Posts
6767
Joined
8/30/2008
Location
Stockholm
SE
Edited Date/Time
12/31/2012 8:26am
I remember when they came 04, and was pushing 30 (the numbers varies, I'm reading from high twenties up to mid thirties tops), and now the KTM is close to 43!!! Damn, this is close to 250 smoker numbers. I really doubt at this point a stock smoker would give any advantage anywhere? Loamy sand? I guess there's some weight benefits with the smoker though?
If the stocker have 43, what are the number of the factory bikes? 47? Smokers can be pushed to close 60 hp, but rideable?
Thoughts?
If the stocker have 43, what are the number of the factory bikes? 47? Smokers can be pushed to close 60 hp, but rideable?
Thoughts?
I'm sure those 250SXFs will sound good behind Tomacs Honda and Baggett's Kawi though.
The Shop
Damn, if only KTM could do a 250 shootout with Rozcen riding both at Lommel and Teutschenthal...
I hate that Cairoli didn't get a chance to rider the smoker two years ago, and the last race...
Motorcycle-usa.com 37.76 http://www.motorcycle-usa.com/90175/Motorcycle-Photo-Gallery-Photo/2013-KTM-250-SX-F-Comparison.aspx
I must admit, my dirt riding is off-road focused these days. Still plenty of 2 Smokes out there weaving thru the trees.
Anyone ever ride a 300KTM? That bike rides itself.
You're that guy, leaning on the fence at the track, who just starts talking, and the collective IQ of the immediate area drops drastically, forcing people to frantically run back to their tail gates.
The correction factor can be adjusted to make it seem like a bike is making more power than it really does. If I had to guess, I'd say MXA is using a dyno that belongs to a company in the aftermarket performance business. If xyz's exhaust system makes an extra 1.5hp on a '13 CRF 250, what sounds better?
"With just our exhaust alone the '13 CRF 250 makes 39.94hp" (MXA's stock 38.44 + 1.5)
or
"With just our exhaust alone the '13 CRF 250 makes 33.08hp" (The new bone stock '13 CRF I dyno tested at 31.58hp + 1.5)
Why do so many people think that today's riders couldn't ride a 2T? A good rider could ride a 3 stroke, shopping cart with a dell'orto carb, and a clutch soaked in cooking oil.
Pit Row
whats kind of nice about the 250f numbers getting so high, eventually the AMA is gonna run out of excuses to keep the current displacement rules in place as the HP numbers are gonna be so close.
Another thing though on the 250 vs 250f debate is that there really shouldnt be that big of a difference between the bikes in terms of HP to lap time relation. i mean you see 250f's post the fastest laps of the night plenty of times vs the much more powerful 450's. there was a guy that breaks the lap times down during the races and his graphs show tomac/barcia/whatever post faster lap times than dungey did on the 450, and when they werent faster they were only a second or so behind.
125 is right that the 150sx is in the range of the 250f in terms of peak power but the spread advantage is so far to the 4 strokes side that it really is unfair except for the most precise small bore pilots. the 250 2 stroke should really be considered the small bore, they should make a ridable 450 with a broad spread (think electric PV with extreme porting that would make a mechanically controlled PV unfavorable for the application) to compete with the 450 4 strokes. the 125 should be considered a "mini" imo since they have more of a mini bike type power spread.
IMO, even if the 250sxf doesnt make 43hp, using MXA back to back reviews at least gives you an idea of about how much it improved over last year.
I think I've read somewhere that in the process of making the new alu-framed CR250 they tried different engines, of which some created bizarre figures in the dyno. Without regards to torque and character suited for mx a 250 2stroke can easily reach the same hp as a 500 2stroke (HP, not torque)
A good rider on a 250 twostrokes has no excuses to loose out against a 250f on the startstraight. Excepts for Poto in Budds Creek at mxon, I don't see the smokes giving away to many starts. In SX the startstraight is so short so it'smore of a lottery there I think.
Just for comparsion... a factory 125 roadracing bike pushes close to 60hp. A factory 125 mx makes 40hp+ at the backwheel.
I would like to see cc vs cc in mx/sx. If you also combine the FIM WC and ama nationals we would have a product to be proud of, and also a more marketable product.
The only fair way to test the numbers is to have all the bikes on the same dyno on the same day. Then you can see the real difference between them.
I for one would believe motorcycle usa numbers of around the 37/38 mark. Most of the 250f's I have seen on the dyno put out around 33-35 stock. With a typical exhaust, cams and some porting work the high 30's is within reach. The 2012 KTM I seen tested last year put out 34.?hp. So with the claimed 5hp gain the we could be looking at the 38/39 mark which was what a 12 had with the typical after market mods worth around 2000 dollars.
I do not believe that they are capable of 43 hp except at GP/AMA top 10 level. Takes a lot of work to increase a bikes performance by 20-25%. One of the local lads over here had Pro Circuit completely mod his Kwak 250f with B kit suspension and just about every bolt on and head mod that can be done by pro circuit. It made just over 40hp on the dyno from the base line 35.? something. But it also was dead at the bottom losing 3hp up until the mid range where it took off. It was a healthy 4hp up at 10500rpm and stayed that way to the power dropped off.
The bike reminded me of the KTM 200 sx in terms of Raw power (which to me is the best 2 stroke engine made for a weekend warrior). Certainly could be raced against any modern 250 2 stroke and not be at a disadvantage except in sheer top end HP.
I don't get these dyno figures people through out, the numbers varies up to 10 hp, and seems both figures are almost valid to print? I understand science can be a bitch, but a dyno should be pretty simple to calibrate on a weekly bases (put up a electrical motor creating fix hp as a base, that sucker will continue spitting out the same HP for ages. How come MXA can loose so big on such a simple task?
hp = (torque * rpm) / 5252
Assuming that the torque of the motor is constant at say 15 ft/lbs and the motor peaks at 10,000 rpm that would equal 28.6 hp. Now if that same motor making the same torque were to peak at a much higher rpm, say 14,000, it would then make 40 hp. The trend is to shorten the stroke and increase the bore allowing the motor to run at higher rpms and achieve a higher calculated hp. I believe KTM did just that with their new motor. Not saying it doesn't rip but there is a little skullduggery involved...
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