Highest power exhaust for GSX-R750 L1 2011-2023?

[ptuomov]

What's the highest power exhaust for GSX-R750 L1 2011-2023?

The criterion is average power in the 11,000-15,000 rpm range and nothing below that matters. The shape of the torque curve doesn't matter and neither does the ground clearance so no need to do the 1-2&3-4 motorcycle 4-2-1s here.

[hoffman900]

What's the highest power exhaust for GSX-R750 L1 2011-2023?

The criterion is average power in the 11,000-15,000 rpm range and nothing below that matters. The shape of the torque curve doesn't matter and neither does the ground clearance so no need to do the 1-2&3-4 motorcycle 4-2-1s here.

The shape of the torque curve matters for anything used in a vehicle / bike, but if you’re dead set on it:

viewtopic.php?t=31606

Read Clint’s (nitro2) posts

[ptuomov]

It’s going to be nice enough no matter what in the 11-15k range, and that’s all that is ever needed with the gear box. 2-6 gears only use 12.5-15k.

That thread never reveals the super duper secret exhaust. What’s the best known exhaust?

IMG_8189.jpeg

IMG_8190.jpeg

[ptuomov]

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S measuring the engine internals for the 1D simulator:

[ptuomov]

I’m thinking that the exhaust port at 31mm is a little small for trying to get the stock exhaust cam to hold up the 150hp+ power for the full 11-15k rpm range.

A pretty exhaust pipe photo here:

IMG_8191.jpeg

[hoffman900]

It’s going to be nice enough no matter what in the 11-15k range, and that’s all that is ever needed with the gear box. 2-6 gears only use 12.5-15k.

That thread never reveals the super duper secret exhaust. What’s the best known exhaust?

IMG_8189.jpeg

IMG_8190.jpeg

Pretty sure they were like 4-6” expanding stubs

I think that exhaust port is fine. We’ve put 190whp + through exhaust ports with that same area.

[ptuomov]

“I think that exhaust port is fine. We’ve put 190whp + through exhaust ports with that same area.”

I agree with free cams. But how about rules mandated short stock cams?

[ptuomov]

Also, what’s the best guess primary length for that rpm range and 4-1 system?

[juuhanaa]

Also, what’s the best guess primary length for that rpm range and 4-1 system?

IMG_20210603_202332__01.jpg

-juhana

[pcnsd]

Does this system require a muffler? If so... Is there a sound test method and db maximum?

[ptuomov]

Does this system require a muffler? If so... Is there a sound test method and db maximum?

No sound test, an object appearing like a muffler required on the pipe, plenty of space and slack weight to make any system appear like an open header to the exhaust flow if sound requirements ever come. So for now it’s to be designed like a fully open header.

[ptuomov]

40-45cm wouldn't sound silly for this rpm range.

Also, what’s the best guess primary length for that rpm range and 4-1 system?

IMG_20210603_202332__01.jpg

-juhana

[ptuomov]

Pretty sure they were like 4-6” expanding stubs

So something like 4 x 4-4.5" or 3 x 5.5-6" primary sections with each section stepping up a pipe size? And then old-F1 style 4-1 collector with a relatively small collector exit pipe diameter?

[nitro2]

That thread never reveals the super duper secret exhaust.

Pretty sure they were like 4-6” expanding stubs

I think not lol.

[hoffman900]

That thread never reveals the super duper secret exhaust.

Pretty sure they were like 4-6” expanding stubs

I think not lol.

I tried