Thread: Exhaust Diameter Recommendations

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Guess I was wrong, the story was about header size not exhaust. Here is the results.

Originally Posted by G.R.

.. in the long ago times a sixer of Coors was $.98 +.02tax. For five bucks you could put gas in your car, get a sixer, take your date to the drive-in, get a couple of burgers and fries at the stand...and if you were real lucky..."get lucky" lol

That brings back some ugly memories. In the summer of '62 my brother and I, along with a couple of buddies, got into the habit of going across the Mississippi to Rock Island to pick up a case, 12 quarts, of Canadian Ace beer (@ a $.25 a quart) Then we would each would buy a 1/2 pint of our favorite (mine was Hiram Walker Imperial), for $1.00.

$3.00 for beer,
$1.00 for the hard stuff
$1.25 for a large pepperoni hand tossed,
$1.00 for a bag of shrimp from the local choke and puke,

staying sick for the entire next day....Priceless.

The problem was we did it dang near every Saturday night all that summer. A kid just never learns. Now just the thoughts of that make me sick to my stomach.
John

Geez, I just reread this and I am not sure if I should admit to being that stupid.

Well maybe I hit it right with the 2.25" diameter just copying from IC2. The shop I went to did not use the H-pipe kit I bought from Speedway which I measured today and found it was 2.50" diameter. But I asked for 2.25" diameter and that is what I got. The initial system on my car is 1 5/8" diameter tight fit tubular headers with ceramic coating. For a shop, the welds are not that smooth but they are not visible unless you really look under the chassis. Back when I was really young on a full scholarship I invested in every book in my field that I could find and benefit even until today using those classic reference books but I still had a little money left and used to buy Bavarian brown beer at $6/six! Years later as a married family man on a budget I found "Old Milwaukee" for $1.97/six and that price held for quite a few years in the 1980s. There is a lot of attention paid to where water comes from for beer and the local beer where I grew up was Ballentine Three Ring for all the Philly games but Valley Forge beer in the suburbs which unfortunately drew it's water from the upper Schuykill river which at that time was at least 20% coal dust but the price was low; maybe the all the coal had a charcoal filtering effect? By the way "Todd", the top guy at the Economy Muffler shop, said he had personally done many, many dyno runs to optimize H-pipe position and pipe size and his opinion is that the H-pipe does nothing! That reminds me of the Preacher who had a horseshoe over his door for luck and one of his congregation wondered if he believed in the luck of the horseshoe. He replied that he did not believe in it but folks said that it worked even if you did not believe in it! Maybe that is how an H-pipe works?

Don Shillady
Retired Scientist/teen rodder

Originally Posted by G.R.

Here in Colorado in the long ago times a sixer of Coors was $.98 +.02tax. For five bucks you could put gas in your car, get a sixer, take your date to the drive-in, get a couple of burgers and fries at the stand...and if you were real lucky..."get lucky" lol

WOW! Thats...aaa ...a long time ago?

But more to the point. Check this

http://www.jcwhitney.com/autoparts/P...exhaust+tubing

I use the 2.5 inch and sandblast or wire wheel the aluminum coating off before I weld. Custom exhaust on a budget. 3" is better but hard to fit most chassis applications. A set of Flowmaster 40's is the "icing on the cake"
Good Luck

In a high RPM situation, the H pipe will probably not contribute much to the performance - if at all. An X pipe might. But what an H pipe will do in a standard driving situation will smooth out the exhaust pulses and probably make the exhaust note more tolerable. In a racing situation - that is engine RPM above a certain number, and for the sake of discussion, let's just use 5000 or above. That high RPM operation just wont allow the pulses/engine exhaust to bleed from one side to another as the speed of that exhaust just pushes it right on out and past the cross over tubing. Now with that said, how often in your driving, day to day do you run your car at an extended RPM operation? Open road driving, depending on transmission and diff. gears, 1800 to +/-2500 at 65mph. Town driving - maybe up to 3000 before the transmission shifts. So keeping that in mind, yes, Don, your guy is right, but.....you aren't driving your car on a dynomometer, nor are you often running it often, if ever, at full throttle. You want a nice sounding exhaust, you don't want annoying drone or resonance while you and your lady are touring the back roads of Virginia.

So far with the very little bit of engine operation for my car (yes, it does run ) the exhaust is a nice, almost too quiet rumble, no drone, but we'll see after a few hours more operation.

Originally Posted by hotroddaddy

How much was beer back then? You guys only mention coke for a nickel.


Hot rod mag did a story in the last couple of months about this subject, they tested all different size pipes on the same car and if i recall right , the horsepower/ rpm range went up with the larger pipe diameter Ie with 1.75 was 300 horse at around 3500 rpm, but with 2.50 pipe it was 425 horse at around 5000 rpm. It was pretty consistant with the highest horse peaking at lower rpm with the smaller pipe, then gaining both with larger pipe diameter.Ill try to find the issue.

In the late 60's 6 packs ran $1-$1.50 depending on brand I drove for PBR around that time Draft was 25 cents and Large pitchers $1.25 to $1.50,but then we had smaller paychecks but with 28 cent gas you could buy more beer