:: R a c i n g S M :: Aprilia RS 250 2003' Specifications & Multimedia



Onboard with ARROW exhausts



LUFO Racing exhausts, reving/warming up



Onboard with LUFO Racing exhausts



Outboard movie


Pistons: 2 x stock pistons (56 mm)
Stroke: Stock (50.6 mm)
Cylinders: Stock.
Cylinder heads: Stock
Radiator: Stock
Sparks: NGK B9EGV
Exhaust valves: Stock with different adjustment, now opening fully
Reeds :Stock
Carburetors: Stock Mikunis 34mm, main jet from 140/145 to 160/165
Air Filters: stock airbox, but without air filters.
Electric part: modified by LUFO with new ignition diagram
Clutch: Stock
Exhaust systems: LUFO side-by-side GP style
Silencers: Carbon M Factory West
Oil: Direct mixture in the deposit, between 1.75% - 2%
Transmission: 13 - 42
Gearbox: Stock 6 gears
Engine maximum rotation in charge: 12 500 - 12 800rpm
HorsePower (crankshaft): Over 70 hp
HorsePower (rear wheel): Over 65hp
Losses between Gears (%): - \| 51% \| 31.58% \| 18.18% \| 14% \| 9.05%
Crankshaft - ConnRod Attack Angle: 76.06º
Linear Piston Movement : 21 meters/second
Number of Explosions per second : 208
Maximum Real Velocity: REAL ~210 km/h

Wheels: PVM, 3.5p front and stock rear wheel

Tires: AVON 120/60/17' front & Michelin 150/60/17' rear

Brakes: BREMBO double 300mm front & rear BREMBO 220mm

Braking system: stainless steal with red terminals.

Suspension: Stock.

Steering Damper: OHLINS.

Frame: Stock.

Swingarm: Stock.

Chain: RK red o'ring 520 chain.

Bodywork: Stock.

Stop light: Stock

After the new LUFO custom exhausts side-by-side using M Factory West carbon 300mm silencers (thanks TZMike), the engine now revs till 12 500 - 12 800 real rpm in charge and till 13 500 rpm in over rev.
The carburetors were rejeted, now using 160 and 165 gigleurs instead of the stock 140 & 145 respectively because now we don't use any kind of air filters on the stock RS 250 airbox.

We're using a front PVM Alloy forged wheel, which is considerably lighter than the stock BREMBO wheel, the rear wheel changed from the 5.5' PVM wheel to the stock one in order to use a Michelin Soft 150/60x17' tire.

As shown in the right table, the Aprilia RS 250 has a good gearbox, not the closest one but still good for road use, which is it's real purpose.

Our objective isn't utopic top speeds in our bikes, we prefer great acceleration and quickness till ~210 km/h.

LUFO modified the electronics in order to get the optimized ignition for his custom exhausts, which were made for a different resonance and engine maximum regime (12500 - 12800) with different measures than the aftermarket exhausts (Jim Lomas, Sugaya, Arrow, TYGA, Jollymoto)

These exhausts were made with LUFO philosophy/doctrine within, but of course, they would require a decent ignition for them.

So, in the table bellow there's the differences between the stock RS 250 ignition and the new values with LUFO modifications. To note that, LUFO used his personal pistol light to check the ignition:

RPM	mm from TDC
	STOCK	LUFO
1 000 - 3 000	1	1.5
5 500	4	5
8 000	2	2.5
10 000	1	1.5
12 000	0.5	1
+12 000	0	0.7

The next future modifications in mind, will be the 1mm cylinder base gasket in order to raise the transfer & exhausts timings.
Increasing of the compression ratio and maybe an o'ring cylinder head.

Also, in order to maintain the reliability of the internal components, when we replace the pistons with WISECO forged ones, we intend to balance/true the crankshafts for ~13 000 rpm and change the exhaust valves with Dave Cooper ones.

With this modifications, we except more than 65 rwhp on a reliable dyno.