mwebb
Elite Member
Joined: June 9th, 2009, 3:35 am

June 17th, 2012, 1:57 am #261

none of those exhaust s pictured above are "headers"
they are all exhaust manifolds of one type or another
why ?
because

real "headers" have equal length primary tubes
the volume of the equal length primary tubes is
the engine displacement divided by the number of cylinders
OR
the displacement of 1 cylinder

in a 10G geo metro header , the volume of 1 primary tube should be
331 cc

diameter of the primary tube should allow / force exhaust gas velocity to be right about 300 feet per second
at the rpm that the header is designed to provide peak performance at

the rpm that the header system is "tuned" for

it's just a word , words are our friend s - they all have meaning .

the 02 sensor must be mounted in the collector
not in a primary tube
if the ECM is to be in fuel control of the engine , not in fuel control for 1 cylinder

does it matter ?
hell yes
Last edited by mwebb on June 17th, 2012, 2:00 am, edited 1 time in total.
10g engine with 3tech economy cam and Singh Grooves otherwise stock
87 octane TOP Tier fuel with 1oz TCW3 synthetic marine 2stroke oil per 5 gallons of fuel
Base ignition timing set to 8 degrees BTDC .
summer wheels are 15" alloy sourced from a late 80s Acura legend
currently has -
185 60 15 Bridgestone RE 92 tires on Acura Legend alloy rims in front
195 55 16 conti pro tires on 16" Nissan Cube Alloy wheels in the rear
===
passenger side wiper is removed - makes no measurable difference - RAINX on the windshield
do not need the wipers anyway

to expand my posted images
click on image , select view image , click 2x
======================
i have removed the 3tech +10 cam wheel - drivability is much better and FE appears to be UNchanged
EXHAUST PIPE diameter 0D = 1 1/8" made from 1" EMT conduit
====
unless you enjoy chasing your own tail without ever catching it
NEVER USE AN OHM METER TO TEST A BROKEN CAR
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Maas562
Elite Member
Joined: July 5th, 2011, 11:35 pm

June 17th, 2012, 4:41 am #262

How technical do we need to be?

Every late model racer at our local half mile track has "manifolds" as Webb calls them but they are not equal length and they still all call them "headers".

Hell even header building companies build "manifolds" or headers rather, as they prefer to call them that are not equal length. They seem to be the pros in the business and don't seem to mind breaking the rules of the English language and calling them headers even though they don't match the text book definition.

My apology if I offended you Webb by titling this as a header. But Nerys is free to name it what he wants.

I'll still call it one though as that is the norm in the industry. I apologize for not always being 100% technically or politically correct.

As for the o2 it is not mounted in a primary tube, if it was it would be above the welded joint. Where the 3 tubes join at the welded seams is wide open inside. Future shorty Headers will have the bung welded on the front center above the flange.

If it does have an affect on the performance, which I doubt it will, I will move it for Nerys since it is already on it's way.
Last edited by Maas562 on June 17th, 2012, 4:48 am, edited 4 times in total.
1995 Metro 3/5 Project Here

[size=100][size=100][size=100][size=100] Check out MMProducts! Your one stop shop for headers, frame braces, collectors, flanges, and anything custom!
MMProducts
[/size][/size][/size][/size]
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nerys
Elite Member
Joined: September 26th, 2009, 3:50 am

June 17th, 2012, 4:51 am #263

I don't care. its stainless and won't rust.

and mwebb your right about fuel control ONLY if the engine is not running right.

so as long as I keep it running right reading C1 is "good enough" and Maas says its "at" the collector just barely so it is getting gasses from all 3 cylinders though C1 is the bulk of it.

good enough for me. they wanted $140 for a stock manifold (mine is leaking)

so to me this was only a few dollars more for something much better.
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mwebb
Elite Member
Joined: June 9th, 2009, 3:35 am

June 17th, 2012, 5:09 am #264

"How technical do we need to be?

Every late model racer at our local half mile track has "manifolds" as Webb calls them but they are not equal length and they still all call them "headers"."


you say others think that mediocrity is good and mediocrity is the correct choice when other choices are available
"they" are wrong .

you have the skills and the ability to produce a a real "header" and as you know, it cost's no more to do that then it does to produce mediocrity ....

to me the choice is clear - you choose your own path


10g engine with 3tech economy cam and Singh Grooves otherwise stock
87 octane TOP Tier fuel with 1oz TCW3 synthetic marine 2stroke oil per 5 gallons of fuel
Base ignition timing set to 8 degrees BTDC .
summer wheels are 15" alloy sourced from a late 80s Acura legend
currently has -
185 60 15 Bridgestone RE 92 tires on Acura Legend alloy rims in front
195 55 16 conti pro tires on 16" Nissan Cube Alloy wheels in the rear
===
passenger side wiper is removed - makes no measurable difference - RAINX on the windshield
do not need the wipers anyway

to expand my posted images
click on image , select view image , click 2x
======================
i have removed the 3tech +10 cam wheel - drivability is much better and FE appears to be UNchanged
EXHAUST PIPE diameter 0D = 1 1/8" made from 1" EMT conduit
====
unless you enjoy chasing your own tail without ever catching it
NEVER USE AN OHM METER TO TEST A BROKEN CAR
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Like
Share

Coche Blanco
Elite Member
Joined: July 16th, 2009, 2:22 am

June 17th, 2012, 5:16 am #265



Is this too ricey?
1993 3/5 2dr Hatch 'The White One' (SOLD)
1995 4/5 4dr Sedan 'Gumby' (SOLD)
1993 3/3 Convertible 'Impulse' (SOLD)
1993 3/5 Convertible 'Impulse V2.0' (SOLD)
1998 4/5 2dr Hatch 'TBD'
[+] Spoiler
Transmission Ratios Explained
Resize your pictures
Make your base Metro an XFi
Easy headlight upgrade
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starscream5000
Elite Member
Joined: August 5th, 2009, 1:42 pm

June 17th, 2012, 5:18 am #266

Give it a rest McWebb
Maas, I know I'm being wishy-washy with what I want here, and do apologize for it, I just don't want to regret my choice later on.
Can you do a normal header for me (long tube), but do the collector as 1.5" with no flange on the end and just open it up a tad so it can slide over the top of the rest of my exhaust and I'll just seal it up with a stainless steel band clamp?
Last edited by starscream5000 on June 17th, 2012, 5:19 am, edited 1 time in total.

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Maas562
Elite Member
Joined: July 5th, 2011, 11:35 pm

June 17th, 2012, 5:55 am #267

For me to produce a true header to webbs definition would cost me 2-3 times the more than the standard ones I produce now. For what a geo is, nobody is going to buy a header that costs just as much if not more than their car is worth. It's just common sense on the business end for me, in no way is it producing mediocrity.

Starscream, I can do that no problem, however I would recommend opening up the exhaust on your car and sliding the collector into the existing exhaust. It is less restricting on flow and more leak proof.
1995 Metro 3/5 Project Here

[size=100][size=100][size=100][size=100] Check out MMProducts! Your one stop shop for headers, frame braces, collectors, flanges, and anything custom!
MMProducts
[/size][/size][/size][/size]
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Murf 59
Elite Member
Joined: July 2nd, 2009, 9:49 am

June 17th, 2012, 6:30 am #268

I just caught up with this thread again. Your new product looks great. You do very nice work, for a whateveryamightcallitthingymabob. :thumb
Last edited by Murf 59 on June 17th, 2012, 6:31 am, edited 1 time in total.
A 13.5 to 1 G10. With GTi twin cam pistons. Performance head package work sponsored by our friends at 3Tech.
A set of 4.38s set up as a 4 spd. MSD ignition, and a Weber card on top. It has a SRD header on the bottom side.
I run a Glow shift tach, and a HF vacuum gauge.
This engine is still in the works. I have all the pieces, but am not able to get the energy to assemble it.

This is what it looks like running at Bonneville from the front seat of a Geo Metro
http://www.youtube.com/watch?v=rOcWzyzyjPw
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Memphis metro
Elite Member
Joined: January 20th, 2010, 2:06 pm

June 17th, 2012, 11:30 am #269

Personally on a 3 cylinder engine I dont believe your going to get much engine performance differance no matter what kind of header you put on it. Maas, I like your work.
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metroschultz
Elite Member
Joined: September 11th, 2008, 7:56 pm

June 17th, 2012, 11:56 am #270

Maas,
How much does that steel-tube-manifold/header/shorty-header/whateveryamightcallitthingymabob cost delivered to 23462?
I, personally, like the design and want to know the cost. Others may want to know also.
I am building an engine for my wife's Metro, I believe that unit would be perfect under her hood.
Thanx,
Schultz


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