headers= loss of power? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cochino12 · 11-20-2003, 01:15 PM

Is it true switching from full length headers to shorty headers would result in a loss of power. I was told I dropped about 10-15 hp when I swithed to my shortys.

bigblock73 · 11-20-2003, 02:05 PM

Full length headers will flow the best, so if you think about it, anything less won't flow/perform as well and there will be a slight decrease in power. I don't think a 10-15 HP loss is realistic...maybe 2-3 or so. A 10-15 loss wold be like going to full length headers to exhaust manifolds.

-Jeff

81lwb350 · 11-20-2003, 02:20 PM

i was told that full length headers give more torque than shorty's.

bigblock73 · 11-20-2003, 02:23 PM

Avatar time 81lwb350!!!

-Jeff

loweredd · 11-20-2003, 03:40 PM

I agree with the full length to manifolds. My truck cant even get out of its way now. I had to ditch my full lengths and put on manifolds when I bagged it. I need to find some shorties now for sure!

81lwb350 · 11-20-2003, 07:41 PM

whoo hooo.....finally 100 posts......whoo hoo......gotta get me an avatar....whoo hoooooooooooooo...

sorry to hijack this thread....
not something i usually do!.... lol

cgrossl · 11-20-2003, 09:44 PM

The header primary length and the collector length have a bigger affect on what RPM that peak power is achieved rather than how much. Shorter primary tubes will result in horsepower and torque peaks that come at a higher RPM. Longer primary tubes will result in horsepower and torqe peaks that come at a lower RPM. There probably won't be much of a difference in the peak number, just at what RPM it occurs at. In a truck, you would probably be much better off with full length headers.

If you really want to know alot more about this, go to http://www.headerdesign.com/ and start reading. There is also a free calculator that will calculate the optimum primary size and length, and the optimum collector size and length. You will probably be surprised to find out that most headers out there aren't designed very efficiently.

stepside454 · 11-30-2003, 10:35 PM

I switched from full length to Sanderson Shortys on my 454 C10. if I lost anything on bottom, it hasnt hurt me.. but it does feel stronger on top.

11-20-2003, 01:15 PM	#1
cochino12 It followed me home? Join Date: Mar 2003 Location: Yup Posts: 5,751	headers= loss of power? Is it true switching from full length headers to shorty headers would result in a loss of power. I was told I dropped about 10-15 hp when I swithed to my shortys. __________________ Adam That's why they call it a shortcut Kyle, if it was easy it would just be the way. 86 c-10 SWB 85 CCSB 90 GMC K30 Crew SRW 1985 C30 Dually

11-20-2003, 02:05 PM	#2
bigblock73 yeller Join Date: Oct 2001 Location: Twin Cities Posts: 13,826	Full length headers will flow the best, so if you think about it, anything less won't flow/perform as well and there will be a slight decrease in power. I don't think a 10-15 HP loss is realistic...maybe 2-3 or so. A 10-15 loss wold be like going to full length headers to exhaust manifolds. -Jeff __________________ Jeff 73-87.com 73-87.com Facebook page 73-87 cab corner 6x9 speaker brackets for sale 67-72 cab corner speaker brackets for sale 47-54 cab corner speaker brackets for sale

11-20-2003, 02:20 PM	#3
81lwb350 big block lover Join Date: Jul 2002 Location: louisiana Posts: 107	i was told that full length headers give more torque than shorty's. __________________ 81 custom deluxe lwb 454 bored .030 over w/ small RV cam. 2.5 exaust- thrush turbo muffs. th350 getting beefed up soon!

11-20-2003, 02:23 PM	#4
bigblock73 yeller Join Date: Oct 2001 Location: Twin Cities Posts: 13,826	Avatar time 81lwb350!!! -Jeff __________________ Jeff 73-87.com 73-87.com Facebook page 73-87 cab corner 6x9 speaker brackets for sale 67-72 cab corner speaker brackets for sale 47-54 cab corner speaker brackets for sale

11-20-2003, 07:41 PM	#6
81lwb350 big block lover Join Date: Jul 2002 Location: louisiana Posts: 107	whoo hooo.....finally 100 posts......whoo hoo......gotta get me an avatar....whoo hoooooooooooooo... sorry to hijack this thread.... not something i usually do!.... lol __________________ 81 custom deluxe lwb 454 bored .030 over w/ small RV cam. 2.5 exaust- thrush turbo muffs. th350 getting beefed up soon!

11-20-2003, 03:40 PM	#5
loweredd www.loweredd.com Join Date: Aug 2002 Location: Struble IA Posts: 808	I agree with the full length to manifolds. My truck cant even get out of its way now. I had to ditch my full lengths and put on manifolds when I bagged it. I need to find some shorties now for sure!

11-20-2003, 09:44 PM	#7
cgrossl Registered User Join Date: Oct 2003 Location: Lexington, KY Posts: 151	The header primary length and the collector length have a bigger affect on what RPM that peak power is achieved rather than how much. Shorter primary tubes will result in horsepower and torque peaks that come at a higher RPM. Longer primary tubes will result in horsepower and torqe peaks that come at a lower RPM. There probably won't be much of a difference in the peak number, just at what RPM it occurs at. In a truck, you would probably be much better off with full length headers. If you really want to know alot more about this, go to http://www.headerdesign.com/ and start reading. There is also a free calculator that will calculate the optimum primary size and length, and the optimum collector size and length. You will probably be surprised to find out that most headers out there aren't designed very efficiently.

11-30-2003, 10:35 PM	#8
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	I switched from full length to Sanderson Shortys on my 454 C10. if I lost anything on bottom, it hasnt hurt me.. but it does feel stronger on top. __________________ 75 GMC C-15 short/step factory 454, lowered

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