BBK shorty headers

Discussion in 'SN95 4.6L Mustang Tech' started by fast97gt, Feb 19, 2010.


  1. fast97gt

    fast97gt Active Member

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    for the money are the bbk shorty headers worht it, i dont like the look of the long tubes and dont like the ideas of the mid length. another reason for the shortys is i want to retain the factory style of the way they bolt up, i have the bassai o/r-x bolted to the stock manifolds, so i know these headers will bolt up as a direct bolt on. and is true the claim of ~8-12hp:shrug:
     
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  2. Midnight2V

    Midnight2V Member

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    Shorties don't give you anything except a lighter wallet and a conversation topic. Waste of money and time as far as performance is concerned. Exhaust flow is not an issue on the 4.6, it simply isn't a restriction. Effective scavenging is however,and the only way to get it is tuned length long tube headers.
     
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  3. D-BOI

    D-BOI Member

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    from what i have read on the forums, i get the idea that either go long tubes or keep the stock ones because shortys are a waste of money for the couple of hp you will gain.
     
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  4. fast97gt

    fast97gt Active Member

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    the shortys a far more cheaper then the long tubes, and they dont give much more then the shortys anyway. however im installing my pi motor in my 97gt so itll save time and be a lot easier for the install at that time, and the bbks that im looking at are tuned shortys
     
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  5. JerseyTrueBlue

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    Buy them, if you want to do headers then do it don't let opinions hold you back. You will get a few horses and isn't every horse worth it? Not to mention a bit better throttle response and the great sound :D I have the BBK's and am very happy with them.
     
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  6. Ryan441

    Ryan441 New Member

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    it deff. gives it a distinct sound and picked up alot by the sotps meter. btw scavanging has nothing todo with long, mid, or short type headers it has to be tuned so some of your exhaust will actually bounce back into the cyclinder and pull out the exhaust of the next ignition cycle.
     
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  7. Winters98GT

    Winters98GT Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!
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    They gained 0 hp on my ported PI headswap car. Worthless. Save your money.
     
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  8. Midnight2V

    Midnight2V Member

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    Not exactly Ryan441, its the pressure wave that bounces back from the collector, not the actual exhaust. You want the "low pressure wave" to get back to the exhaust valve at about the same time as the valve event starts. The pressure wave travels at the speed of sound and bounces back way to soon in shorties and even midlength headers. Depending on your cam profile you will need between 24 to 28 inches from valve to collector. This also includes the length of the exhaust port in the cylinder head. That is what is referred to as "tuned length", it has nothing to do with the electronic tune on the ECM.
     
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  9. Ryan441

    Ryan441 New Member

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    i never said it had anything to do with the ecm. that basicly what i said except why would the "sound wave" bounce back at the collector?


    regardless if the motor is out of the car there really isnt any reason not to. if anything it sounds alot better
     
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  10. fast97gt

    fast97gt Active Member

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    thanks ryan, surely if it sounds any better i would die. it already sounds like a 4valve, check it out on youtube. all of my vids are under fast97gt.
     
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  11. Midnight2V

    Midnight2V Member

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    It's not a sound wave, its a pressure wave which simply happens to travel at the speed of sound.

    It starts out as a high pressure wave leaving the cylinder as the exhaust valve opens and the wave goes down the exhaust port and header, this is an exhaust pulse. When it gets to the collector, this wave spreads out and decreases in pressure due to the larger volume and lowering gas temperature.

    This new lower pressure wave (much lower than the exhaust pulse pressure) spreads back up the header to the exhaust port(at the speed of sound).

    If timed correctly, the wave arrives just as the exhaust valve opens. This causes some of the cylinder gases to be pulled out of the cylinder due to the difference in pressure across the exhaust valve instead of being pumped out by the piston.

    This reduction in pumping loss is the exhaust scavenging affect, and is the source of the extra horsepower tuned length headers deliver. Scavenging relies on good timing between the exhaust valve events and the distance to the collector. You simply can't get any level of effective scavenging in shorties because the pressure wave has already bounced back to the exhaust valve and dissipated by the time the next valve event ocurrs.

    In truth stock manifolds flow better than shorties, you are pumping the gasses through less pipe length. The only reason that longtubes are not stock pieces, is they are not good for use with catalytic converters. Because the gases cool much more prior to reaching the converter than stock manifolds, the converters light off much later or not at all. The converter then fails to burn off exhaust fumes for a much longer period of time.
     
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  12. fast97gt

    fast97gt Active Member

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    well from what ive seen today of the design of the stock peices, a round exhaust port form the head into the manifold which is rectanguler in shape has to have some sort of restricting flow. i guess thats just me, but from common knowledge round pegs go into round holes a lot smoother and faster found pegs going into rectangles that are the same volume if you will.
     
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  13. Rickyll7

    Rickyll7 Member

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    ok. so go get a dyno reading before and after with no other changes.
     
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  14. fast97gt

    fast97gt Active Member

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    well that wont do either, because ther going on a pi motor, then thats going in my npi 97gt. i will say the pi engine will get the current boltons that my npi has on it.
     
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  15. Ryan441

    Ryan441 New Member

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    how about this ill dyno my car with the complete unmolested pi motor with bbk shorties mac-x pipe and magnaflow catback along with a steeda cai. the shorties are easier and work well you can sit here and say they dont work at all or work great, but what it comes down to is combonation. ie. cams w/out exhaust is stupid, or cams with the wrong intake or headers with the stock exhaust. just run everything in combo. my car with those worthless headers a mac h-pipe and stock mufflers along with homemade intake, 10:1 pistons out of a mark VIII ran door to door with a 04 mach1 w/ exhaust and intake
     
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  16. Nightfire

    Nightfire Mustang Master

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    I can't believe that there are actually idiots that honestly feel that aftermarket shorty headers are a valuable mod and that they truly offer increased performance.

    Aftermarket shorty headers are to a Mustang as the Turbonator is to any car. The only "performance difference" is your lighter wallet. But then again, if you're dumb enough to buy shorty headers than you deserve to lose that amount of money.
     
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  17. Winters98GT

    Winters98GT Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!
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    What the heck is your point? I spanked a Hennessey Viper that had 300hp more than me in 2001 in high school. I cut a light, hooked, and ran a 13.22 to his 13.05, even though he trapped 14mph faster than me. Was my car faster? No, He had a mid/low 11 second car, at the least.


    Shorty headers are not worth it on an NA 2v PI car. It doesn't matter if the motor is out of the car. Just not worth it. You will be lucky to gain 1hp, and any trap speed. I've done it twice, one with the motor in, and once out. Gained nothing. I thought I would have learned the first time. Stupid to do it again.

    Feel free to spend your money however you like, but take in to consideration those that have done this before. Shorty headers on an NA 2v has been a no brainer for 10 years. Not worth it.
     
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  18. 007

    007
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    I gained very little by the SOTP meter. It changed the way the exhaust sounds. Thats about it.
     
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  19. fast97gt

    fast97gt Active Member

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    im hearing all the talk about horsepower, what about torque? like i said from what i saw of the stock manifolds to the wide open header design they gotta be better over all.
     
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  20. 98COBRA281

    98COBRA281 Active Member

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    shorites suck! you can get some flowtech longtubes for about $280 from summit, and there a decent header! i have them..........
     
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