Kart race engines vs. the big displacement....

He is surely missed and you know you are making him proud that you are continuing racing karts
Oh no doubt it's expensive to race. I am pretty lucky to have all the stuff that I have. All my karting stuff was my dad's that he gave me right before he died this past June.
 
I will say I sure do miss the old man. I don't have him to turn to to ask questions anymore. It really sucks. I would give anything to hear him say " Go home Frankie we don't have any milk" man I miss that LOL

Frankie
 
PD- Its not legal nor do I foresee that ever happening. Its a 20 grand superkart motor and way past innovation for years now. It as well has multiple overseas competition from other billet inline motors
According to the new "innovation"
rules, it will be legal within a couple of years.
Cannot stop the present version of "innovation."
 
OK scratching up this old thread just to say 2 things: Torque is an applied force of rotation measured in inch pounds, foot pounds or newton meters. (I recently won a bet on who'd buy the beer among some fellow racers, when I said I can make torque applied to the axle without the engine even running while they made he beer run to the store, I locked the brakes using a bungee cord, plug out and the kart in gear, place a torque wrench on the starter nut with concrete block tied to the handle, causing it to read a constant 22.5 ft. pounds.)
Horse Power on the other hand is a measure of actual work being done. (generally understood by James Watt as the force it takes one horse to lift 550 pounds one one foot in one second.)
https://en.wikipedia.org/wiki/Horsepower#/media/File:Imperial_Horsepower.svg
 
Torque / time is really the only useful number... Everything else is trying to maximize that. You either try to widen the time factor (Wankel / JAWA) or widen the torque number and gear to stay in that window (270s, BRC250s, etc.)
 
Hopefully I'm not drifting off topic, but I read through these messages, a great portion of it is way beyond my knowledge, but I couldn't help but think, the level of creativeness and ingenuity, at least as far as I'm concerned, lacking in the majority of kart classes is a major reason for the lack of popularity karting has, generally speaking...when you by a cookie cutter frame, put a cookie cutter looking body, clutch/engine and tires on a kart in any of the various spec classes out there these days, there is no room for creativity/ingenuity, rather only the desire to look outside the rules for any kind of advantage.... whereas, open/rwyb racing, leaves the window wide open, where a little creativity ingenuity and driver ability can overcome and succeed...jm2c
 
Do the calculations, it all comes down to "power under the usable curve"!

Engine A = 10,000 – 15,000 usable curve.
Engine B = 8,000 – 18,000 usable curve.
Engine B, depending on the power under the curve, depending on the gear ratio, could possibly beat engine A, even if engine A's HP was higher everywhere, under "it's" usable curve.

My dyno curve Excel spreadsheet, for plotting HP, has a "total power under the curve" cell. It's sometimes fun to compare "peak" HP numbers, but it's the power under the curve (in most cases) that counts!

By the way; in a direct drive system, the HP at the engine is always exactly (less power transmission losses) the same as the HP at the axle.
 
The "usable curve" doesn't matter as much as "the curve the engine spends its' time in." Which is why there's always a compromise between peak hp and torque curve. Just wait until the electrics arrive. There's not even a weight formula for them...
 
And how come nobody's tried a 2 clutch system...
1601053726389.png
 
They are one and the same!
No, Al, they're not. Performance depends on whether you're able to spend the whole race in the 400-600 rpm drop between straights and corners like the elliptical tracks here in NC/SC with a Briggs flathead or whether you're having to let way off and deal with a long straight (paperclip track). It also depends on how many restarts and cautions there are, and how skilled the other drivers are at maintaining momentum. If my engine has a usable (optimal) RPM range of 1500 RPM, from 11,000 to 12,500, but I'm having to do a lot of restarts or the straights are too long and I don't have over-rev, then an engine like a Wankel is going to beat me. But if my little 116 can spend the whole race in its' optimum range and it never has to expend extra HP beyond its' limits (compared to, say, a 450) to get me off the line, then I can be competitive. I suspect that we're dealing with a semantics issue here, but just because an engine has a "usable RPM" band doesn't mean that the track or race is allowing you to make full use of that. And, more likely, conditions are forcing use OUTSIDE of the usable RPM band, and compromises are required. This is where a setup like the dual clutch above, or a CVT system would shine. It would widen the usable curve to match the operating range.
 
6 years since this thread started and the UAS is the best it’s ever been in terms of competitive racing, kart count (which is NOT the objective as stated in the rule book) and most importantly, exposure to the racing world. And that little BRC is STILL not being outran by the swathes of 450’s that have worked their way in to make up a majority of the field at most races. Pretty impressive if you ask me.
 
I was into 1/8 scale RC racing in 1990 and they had 2 speed and 3 speed clutch's I always wondered why nobody ever tried it on a kart. And 4wd! Just driving a awd over a rwd you could see a big advantage. Maybe we need awd karts. lol
 
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