Rocket
Extreme
Just thought I'd let you all know, we did get started finally on the Apex runs on the dyno. Today was just a shakedown day, made sure everything worked and got some breakin time. Will run more breakin time tomorrow and maybe start some runs after noon. The motor is real smooth, doesn't shake the dyno or anything. have had some motors on there that shook the hell outta the room. This motor is real smooth, seems to pull real nice, and so far everything looks good.
The one quick pull that we did showed some decent numbers, 148 at about 10100 or so. Don't remember any torque numbers exactly, I think around 100 or so. BSFC looks pretty good, things are ok.
I probably won't update anything until after 5 everyday, if I can. either here, or on our website.
Rocket
The one quick pull that we did showed some decent numbers, 148 at about 10100 or so. Don't remember any torque numbers exactly, I think around 100 or so. BSFC looks pretty good, things are ok.
I probably won't update anything until after 5 everyday, if I can. either here, or on our website.
Rocket
snowbeast
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Thanks rocket,is it a superflow 901 or 77 or a land and sea,do you control load manually or is it automated ?? Just asking not judging i have had my motors over the years on both types and numbers are only as good as the calibration of the dyno and the knoledge of the operator. So keep us posted thanks. Pete
did u say torque #'s around a 100 or so,that would be sweeet 
i was told in the 80's.....keep us informed 
i was told in the 80's.....keep us informed 
LazyBastard
TY 4 Stroke God
Engine torque is irrelevant. Its DRIVESHAFT torque that you want, which is a function of POWER (150 hp) and speed (0-whatever mph)
LazyBastard said:
Your posts always provide such entertainment...... :ORC
sx7001
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LB, so where would the drive shaft torque come from? I'm kinda leaning towards the engine myself.
LazyBastard
TY 4 Stroke God
Torque = Power * 5252 / rpm.
Power is not affected by rpm, it is constant regardless.
For example; 100 hp @ 1000 rpm = 525.2 footpounds.
Now lets gear that down 2:1,
100 hp @ 500 rpm = 1050.4 footpounds.
Or lets gear it up to 1:10,
100 hp @ 10000 rpm = 52.52 footpounds.
Now lets go for some more interesting real world numbers;
Taken from a dyno sheet for CPR turbo on RX1 http://thespeedshop1.com/Turbo Chargers.htm;
PEAK TORQUE is 113.4 footpounds at 6100 rpm where it makes.... 113.4 * 6100 rpm / 5252 = 131.7 hp. Their sheet actually reports 131.6
PEAK POWER is 192.1 @ 9900 rpm where it makes....192.1 * 5252 / 9900 = 101.9 footpounds. Precisely what they report on the sheet.
NOW to add to this, lets pick our speed.... 50 MPH....
9 tooth driver, 2.52 pitch = 22.68 inch, 1 inch = 1.579293*10^-4 mile, 1 driver revolution = 3.579*10^-4 miles.
50 MPH = 0.8333 M/minute / 3.579^-4 = 2328.4 rpm
Ok, we've established 2328.4 rpm.
Now this is what we've got;
at PEAK TORQUE (you'll check above) we have 131.6 hp.
131.6 * 5252 / 2328 = 296.9 footpounds torque ("forward acceleration").
at PEAK POWER we have 192.1 hp.
192.1 * 5252 / 2328 = 433.4 footpounds torque.
Now just to make you happy, lets calculate this through using gear ratios and torque instead of power;
at PEAK TORQUE 113.4 footpounds we have 6100 rpm geared down to 2328 rpm at a ratio of 6100/2328 (overall). 113.4 * 6100 / 2328 = 297.1 footpounds torque.... same as we got in the last calculation.
at PEAK POWER 101.9 footpounds we have 9900 rpm geared down to 2328 rpm at a ratio of 9900/2328 (overall). 101.9 * 9900 / 2328 = 433.3 footpounds torque. Again thats the same as calculated above.
For anyone having a hard time following that math (its really easy math BTW), take careful note of the fact that we obtained MORE driveshaft torque from LESS crankshaft torque at the same speed. In particular, at any speed, where it makes the most POWER will result in the greatest driveshaft torque.
LESSON TODAY: WE DON'T CARE ABOUT CRANKSHAFT TORQUE, ONLY IN HORSEPOWER BECAUSE WE CAN ALWAYS GET MORE DRIVESHAFT TORQUE BY GEARING DOWN FROM PEAK POWER.
Power is not affected by rpm, it is constant regardless.
For example; 100 hp @ 1000 rpm = 525.2 footpounds.
Now lets gear that down 2:1,
100 hp @ 500 rpm = 1050.4 footpounds.
Or lets gear it up to 1:10,
100 hp @ 10000 rpm = 52.52 footpounds.
Now lets go for some more interesting real world numbers;
Taken from a dyno sheet for CPR turbo on RX1 http://thespeedshop1.com/Turbo Chargers.htm;
PEAK TORQUE is 113.4 footpounds at 6100 rpm where it makes.... 113.4 * 6100 rpm / 5252 = 131.7 hp. Their sheet actually reports 131.6
PEAK POWER is 192.1 @ 9900 rpm where it makes....192.1 * 5252 / 9900 = 101.9 footpounds. Precisely what they report on the sheet.
NOW to add to this, lets pick our speed.... 50 MPH....
9 tooth driver, 2.52 pitch = 22.68 inch, 1 inch = 1.579293*10^-4 mile, 1 driver revolution = 3.579*10^-4 miles.
50 MPH = 0.8333 M/minute / 3.579^-4 = 2328.4 rpm
Ok, we've established 2328.4 rpm.
Now this is what we've got;
at PEAK TORQUE (you'll check above) we have 131.6 hp.
131.6 * 5252 / 2328 = 296.9 footpounds torque ("forward acceleration").
at PEAK POWER we have 192.1 hp.
192.1 * 5252 / 2328 = 433.4 footpounds torque.
Now just to make you happy, lets calculate this through using gear ratios and torque instead of power;
at PEAK TORQUE 113.4 footpounds we have 6100 rpm geared down to 2328 rpm at a ratio of 6100/2328 (overall). 113.4 * 6100 / 2328 = 297.1 footpounds torque.... same as we got in the last calculation.
at PEAK POWER 101.9 footpounds we have 9900 rpm geared down to 2328 rpm at a ratio of 9900/2328 (overall). 101.9 * 9900 / 2328 = 433.3 footpounds torque. Again thats the same as calculated above.
For anyone having a hard time following that math (its really easy math BTW), take careful note of the fact that we obtained MORE driveshaft torque from LESS crankshaft torque at the same speed. In particular, at any speed, where it makes the most POWER will result in the greatest driveshaft torque.
LESSON TODAY: WE DON'T CARE ABOUT CRANKSHAFT TORQUE, ONLY IN HORSEPOWER BECAUSE WE CAN ALWAYS GET MORE DRIVESHAFT TORQUE BY GEARING DOWN FROM PEAK POWER.
RTX Meirda
TY 4 Stroke Master
wow....impressive!
so if the apex has torque#'s in the 80's it wont be that bad,versus a mach at 117 torque#'s,i know the apex has a very wide band....o and i didnt get a thing u wrote,is the apex gonna rock
flyingpig
Expert
Im convinced! LB is a lazy bastard genius!!!!
What is most impressive is sx 700 posted his question at 7:47 and LB figured all that out and had it posted 3 minutes later at 7:50. That is genius for sure!
zr900/650twins
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way,way way to techinical for me.LB,very impressive! can you tell me this?IS THE FREAKING SLED GONNA GO OR WHAT??....thank....al
LazyBastard
TY 4 Stroke God
Its gonna fly.
Yes, MZ has higher torque numbers than RX1 (Apex), These Yammie 4-strokes get it back by spinning bloody fast. Also keep in mind though that MZ is 15-20 hp bigger than RX.
Yes, MZ has higher torque numbers than RX1 (Apex), These Yammie 4-strokes get it back by spinning bloody fast. Also keep in mind though that MZ is 15-20 hp bigger than RX.
Yamanator
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Sorry guy's, I don't mean to interupt here with all this knowledge going on and stuff, but just wanted to mention something I learned from my dealer the other day about Yamaha. He told me (and showed me) that the title's that Yami ships with the sleds have the HP number on it for each individual sled. I guess Yami runs and dyno's each engine before it leaves the factory and then stamp's it on the title for the dealerships. He showed me one for the Apex they had and it showed 148 HP, then he showed me one for another new sled and it was 149 Hp, I thought this was way cool, did anybody else know this ?
If I was getting a new sled, I would for sure like to see that whenI picked it up, just to know.
If I was getting a new sled, I would for sure like to see that whenI picked it up, just to know.
Rocket
Extreme
Mnmsnowbeast: We have a Huff hth325. It's a pretty basic unit, just does enough for what we need it to do, compare apples to apples. It gives us good consistant reliable numbers. It's a hydraulic brake dyno, work I guess on the same premise of a water brake. The numbers from our dyno seem to be consistant to others I've check numbers against. I guess you can say I control the load, kinda, I control the acceleration rate, the dyno does the rest.
I've been comparing some of the numbers to the RX-1 and the Vector. It is interesting to say the least. The Apex seems to have a very broad torque curve, I didn't graph it, but from about 6500 to 8300 clutch rpms, which is about 7900 to 10200 engine rpms the torque numbers are within 6, from about 96 up to 100+ and gradually back down to 96. Hp numbers are within range of other numbers I've seen also.
I won't get much more time on the dyno today as I have meetings the rest of the afternoon.
I've been comparing some of the numbers to the RX-1 and the Vector. It is interesting to say the least. The Apex seems to have a very broad torque curve, I didn't graph it, but from about 6500 to 8300 clutch rpms, which is about 7900 to 10200 engine rpms the torque numbers are within 6, from about 96 up to 100+ and gradually back down to 96. Hp numbers are within range of other numbers I've seen also.
I won't get much more time on the dyno today as I have meetings the rest of the afternoon.
