to 7.5k. Oil and filter every 3k, and on average you changed it out to 2.7k. Trans and primary are also same day as the oil.

"Why change the muffler to annoy my neighbors? Why mess with the factory settings? Why not just ride?"
Because you and I ride the same bike. Bone stock right out of the crate, let the engineers take care of the tuning. Let the sound remain quiet and when stealth meets 100plus mph for a few seconds, no one's neck is snapping where is that coming from, I can hear it where you're sitting! All quiet on deadman's curve.
 

·
Registered
Joined
·
59 Posts
Hi,

I wanted to know that is it compulsory to tune my bike if I have added a slip on exhaust (V & H Hi Output) and upgraded my air filter (K & N Air Filter).

I know obviously it is better/suggested to tune if the intake has been changed.

My question is that, what if i don't tune and ride my bike with these add on's. Will it create any problems to my bike ? and if it does create problems, what are the potential problems am looking at ?

i have a 2017 street 750.
It’s good to tune the configuration. These bikes are very sensitive to such changes. More heat in cylinders with wear down the components faster. The fuel injection is also supposed to have a cooling affect for the engine.

regards,
AJ
 
1 - 19 of 19 Posts
Top