# Long or Short



## AaronGough (Nov 20, 2008)

Hey guys, I am really looking into buying a set of headers to finishe off the exhaust on my goat, and I have been wondering which would be suitable for more power, or should I say more bang for my buck, The long tube headers or short tube. I have heard different stories about the both but am not sure which one to go with for this car.


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## AaronGough (Nov 20, 2008)

Oh and if anyone has actual dyno proof of what which ones will do the best or where i can go online to look at dyno sheets for all kinds and brands.


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## Aramz06 (Mar 2, 2008)

Usually the LT's will outperform Shorties, but like most people do... if you don't have Major plans for your car, go with the shorties, they are cheaper.


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## AaronGough (Nov 20, 2008)

Thanks, that just helped me decide on which route to take. I will deffinately be doing some major work in the future so long tube it is. Again thanks a lot.


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## B-ville Goat (Oct 5, 2008)

I love my Edelbrock shorties. The guy that dyno tuned my car was happy with the quality, and my car put down just shy of what many long tube cars put down. I couldn't see spending almost 2 grand for long tubes and mids to gain an extra 5-10 horses.


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## svede1212 (Nov 1, 2005)

exhausts are a much more complicated subject than it at first appears. the purpose of a header is to maximize the "scavenging effect". most people i've talked to think of exhaust only as flow. a good exhaust is actually tuned just like a pipe organ. the sound (a pressure wave) travels at the speed of sound while the gases travel at the speed of the actual flow. they are not the same. the pressure wave travels down the primary tube to the end and then back up it (just like sound can travel against the wind) and timed right creates a low pressure area as the next pulse of gas comes down. because it's a sound wave the length can't be compromised anymore than a speaker box or pipe organ can. it needs to be a certain length at a certain frequency (RPM). that said shorties can't do the same job making power a properly tuned long pipe can (that's also why shorties work a little better "down low". it's a lower frequency). the other factor is diameter. it's important that the speed of the gases remain high. too large of a pipe (more important in the catback) and the gases slow down and cool and kind of slug up the system. too small and you create back pressure which despite what some think isn't good. like i said it's complicated but LTs trump STs if you want power in your power bandwidth.


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## 6QTS11OZ (Mar 27, 2005)

My set up is geared for low end grunt thanks to the Maggie so for me shorties were the best option. 

Buy which ever is best for the set up you're going after. Just because LT's make more hp doesn't necessarily mean that it's the better choice.


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## AaronGough (Nov 20, 2008)

I agree with you completely about the difference in long or short tube but at the same time you have to put into consideration the type of headers you want for the application you will have. Say like if you are going NA or supercharged then most of the time you want to run with long tube headers, but turbocharging is just opposite. In the turbo system you aren't looking for a scavenging effect as much as you want to be able to spin the turbo to full RPM or get the most boost out of it as you can without damaging the motor of course. The most important thing in looking for a manifold for a turbo system is not so much the length or diameter of the piping but what the header or manifold material is made of. You want something that can handle an extreme amount of heat. Now in the case of STS turbo systems that mount after the cats, one might want to go with a long tube small diameter header set to not only scavenge the motor of the exhaust but also to get a little more flow and pressure to the turbo, in which if anyone has tried this system, please post something cause I am really interested in hearing what kind of numbers they made. STS claims that you can get 7 psi with this system. If is true then it would deffinately benefit in more than one way for a car looking to put down just a little boost.


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## Rukee (Feb 8, 2007)

I thought long tubes = more power but no chance of passing a sniff test.
Short tube header = not as much power, but could/may pass a sniffer test.
Or am I totally off base here?


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## REDGTO89 (Jul 19, 2008)

Rukee said:


> I thought long tubes = more power but no chance of passing a sniff test.
> Short tube header = not as much power, but could/may pass a sniffer test.
> Or am I totally off base here?


:agree






thats what i thought to!!:willy:


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## Aramz06 (Mar 2, 2008)

svede1212 said:


> exhausts are a much more complicated subject than it at first appears. *the purpose of a header is to maximize the "scavenging effect".* most people i've talked to think of exhaust only as flow. a good exhaust is actually tuned just like a pipe organ. the sound (a pressure wave) travels at the speed of sound while the gases travel at the speed of the actual flow. they are not the same. the pressure wave travels down the primary tube to the end and then back up it (just like sound can travel against the wind) and timed right creates a low pressure area as the next pulse of gas comes down. because it's a sound wave the length can't be compromised anymore than a speaker box or pipe organ can. it needs to be a certain length at a certain frequency (RPM). that said shorties can't do the same job making power a properly tuned long pipe can (that's also why shorties work a little better "down low". it's a lower frequency). the other factor is diameter. it's important that the speed of the gases remain high. too large of a pipe (more important in the catback) and the gases slow down and cool and kind of slug up the system. too small and you create back pressure which despite what some think isn't good. like i said it's complicated but LTs trump STs if you want power in your power bandwidth.


I'm really learning alot from this thread, but I'm not really getting why we want a "scavenging effect, can someone explain this please?


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## Rukee (Feb 8, 2007)

The exhaust gasses pulsate as they come out the pipe with each cylinder's exhaust stroke. As one pulsation stops you want the next one to start with no overlap of the pulsations. So then the whole exhaust pipe diameter is only being filled by one cylinder of exhaust gas at a time, followed by the next, followed by the next. So done correctly it 'scavenges' as much HP as possable by tuning the pulsations so there is no overlap of the cyinder's exhaust gasses inside the exhaust pipe. Hope this helps.


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## Aramz06 (Mar 2, 2008)

Rukee said:


> The exhaust gasses pulsate as they come out the pipe with each cylinder's exhaust stroke. As one pulsation stops you want the next one to start with no overlap of the pulsations. So then the whole exhaust pipe diameter is only being filled by one cylinder of exhaust gas at a time, followed by the next, followed by the next. So done correctly it 'scavenges' as much HP as possable by tuning the pulsations so there is no overlap of the cyinder's exhaust gasses inside the exhaust pipe. Hope this helps.


I get it now, well put Rukee, so for good scavenging, is it better to have a larger diameter exhaust pipe to get as much pulse flow as possible or on the smaller side to keep the pulses in line, and to keep as little overlapping as possible?


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## Rukee (Feb 8, 2007)

Aramz06 said:


> I get it now, well put Rukee, so for good scavenging, is it better to have a larger diameter exhaust pipe to get as much pulse flow as possible or on the smaller side to keep the pulses in line, and to keep as little overlapping as possible?


The diameter is matched to the flow of the engine, the pulses are kept in line and kept from overlapping by the 'tuned' length of each exhaust pipe between the header mounting flange and the 4-into-1 collector. That's why there are 4 different tubes between the flange and the collector, each one is 'tuned' to prevent overlapping of the exhaust pulses and thus 'scavanging HP'.


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## Aramz06 (Mar 2, 2008)

Sounds good, thanks for the explanation Rukee. :cheers


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## GM4life (Mar 18, 2007)

6QTS11OZ said:


> Buy which ever is best for the set up you're going after. Just because LT's make more hp doesn't necessarily mean that it's the better choice.


:agree


Rukee said:


> I thought long tubes = more power but no chance of passing a sniff test.
> Short tube header = not as much power, but could/may pass a sniffer test.
> Or am I totally off base here?


You can still pass the sniffer with LT's if tuned correctly and have cats but it won't pass a visual in some states.


Rukee said:


> The exhaust gasses pulsate as they come out the pipe with each cylinder's exhaust stroke. As one pulsation stops you want the next one to start with no overlap of the pulsations. So then the whole exhaust pipe diameter is only being filled by one cylinder of exhaust gas at a time, followed by the next, followed by the next. So done correctly it 'scavenges' as much HP as possable by tuning the pulsations so there is no overlap of the cyinder's exhaust gasses inside the exhaust pipe. Hope this helps.


:agree Rukee is on point.


One thing that is not mention is the primary pipe diameter, little more important than pipe length because of exhaust gas velocity. Many people think bigger is better, wrong. Smaller tubes have higher velocity and can help the exhaust gasses excape from the chamber at lower engine speeds this helps increase low end torque. The same small tubes become a restriction at high engine speeds. Large pipe diameter pipes do the opposite they tend to slow down the flow of exhaust at low to mid engine speeds and leave some of the exhaust gas in the chamber. You can't burn exhaust twice, thus not as much power down low. The engine is an air pump, and where does you engine spends the most time.


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## WanaGTO (Sep 7, 2008)

This thread is seriously making me reconsider going with shorties over the longtubes. Im fairly certain that I am going to go with a turbo set up...BUT the LS2 is a top end type of car so I always wanted to build off of that. Now, Im confused.


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