At 08:00 AM 05/22/2003 -0400, Henry Frye wrote:
>I am thinking I want to have a very low restriction muffler for track days,
>and a bypass pipe for race days.
First of all, thanks to everybody who responded to this question.
I have to say I was surprised how many people stick a muffler of sorts on
their car and just leave 'em. Yes, I know it is a pain to deal with the
exhaust, especially trackside, but read on.
Several responses from guys said they dyno'ed their car with and without
what they thought were low/no restriction mufflers but found out they were
giving away big horsepower. Look at the HP numbers gained by removing the
muffler and then perhaps a few more by optimizing the length of the exhaust
pipe, then compare the gain to the total HP available. Some people reported
finding close to 10% more HP.
On the other hand, I have one response running a straight through glasspack
that did not effect HP, confirmed on a dyno. This seems to fit Bill
Babcock's response, install a reasonable muffler and forget about it.
I spent good money on my engine to extract maximum umph and to give
away HP seems very counter-productive. All I am looking to do on a track
day is be quiet enough to satisfy the noise police, get my testing and
tuning done and get in some seat time. If I am down a few HP from my max
potential on track days that's fine with me. Track days are not wheel to
wheel racing.
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