Muffler outlet pipes

[Digger89L]

I've often wondered why the "stock" muffler outlet pipes have to be of such small diameter ...to the point where the exhaust almost seems to whistle. Is there any "rule" against welding larger diameter pipes onto the muffler, or will this negatively impact the way the engine runs? Is the amount of backpressure in the muffler critical?? etc. etc.

[darzoom]

This is a good read and explains the collector can and peashooters (real mufflers) and how it all works together.

http://www.vw-resource.com/muffler_discussion.html

[Blue Baron]

First of all, the tailpipes don't get welded to the muffler. They're held with muffler clamps and seals. (My own trick is to add a small sheet metal screw at 6 o'clock through the muffler and pea shooter just ahead of the clamp to keep the pipe from coming loose and falling off on the road.)

Yes, people have been replacing the baffled peashooters with straight through pipes for many years to get rid of the whistle, or "fweem." (I've always called it a cricket chirp.) You can purchase them from various sources. They will make the muffler a lot louder, because those peashooters do most of the actual muffling, as the linked article states. (The muffler itself is really just an expansion chamber.)

The loss of back pressure won't hurt the engine, though it really won't help it much either. Those narrow diameter peashooters were engineered to match the output of the engine.

[Digger89L]

Thanks for the info, guys. Helpful. I guess those (us ?) Germans knew what they were doing when they designed the system. Actually don't mind the "fweem" and whistle-like tone ...kinda of nostalgic. Just wondering if it was "necessary" ...

[darzoom]

Look at these performance alternatives to the stock but fits in same place and same peashooter look.

http://www.vintagespeed.com.tw/Exhausts ... -main.html

[Blue Baron]

I've heard good things about these systems, but No. 1, they're expensive, and No. 2, the pipes look more like bazookas than peashooters.

[darzoom]

Expensive yes. But, they give good performance and provide a better sound than that of a little bird. I guess it is the same thing I run into on this site. The difference between being a purist or making things just a bit better. A purist would love the chirp. Me, I want a bit different and better in performance. It's all a choice.

Does anyone have a source for horse hair seat pads? I checked with TMI and they only have foam. THANK GOODNESS FOR THAT!

[Blue Baron]

The difference between being a purist or making things just a bit better.

So we can assume your endorsement of this muffler comes from running one on your car?

[darzoom]

I was not endorsing. There are many options out there but in that the orginal post it was obvious he wanted a stock look with a different sound and larger pea shooters. That was the criteria in selecting the information I sent to allow him information to make a choice.

I have owned and worked on VWs since the late 70's and have heard about a lot of performance gimmicks and tried many. When I ran a stock exaust, I went to the larger pea shooters with no baffles and flaired ends for the sound.

Since then, I had put many performance engines of many sizes and have settled on a 1776 with counter balanced cranks and a VZ125 Engle cam. The case is full flowed and I run 1 5/8" extractor with the muffler under the passenger rear fender. I do all the work myself as a trained mechanic. So, not a purist.

BTW, in the early years of the Beetle they, the German engineers, came out with a Okrasa kit to make performance mods they "endorsed". You can get a replica Okrasa muffler that has 4 pea skooters with no baffling. I have not heard one in years but there is tons of info on them on the web.

Happy muffling.........