Mufflers

[JohnD]

Greetings Faithful,

I'm in need of a little advise on exhaust/muffler choices for my repower..

I'm putting 420hp cats in my B35 and had intended on using a 6" exhaust until I read the spec's on the mufflers which say I'll need 8" exhaust.

The last thing I want to do is cheap out at this point. However, the difference between 6 & 8 inch exhaust/mufflers is at least $1k and probably closer to $2k.

So, do you think going with the 6" mufflers/exhaust be too restrictive?

Another option I thought of was to use 6" from eng=>muffler & then 8" from muffler=>transom. That way the out side of the muffler would not be as restricted.

Also, I'd like to go with fiberglass thru-hull for the exhaust but am not sure of how much reinforcement is needed between the fiberglass tube and the transom.

br,
JohnD

[Bruce]

I'm putting 420hp cats in my B35 and had intended on using a 6" exhaust until I read the spec's on the mufflers which say I'll need 8" exhaust.

I think you already answered your question.

[JohnD]

Bruce, Thanks for the quick response, the one I was afraid of.

So for the next step, there seems to be some cost differences between the muffler mfg. Any mfg you prefer over others?

It looks like it will be at least $600 per muffler for the 8" models...

Thanks,
John

[Bruce]

John,
Depends on the application and what fits who I use.

When your done, always check the exhaust back pressure at the engine to confirm system is proper.

Back pressure and higher cylinder temps is a real quick way to the engine grave yard.

Two best things you can do for any engine is proper air in and proper air out.