Approximate HP increase between stock and full aftermarket exhaust?

Discussion in 'Engine and Performance mods' started by dx3, May 31, 2011.

  1. dx3

    dx3 Registered

    Guys,

    Does anyone have any numbers on HP gains by adding a full exhaust (Yosh) over just adding bolt on cans, over staying stock.

    Basically, is the $1000 for the full system (headers etc.) worth it for power, or moreso just for looks/sound?

    This would be on a Gen I.

    Thanks,
    Jonny
     
  2. BusaWhipped

    BusaWhipped Moderator

    I picked up 11hp, 6ft#s with the 4-2-1 high mount HMF. The high mount doesn't produce the biggest numbers.
     
  3. jch364

    jch364 Registered

    it would depend on the exhaust you decide on. either way you would want to get it tuned and do the airbox mod and get rid of the pair valve. if you get a brock exhaust and get a powercommander you can get the map from him. if you get it tuned you can do the ecu editor instead of the pc. its better i think. I got the alien head myself. i would bet somewhere between 5 and 10 with a tune or map from brock. plus you drop a good amount of weight so that helps all by itself. just doing the exhaust without tuning i think is conter productive. jmo
     
  4. Busa1166

    Busa1166 Donating Member

    A lot of money for 11 hp :whistle: just saying :hide: :laugh:
     
  5. H2447INTX

    H2447INTX Registered

    HP is not cheap !!!!!!!!!!!!!!!
     
  6. Busa1166

    Busa1166 Donating Member

    It's turbo or nothing ::25 :laugh:
     
  7. Shinobi'sZ

    Shinobi'sZ Registered

  8. dadofthree

    dadofthree Seasoned Beef Donating Member

    Most manufacturers post up their expected gains. From memory Yosh around 5 RWHP and Brocks around 12 - 15 RWHP. I haven't looked at the many, many others available. Check out their websites.

    Slip-ons don't do a lot for you and can hurt you. With the full systems you also reduce the weight of the bike.

    I don't remember how many set ups he tested, but GPW did a lot of testing if you do a search.
     
  9. Commuta_Busa

    Commuta_Busa Donating Member

    say about 10hp which is around a 5% increase in power. The other thing you gain with a full system is a drop in overall weight which means less hp needed to accelerate the bike.

    slip-ons are good to add change the look of the bike and make a little more noise.
     
  10. PaLVBusa

    PaLVBusa Registered

    You'll gain the most with a brocks system; however, your gonna pay more then 1000 for them in "MOST" cases... Unless you find used or a good deal somewhere.
     
  11. Shinobi'sZ

    Shinobi'sZ Registered

    I think something that was mentioned but needs a little more emphasis is that there is an equivalent to hp in dropping weight. I am forgetting what it is exactly but for every 10lbs that is dropped drops 1/10th or something like that in the 1/4 mile. So if you look at it that way...gaining 10/6 hp/tq and dropping 30lbs...could be like picking up almost .5 second in the 1/4 mile...which for $1K is really good.
     
  12. dx3

    dx3 Registered

    So the stock headers/piping carry more relative weight over aftermarket than the cans do? Note I said "relative" weight...

    Jonny
     
  13. Commuta_Busa

    Commuta_Busa Donating Member

    stock header are heavier than aftermarket and stock cans and cat are heavier as well. At least in most cases.

    Granted just removing stock cans and replacing them with something else does make a largest reduction in weight.
     
  14. Birdoprey

    Birdoprey Registered

    In general, every 22-25lbs you lose off your bike(or rider!) will gain you .1 and 2mph in the 1/4mi.
     
  15. BiggDaddyBusa08

    BiggDaddyBusa08 Registered

    I spent $1200 on a TiForce 4-2-1-2 titanium system. It dropped 20 pounds off the bike compared to the stock exhaust. Im not sure of the HP gain but,b4 the swap my best ET was a 10.32 and after the swap on my 2nd run with the new pipes I ran a 10.18 and the corrected air was nearly the same on those runs(within a few hundred ft). This was on GENII 08 so yeah it was worth it.
     
  16. bisquit61

    bisquit61 Registered

    This sounds about right
     
  17. Busashot

    Busashot Registered

    I agree with the ET but I have never seen trap speed increase that much unless the rider lost weight along with size of rider reduced as well.

    I still believe in 25lbs can give net .10 and 1mph. Technically some say as little as 17lbs will do this but with inconsitencies with riders and conditions, 25lbs is more realistic.

    I also don't know how some people claim more than 10hp from an exhaust on a Gen I. 8-10hp is about all I have seen from at least 5 different exhaust systems ranging from Akrapovic, D&D, Yoshimura and Brock GEN3 systems and that is with a tune. Now maybe the sidewinders might give a slight increase over these but the Gen I Busa is a really mild setup from the factory which doesn't get the increases like some of the other Jap bikes. I remember putting on a Hindle step exhaust on several ZX12s and they all gained between 14-16hp without a tune. Put in a tune and another 3-5hp could be seen.
     
  18. Birdoprey

    Birdoprey Registered

    I have seen 1.5-2mph gain by dropping 22-23lbs. Just said "in general" and figured that was close enough for a game of hand grenades:laugh:
    I may not know what I'm talking about though...???
    I can barely stay on the bike while going down the track::4
     
  19. dadofthree

    dadofthree Seasoned Beef Donating Member

    You really need a shifter for the drag strip don't ya brother ::25
     
  20. Birdoprey

    Birdoprey Registered

    That's what my problem was!:thumbsup:

    I've heard claims that an air shifter will allow one to knock off .1-.3 in the 1/4mi on a stock wheelbase bike. I did most of my passes foot shifting but did a comparison at the track with one. I made 2 passes with and then 2 passes without. Did this for 8 passes and saw no gain what so ever in ET or mph. Btw, I was clutchless shifting. All 8 passes were within .07 from best to worst. Air shifter passes were not grouped at one end or the other. I will admit that I had less to pay attention to! I like them...::4
     

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