Does anybody know how much HP a GP spec RS250 makes, and regular production racer RS250?
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james
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My 93 with ram air update shows 78.5 HP on the dyno. I did not have fans to simulate movement for the ram air, so it's probably a little short.

So, is that at the rear wheel? Add 10% for drivetrain loss?
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Yep, rear wheel.

OK, I found something that says the 2002 rs250 has 92 PS, which is about 91 HP, but I guess that is not rear wheel HP.Anybody know how much to expect for drivetrain loss? I know its about 18%-22% for cars. Also still looking for some estimates for the power of the GP bikes.

TIA
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Most stock 93-00 RS's I've seen make between 79 to 86 rwhp. A National bike I've seen at 91rwhp and the current GP250's are all rumoured to be making 110+... Go figure... 110bhp, 100Kg, no pussy traction control or anti-wheelie, I'd rather ride a MotoGP bike to be honest!
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NSR300R - Why did i ever have a 250...

All the stock '93-'98 NX5's I've tested have been around 76rwhp.
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If I have to take the carbs off once more...

My '92 RS250 NF5 made 76bhp on Steve's dyno. That's the one that is similar to an NSR road bike.......Steve NSR F3 makes about 74bhp. Both are stupid fast, so can't begin to imagine what a 100kg 110bhp RSW feels like!

Tom, your NF5 made 74hp, the F3 is only 72hp I'm afraid.

Your NF5 does feel really good though. The NX5 range seem to make little or no more power over an NF5 untill the last 1000rpm where stock vs stock it just pulls 2-3hp over the NF5.
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If I have to take the carbs off once more...

You could work out what power GP bikes must have by the speed they do

This nomogram was put up a while back on the RGV forum, thread here.

So what we need to know now is how fast a standard RS250 will go as it's power is known.

So we know a 65bhp or so NSR will do around 135 with a flyweight on (Bill Limb can get his to the redline in 6th geared for around 135 on the flat). So an NSR 250 has a CDI of 2.85 and it's fairly RS shaped.

If a std RS250 has got 90bhp and we take it's CDI is 2.85 (ish) it's going to do around 155mph, which sounds about right.

Then by the fact we know a works NSR will do 166mph we know it must have around 110bhp.

We can also see the Aprilia's which top out around 175mph must be knocking on the door of 120bhp!

Capiche?
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Matt did 150+mph on a 76hp NSR-F3.
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If I have to take the carbs off once more...

151mph actually

Bloody long straight at an airfield, in the middle of the jungle in Southern thailand. Must have been all the extra oxygen from the trees 'cos I was usually jetted around the mid #170's for normal tracks. Even fast one's rarely saw #180, but at the airfield I was up to #190's.

Must have been perfect conditions. It was pulling just over 13500rpm acording to the (optimistic) MC28 tacho.

Who knows the real truth about factory horse power? Not I. The A kitted RS250 in '98 (was a '97 NSR250 factory engine) put out 91 horse at the wheel. The factory nikes were about 98~100 bacvk then, with the Aprilia the only one over the magic ton, at about 104.

The Aprilia is still far faster than the Honda (poor Dovi), but 120hp may be hoping a little. 110hp is feasible and the rest is down to how much power they have either side of peak I would guess, and of course well developed aerodynamics. I suspect that the graph of the Aprilia RSW250 GP bike would make a stock NSR look peaky!

Definately. The 2000 RS I've seen tested had way more mid than my 300, then eats it for breakfast over 10K... Fastest I remember a GP250 going is 173mph at Mugello a few years back... 173mph and 250cc doesn't seem lik it should be used in the same sentence!
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NSR300R - Why did i ever have a 250...

Hector Barbera did 278.6 km/h (173.1 mph) through the speedtrap at Shanghai this year.
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Thanks for the input guys. The reason I ask is because my friend and I were having an argument about how much power the 250gp bikes makes. He was thinking about 130+. I was thinking less than 100. I guess we were both wrong. Hard to believe they can get 110 hp when the productions racers can only get 90.

Any guesses on RS125HP?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm