5.0 mag: BBK longtubes make LESS power than shorties

N8Miller

I need NOS....make it 2 of the big ones
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Jul 26, 2000
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Kingston, PA, USA
i just got the new 5.0 mag and on the cover i was happy to see that they were going a 347 BBK header dyno shootout. they did equal shorties, unequal shorties, 1 5/8 long tubes and 1 3/4 long tubes (which i just bought today).
now, in the dyno, the winner was the unequal shorties at 410 horses. now, everyone says that long tubes are the only way to go with a decent motor buildup. but, the 1 5/8 long tubes only made 404 hp and the 1 3/4s were at 408 hp.
am i missing something? does BBK have a surplus of shorties they need to get rid of? maybe hit up 5.0 with like $500k to imbelish the #s a bit :shrug:

what do you guys think? its the may edition btw and i got it today.
 
I haven't gotten my 5.0 mag yet, sounds interesting. One thing though, it's only four horsepower, hardly something you would notice. You could gain or lose four horsepower from the temperature outside and many other things.
 
just got the mag day also. my uncle had said about the difference between long and short tube headers. That long tubes really don't give you much if any more power if your exhaust is setup right (equal length does help, also tuned headers but only marginal). I think the muffler and routing etc is where more atention should be paid. if you rally think about it, all longtubes are is an extention of the header.. how can that be much different from short tubes?? :shrug: look close, same thing just extended, and about 2x more cost wise, add a little hype to it and whala! money maker!! (my opinion though, mighit be wrog but at least it'll make ya think lol)
 
The soundwaves in the long tubes will reach the 3rd or 4th harmonic which is 3 or 4 times the wavelength of the fundamental frequency,... the fundamental frequency in the open tubes is 1/4 the wavelength. Now depending on the wavelength and how long the tube is, if the length of the tube is the proper length to reace that waves harmonic,... then the sound will increase directly proportional with it,.... this has nothing to do with the flow of the air. Its the sound only. Thats all the help my degree in acoustic engineering will help
 
i think the reason they use long tubes could also be the place the exhaust under the car without haveing to add other exhaust peices. i doubt anyone in there right mind would run shorties with notuing else the exhaustr woudl go right into the engine bay. plus like our accustic engeneer said they sound better. when your talking 3-4 hp, and you have 400, does it really matter otern then the sound, prob not.. maybe if we had an import, but then again they never sound like a v8!
 
From what I always understood is that longtubes are better at exhaust scavenging...and tend to create more torque than the shorties. But how many engines did they test the headers on? Who's to say that the longtubes won't outperform the shorties on a higher hp or more radical engine!?
 
I don't like the 5.0 mag much anymore. They are always coming out with this junk. Remember the one buildup they did comparing a supercharged stock 5.0 to a H/C/I 5.0 setup. First of all they did everything back a$$wards building it the oppisite of how everyone else does it, then added the 70mm tb and lost power after the intake and heads, what a bunch of BS. After all was said and done, they put the S trim on the Edelbrock H/C/I combo and only pulled the low-mid 300hp numbers, a FTI combo makes more completley N/A.
 
axeman said:
funny that majority of nmra racers use long tubes. i guess they wasted their money and countless hours of dyno tuning. :shrug:
I went back to shorties after using longtubes. A couple different brands of LT's also. I'm very happy with my shorties. Made plenty of power with them.
 
Yea, I was always under the impression that longtubes made more power than shorties. Im guessing the way the car was tuned had something to do with it... If it wasn't for emissions testing and ease of installation, I would have gone with longtubes in a heart beat.

Blue89GT, did you gain mph after you installed longtubes?