2012-2016 600cc U6SA Engine Rules
TERMS & CONDITIONS
• If a change or modification to the stock engine or its parts is not included in these rules then the modification is
considered legal.
• The word “Stock” means unmodified factory original parts or components.
OVERALL ENGINE
• No limited production race motors allowed. Must be a production motorcycle engine, 4 cylinders, 4 stroke
• No titanium anywhere in or on the engine, unless it comes stock form manufacturer of engine on the production
bike
• Must have engine, clutch, and transmission all in one unit
• Must be Chain Drive
BORE AND STROKE
• 600cc Maximum displacement for an engine model that was new in 2006 or newer. Older engines maximum
displacement is 637cc. Engine model is defined as a manufacturer redesign of overall engine. See Specification
list.
• No strokers or de-stroked engines
HEAD AND CAMS
• NO PORTING or deporting of intake or exhaust runners.
• Valve jobs, valve grinding, valve seating, valve seal modification and valve seat cutting are allowed.
• Valve seat inserts may be reworked or replaced with any seat of original dimensions. Any dimensional
thickness of the stock inserts may not be increased. Valve seats can be ground with multiple angles.
Blending of the valve seat into the head is permitted but cannot extend more than ¼” into the aluminum
head measured from where the seat meets the head.
• OEM Head only.
• Cam may not have a higher lift than the stock factory cam. (duration is open)
• Valves can not be larger in diameter than factory stock valves.
CLUTCH/TRANSMISSION
•
•
•
•
No removal of clutch.
Clutch must remain operational
No modification to the stock transmission gears, no close-ratio gears or nonstandard gear-ratios.
All gears must remain in transmission, no removing any gears.
IGNITION
• No aftermarket ECU’s, stock appearing ECU only. Reflashing of ECU and factory race ECU’s are allowed. Stock
factory rev limit must remain in place for all engines larger than 600cc. Rev limit for all 600cc (nothing larger
than 600cc) engines is 16,100 rpms. U6SA specified Rev Limit must remain intact at all times (no switched or
gear specific limiters). If a computer is hooked up to check the ECU it must be set to U6SA specified rpm’s, no
tolerance. See specifications list for RPM limits.
• All cars must have the PA standard connector for the track to check engine rpm rev limit. These are available
from the chassis manufactures and engine builders, and at the track. All cars must leave intact the rpm wire
coming from the ECU.
• May use different year ignitions from same manufacturer as long as stock rev limit of engine (not ignition) is
retained.
• No aftermarket coils
IGNITION (cont.)
• No gear position sensor may be used. The sensor may be in place on the engine, but can not have any wires
connected to it. Gear position wire from ECU may not be switchable.
• No traction control device.
• No more than one ECU box present in or on car.
• A 50 rpm over rev tolerance for the purpose of tech inspection is acceptable. (Note: this does not mean you can
turn up the rpms in any ECU by any amount)
AIR INDUCTION SYSTEM
• No mechanically forced induction (turbo charging, supercharging)
• Any carburetors may be used on any engine, regardless of year of engine.
• Note: Switching to carburetors on engines that came with fuel injection usually increases the rev limiter due
to the removal of the injectors as the ECU cuts fuel to limit rpm’s before it cuts the ignition. A reflash of the
ECU will be required if using carburetors in order to comply with the rev limit rule 7. a)
• If the engine did not come from the factory with fuel injection, fuel injection may not be used.
• No after market throttle bodies.
• Mechanical Fuel Injection (MFI) can be used.
EXHAUST
• A muffler must be used with the exhaust system that will keep noise levels within individual track limits.
CHARGING SYSTEM
• No removing the charging system, it must remain in complete working order, no factory racing charging systems.
SELF-STARTING
• The engine must self-start at the beginning of the event. If it does not self-start, the car may be pushed off and
must start at the rear of the event as the penalty.
FUEL
• No fuels other than alcohol, gasoline, and/or top lube. Non flammable top lube only, no exotic fuel additives, no
oxidizers, no fuel enhancer top lube.
• Fuel tanks must contain a bladder. A fuel tank with a bladder is further defined as a plastic outer shell with a
rubber inner container.
MINIMUM WEIGHT
• Minimum weight at all times is 775 pounds for winged classes and 750 pounds for wingless classes, car and driver.
If weight is added it must be firmly bolted in place.
600cc Universal Engines Rules Specifications List
Engine
Kawasaki
Kawasaki
**Kawasaki
Yamaha
Yamaha
**Yamaha
Suzuki
Suzuki
**Suzuki
**Suzuki
Honda
Honda
Honda
**Honda
Model
ZX-6R
ZX-6R
ZX-6R
R6
R6 or (R6S)
R6
GSXR
GSXR
GSXR
GSXR
CBR F1-F3
CBR F4
CBR RR
CBR RR
Year
03-04
05-06
07-11
99-02
03-05 (08)
06-11
01-03
04-05
06-07
08-11
90-98
99-04
05-06
07-11
Rev Limit
14,400
14,800
15,400
15,000
15,000
16,100
13,900
14,500
15,500
15,500
13,200
13,900
15,200
15,300
Tach Wire Color
Light/Blue
Light/Blue
Light/Blue
Yellow/Black
Yellow/Black
Yellow/Black
Yellow/Blue
Yellow/Blue
Yellow/Blue
Yellow/Blue
Yellow/Green
Yellow/Green
Yellow/Green
Yellow/Green
PPR
2
2
2
2
2
2
1
1
1
1
2
2
2
2
Bore
68mm
68mm
67mm
65.5mm
65.5mm
67mm
Stroke
43.8mm
43.8mm
42.6mm
44.5mm
44.5mm
42.5mm
In Cam
7.9mm
7.9mm
8.3mm
7.9mm
8.5mm
8.5mm
67mm
67mm
67mm
42.5mm 8.6mm
42.5mm 8.6mm
42.5mm 8.2mm
67mm
67mm
67mm
42.5mm 8.5mm
42.5mm 8.3mm
42.5mm 8.3mm
Ex Cam
7.1mm
7.1mm
7.5mm
7.5mm
7.6mm
7.7mm
7.3mm
8.0mm
8.0mm
1st
5.910
5.527
5.157
5.564
5.564
5.355
5.364
5.364
5.497
5.497
2nd
4.155
3.894
4.180
3.806
3.806
4.146
3.952
3.952
4.051
4.051
3rd
3.482
3.158
3.515
3.042
3.042
3.456
3.238
3.238
3.383
3.383
4th
2.932
2.742
3.040
2.606
2.606
2.993
2.793
2.793
2.961
2.961
5th
2.572
2.405
2.700
2.326
2.326
2.666
2.511
2.511
2.659
2.659
6th
2.180
2.470
2.117
2.117
2.384
2.275
2.275
2.385
2.385
7.2mm
7.2mm
7.2mm
5.162 3.757 3.001 2.589 2.277 2.059
5.628 4.089 3.401 2.974 2.662 2.461
5.805 4.222 3.517 3.048 2.753 2.550
** =Must remain 600cc
PPR =Pulses Per Revolution for tach setting
In Cam and Ex Cam = Maximum Cam Lift for intake and exhaust
1st, 2nd, 3rd, 4th, 5th , and 6th = Stock Primary x Secondary Transmission Ratios
This is the relationship between the crank and the output shaft in the respective gears.