Posts
2373
Joined
8/17/2006
Location
Delmar, DE, USA
Edited Date/Time
1/26/2012 6:05am
Just for you T-Fish - taken from MXA:
[img:1kmmu49d]http://www.motocrossactionmag.com/Media/News/GoKTM_ENGINE_0.jpg[/img:1k…]
Dear MXA,
Have you dyno tested the KTM 144SX? Have you compared it to the KTM 125SX? Have you tested it against 250 four-strokes?
Yes, yes and yes. Where the 125SX has a smooth, linear and road racy powerband, the 2008 KTM 144SX powerband is much chunkier off the bottom and through the middle. Torque is up two foot-pounds from 6000 rpm to 10,000 rpm (and one foot-pound until sign-off). A more telling comparison is between the torque of the 125SX (17.8 ft-lb), 144SX (18.9 ft-lb) and 250SXF four-stroke (19.2 ft-lb). The 144SX closes the torque gap, which is what four-strokes use to get hooked up better than two-strokes. The 144SX’s additional torque is more important on the track than its horsepower figures.
The horsepower numbers favor the 144SX over the 125SX (and over the 250SXF also). The 2008 KTM 144SX tops 40 horsepower at peak (which is about 300 rpm lower and two horsepower more than the 125SX’s peak). Best of all the 144SX makes as much as three horsepower more than the 125SX in the meat of the powerband.
If we were going to choose a 125 two-stroke to race against 250 four-strokes we would choose a big bore. The extra horsepower and torque (especially the torque) make the 144 a better bike to go up against four-strokes. Do we think it will beat a250 four-stroke? We’ve seen guys on weak RM125’s win Vet races against riders on 450s. So, anything can happen. The 144 can beat them when used to its fullest. It will definitely beat a 125.
[img:1kmmu49d]http://www.motocrossactionmag.com/Media/News/GoKTM_ENGINE_0.jpg[/img:1k…]
Dear MXA,
Have you dyno tested the KTM 144SX? Have you compared it to the KTM 125SX? Have you tested it against 250 four-strokes?
Yes, yes and yes. Where the 125SX has a smooth, linear and road racy powerband, the 2008 KTM 144SX powerband is much chunkier off the bottom and through the middle. Torque is up two foot-pounds from 6000 rpm to 10,000 rpm (and one foot-pound until sign-off). A more telling comparison is between the torque of the 125SX (17.8 ft-lb), 144SX (18.9 ft-lb) and 250SXF four-stroke (19.2 ft-lb). The 144SX closes the torque gap, which is what four-strokes use to get hooked up better than two-strokes. The 144SX’s additional torque is more important on the track than its horsepower figures.
The horsepower numbers favor the 144SX over the 125SX (and over the 250SXF also). The 2008 KTM 144SX tops 40 horsepower at peak (which is about 300 rpm lower and two horsepower more than the 125SX’s peak). Best of all the 144SX makes as much as three horsepower more than the 125SX in the meat of the powerband.
If we were going to choose a 125 two-stroke to race against 250 four-strokes we would choose a big bore. The extra horsepower and torque (especially the torque) make the 144 a better bike to go up against four-strokes. Do we think it will beat a250 four-stroke? We’ve seen guys on weak RM125’s win Vet races against riders on 450s. So, anything can happen. The 144 can beat them when used to its fullest. It will definitely beat a 125.
viewtopic.php?f=2&t=49380&st=0&sk=t&sd=a&start=25
What do we really think? Is the final MXA question.
We don't really have to tell you who won between the 125 and 144. The proof lies in the fact that KTM will make TWICE as many 144SX's in 2008 as they will 125's. That's a good thing because the 144 is the choice of every MXA test rider.
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Luxon 4-Post Bar Mounts
$189.95 - $239.95
[/quote:28luquob]
You know you're more than welcome to ride it whenever you want to! How many other friends do you have that would let you put in the very first real laps on a brand new bike?
One thing they left out - four strokes hook up better not because of torque, but because they fire every other revolution, which gives the rear tire more time between power bursts. Road racers have been doing that for years, it makes a huge difference.
One thing they left out - four strokes hook up better not because of torque, but because they fire every other revolution, which gives the rear tire more time between power bursts. Road racers have been doing that for years, it makes a huge difference.[/quote:21swlnxi]
It's funny you should mention that, and equally amusing that it was Honda that figured it out first with the "Big Bang" NSR 500 engine. It fired all 4 cylinders within 90 degrees of crank rotation or some such (I can't remember the exact timing). I say it's amusing that Honda figured it out first because it was Yamaha that hung themselves out on a limb with the first "real" mx 4 stroke.
One thing they left out - four strokes hook up better not because of torque, but because they fire every other revolution, which gives the rear tire more time between power bursts. Road racers have been doing that for years, it makes a huge difference.[/quote:73tnfzcv]
Exactly White Knuckle. At 10,000 RPM; 5,000 power bursts in 2st.. 2,500 power bursts in 4st.
One thing they left out - four strokes hook up better not because of torque, but because they fire every other revolution, which gives the rear tire more time between power bursts. Road racers have been doing that for years, it makes a huge difference.[/quote:2oasusf8]
Exactly White Knuckle. At 10,000 RPM; 5,000 power bursts in 2st.. 2,500 power bursts in 4st.[/quote:2oasusf8]
Actually a 2 stroke has 10K power events at 10K RPM and a 4 stroke has half that many.
Yes, the longer the delay between power pulses the better rider feel is for traction. In an open bike (such as a 450) this is a notable advantage.
Post a reply to: More KTM144 madness