Straight Pipe Solution?

The date of my purchase for my first wagon is approaching.

-85 Wagon, manual, 60k.

I've solidified that I will replace the keihin carb with a weber, and now I'm beginning to have dreams of opening the exhaust.
Also, in Texas, those vehicles that are 25 years+ can be classified as a "Classic Car", meaning they do not have to deal with emissions testing. (I love this state!)

So my initial thought: Just pull off the muffler! However, I remember the effects of removing the muffler from my first motorcycle (fzr600, '96), leaving only the exhaust manifold and the downpipe. It turned the "Yin-Yin" and tin can rattle into a throaty growl. Conversely, I lost most of my low end power and the bike didn't run really well until I put it back on.

I used this website to make a calculation of the ideal size pipes.
http://victorylibrary.com/mopar/header-tech-c.htm

According to this calculator- the 1.5 with 6.8k redline would work best with a 1.2" straight pipe!
The Stock is 1 7/8?

What can I do about this?
A reduced size pipe will require a smaller manifold too. I'm sure I could find larger, but a smaller than stock manifold?
Anyone have any ideas?


After doing some research- it seems like I would still have the same problem with the car.

Also, I like the sound of straight/open pipes, but I also like my ears. The logical solution is an exhaust that preserves openness but still works. I've built a straight through "Custom" exhaust with a friend for his bike once (ninja 250). It involved gutting his old can, inserting a perforated tube and some two stroke stuffing into the surrounding space. It sounds like glasspacks/cherry bombs are about the same thing.

So I would remove the muffler, take a long straight section of the exhaust, perforate (read: drill lots of holes), and encase it in fiberglass/two stroke stuffing, with a larger tube holding the packing by welds or rivet&sealant.
However, I'm skeptical. There must be a reason why no one does this. Some other wrench turner would have made a custom glass pack, but I can't find anything to corroborate that.

Thoughts?

Comments

  • bam-bambam-bam Council Member
    I think a glass-pack muffler costs $20.

    Also, I don't think the stock pipe is 1 7/8". It probably is closer to 1 1/2.
  • zenitzenit Band Wagon
    1.5 to 1.2 is a better ratio, but it's still off by a significant amount.

    I thought about using a commercial glass pack, but then, finding one for the size and length.
    Ideally, I would like to build it with as long as possible to reduce the noise as long as much as possible. Also, a longer glasspack would have a insulating effect on the exhaust? The longest I've found is 42"x2".
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