Popular Post BR46 Posted January 17 Popular Post Share #1 Posted January 17 Just finished up dyno testing the 500 and the sidecar.....I am ready for the 2023 season. 4 3 Link to comment Share on other sites More sharing options...
Razors Edge ★ Posted January 17 Share #2 Posted January 17 Well????? Give us some numbers! Guys like @donkpow like to have numbers! 2 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 17 Share #3 Posted January 17 How were the runs? Any surprises? Power up or down? Do you have to have a monkey on the sidecar rig to dyno? 1 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 17 Share #4 Posted January 17 1 minute ago, Razors Edge said: Well????? Give us some numbers! Guys like @donkpow like to have numbers! 6 Link to comment Share on other sites More sharing options...
Razors Edge ★ Posted January 17 Share #5 Posted January 17 Just now, jsharr said: How were the runs? Any surprises? Power up or down? Do you have to have a monkey on the sidecar rig to dyno? Yep - we need numbers! And maybe a graph or two! Link to comment Share on other sites More sharing options...
Razors Edge ★ Posted January 17 Share #6 Posted January 17 Just now, jsharr said: 6 Don't go any higher, bubba! 1 Link to comment Share on other sites More sharing options...
donkpow Posted January 17 Share #7 Posted January 17 This is something that should be seriously considered for installation in @Square Wheels's garage. He needs one. Maybe two. 1 1 1 Link to comment Share on other sites More sharing options...
Popular Post BR46 Posted January 17 Author Popular Post Share #8 Posted January 17 5 minutes ago, jsharr said: How were the runs? Any surprises? Power up or down? Do you have to have a monkey on the sidecar rig to dyno? I spent the off season building a new exhaust system trying to get more mid range toque and power. The BMW sidecars make more power in the mid range where the yamaha makes all the power at top end. We lost 4 races by less than 2 seconds because the BMWs make more power coming out of the turn and beating us to the line. The results. More power in the mid range and a slight improvement at topend over the old exhaust. Blue is old exhaust red is new exhaust. 4 1 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 17 Share #9 Posted January 17 How much does a mid range toque cost? Do you wear it under your helmet or just between races? 1 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 17 Author Share #10 Posted January 17 3 minutes ago, donkpow said: This is something that should be seriously considered for installation in @Square Wheels's garage. He needs one. Maybe two. Dyno hourly rate is on average $100 to $150. 2 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 17 Share #11 Posted January 17 Does that loss of power at the start matter at all? I assume you spend most of your time at speed? Do you have a rolling start or a standing start? 1 Link to comment Share on other sites More sharing options...
donkpow Posted January 17 Share #12 Posted January 17 I say run open pipes and burn the valves. Winning is worth it! Link to comment Share on other sites More sharing options...
Popular Post Kirby ★ Posted January 17 Popular Post Share #13 Posted January 17 I kind of thought this thread would have dinosaurs in it. 2 1 1 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 17 Author Share #14 Posted January 17 11 minutes ago, jsharr said: Does that loss of power at the start matter at all? I assume you spend most of your time at speed? Do you have a rolling start or a standing start? The power loss is under 3,500rpm and that doesn't matter. We have standing starts and we launch at 6,000 to 6,500rpm and in the race I try to never let the rpms drop below 4,500. The motor performs the best between 5,500 to 8,200. 10 minutes ago, donkpow said: I say run open pipes and burn the valves. Winning is worth it! It's 2 inch diameter straight through the reverse megaphone exhaust 2 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 17 Share #15 Posted January 17 10 minutes ago, Kirby said: I kind of thought this thread would have dinosaurs in it. BR46 is not that old. 2 Link to comment Share on other sites More sharing options...
BR46 Posted January 17 Author Share #16 Posted January 17 4 minutes ago, jsharr said: BR46 is not that old. Just feel that way somedays 1 Link to comment Share on other sites More sharing options...
donkpow Posted January 17 Share #17 Posted January 17 19 minutes ago, BR46 said: It's 2 inch diameter straight through the reverse megaphone exhaust Just saying those words should get you at least 3 seconds per lap. 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 17 Author Share #18 Posted January 17 3 minutes ago, donkpow said: Just saying those words should get you at least 3 seconds per lap. We were trying to find a average of 2 seconds per lap.....but I'll take 3 if I can. 1 2 Link to comment Share on other sites More sharing options...
Thaddeus Kosciuszko Posted January 18 Share #19 Posted January 18 8 hours ago, BR46 said: It's 2 inch diameter straight through the reverse megaphone I remember a song about a guy who had two turntables and a reverse megaphone... 2 Link to comment Share on other sites More sharing options...
Bikeguy Posted January 18 Share #20 Posted January 18 So is that 43.17 ft-lbs of torque at 6020 rpm? That's 61% more than stock (assuming I found the correct engine data). 2 Link to comment Share on other sites More sharing options...
BR46 Posted January 18 Author Share #21 Posted January 18 10 minutes ago, Bikeguy said: So is that 43.17 ft-lbs of torque at 6020 rpm? That's 61% more than stock (assuming I found the correct engine data). 1974 Yamaha XS 650 / TX 650 - Motorcycle Specs Stock...Yamaha XS 650 / TX 650 ; Max Power. 39.5 kW / 53 hp @ 7200 rpm ; Max Torque. 54 Nm / 5.5 kgf-m / 39.8 lb-ft @ 6800 rpm ; Transmission. 5 Speed I know that if I would have spent more time on the dyno I can improve those numbers. When I booked the dyno I only booked one hour. What I was interested in is what changes were made in the 4,500 to 6,000 RPM range with making the collector 2 inches longer and the megaphone 1/2 inch bigger in diameter and 6 inches longer. The BMW sidecars are hard to beat because they corner better with their lower center of gravity and they produced 4 more hp in the 4,000 to 6,000 range then the Yamaha 650. I would pass them on the straight just to get passed back coming out of the turns. I'm trying to change that. A famous racer / engine builder told me that his goal was to get 1 bike length on his computers coming out of the trurn. He looked at me and said ....how many turns on this track? Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 18 Share #22 Posted January 18 21 hours ago, jsharr said: 6 42 1 Link to comment Share on other sites More sharing options...
donkpow Posted January 18 Share #23 Posted January 18 Can you get a bigger gas pedal? That would probably help. 2 Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 18 Share #24 Posted January 18 I spent part of yesterday at the carbon fab shop yesterday doing final fit checks for "2". He has a rc motor dyno. Relative numbers only but it's more than i have 1 Link to comment Share on other sites More sharing options...
Parr8hed Posted January 18 Share #25 Posted January 18 I get the wanting to improve what you have. But I also get wanting to go the fastest that you can regardless of the equipment. So have you considered just selling the yamaha stuff and going BMW? Link to comment Share on other sites More sharing options...
BR46 Posted January 18 Author Share #26 Posted January 18 39 minutes ago, maddmaxx said: I spent part of yesterday at the carbon fab shop yesterday doing final fit checks for "2". He has a rc motor dyno. Relative numbers only but it's more than i have Numbers are good With racing you know as well as I do there are so many factors that will win or lose a race and in sidecar racing its double. Link to comment Share on other sites More sharing options...
BR46 Posted January 18 Author Share #27 Posted January 18 4 minutes ago, Parr8hed said: I get the wanting to improve what you have. But I also get wanting to go the fastest that you can regardless of the equipment. So have you considered just selling the yamaha stuff and going BMW? Part of the fun is trying to figure out on how to beat them. They don't make any more hp they just make power in different places of the power curve. The BMW sidecars are all racing with frames made by some famous racing shops in the UK and I'm racing with a frame made in a little garage in my backyard. Their running crate motors and I built mine in the garage doing 97% of my own machining. 3 Link to comment Share on other sites More sharing options...
Parr8hed Posted January 18 Share #28 Posted January 18 9 minutes ago, BR46 said: Part of the fun is trying to figure out on how to beat them. They don't make any more hp they just make power in different places of the power curve. The BMW sidecars are all racing with frames made by some famous racing shops in the UK and I'm racing with a frame made in a little garage in my backyard. Their running crate motors and I built mine in the garage doing 97% of my own machining. And that is pretty awesome. Just curious about if you have thought about it. I like the way you're doing it. Link to comment Share on other sites More sharing options...
BR46 Posted January 18 Author Share #29 Posted January 18 9 minutes ago, Parr8hed said: And that is pretty awesome. Just curious about if you have thought about it. I like the way you're doing it. Also...when you blow up a BMW it's almost twice as expensive. 2 Link to comment Share on other sites More sharing options...
Parr8hed Posted January 18 Share #30 Posted January 18 8 minutes ago, BR46 said: Also...when you blow up a BMW it's almost twice as expensive. And you have to delete all turn signals. 1 Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 18 Share #31 Posted January 18 1 hour ago, BR46 said: Part of the fun is trying to figure out on how to beat them. They don't make any more hp they just make power in different places of the power curve. The BMW sidecars are all racing with frames made by some famous racing shops in the UK and I'm racing with a frame made in a little garage in my backyard. Their running crate motors and I built mine in the garage doing 97% of my own machining. This is the way. 1 Link to comment Share on other sites More sharing options...
12string Posted January 18 Share #32 Posted January 18 I suppose you can use the sidecar as a bike rack, so it's a pass. Link to comment Share on other sites More sharing options...
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