Slip-On without tuner
I imagen it this way. You normally run your shower wide open, both hot and cold to achieve a comfortable temperature (perfect mix) but you would really like to have a higher flow rate so you install a larger line and valve on the hot side only. What’s the result? More flow but the temperature is going up.
Now on you bike, you increase the airflow but the FI can’t supply more fuel what happens? Too much air (O2) which causes more heat I would guess. I’m not much of a mechanic but sure what it sounds like to me. My question would be how would you know if the FI is maxed out or not? I’ll leave it to the mechanics.
Now on you bike, you increase the airflow but the FI can’t supply more fuel what happens? Too much air (O2) which causes more heat I would guess. I’m not much of a mechanic but sure what it sounds like to me. My question would be how would you know if the FI is maxed out or not? I’ll leave it to the mechanics.
Cruiser
Joined: Jul 2009
Posts: 181
Likes: 39
From: Delaware
I don't think anyone is saying that. I'm with the others in that I have heard from dealers and others that slip-ons alone will not necessitate a tune. However, if you start talking full exhaust systems or gutting your cat along with slip-ons, then that is a different story. In those situations you can have a tuned exhaust that can actually work to scavenge more air through the system, which is what tuned exhaust systems are meant to do, even with a stock AF. Maybe it only happens at high RPMs, but it is a possibility that requires system management that doesn't exist with slip-ons alone, which are mostly megaphones to tune the sound more than bike performance.
Ultimate HDF Member
Joined: Oct 2010
Posts: 5,456
Likes: 2,860
From: SW FL-Jersey Shore Emigre
Actually, somebody DID say that:
Was talking to a service tech at Harley that does wrenching last Thursday and I asked the pipe, air cleaner and or slipon question and this is what he said.
" On the 16's you could either swap out the exaust mufflers or have a high flow air cleaner but not both as the ecm only had a big enough map window to compensate for subtle changes in air / exhaust flow"
But the 17's run so lean you can't change anything, Even people that have put slipons and cleaners on earlier bikes including the 16's have had excessive engine heat and he's fixed plenty of burnt rear valves. Dynojet even has an advanced stock tune for un modified Harley's just to fatten them up a bit.
Wiz
" On the 16's you could either swap out the exaust mufflers or have a high flow air cleaner but not both as the ecm only had a big enough map window to compensate for subtle changes in air / exhaust flow"
But the 17's run so lean you can't change anything, Even people that have put slipons and cleaners on earlier bikes including the 16's have had excessive engine heat and he's fixed plenty of burnt rear valves. Dynojet even has an advanced stock tune for un modified Harley's just to fatten them up a bit.
Wiz
Ultimate HDF Member
Joined: Oct 2016
Posts: 5,063
Likes: 2,582
From: On my bike!
I ran RCX 4.5's and HD high flow filter without a tuner for a bit, it ran like a champ! I have since tuned it because wasn't sure of the long term effect. For what its worth, I did much research and personally spoke with dealers in 3 different states, all the service managers I spoke to said the same thing, tuner was not really necessary for slip ons and AC and more than likely would not do any harm but they recommended using a tuner for prolonged use.
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,679
Likes: 11,472
From: State of Confusion
I ran RCX 4.5's and HD high flow filter without a tuner for a bit, it ran like a champ! I have since tuned it because wasn't sure of the long term effect. For what its worth, I did much research and personally spoke with dealers in 3 different states, all the service managers I spoke to said the same thing, tuner was not really necessary for slip ons and AC and more than likely would not do any harm but they recommended using a tuner for prolonged use.
"You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. "
Road Warrior
Joined: Apr 2017
Posts: 1,451
Likes: 230
From: United States
folks can roll the dice and personally I'd like to see someone report back after long term testing without tune..I can't get myself to ignore the folks who built the engines when they say about just adding a air cleaner
"You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. "
"You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. "
I went with the power vision from fuelmoto and got the unit delivered with the recommended tune to match my mods installed and ready to flash my ecm once I get my bike back.
Everyone I talk to that wrenches for Harley says 2016's you can do pipes or air but not both.
17's need flashed no matter what ya do as their so EPA lean it's stupid.
I'm going to plug the tuner in and take a few engine temps before and after the flash , pipes and air 'm looking for power and touqe and a cooler running motor and lower oil temps
Really it's your bike run it as you see if. But for the sake of a tuner even if you don't mod anything, cooler is better
Wiz
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Road Warrior
Joined: Apr 2017
Posts: 1,451
Likes: 230
From: United States
Yep pretty much word for word from a Harley wrencher ....just what the guy told me when my 17 custom was in for its 1'st service.
Wiz
Wiz
Seasoned HDF Member
Joined: Jan 2008
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From: State of Confusion
I read this over and over here..isn't Closed Loop the same as it's been for years, and my understanding is that in Open Loop it's Richer than its predecessors....