Cut away of a Dyno Max muffler #18381
Every 318 iv owned (quite a few) has been straight piped none of them have been over bearing loud. They have all been single pipe with manifolds. Is there any performance benefits in a straight pipe ( no muffler at all) or does it hurt performance? Iv heard that no muffler hurts performance and can damage valves etc is any of that true?
When I called up TTI to order their stuff, I asked for the dual 3" full length system. I was promptly told that, that would be too much for my little 367, and I wouldn't have enough back-pressure.
So stop the clock right there.
So now I'm thinking to myself. Back-pressure. What could possibly be good about back pressure? What is the first thing anybody does when they hop up their engine? Headers right? Headers work by EXTRACTING the exhaust, by initiating a pull on the carb to get the air moving a wee bit earlier. That's what they do. So back-pressure would destroy the header's ability to do that. We all know that processing air is what the engine does, and the more it can process, the more potential to make power it has. How can back pressure help in any way.
So Still thinking, I see a picture in my mind of a race car at the track, running straight headers, no exhaust at all. If backpressure was a good thing, wouldn't racers have some kind of restrictors welded on their header exits?
So still thinking, I see my lowly lawnmower,3.5 Briggs that has been running with a blown "muffler" for 10 years, and seems to be doing just fine. And I see my roto-tiller dumping straight to atmosphere, and it roto-tills just fine. And then I see the Karts,at the track where I am a tech-inspector and a volunteer flagman, and the Karts all have short sections of straight pipe on them;every one. And my mind goes into a million different rabbit holes, and none of them support back-pressure.
Restart the clock.
Ok says I, I'll just take the full-length dual 3s then. And I'll do whatever it takes at my end to ensure the engine lives.
Ok Sir, how would you like that shipped?
So I bolt my dual 3s on and the engine ran perfect, and has done so since 1999. Yeah it might be a lil loud at full song,but I sit ahead of the exits, and it takes a while before the sound catches up to me. I often slow down,just to hear those screaming banshees,lol. I didn't buy the 3s to make power; I bought them to suck heat outta the exhaust,so the gases could have a place to cool off and condense,to provide a low-pressure area for the headers to dump into, and 3" exits so the engine wouldn't have to work so hard to pump the gasses out the ends. 3" pipes have a lotta metal and a lotta mass, and they suck a lotta heat outta the exhaust.
The thinking seems to be right, at least to me,cuz dang that car is fast..... for what it is; just a lil 367. The 70 pounds of exhaust doesn't seem to slow it down one bit.
