Results 1 to 19 of 19

Hybrid View

  1. #1
    Active Member
    Join Date
    Dec 2022
    Location
    Florida
    Posts
    124
    Spyder Garage
    0

    Default Here's an article explaining Back Pressure BS!

    People please, back pressure doesn't make torque or power, it just retains heat, changes exhaust notes, & kills power. When I tune an engine (yes, I have for 30 years) all back pressure does is exhaust reversal of burned gases into combustion chamber, contaminating the fresh air fuel mix, kind of like an EGR effect, making advance of ignition timing less tolerant. If you want the exhaust to make torque, header primary, secondary tubes, and the collector is what you tune, not the muffler. Read this article in simple plain language.

    https://www.motortrend.com/how-to/ma...N%3Atrueanthem
    Last edited by Peter Aawen; 03-02-2023 at 06:14 PM. Reason: Expanded title to briefly state the reason for this thread! ;-)

  2. #2
    Very Active Member
    Join Date
    Sep 2018
    Location
    Australia
    Posts
    786
    Spyder Garage
    1

    Default

    Why does my wifes stock exhaust F3 feel heaps gruntier down low than my F3s with open exhaust then?
    P.S. I'm typing in my sleep if anyone asks.hidesbehindsofa.gif
    2017 F3S Daytona , Circuit Yellow Metalic

  3. #3
    Very Active Member
    Join Date
    Aug 2014
    Location
    Northern Kalifornia
    Posts
    3,398
    Spyder Garage
    0

    Default

    In days gone by old harley riders with straight pipes used put a nut with a long bolt up through the end of their pipes to create back pressure. Is that an old wives' tale or did it really work?

  4. #4
    Active Member Tourer's Avatar
    Join Date
    Jul 2022
    Location
    North Carolina
    Posts
    131
    Spyder Garage
    0

    Default

    The Harley riders put bolts through their exhaust to prevent the police from inserting their nightsticks and issuing illegal exhaust tickets.
    2015 F3S SE6

  5. #5
    Very Active Member SLICE's Avatar
    Join Date
    Aug 2022
    Location
    manatee county Florida
    Posts
    575
    Spyder Garage
    0

    Default

    Quote Originally Posted by Tourer View Post
    The Harley riders put bolts through their exhaust to prevent the police from inserting their nightsticks and issuing illegal exhaust tickets.
    i got written up in Newburyport MA for having straight pipes. i took it to court.
    i had 2 pieces of PVC pipe and pictures of my exhaust with several bends.
    judge was not happy.
    issuing cop was beyond miffed.
    judge gave stern warning to cop about wording .
    case dismissed.
    i was smart and parked in the next town over and took a taxi to the court.

  6. #6
    Very Active Member
    Join Date
    Aug 2014
    Location
    Northern Kalifornia
    Posts
    3,398
    Spyder Garage
    0

    Default

    I don't think too many patrolman were that naive.

  7. #7
    Very Active Member
    Join Date
    Aug 2014
    Location
    Northern Kalifornia
    Posts
    3,398
    Spyder Garage
    0

    Default

    LOL, you got away with it with considerable effort—smooth move. "Straight Pipes" is a misnomer. I ran "snuffer-nots" for a while instead of baffles and got stopped for excessive noise. The judge where I lived was known for leniency but was also known for "tow and store" until the issue was rectified to his satisfaction. Tow and store cost more but was better than a citation on your driving record.

  8. #8
    Active Member
    Join Date
    Jul 2021
    Location
    IL
    Posts
    376
    Spyder Garage
    1

    Default

    I always have thought that there is something pathetic about those intent on making their motorcycles as noisy as possible. Those riders are not content to enjoy the ride itself, but need the attention of others, even if it is negative attention, by creating as much annoyance as possible. And of course, blipping their engines while stopped, to further annoy everyone around them. This is not something unique to Harley riders, but does seem to be much more of a Harley thing than for owners of other brands. The "loud pipes saves lives" is nonsense. The places in this country where there are restrictions on motorcycles is almost always based upon the bikes making excessive noise. If you want more power, buy a different motorcycle.
    2021 Spyder RT
    Retired U.S. Army
    Life Member, NRA
    2021 RT , Petrol (blue)

  9. #9
    Very Active Member
    Join Date
    Sep 2018
    Location
    Australia
    Posts
    786
    Spyder Garage
    1

    Default

    Quote Originally Posted by vito1943 View Post
    I always have thought that there is something pathetic about those intent on making their motorcycles as noisy as possible. Those riders are not content to enjoy the ride itself, but need the attention of others, even if it is negative attention, by creating as much annoyance as possible. And of course, blipping their engines while stopped, to further annoy everyone around them. This is not something unique to Harley riders, but does seem to be much more of a Harley thing than for owners of other brands. The "loud pipes saves lives" is nonsense. The places in this country where there are restrictions on motorcycles is almost always based upon the bikes making excessive noise. If you want more power, buy a different motorcycle.
    Not that I do but you could raise the same argument about guns with zero evidence. If you want more power take it back from those that have stolen it from you.
    2017 F3S Daytona , Circuit Yellow Metalic

  10. #10
    Very Active Member cruisinTX's Avatar
    Join Date
    Mar 2015
    Location
    Fritch, Tx
    Posts
    765
    Spyder Garage
    1

    Default

    Quote Originally Posted by vito1943 View Post
    i always have thought that there is something pathetic about those intent on making their motorcycles as noisy as possible. Those riders are not content to enjoy the ride itself, but need the attention of others, even if it is negative attention, by creating as much annoyance as possible. And of course, blipping their engines while stopped, to further annoy everyone around them. This is not something unique to harley riders, but does seem to be much more of a harley thing than for owners of other brands. The "loud pipes saves lives" is nonsense. The places in this country where there are restrictions on motorcycles is almost always based upon the bikes making excessive noise. If you want more power, buy a different motorcycle.
    bingo!

    Those who say " I can't" will always be right.
    2014 RT Limited , pewter (magnesium?)

  11. #11
    Very Active Member
    Join Date
    Sep 2018
    Location
    Australia
    Posts
    786
    Spyder Garage
    1

    Default

    Quote Originally Posted by vito1943 View Post
    ..... The places in this country where there are restrictions on motorcycles is almost always based upon the bikes making excessive noise. .....
    Quote Originally Posted by cruisinTX View Post
    bingo!
    Evidence???????????
    You guys amuse me, have you forgotten why we ride, why we extract every possible visceral moment from our lives, or are you asleep at the wheel like the rest of them?
    Couldn't possibly be a psychopathic bunch of power-hungry motorcycle hating bureaucrats trying to justify their mundane existence from the luxury of their self-imposed square box imprisonment could it?
    Last edited by Peter Aawen; 03-08-2023 at 05:26 PM. Reason: Fixed quote display + ;-)
    2017 F3S Daytona , Circuit Yellow Metalic

  12. #12
    Very Active Member FrogmanDave's Avatar
    Join Date
    Oct 2021
    Location
    Wichita, KS
    Posts
    957
    Spyder Garage
    0

    Default

    Quote Originally Posted by Cobwebs View Post
    Evidence???????????
    You guys amuse me, have you forgotten why we ride, why we extract every possible visceral moment from our lives, or are you asleep at the wheel like the rest of them?
    Couldn't possibly be a psychopathic bunch of power-hungry motorcycle hating bureaucrats trying to justify their mundane existence from the luxury of their self-imposed square box imprisonment could it?
    Could you please tell us how you really feel?
    Last edited by Peter Aawen; 03-08-2023 at 05:27 PM. Reason: Fixed quote display ;-)
    2022 Petrol Metallic RT Limited / 'PYDER'
    There's no place like G28 X0 Y0 Z0

  13. #13
    Member
    Join Date
    Dec 2022
    Location
    Northwestern ontario
    Posts
    7
    Spyder Garage
    0

    Default

    I wholeheartedly agree!��

  14. #14
    Very Active Member
    Join Date
    Sep 2008
    Location
    TX
    Posts
    787
    Spyder Garage
    1

    Default

    Perhaps it is terminology in the Spyder world: that being primary and secondary muffler terms in the exhaust system. While the muffler, especially in a car, if far removed from the exhaust port, the header system, exhaust pipe, catalytic converter are all prior to the location of the muffler. Horsepower, torque, and fuel efficiency are all affected by the design of the exhaust system, not just the muffler. Efficient scavaging of the spent air/fuel mixture is needed develop maximum horsepower, hence the short header pipes emitting burning exhaust on a drag racing engine develop maximum hp. Those engines also rate very low on fuel efficiency. Beyond theory, show me a dyno report to document any changes. Seat-of-the-pants dyno testing is relative but not accurate.

    BTW, torque is a basic design parameter of the engine when looking at bore vs stroke vs combustion, and swept cylinder volume vs combustion chamber volume, relationships. It is affected by air/fuel charge into the cylinder and combustion efficiency.
    pauly1 - SpyderDeb's 'wrench'
    2018 F3-T & 2015 F3-S Road Warrior Foundation Tribute customs
    IBA #48220 SS1000 BB1500
    2015 F3-S , OEM na Basic Black with Custom Wrap

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •