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-   -   Shorty Headers with short or long collectors? (http://www.hotrodders.com/forum/shorty-headers-short-long-collectors-223321.html)

Cridder 08-25-2012 02:02 AM

Shorty Headers with short or long collectors?
 
The headers for my 88 S-10 are 1 5/8" shorty's with a collector thats like 2 inch's long, i was thinking of extending the collectors out to 18" , i was thinking this mite act like an expansion chamber, maybe create a quazi long tube header effect and broaden the power range a little more off the bottom hopefully without hurtin the low end to much. any ideas? experience.

bigdog7373 08-25-2012 10:45 AM

I dont think it will do anything. The long tube headers are better because of the longer primary tubes, not the collectors.

cdminter59 08-25-2012 12:22 PM

Long primaries or shorty headers?
 
You need to read this article from Sanderson Headers so you can make a more informed decision. Let's get technical. The biggest controversy in header design is the "equal length" versus "shorty" styles - which is best?

vinniekq2 08-26-2012 09:36 AM

contact jere stahl,they know more there about headers than anyone Ivetalked to before

Cridder 08-26-2012 11:35 PM

The long and short of it
 
From what i,'ve been reading collector length don't get much consideration, seems to be all about tube size, diameter of the primary's and the exhaust pipe.
1.625" Primary's and 2.5" pipe is good to like 5-550 horse.
I ran the optimizer in my Engine Analyzer +3.2 and it looks like long collectors help the mid a little bit at the cost of top end. long primary's on the other hand pay big dividends on top. I need a header for S-10 chassis thats got 41" primary's.

vinniekq2 08-26-2012 11:42 PM

cridder,did you contact jere stahl? do you remember him?

Cridder 08-27-2012 01:05 AM

Talkin to jerry
 
Quote:

Originally Posted by vinniekq2 (Post 1586215)
cridder,did you contact jere stahl? do you remember him?

That would reqiuere me (shiftworker) getting up before 4pm, checked out the web site though, some really good info.

oldbogie 08-27-2012 10:42 AM

Quote:

Originally Posted by Cridder (Post 1585775)
The headers for my 88 S-10 are 1 5/8" shorty's with a collector thats like 2 inch's long, i was thinking of extending the collectors out to 18" , i was thinking this mite act like an expansion chamber, maybe create a quazi long tube header effect and broaden the power range a little more off the bottom hopefully without hurtin the low end to much. any ideas? experience.

You are on the right track, the issue in this case is how to create and manage a returning negative pressure wave. Now be aware that no matter what you do you cannot duplicate the effect of full length tubes empting into a suitable collector; but by adding enough collector length to shorties so that the total length of the shorty and the attached collector is about the same as a set of long tubes with their collector. However in the case of the shorties with long collector the collector needs to either end into the atmosphere or into a large resonator box, so as to trip the return signal. However, given the signals will be diluted there will not be the hard pull from the exhaust on each cylinder at certain RPMs because that level of harmonic tune just won't be there. Keep in mind that long tubes do not continuously optimize this, the harmonic tune frequencies come and go with RPMs and they can be as much a negative element on making power at one RPM as they are a positive one at other RPMs. This is very apparent on raw dyno readings where the power is rising and falling within a band of general rising. Most of the dyno data you see published is smoothed; the real world is seldom like that. On a positive note, diluting out the signal peaks will tend to remove these up and down power excursions. For a street driven engine that sees most of its time in a moderate RPM range this stability can be a good thing for operating efficiencies at cruise rather than tuning to a peak power output at a high RPM that is seldom seen in normal use. The late model Ford Mustang gets by very well with shorty headers, thank you very much.
Bogie

Cridder 08-28-2012 05:35 PM

Headman, Flowtec, Hooker, etc
 
Headman, Flowtec, Hooker, etc...these people must have stacks of dyno sheets and reams of info on exhaut systems, they can't share that dope with us cause it's gona turn into a war of numbers, well i geuss david vizard and hotrod magazine are gona save the day.


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