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HP numbers
- Thread starter Quicksand
- Start date
Since when does the rev limit have to
Do with peak HP output?
Do with peak HP output?
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Not the right Polaris engineer to refer to in this instance. Try those from the Powertrain engineering team like Dallas Blake and Darren Hedlund
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Probably not.
It turns about 8450.
157Hp @ 8450 on its best run.
You obviously have good info directly from Polaris, but in this instance we know the numbers are real and supported by the Polaris engineers themselves. That's the cool think about Polaris.
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It's higher than I thought. I edited my previous post to add my own correction factor @ 8450 rpm :face-icon-small-ton
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Below are the numbers closest to160Hp for the 3 dyno runs done back to back with pipe/muffler temps increasing for each run.
MAX Power Engine RPM changes very little by only 50 rpm.
MAX Power drop changes very little by only 1.4 Hp.
@ 8100 rpm (blue lines). As the pipe/muffler temps increase for each run it causes the engine management to run richer in fuel for a safer running engine.
The Polaris Powertrain engineering team appear to have done an awesome job in Engine Management to bring consistency to a high strung two stroke.
1st run
7750
7800
7900
8000
8100 167.6 Hp 12.84 a/f
8200
8300
8350
2nd run
7850
7900
8000
8100 166.8 Hp 12.45 a/f
8150 167.3 Hp 12.39 a/f
8200
8300
8400
3rd run
7900
8000
8100 166.0 Hp 12.29 a/f
8150 166.2 Hp 12.21 a/f
8200
8300
8350
8400
MAX Power Engine RPM changes very little by only 50 rpm.
MAX Power drop changes very little by only 1.4 Hp.
@ 8100 rpm (blue lines). As the pipe/muffler temps increase for each run it causes the engine management to run richer in fuel for a safer running engine.
The Polaris Powertrain engineering team appear to have done an awesome job in Engine Management to bring consistency to a high strung two stroke.
1st run
7750
7800
7900
8000
8100 167.6 Hp 12.84 a/f
8200
8300
8350
2nd run
7850
7900
8000
8100 166.8 Hp 12.45 a/f
8150 167.3 Hp 12.39 a/f
8200
8300
8400
3rd run
7900
8000
8100 166.0 Hp 12.29 a/f
8150 166.2 Hp 12.21 a/f
8200
8300
8350
8400
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Not the right Polaris engineer to refer to in this instance. Try those from the Powertrain engineering team like Dallas Blake and Darren Hedlund
I rode with Jim, one of the engine designers.
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- Oct 14, 2008
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Daag ffs. That's dynotech info and it's not supposed be posted. That's how Dynotech earns income by doing honest, no bs tests. If you post the results, nobody will buy the dynotech $30/year subscription and if it gets out of hand, Jim loses more money and eventually he will quit. Then we will have no true dyno info available for future sleds. Come on guys, spend the measly 30 and lets help keep one of the last honest sled business guys around.
30 bux will save you thousands on unnecessary parts and wasted days wrenching.
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What he posted isn’t going to make anybody subscribe or not subscribe.
Nothing top Secret there.
I had a subscription for a couple years and frankly didn’t get much out of it. ??*
??*
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I'm actually glad that you posted what you did, and there is a fine line with what we can share. But there is a reasonable amount that is permitted to encourage a discussion. I only posted peak Hp and the details for 8100 and 8150 rpm.
Note that you quoted my complete post with the numbers. So if I wanted to edit my post to provide a little less, yours would still be showing. So in effect you have also posted those numbers
In other words, edit it out of your post.Had an 07 xps rev that ran like a scalded dog for 361 miles before it lost a bearing 8450 was the sweet spot on that motor. New motor under warranty and was detuned to live at 8100 minus at least 10 ponies. I don't think Polaris is leaving much on the table to gain with a single pipe because slp is having a hard time making one that is up to there standard.
D
What he posted isn’t going to make anybody subscribe or not subscribe.
Nothing top Secret there.
I had a subscription for a couple years and frankly didn’t get much out of it. ??*
Much of the good stuff comes from the accompanied text that Jim provides. It does need some work to get something out of dyno sheets. Without a spreadsheet to make graphs it can look like just a bunch of numbers.
What Kanedog mentioned is a double edged sword. To keep the dyno sheets coming he needs subscribers which needs an interest. To generate an interest there needs to be some numbers to show meaning.
- Oct 14, 2008
- 3,106
- 3,859
- 113
- 60
Correct its not a secret. Talk about numbers and everything just dont post the sheets. Thats all.
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- Oct 14, 2008
- 3,106
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The dyno sheets tell you what rpm your engine makes the most power and hence, what rpm to calibrate for.
If max hp is at 8000 rpm and max torque is also at 8000 rpm, calibrate your sled to run at 8000 rpm.
If your max power is at 8000 and it's only revving to 7800, its losing speed and power and your buddies are beating you and your probs getting stuck more often.
I like to calibrate rpms a little past the hp/tq peak so when the sled encounters a heavy load like spring snow, extra weight, steep hill or warmer weather the rpms will drop down to(but actually up to) peak hp/tq. I hope that makes sense.
There's other small tips but that's the jist of it.
True, honest Dyno sheets are an invaluble tuning tool. It's not possible to tune properly without them.
Sent from my SM-G920W8 using Tapatalk
If max hp is at 8000 rpm and max torque is also at 8000 rpm, calibrate your sled to run at 8000 rpm.
If your max power is at 8000 and it's only revving to 7800, its losing speed and power and your buddies are beating you and your probs getting stuck more often.
I like to calibrate rpms a little past the hp/tq peak so when the sled encounters a heavy load like spring snow, extra weight, steep hill or warmer weather the rpms will drop down to(but actually up to) peak hp/tq. I hope that makes sense.
There's other small tips but that's the jist of it.
True, honest Dyno sheets are an invaluble tuning tool. It's not possible to tune properly without them.
Sent from my SM-G920W8 using Tapatalk
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Another tip. Play with yours when you get it and not just take this as gospel off 1 dyno and 1 guy posted second hand.
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