cliby

the only thing I have to add isn't promising. I have a stage I exhaust, along with other stage I parts (pistons/cams). When looking I checked into the stage II exhaust with some experienced SH tuners. All advised me that without the other stage II components and more radical cams I would most certainly lose power using the stage II exhaust. You may know something I don't and others can chime in, but that is what I know.

HisHawkiness

I don't really see how I would lose power running a full system vs a slipon (the difference between stage I and II im guessing) I might lose a bit of torque and not gain the kind of power I would with a set of cams and pistons to go with it but I doubt a freer flowing exhaust would actually lose power. i could be definately be wrong though.

I got the system through a forum member at a really good price so i couldn't pass it up. hopefully I can get it jetting right to run smoothly.

cliby

its not full vs. slipon. the stage I mori system is a full system. I think the diameter on the stage II is much larger and oversized relative to what you are pumping - my simple interpretation. it is a larger diameter however.

HisHawkiness

ohh ok,

The Diameter is rather large, Its so big in fact that its pushing against the front of the bellypan and one of the rear lower mounts on my new Mario Nava Bodywork.

hopefully the high flow doesnt kill torque too much, if It causes a big problem i guess ill have to start searching for cams and pistons.

on a side note the Stage II isnt nearly as loud as I thought it would be, but thats just judging from starting and revving it in the garage.

cliby

you ought to get some advice from one of the gurus on this stuff - I think its doubtful you'll be able to get it to run well. RCVTR worked a lot with one of the US moriwaki experts and there is a Roger Ditchfield in the UK, at Revolution racing I believe that knows these things inside out and imports moriwaki stuff.

shayne

I can only add to what Cliby has said. I have a street Moriwaki system, which I assume is Stage 1. Headers are about normal size but it has a nice siamesed collector as opposed to the badly designed standrad one.

If you have oversized headers without any increase in compression ratio and camshaft lift or duration, then you may find that you are just losing exhaust gas speed.

Revolution Racing will be able to tell you I reckon, but you could always go your own way and just experiment with it. A dyno tune will be a good place to start.

RCVTR

Bill's right. The Stage II primary diameter is too big for stock or stage 1 cams and stock RPM. I think you lose midrange with a stage II engine as well, in exchange for better scavenging at high RPM.

I'm surprised you were able to install it with a stock oil sump. The stage II (superbike) exhaust required a modified sump and ran closer to centerline.