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-   -   Equal length Pipes are wrong (http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/810345-equal-length-pipes-wrong.html)

Robbbyg 05-08-2014 09:23 PM

Equal length Pipes are wrong
 
How can they be efficent if the hot air is hitting at the same time??!
shouldnt they be lengthened/ made with the firing order of the engine in mind? for the Most efficent air delivery?:confused:

Well that's my view on it, anyone try it?:D

quattrorunner 05-08-2014 09:40 PM

It's not the same time if the engine has a fireing order.

Maltese Falcon 05-08-2014 11:16 PM

Everybody buy some u-bends, j-bends, and straight sections from Jegs or Summit.
Start putting together some various headers like;
equal length, pulse tuned length, 180 , tri-y, 6 into 1. Then build all of these one more time, but in step-tube sizes.
Then lets install and run on the dyno for comparisons of rwhp/Tq.
Keep in mind that forced induction engines push exhaust gasses around different from n/a engines, yet another variable in the design criteria.
Lots of work ahead of us !
Marty

willtel 05-09-2014 04:49 AM

Quote:

Originally Posted by Maltese Falcon (Post 8055704)
Everybody buy some u-bends, j-bends, and straight sections from Jegs or Summit.
Start putting together some various headers like;
equal length, pulse tuned length, 180 , tri-y, 6 into 1. Then build all of these one more time, but in step-tube sizes.
Then lets install and run on the dyno for comparisons of rwhp/Tq.
Keep in mind that forced induction engines push exhaust gasses around different from n/a engines, yet another variable in the design criteria.
Lots of work ahead of us !
Marty

Can we use zip-ties and bungee cords to hold them together? I'm not confident in my welding skills.

Tilikum Turbo 05-09-2014 07:56 AM

Your lead-in to the question "are wrong" and then proposing a "view" is a disconnect in logic.

16Volt 05-09-2014 08:28 AM

Quote:

Originally Posted by willtel (Post 8055845)
Can we use zip-ties and bungee cords to hold them together? I'm not confident in my welding skills.

JB Weld.

T77911S 05-09-2014 09:56 AM

Quote:

Originally Posted by Robbbyg (Post 8055674)
How can they be efficent if the hot air is hitting at the same time??!
shouldnt they be lengthened/ made with the firing order of the engine in mind? for the Most efficent air delivery?:confused:

Well that's my view on it, anyone try it?:D

i think i know what you are trying to say, so look at it this way.

if all the pipes are the same length, then the fact that no 2 cyclinders fire at the same time, there will be no chance of 2 exhaust gases trying to occupy the same space at the same time since each one travels the same distance. cut #1 long and #2 short, they could try to combine at the same time where the 2 pipes come together since #1 fires then 6 then #2.

far from expert here but i think it really comes down to equal back pressure and makeing each cyclinder produce the same power. also, if you have one cyclinder with a short pipe producing less back pressure, that could lean out that cylinder, or make you richen the others to compensate.

S1000RR 05-09-2014 10:54 AM

Track, hi RPM, open exhaust: equals
Street: shortys

atcjorg 05-09-2014 12:45 PM

if he has a tool box somebody needs to weld it shut!!!!!!!!

Ken911 05-09-2014 02:14 PM

OK i know I'm going to get a lot of negative feedback here. But here goes. For a forced induction engine equal length headers are useless. The fact that there is a turbocharger in the line causes back pressure which negates any scavenging effect of having the pulses of each exhaust valve opening and closing being lined up. The best bet for a forced induction set of headers is the smallest volume ie shorties length possible to reduce turbo lag. Now there is an exception for the twin scroll versions since the sides have to be balanced to take advantage of it. I have talked to a few people who have actually tested this on a dyno and they confirmed what i was thinking. Equal length headers are designed for normally aspirated motors so that the exhaust pulses line up behind one another ans they flow into the collector. This results in a vacuum scavenging effect in the primaries and increased flow through the exhaust valves. Any way chose to believe it or not but if there really was anything to gain by equal length headers on a turbo motor all of the factory race teams would have used them. Instead they went with shorties on the 935's and also later turbo 3.6's etc.

copbait73 05-09-2014 03:51 PM

You may want to check out what ALL high performance turbo motors (F1, Indy, IMSA, etc.) do with their headers.

quattrorunner 05-09-2014 04:02 PM

Why are we talking about this?

Ronnie's.930 05-09-2014 04:09 PM

Quote:

Originally Posted by quattrorunner (Post 8056757)
Why are we talking about this?

Probably because Robby wanted a diversion from trying to unfu@k that insane mess he made of his fuse/relay panel! :D

OldSpool87 05-09-2014 04:42 PM

That was pretty funny. God bless that fuse panel and props to guy who took it on. Just to clarify, "unf@ck" is German for "reorganize" right?

Ronnie's.930 05-09-2014 04:52 PM

Quote:

Originally Posted by OldSpool87 (Post 8056808)
Just to clarify, "unf@ck" is German for "reorganize" right?

Nope, it's definitely "Texan" in origin! Or as Paul would say, originates from TexASS! But yes, you've got the translation spot on! :D

RarlyL8 05-09-2014 05:07 PM

I did a fair amount of header research when designing our equal length 930 headers. Conventional wisdom at the time was the shorter the better. Turned out that was only half the story. The full story was the shorter the equal length the better. What true equal length primaries and secondaries do for you in a turbo application is allow the engine to produce more torque off boost and then to produce more peak power on boost. This is in a street application mind you, racing is a whole different ballgame. I dyno tested every system I could get my hands on using the same engine. The equal length system is magic. The tuned sound alone was worth the effort. The key is for each pulse to reach the turbo in the same timing as the firing order, not a mish mash of odd fire pulses. Each pulse hits the turbine in a coordinated efficient beat.
Building short tube headers is easy and gives you a high percentage of gain over standard heat exchangers. I would not have gone to all the effort and expense to build a tuned system if it had no added benefit. This is not a new or unique idea.


http://forums.pelicanparts.com/uploa...1399684032.jpg

full quack 05-09-2014 06:10 PM

I'm with Brian, full quantitative science over conjecture.....remember math & science do not lie!

Mark

Robbbyg 05-09-2014 08:06 PM

Quote:

Originally Posted by Ronnie's.930 (Post 8056768)
Probably because Robby wanted a diversion from trying to unfu@k that insane mess he made of his fuse/relay panel! :D


HAHAHA bugger ive been found out :rolleyes::D

Actually its not too bad ive actually inadvertently installed a 4 point floaing suspension system for my relay panel, its completely unaffected by bumps.. :D


http://forums.pelicanparts.com/uploa...1399694723.jpg

Robbbyg 05-09-2014 08:15 PM

[QUOTE=RarlyL8;8056849]I did a fair amount of header research when designing our equal length 930 headers. Conventional wisdom at the time was the shorter the better. Turned out that was only half the story. The full story was the shorter the equal length the better. What true equal length primaries and secondaries do for you in a turbo application is allow the engine to produce more torque off boost and then to produce more peak power on boost. This is in a street application mind you, racing is a whole different ballgame. I dyno tested every system I could get my hands on using the same engine. The equal length system is magic. The tuned sound alone was worth the effort. The key is for each pulse to reach the turbo in the same timing as the firing order, not a mish mash of odd fire pulses. Each pulse hits the turbine in a coordinated efficient beat.
Building short tube headers is easy and gives you a high percentage of gain over standard heat exchangers. I would not have gone to all the effort and expense to build a tuned system if it had no added benefit. This is not a new or unique idea.


I was waiting to hear for some live facts thankyou
But and im sure this has been argued, and i think we already have sort of..

Definitively between a NA and Turbo motor????

diameters of pipes?

I read Corky Bells Turbo book and there is a consensus that Bigger is not always better in turboed motors, ie one site promotes the fact that you can roll a tennis ball down their pipes as theyre so large,

So Equal length is good!

But Velocity?

If i went out and got large diameter headers put on my engine with my little 3ldz would i have slower time to max boost?


and small diameter headers, Faster time to Max Boost?

Robbbyg 05-09-2014 08:19 PM

Quote:

Originally Posted by OldSpool87 (Post 8056808)
That was pretty funny. God bless that fuse panel and props to guy who took it on. Just to clarify, "unf@ck" is German for "reorganize" right?

yeah theyre all jealous of my inventiveness :)


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