[realpsi]

keep posting good stuff. I would be interested to see if you have velocity stacks, Superbike Unlimted found none in the airbox. It doesn't look like there is a cat in the header as others thought there might be.

 

[realpsi]

That is what Superbike Unlimited said no stacks. Seems strange. I knew the cat had always been in the second half, but a post earlier thought there might be a precat in the section before the old cat location. Do you have any idea why the stacks are missing on the RR?

 

[realpsi]

Please ,would you measure the diameter of the Akra and stock primary tubes? The 2 section diameter? and the collector diameter?

If you could do the same on the GSXR as well? If I could have any of the measurements it would be the GSXR.

 

[realpsi]

@realpsi, that's a LOT of work dude, lol. Pull up a picture of the Akra exhaust from their site and circle the parts you want measured and post that below. I can only measure the outside of the exhausts because I am not going to remove the exhaust to measure the internal

Sorry, I know. Just the od is great. On the gsxr is my preference because that is what i am shopping for. I’ve been running simulations and I am the point where I can duplicate curves with the right inputs. I’m down to Akra and Arrow I believe offer the most for a modified bike.

 

[realpsi]

What is the primary size? I don't want to take from this thread so an explanation. The 75mm posted from a Gen6 made me start running more simulations on exhaust primary and collector sizes. What I found is the primary size a little larger than 41mm and the collector size larger add a little horsepower. I suppose the balance connections might allow the primaries to perform as larger pipes. So I started looking, 60 and 65mm silencers make more power as well. I think the 75mm is planned and actually done to add power.