louder exhaust

[gbusa66]

anyone interested in open exhaust
simple mod no good for racing
but good for us hoons hehe
have a listen
http://www.youtube.com/watch?v=DD7YLHMTukA

[gtf]

Originally Posted by gbusa66

anyone interested in open exhaust
simple mod no good for racing
but good for us hoons hehe
have a listen
http://www.youtube.com/watch?v=DD7YLHMTukA

is that anything like this photo,or is that a tuner on that motor?

[gbusa66]

something similar just not as noticable
ist pic were red was plate cut out
2nd 3rd pic exhaust now exits here

[Bus_Boy]

I'm keen to learn more on this. Hard to tell from the video because the camera was so far away, but just how loud is it? Is it as loud as if you were to start the motor out fo the water when flushing?

I'd like to do this to the 25 on my SIB

[gbusa66]

if it didnt have mod u wouldnt hear it at all

[gbusa66]

ill post another vid before mod

[gbusa66]

only vid i got of before mod
http://www.youtube.com/watch?v=faUdCcQhxeQ

[Eduardo]

I reed that in USA Superlight Tunnel Hull Boats APBA rules they use two exhaust holes in the lower unit to improve performance.

50.127 Exhaust Holes: A 1- 1/32” (one and one-thirty-second of an inch) diameter maximum exhaust relief hole shall be allowed on each side of the
gearcase only. This dimension may be measured in any two directions (Mercury/Mariner 59 ci excluded).

Anyone have experience about better performance by this way?

[gbusa66]

Eduardo if u look at photo by gtf it has the relief holes you
are talking about. my way same princliple but no obvious mod
i

[Eduardo]

Yes, you are true.
But,how much will increase Performance?

[gbusa66]

i found a small increase in performane
mainly acceleration and noise hehe

[gbusa66]

took some more fotage today
better quality vid sound
sounds good i reckon
let me no what u think

http://www.youtube.com/user/gbusa66#p/a

the link to my vid

[gbusa66]

just put a vid up on how it sounds on the
tap
http://www.youtube.com/watch?v=tceWIOZU11A

[Bus_Boy]

Can you mark out on this picture where the holes need to go?

[adrenalinmydrug]

Where would I make this hole on a yamaha? I really want that raw note

[gbusa66]

Originally Posted by Bus_Boy

Can you mark out on this picture where the holes need to go?

can u take some more photos similar to mine

[madcat]

done this mod to mine aswell. . .not only sounds filth spins cleaver 200rpm more so = faster

[Bus_Boy]

Originally Posted by gbusa66

can u take some more photos similar to mine

Are these one's ok?

I read somewhere elsewhere about this mod, and quite oddly, it was performed to an 8 hp 4 str Honda. The guy did it because apparaently it had no effective reverse thrust when used on a yatch, and this suppsoedly fixed it... The holes he made were in the leg itself though.

I would be a bit concerned about putting holes in the leg. This might be the dumbest question ever asked, but isn't the exhasut section of the leg suppsoed to remian dry? What happens with water getting in it? If the holes were in the leg, it would be loud all the time, rather than just loud when your trimmed higher enough to expose the holes above water line, which is what i would prefer