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With all the talk of the magical peak horsepower, that is only part of the equation.
How wide is the torque curve? I remember before everyone was using exhaust valves the horsepower was so peaky sleds were a challenge to clutch. Miss the peak rpm by a few hundred rpm and the sled would fall on its face.
 

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With all the talk of the magical peak horsepower, that is only part of the equation.
How wide is the torque curve? I remember before everyone was using exhaust valves the horsepower was so peaky sleds were a challenge to clutch. Miss the peak rpm by a few hundred rpm and the sled would fall on its face.
I dont know about that.The non ves 700/800 Big block Polaris ran as good if not better than their ves counterparts.
 

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Sorry SD, I wasn't just talking Polaris, but sled engines in general.
I remember clutching a skidoo 9500 with a 440 rotary valve engine. If that bitch wasn't on the pipe it wasn't making horsepower. The horsepower graph on that engine looked like the stock market crash.
It was the finickiest, boggiest engine I ever worked with.
Thank God those days are over.


I know we are WAY off track here, so back to the 850 Indy thread.
 

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With all the talk of the magical peak horsepower, that is only part of the equation.
How wide is the torque curve? I remember before everyone was using exhaust valves the horsepower was so peaky sleds were a challenge to clutch. Miss the peak rpm by a few hundred rpm and the sled would fall on its face.
Exactly. Avg torque/hp is the way to evaluate engine power. Peak is not nearly as important. With a typical 2-stroke, dyno results usually aren't the best indicator of in the field performance. Mainly because they only assess WOT and only at a controlled rate of rpm increase.

I've been involved in many in the field vehicle acceleration tests. The low rpm engine response is a key factor in improving acceleration.

A few weeks ago, I loaned a special vaporizing anti-reversion 4 barrel plate to a friend for testing. He gained .2 seconds in the quarter mile.
The car runs in the 9 second range. His previous setup had so much reversion in the carb at WOT that the wide-band O2 sensors were reading around 12:1. When he installed the plate, it went to 16:1. He had to add 4 main jet sizes and it was still 15:1. He ran it anyway. Said it made so much more low end power that he hit the rev limiter before the traps and lost control. This was at Milan Dragway. Had to deploy his chute. Car flipped and was destroyed. He is purchasing the plates for his new car.

I've done the same testing on snowmobiles, dirt bikes, PWCs, etc, with similar results.

The point is that a dyno can't easily assess this effect. DTR Jim and I have discussed this issue numerous times.

Any engine mod that broadens the power band will usually improve in the field performance.

So, don't get hung up on peak power dyno readings.:bc:
 

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Brand loyal, not brand blind
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Exactly. Avg torque/hp is the way to evaluate engine power. Peak is not nearly as important. With a typical 2-stroke, dyno results usually aren't the best indicator of in the field performance. Mainly because they only assess WOT and only at a controlled rate of rpm increase.

I've been involved in many in the field vehicle acceleration tests. The low rpm engine response is a key factor in improving acceleration.

A few weeks ago, I loaned a special vaporizing anti-reversion 4 barrel plate to a friend for testing. He gained .2 seconds in the quarter mile.
The car runs in the 9 second range. His previous setup had so much reversion in the carb at WOT that the wide-band O2 sensors were reading around 12:1. When he installed the plate, it went to 16:1. He had to add 4 main jet sizes and it was still 15:1. He ran it anyway. Said it made so much more low end power that he hit the rev limiter before the traps and lost control. This was at Milan Dragway. Had to deploy his chute. Car flipped and was destroyed. He is purchasing the plates for his new car.

I've done the same testing on snowmobiles, dirt bikes, PWCs, etc, with similar results.

The point is that a dyno can't easily assess this effect. DTR Jim and I have discussed this issue numerous times.

Any engine mod that broadens the power band will usually improve in the field performance.

So, don't get hung up on peak power dyno readings.:bc:
Wasn't anti reversion some of the things Boswell worked with? Recyclers?
 

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Yes, and it works like a charm. I bought the patents. Reduces emissions too. I've dynoed and field-tested these devices on everything you can imagine with outstanding results.:bc:
Including AXYS 800 fuel injected motor?
 

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Not a preproduction model. As I stated earlier hot pipe, cold water running through motor, ethanol to cool things even more.

The Cat dealer was there and stated, “ make this thing hit 160hp”
Read my signature,,, it's a quote from Jim at Dynotech
:thumbsup:
 

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Discussion Starter #30 (Edited)
Read my signature,,, it's a quote from Jim at Dynotech
:thumbsup:
So then Jim lied when he told everyone else 160.6hp .

I spoke with him, Arctic Adventure was there and said, “make this thing 160hp”......so he did with the tricks listed above and a few more.

Call D and D and ask them about the DynoTech test with arctic adventure there then report back here.

I never said it’s 160 hp.......DynoTech did !!

It’s no secret they are 152 hp at Speedwerx and bikeman, and not 160.
 

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So then Jim lied when he told everyone else 160.6hp .

I spoke with him, Arctic Adventure was there and said, “make this thing 160hp”......so he did with the tricks listed above and a few more.

Call D and D and ask them about the DynoTech test with arctic adventure there then report back here.

I never said it’s 160 hp.......DynoTech did !!

It’s no secret they are 152 hp at Speedwerx and bikeman, and not 160.
1 sled made that HP,,,,ONE SLED.
A pre production model made that 160 number. They sent a hot ecu:thumbsup:. Jim doesn't lie . What my quote said is straight from Jim's mouth and posted on HIS site. maybe you should call him and ask him if he's lying:bc:. Sorry if it's the lowest HP 800 out there but I didn't need a dyno to know that,,, it's very apparent in the real world,, they're dogs
 

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The joke is, my fathers high country is still way faster than my sks with it being such a dog.
Same lug height on both sleds?? HC is 146" also??? Not up on my Cat models
 

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The joke is, my fathers high country is still way faster than my sks with it being such a dog.
Here's my Assault box stock with 2" Lug running an XF 800 with a big lug track...around 2" or whatever comes on them sleds. It was real hard packed and he got the holeshot and it was no contest for him.

Make sure you are comparing track length and lug size that are very close.

 

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The joke is, my fathers high country is still way faster than my sks with it being such a dog.
You dad has a good one if it's stock. There are quite a few "my 800 is slow" threads in the Cat forum.

<edit>

A brief search reveals that Cat High Country models commonly come with 19:50 gearing (or 22:48 gearing on older models). SKS models come with 20:40 or 20:42 gearing. Based on that information, how the hell is it possible for your dad's HC to be faster? That makes no sense. Are you neglecting to tell us about some mods that were needed to make the lower-horsepower, heavier Cat seem more impressive than it really is in stock form?
 

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Polaris will never post a number. To much variation in dynos,methods,condition etc. they are not gonna say it's 168 and hav somebody else make a pull and have it not match up.
It’s beacuse they are scared to give a HP # and 1 hp off everyone is upset.

Funny........... that per year manufactured
72 million cars
3.5 million bikes
4 million outboard motors all give a HP rating all before they are sold or listed for sale.
A 100,000 2 strokes sleds 800/850 and they have no clue because one could be differant than the one next to it because of lackluster quality control or they are scared to post, I go with scared.
EPA is BS made up excuse , EPA only needs one engine to test if the EPA decides it would like to audit the test motor results the manufacture sends in . Takes 30 days to review the info that the manufacture sends in and they need to keep the test motor on hand until the end of that model year. I’m sure Polaris is well within EPA standards on the 850 years ago and has the ok For 2019 already.

BTW WHO CARES!
Round it to 165 or 170 and make it a day............
 

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Discussion Starter #40 (Edited)
1 sled made that HP,,,,ONE SLED.
A pre production model made that 160 number. They sent a hot ecu:thumbsup:. Jim doesn't lie . What my quote said is straight from Jim's mouth and posted on HIS site. maybe you should call him and ask him if he's lying:bc:. Sorry if it's the lowest HP 800 out there but I didn't need a dyno to know that,,, it's very apparent in the real world,, they're dogs
Are you even reading the posts you are responding too ?

The 800s make 152 hp and after all Jim’s tricks made 160hp. Arctic Adventure told them, MAKE THIS THING 160HP.........hot pipe, cold water, high ethanol for more cooling.

I spoke with Spaulding extensively and he agreed 160 is possible with simple dyno tweaking. As well as there are 4.5hp more to be had with reeds.

Call D and D and ask them about the Dyno session with Arctic Adventure, you will learn a little something and then can recall or delete your inaccurate posts.
 
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