WANTED: Exhaust Sound! Low Rumble!

[PancakeShake]

So I have an 82 GS 450, and an 80 XS 400 and they both have an awesome low rumble to them when they run.

I also have an 83 GPZ 750, but (IMO) it sounds like crap. I really like the separate "glug - glug - glug - glug!" of an engine (from the GS and XS) rather than the constant "merrrrrrr!" that I am getting from my GPZ.

The GPZ has a 4 to 1 Exhaust, So i think that plays a big part of the sound. If I were to make an exhaust with 2 separate 2 to 1 pipes (heads 1&2 together and heads 3&4 together) and put some pretty light baffles in there, do you think that would make the exhaust rumble a bit more "separated" if you know what I mean?

Any other ideas to make a 4Cyl engine to sound, well, basically like a harley?

Making the final touches to the bike and I would really love to do this if its possible.

Thanks guys!

 

[rubber-side-down]

:-\ a big cam but not really

 

[hillsy]

I remember the 4-2 exhausts on the original Katanas sounded a bit rumblier than with a 4-1, but it wasn't by much.


You are kinda stuck with the drone of the 4 cylinder IMO. Unless you drop a coil :

 

[gk45011]

Alright Pancake. Exhaust work may be in my future. How did you get a deep throaty sound out of you GS450? Do you have a link to some pictures or a build thread?

 

[PancakeShake]

Literally, cut the pipes clean off, and put on some 2" tips. Sooo, straights haha. But it still passes inspection and actually sounds really nice.

Rejetted the carbs to work with the new pipes and new Pods, and the bike ran like a top.

 

[teazer]

Take two of the plugs out.

A four will never sound like a twin because it revs faster and has smaller pistons so smaller gas pulses at higher frequencies.

You could regrind the cams so that 1-4 fir together and 2-3 fire together and tie those pairs of pipes together. It will still rev too high but at least it would change from 4 exhaust events every two revolutions to two and that would potentially make a difference.

Then you need to accentuate low frequency sounds and flatten off the higher frequencies.

It would never sound like a V twin of 1200 plus cc , but it would sound different.

 

[PancakeShake]

Sounds like alot more work than its worth haha.

I like the idea of buffing out high frequencies tho. Maybe I can find a way to get rid of those while amping up the low freq's

Thanks!

 

[crazypj]

Glasspack silencers absorb higher frequencies more than low frequencies.
A Dunstall type multiple tube with glasspacking should make a difference (although you may have to make it yourself?)