I do not think that you need a bike 4,000 miles away to verify your spread sheet calculator? I suspect you have plenty of bikes much closer that you can verify the accuracy of your spread sheet? correct??
So I will ask again.... What is it your are trying to determine?
I am asking in a a very nice manner. Just want a straight answer please..
The bike I race is located on the other side of Australia,check the map it's a long way. In any case being an MX bike it does not have a speedo or a tacho. The spreadsheet developed by myself and Ed is a useful tool to see what the changes to your gearing are for top speed ,I've never been able to prove it until now.
No there are very few active Hodaka motorcycles in Australia, I probably know half of the owners it's that small.
16 x 47 sprockets and 33 cm radius at 8500 rpm gives a calculated speed of 79.63 mph.
If you can get it to rev to 10700 in top gear you could get 100.24 mph . The spreadsheet does not take into account tyre stretch from centrifugal force.
This is the new pipe that CPI Racing made for the hodaka. Today I'm going to Tim's (TTR Performance dyno) to see what it does and see if we need to make changes to it. DG
I ran the new CPI pipe on the dyno and this is what we got. The CPI made 15.65 HP at 7554 and the circle f made 14.28 hp at 7332. The CPI made 11.00 tq at 7405 and the circle f was 10.37 tq at 7218. The pipe would be a great pipe for a combat wombat that was a play bike / race bike. The low end tq is down just a bit from the circle f but when it comes on WOW it is fast. But for what I'm doing I need more low end TQ so we're going to make some changes to the pipe.....or I may keep this pipe and have a new one made that is more for TQ down low. Sorry I can't get the dyno run to down load. Oh and it also revved out to 10,500 rpm with out just dropping off on the HP and TQ and the circle f would fall off at about 8300 rpm. DG
Would that pipe be AHRMA Classic class legal (straight head pipe)? Or does it have a tapered head pipe? (There may be other things which might take it out of AHRMA Classic class specs, but tapered head pipes are biggies.) If it is Classic legal, I suspect it might be pretty easy to find a new home for it.
Ed
Ed,
AHRMA 125 Classic rules as I interpret them indicate that the expansion chamber can only have up to 4 rolled cones. This one appears to have 5 and arguably up to 7 rolled cones depending on how the connecting cones are considered. On the flip side one of the 5 obvious rolled cones could be argued as an extension of the angle of the adjacent cone. This may or may not be allowed under the rules as written. I guess it would depend on what kind of mood the tech inspectors are in, and whether your competition wants to protest. All that aside I would love to ride a bike with this pipe!
Here's the dyno run for the circle f and the CPI pipe. As I said earlier the CPI is a bit soft on the TQ down low compared to the circle F. For a first try at making a pipe for a hodaka I think CPI did a great job! I have showed Mike the dyno run and he ask me to bring the pipe back for some changes. If he can get the TQ down in the lower RPM and have it still rev out, I think we would have a winner here. I need to take a combat wombat up to him to have a pipe made also.
So Dale. Do each one of those peaks represent the top end of each gear before it peaks and drops power, or am I reading this wrong? That's what it looks like to me. ; D Victor
Victor
The dyno run is done in forth gear, it starts at 3000 RPM and this run was shut down at 10,000 RPM. We did some to 10,500 RPM ....but man I didn't wont to blow it up so we shut it down at 10,000 RPM. DG
