Do you have to mod engine
Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Do you have to mod engine
No, and nothing.
Put 'em on...it might runa little better as you can breathe a little better. If you change the intake (Stage I), you'll need to do something to ECM if you have fuel injection or it will be running even leaner than it already is.
Do a search on this, it's been covered numerous times...check the DIY, it has a ton of information on this as well.
Mac
Put 'em on...it might runa little better as you can breathe a little better. If you change the intake (Stage I), you'll need to do something to ECM if you have fuel injection or it will be running even leaner than it already is.
Do a search on this, it's been covered numerous times...check the DIY, it has a ton of information on this as well.
Mac
Banned
Joined: Nov 2005
Posts: 3,499
Likes: 2
From: CANADA
RE: Do you have to mod engine
If you change the exhaust you will undoubtedly have to put on a high flow air kit and a power commander or SERT and then get it dynoed if you want it to run perfect. It is well worth it for what you get. If not, it will likely run like crap!
Cruiser
Joined: Dec 2005
Posts: 104
Likes: 0
From: NH
RE: Do you have to mod engine
Well, it may not necessarily run like crap - generally they will just pop and crack a bit on deceleration, if you change pipes without recalibrating the ECM. Or re-jetting the carb.
As noted above, changing pipes AND air cleaner makes the motor run even leaner (due to much more air flow, but same amount of gas), and run even hotter, and you should do re-do your calibration, e.g., powercommander, etc.
My FLHTPI runs good with stock air cleaner, and Samson slip ons. Once I change to high flow air cleaner, I will get the powercommander and have it fine tuned...
As noted above, changing pipes AND air cleaner makes the motor run even leaner (due to much more air flow, but same amount of gas), and run even hotter, and you should do re-do your calibration, e.g., powercommander, etc.
My FLHTPI runs good with stock air cleaner, and Samson slip ons. Once I change to high flow air cleaner, I will get the powercommander and have it fine tuned...
Elite HDF Member
Joined: Sep 2005
Posts: 3,947
Likes: 5
From: Ontario, Canada
RE: Do you have to mod engine
ORIGINAL: bountyhunter
If you change the exhaust you will undoubtedly have to put on a high flow air kit and a power commander or SERT and then get it dynoed if you want it to run perfect. It is well worth it for what you get. If not, it will likely run like crap!
If you change the exhaust you will undoubtedly have to put on a high flow air kit and a power commander or SERT and then get it dynoed if you want it to run perfect. It is well worth it for what you get. If not, it will likely run like crap!
RE: Do you have to mod engine
ORIGINAL: Wally
Hold on here folks! I beg to differ. If you don't change the intake, you aren't going to suck in an more air and the bike will not run any leaner. It will not run as strong as if you do the air cleaner and retune with download, SERT or PC III. It won't hurt anything, except your ego when you get blown off the road by someone that sprung for the tuner!
ORIGINAL: bountyhunter
If you change the exhaust you will undoubtedly have to put on a high flow air kit and a power commander or SERT and then get it dynoed if you want it to run perfect. It is well worth it for what you get. If not, it will likely run like crap!
If you change the exhaust you will undoubtedly have to put on a high flow air kit and a power commander or SERT and then get it dynoed if you want it to run perfect. It is well worth it for what you get. If not, it will likely run like crap!
Road Warrior
Joined: Aug 2005
Posts: 1,545
Likes: 5
From: NEW LENOX, IL
RE: Do you have to mod engine
ORIGINAL: terryt1955
This is correct. You don't have to change anything with a simple exhaust upgrade. Keep it simple and ride it. If you want to keep up with the big dogs you'll have to spend a little more money.
This is correct. You don't have to change anything with a simple exhaust upgrade. Keep it simple and ride it. If you want to keep up with the big dogs you'll have to spend a little more money.
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RE: Do you have to mod engine
So not replacing the air filter will not hurt the engine.
What is a SERT or PCIII (sorry I am new to this)
What is a SERT or PCIII (sorry I am new to this)
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Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Do you have to mod engine
ORIGINAL: SaBiGe
So not replacing the air filter will not hurt the engine.
What is a SERT or PCIII (sorry I am new to this)
So not replacing the air filter will not hurt the engine.
What is a SERT or PCIII (sorry I am new to this)
SERT = Screamin' Eagle Race Tuner, PCIII is an aftermarket deal-e-o that does essentially the same thing, however: the SERT reprograms your ECM the PCIII attaches to the bike, stays attached and changes the ECM performance by altering inputs...end result is the same, except on is still attached to the bike under the seat, SERT is not...both need a dyno to get the best tune for your motor.
If you want new exhaust and not new intake, no extra mods required.
New intake means more air in the combustion chamber means different mixture than what the ECM thinks is there means you need to do something...options are have the dealer give you a generic download or get a SERT or PCIII and swag it, or get the SERT or PCII and a dyno tune.
Hit the DIY forums...do a search, this has been covered far better up there...tons of information for newbies and oldies.
Mac
Elite HDF Member
Joined: Sep 2005
Posts: 3,947
Likes: 5
From: Ontario, Canada
RE: Do you have to mod engine
FYI, my bike had a Stage I download with Screamin' Eagle K&N filter running stock pipes for the first 20,000 miles. Ran fine.If you change the intake you have to retune the fuel injection somehow. If you change the pipes you don't have to, but, you aren't going to realize the full benefit of the pipes until you do something about the breather and ECM.