Silly question

[goldenturtle]

At work, one of the older mechanics told me adding a performance muffler do to lower backpressure I could burn exhaust valves. He used to work on Harley's and claimed to see a bunch of burned valve on bikes that had the baffles removed. Is he full it or on the level?? I am looking at the Walker turbo muffler.

[Mark1]

I have never heard if this. It is more on the part of tuning the motor. Most Harley owners remove the baffels but do not re tune the motor to deal with the lack of back pressure. This is also what Blues the exhaust on harleys. I have seen chrome pipes on a harley that are 10 years old that look new. And others less than 3 weeks that have 8 inches of blue. With fuel injection the computer can rectify the situation on a basicaly stock motor. So i beleave there is no fear in any trouble in the free flow mufflers.

A lot of "old" mechanics live and die by what they learned so long ago, and refuse to realize what technology can do today. I am not slaming mechanics, this hapens in every industry. But as far as mechanics I like to find the middle ground---Not the "old Boys" Nor the sparkeling new guys. But the guys that learned from the old guys but are young enough to learn the new stuff.

[dart55]

Let's touch on this back pressure thing again, your back pressure is regulated by your Cat. convertor, so no muffler needed on either the stock or Turbo.

[Mark1]

the cat is the first restriction of conciderable size, but it does not regulate the pressure. There are no specs on flow for cats, just exchange rates. But what you mean i beleave is true as well... the restriction incured with the cat is great enuf to minimize the restriction in the muffler.

For thoes who dont know what we are talking about, think of your exhaust as a fire drill. Remember thoes from grade school?

Every body ( the exhaust gas) is rushing out the classroom door (the cat) it filters the people through 1 at a time this is a restriction. The doors at the end of the hall are double doors (the muffler). They too slow every body down but mabie too 3 at a time, not near as much as the classroom door.

Because the class room door slows every body down so much the double doors never really get backed up enuf to be that big of a restriction, but slow down people just because they are there.

This is why we do not see that big of a performance jump when we add a better flowing muffler.

[bigdogdad]

Mark1

Boy, I actually understood the explanation. I was able to make since of it. Coming down to the non mechanics level. Nice

[PTRON]

Originally posted by bigdogdad
Mark1

Boy, I actually understood the explanation. Coming down to the non mechanics level. Nice

DITTO!!

[Bottle Baby]

That's the way things were.... before computer controled fuel injection engines came into being the norm.
Also, valves are made of better steel, to handle the increased heat of
the modern no lead engines.

[GOLDMEMBER]

No problems on my Suzuki 240,000 km on it
it has a 3/4 Race Cam, Headers, No Cat, 2.5 pipe with high flow cherry bomb muffler.

The only problem is maybe the noise but once I get motoring 30mph or faster you can't hear the engine noise over the drone of the 33" Micky Thompson's

[Mark1]

Originally posted by GOLDMEMBER
No problems on my Suzuki 240,000 km on it
it has a 3/4 Race Cam, Headers, No Cat, 2.5 pipe with high flow cherry bomb muffler.

The only problem is maybe the noise but once I get motoring 30mph or faster you can't hear the engine noise over the drone of the 33" Micky Thompson's

A late 70's bronco passed me last week with 44in Swampers. It drowned out my sterio that was turned up with the windows closed!

[Bosch]

Thanks Mark1 that explantion was excellent...