Thanks for the info these will not be used on the turbo. I guess we could cut the 3" pipe close to primary pipes then mount collectors. We just wanted to chang the ones we run now. the system is 2 X 2 1/4 till the trans mount then single pipe to muffler. What about N/A or a spray system?

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

Thank you Wesola 78 for the coodoes I will get some video with sound soon. Talk to yall later have a good day Don

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

The outside pipes should not point at each other, but face downstream. I would also terminate the header were the individual pipes meet and tie them together with a collector flange. This would be fairly close to what the Dutra's and/or the Clifford shorties are doing.

NA your max tube size is going to be determined by how radical your building the engine, and how fast it turns. To keep velocities high, you want to go with the smallest down tube that won't restrict flow appreciably. How big really is determined by the build. I really don't see needing larger than two 2" down pipes at the engine speeds we normally see. I have Dual Dutra Duals with 2-1/4" head pipes. I wish I'd gone 2". It works, but makes maintenance an absolute bear, and doesn't help scavenging. As I mentioned before, the increased surface area of the head pipes radiates heat like mad.

Keep in mind, any pipe is a restriction. Gasses flowing through a six inch pipe encounter resistance. Every bend, or choke point increases that resistance. For a purely racing application, you just dump at the collector.
This of course makes no points with neighbors, or constabulary out on the street.

If you can shoot for twin two inch down pipes, or maximum 2-1/2", reducing down after the muffler, I think you'll be happier with the power. Depending on what your trying to do, twin 2" joined into a single 2-1/2" back to the muffler, with 1-7/8" or 2" for a tailpipe is more than adequate.
The sound isn't quite as cool as dual exhaust, but it weighs less, and will perform well for most slant six builds. To keep velocity up through a dual system, smaller pipe is needed

I ran a single 3" on my last built up 318LA with excellent results. That system was far too large for most slants.

Doc had a post some place of how he set up his collectors to keep pulses from creating high pressure waves from travelling back up an adjacent pipe.

CJ

_________________
Part of Tyrde-Browne Racing

Hello kesteb are you watching me work. Let say the 3" pipe has been cut where primary tubes enter. There was a diamond shaped pulse deflector in stalled, high enough to deflect #1 and #3 down streamand not shove air up the other ports. Do yall think this will help? So the collectors will be very close to the Dutra connection. Yall can use whatever size pipe after the collectors you think is right no matter where connection is?

We are working A choke pod install on the next set. Thanks for the input Don.

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

No, I don't think that will work. The pipes should all be facing downstream. There may be a "cone" between the pipes to help direct the flow downstream. With the outlets pointing at each other, there will be turbulence, even with a "diverter" plate.

I would take a look at the current "shorty" headers for the newer cars. All of them have unequal length primary tubes and very little collector length. But they do have smooth bends and all the pipes are pointed downstream.

Did you ever come up with some before/after numbers for your headers over the stock exhaust?

I give you an "A" for beautiful, talented, skillful metalwork. That's the good news.

The bad news is I have to give you a "D-" for less-than-zero understanding of exhaust system operational theory. You are taking blind guesses and as a result you are making very pretty but useless items. Try to find a knowledgeable person or persons to team up with. Leave the manifold/header design and specifications to them, then have them leave the buildwork to you. Then you'll be moving forward instead of chasing your tail.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yes we did on the first Powerpipe made ended up with a small gain over stock manifold. The dyno testing is posted on A-Bodys @ this time for viewing, not the ones we have made now.

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

Hello Dan if we take the A and D- does that mean over all grade is a C+ and room to improve. Yes the first thing I will have to admit is, I have a tendency to do things I come up with before testing and I will admit this has been costly in the past. In my defence this also has worked for me in the past with a differant style of enginearing and compition.

We started the standard header design. These will be what I call medium tube header with choke mounting and will connect where the new PowerPipe is at in photos, in the engine compartment. This set will be tested against new and old PowerPipe designs. Alot of the testing will be at Bradenton Motor Sports Park 1/4 mile track. We hope more slants come out of the wood work during testing. I will let everyone know ahead of time. This will not be a one weekend event!!
Thank you all for the input on this. I'm here to take this data and make the best I can for the slant world and have some fun doing it see yall later Don

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

Question , why waste your time and go through the trouble and money to have a two piece/DUAL exaust manifold if your not going to have DUAL exaust all the way to the exhaust tips? If your gonna do a single exhaust (and I can't find a justified reason for that on a muscle car anyways other than for turbo applications or because of a genuine lack of room) why not have a bigger single piece header and a bigger single piece exhaust instead of a smaller two piece header leading into a bigger single exhaust? Or being as its N/A just do a smaller two piece header with two small pipes ALL THE WAY to the tips? Givin' the room of course.

seems to me like your defeating the whole purpose of having a single or dual exhaust when you try cross breed the ideas...

If this is an ignorant question, please excuse me, I'm only sixteen

Hello Dartman,
The reason for tieing the two pipes together is I read somewhere a long time ago that it was supposed to increase torque. I have not done this testing myself. Maybe one of the fellas on the board will chime in. I do run one pipe to the muffler, then 2 - 2 1/4 inch pipes all the way out the rear from there. Basically a 4 1/2 inch tailpipe. Which is probably way too large but looks cool anyway.


I would be interested in what other builds may be running. Maybe we could start a "tell us about your exhaust config" thread.

_________________
'72 Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page

You get more HP and better low end especially by running 3X1 pipes of 2" or 2.25" and then into a Y-pipe to a signle 2.5" or 3" just behind the trans X-member. 3" should only be for really high output Slants.

Lou

_________________
Home of Slant6-powered fun machines since 1988

No, no, no. That's not how it works. .065" wall thickness 2 1/4" OD tube has an ID of 2.12" and an internal cross sectional area of 3.53 square inches. A 3" OD, .065" wall tube has a 6.47" cross sectional area. 4.5" tube is 14.99 cross sectional area or 4.25" times the flow area of a 2 1/4" tube.

_________________
Joshua

I would have figured that it wouldn't have made any difference so long as you have the appropriate diameter (both for the headers and the rest of the exhaust) and given that your using an X-Pipe on the dual exhaust setup.

It's not just raw flow capacity that determines the performance benefit (or drawback) of an exhaust system. Gas velocity through the system is very crucial. Faster velocity means better scavenging of the cylinders, which means better performance Bigger-diameter pipe reduces velocity, which reduces scavenging, which lowers performance. You want to come as close as possible to the optimal flow capacity for any given engine configuration; extra flow capacity is not better, it's worse.

That's just one example of why throwing together exhaust systems or trying to make headers without knowing what the H-E-double-hockeysticks you're doing is a waste of time, money, metal, and weld rod.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.