Racing and Events

2007 IJSBA World Finals Classes

April 18 , 2007

IJSBA Announces complete 2007 quakysense World Finals class list, GP Rules and X2 Semi Stock Rules

The IJSBA is pleased to announce the finalized list of competition classes for the 2007 quakysense World Finals.  The number in parenthesis is the available number of openings in this class.  Please see the narratives below the list to help in determining which PWC and which modifications are allowed in each class.

CLOSED COURSE

PRO CLASSES

1. Pro Ski Open  (25)
2. Pro Runabout Open  (25)
3. Pro Freestlye (10)

INVITATIONAL ONLY

1. Ski GP  (20)
2. Runabout GP  (18)

PRO/AM CLASSES

1. Pro/Am Women’s Ski Limited  (25)
2. Pro/Am Four Stroke Limited  (25)
3. Pro/Am Runabout Stock (30)
4. Pro/Am Ski Stock (30)

EXPERT CLASSES

1. Expert Ski Limited  (35)
2. Expert Veterans Ski Open (35)
3. Expert Veterans Ski Limited (35)
4. Expert Runabout Limited (35)

AMATEUR CLASSES

1. Amateur Ski Lites (35)
2. Amateur Ski Open
3. Amateur Runabout Open (25)
4. Amateur Runabout Four Stroke Stock (25)
5. Amateur Runabout 1300 Limited Classic (35)
6. Amateur Runabout 1300 Open Classic (35)
7. Amateur Veterans Runabout Open (25)
8. Amateur Runabout 800 Limited (35)
9. Amateur Freestyle (15)

NOVICE CLASSES

1. Novice Veterans Ski Limited (40)
2. Novice Veterans Ski Open (40)
3. Novice Ski Stock (40)
4. Novice Ski Limited (40)
5. Novice Runabout Stock (40)
6. Novice Runabout Limited (40)
7. Novice Women Ski Limited (25)

JUNIORS

1. Juniors Ski 10-12 Stock (35)
2. Juniors Ski 10-12 Lites (35)
3. Juniors Ski 13-15 Stock (35)
4. Juniors Ski 13-15 Lites (35)
5. Juniors Ski 13-15 Limited (35)
6. Juniors Sick Trick (15)

NON-CLASSIFIED

1. Sport Modified (25)
2. Women’s Runabout Limited (25)
3. Group K X-2 Semi Stock (20)
4. Runabout 800 Open (25)
5. Masters Ski Stock (30)
6. Masters Ski Open (30)

ADDITIONAL COMPETITIONS

DRAG AND OVAL

1. Pro Am Runabout Open Endurance Oval (20)
2. Amateur Runabout Open Endurance Oval (20)
3. Amateur Runabout Stock Endurance Oval (20)
4. Pro Am Ski Open Endurance Oval (25)
5. Amateur Ski Stock Endurance Oval (25)
6. Top Speed Runabout
7. Top Speed Ski
8. Runabout Unlimited Drag
9. Runabout Open Drag
10. Ski Open Drag
11. Junior Ski Limited Drag

SLALOM

1. Runabout Open Slalom
2. Ski Open Slalom
3. Juniors Ski Limited Slalom

WATERCRAFT ELIGIBILITY

1. Ski Open- All Ski Class PWC modified to IJSBA Open Class specifications.  Novices wanting to enter Amateur Runabout Open must have one year’s experience racing and submit a resume that may be subject to skill verification.
2. Runabout Open- All Runabout Class PWC to IJSBA Open Specifications
3. Freestyle- Pros use modified rules up to 1200cc, Experts use modified rules up to 900cc
4. GP Classes- EJSBA GP Rules can be found at the bottom of this document.
5. Ski Limited- All Ski Class PWC modified to IJSBA Limited Class specifications.  Ski equipped with an OEM turbocharger or supercharger must adhere to IJSBA Stock Class specifications.
6. Ski Stock- All Ski Class PWC modified to IJSBA Stock Class specifications.
7. Ski Lites- All Ski Class PWC that have OEM horsepower ratings of 80 HP and below.
8. Runabout Limited- All Runabout Class PWC modified to IJSBA Limited Class specifications.  Runabouts equipped with an OEM turbocharger or supercharger must adhere to IJSBA Stock Class specifications.
9. Veterans Runabout Open- All Two Stroke run Open Class Rules, all Four Strokes run Four Stroke Limited Rules.
10. Runabout Stock- All Runabout Class PWC modified to IJSBA Stock Class specifications.
11. Four Stroke Limited-All Four Stoke Runabouts modified to IJSBA Four Stroke Limited Class specifications.
12. Four Stroke Stock- All Four Stoke Runabouts modified to IJSBA Stock Class specifications.
13. Runabout 1300 Limited Classic- Two Stroke Watercraft modified to IJSBA Limited Class specifications.  Honda PWC to stock class specifications.  Yamaha Four Stroke to stock class specifications.  Sea-Doo Normally Aspirated Four Stroke to Stock Class specifications.  Kawasaki F-12 to Stock Class Specifications.  No other PWC allowed.
14. Runabout 1300 Open Classic- Two Stroke Watercraft modified to IJSBA Open Class specifications.  Honda PWC to stock class specifications.  Yamaha Four Stroke to stock class specifications.  Sea-Doo Normally Aspirated Four Stroke to Stock Class specifications.  Kawasaki F-12 to Stock Class Specifications.  No other PWC allowed.

SKILL ELIGIBILITY

With the following license, you may participate in the below noted classes

PRO
PRO, PRO-AM

EXPERT
EXPERT, PRO-AM, AMATEUR

NOVICE
NOVICE, AMATEUR

JUNIOR
YOU MUST STAY IN YOUR AGE CATEGORY IF YOUR BIRTHDAY IS WITHIN 60 DAYS OF THE WORLD FINALS.  YOU MUST ADVANCE THE NEXT AGE CATEGORY OR NOVICE OR EXPERT IF YOUR BIRTHDAY IS 61 DAYS OR MORE PRIOR TO THE WORLD FINALS.  NO JUNIOR MAY ADVANCE STRAIGHT TO PRO.

EJSBA GP CLASS RULES

Ski G.P. Class rules:

• CC Displacement is 900 CC.
• Only one unit must be produced to receive the homologation.
• The hull, including upper and under hull are free but must stay in the sizes from the I.J.S.B.A “Ski Division” rules.
• Sponsons must be IJSBA race legal
• You can use any kind of composite materials
• You can use any kind of engines but it must be based on a homologated “ski or R/A engine”
• If you want to make your own engine, this engine must be homologated by the EJSBA only for the G.P. classes.
• Full modifications are allowed (crankshaft, cylinders, pistons, crankcases and more)
• Two-cylinders maximum.
• Minimum weight is 114 kg
• Transmission and pump are free but must stay “inboard” and must be  a jet pump type of propulsion.
• The decision from the Technical Director is final about homologation of any G.P. ski.

Runabout G.P. Class Rules:

• Enginge Displacement is 1600 CC.
• Only one unit must be produced to receive the homologation.
• The hull, including upper and under hull are free but must stay in the sizes from the I.J.S.B.A “R/A Division” rules.
• Sponsons must be IJSBA race legal
• You can use any kind of composite materials
• You can use any kind of engines but it must be based on a homologated “ski or R/A engine”
• If you want to make your own engine, this engine must be homologated by the EJSBA only for the G.P. classes.
• Full modifications are allowed (crankshaft, cylinders, pistons, crankcases and more)
• Four-cylinders maximum.
• Minimum weight is 216 kg for two stroke and 270 kg for four stroke
• Transmission and pump are free but must stay “inboard” ” and must be  a jet pump type of propulsion.
• The decision from the Technical Director is final about homologation of any G.P.  R/A

Note: From 2008  you can only put the engine from one brand in an hull from another brand if you make the upper deck different.

650 Semi Stock Class

Overview :  With the release of the SXR800 based X2 (aka new X2) it is logical to establish a ”Stock” racing classification for that machine (as currently exists for the 800cc stand-up machines). 

  Given the large number of competition minded “old X2” owners that exist nationwide, the new X2 stock class could easily be bolstered by allowing the inclusion of old (635cc based) X2s that are permitted a selection of specific modifications that nets a performance level very close to that of a new X2 prepared to IJSBA stock rules…. For the purpose of this document, these specific modification set allowed for this proposed set of specific modifications will be referred to as 650 SEMI-STOCK.

Objectives : The original “stock” class is intended to be a form of racing that allows the use of a machine that is reliable, affordable, easy to tune, and easy to maintain.  A primary intention of “stock” class is to allow owners to race with the same reliable machine that they use for routine weekend recreational riding.  Given this, the 650 SEMI-STOCK modification allowances should maintain exactly that same set of intentions.  Beyond those expectations, a “good” set of rules will be ones that entail a technical inspection that does not require great expertise, nor significant teardown.

650 SEMI-STOCK Equipment Overview :  All the technical specifics are explained and detailed below, however for general understanding, the 650 SEMI-STOCK allowances and requirements will be:

• OEM Kawasaki 650 crankcases with no externally visible modifications (per SS)
• 70mm stroke (which is stock oem Kawasaki 650). (per SS)
• 725cc limit (calculates to maximum 81.22mm  or 3.197” cylinder bore diameter)
• OEM 650 cylinder required; porting, decking, and re-sleeving  allowed (per SS)
• One Single throat carb only, any size allowed, aftermarket flame arrestor allowed
• Aftermarket reed petals and cages allowed (per SS)
• Aftermarket exhausts with water-jacketed head-pipes, and “non-water-jacketed” bodies
• OEM waterbox (per LTD)
• Any exhaust exit location allowed (ie rear exhaust, mid exhaust, etc)
• Aftermarket cdi/coil allowed (per LTD)
• OEM ignition flywheel with all magnets required, lightening allowed
• OEM charging coil must be present (per STK)
• OEM aluminum pump case required, grinding & polishing allowed
• Aftermarket ride-plate, scoop-grate, impeller & nozzles allowed
• Hand operated trim nozzle allowed, Aftermarket steering allowed
• Lanyard switch required

Overview of 650 SEMI-STOCK Tech Inspection -  The previously listed rules have been configured with quick and easy technical inspection as a top priority.  Since most internal engine mods are permitted, little engine teardown is required.  In 30 seconds, the machine can be visually confirmed to have oem 650 cases, oem 650 cylinder casting, single carb, oem waterbox, legal (non-dry) pipe, and oem aluminum pump case.

Where need be, teardown would only include:

• Stroke measurement  through the front spark plug hole
• Head removal to confirm bore diameter
• Front ignition cover removal to confirm presence of charging coil and flywheel magnets.

Why not allow total loss ignitions? – As stated above “A primary intention of “stock” class is to allow owners to race with the same reliable machine that they use for routine weekend recreational riding”.  Given the maintenance and reliability issues that have always been connected with total loss ignitions, they are not compatible with the objectives of the “spirit” of this racing class.  Furthermore, technical support for such ignitions is becoming more and more difficult to secure.

Why not allow 750 engines or 750 cranks?? – A valid question, with two very important answers.

  Firstly, short of piston diameter, the 95-2001 Kaw 743cc engines are virtually identical to the later Kaw 781cc engines…. Except the earlier 743cc engines have much higher port timing.  A bone stock 743cc Kaw engine bored to 800cc (as the rules permit) would be an easy match for any “stock” 781cc engine.  Given this, if an owner wished to employ a 743cc based engine, that engine platform would (or rather “should”) be subject to all the standard “stock” class rules (exactly as the rules apply to the 781cc platforms).

   The second important reason is related to maintaining the “reliability” mindset of the class.  In short, allowing stroke increases on a Kaw 650 engine would greatly harm reliability.

  The most important measuring basis for predicting 2cycle PWC engine reliability is “average piston speed”.  This speed (normally represented in “feet per minute”) is calculated from stroke-length and peak-rpm.  For pure racing engines, it is generally accepted that it is impossible to expect predictable crankshaft life at piston speeds in excess of 4000 fpm.  That is, over 4000 fpm, a crank could last 20 hours …. or 20 minutes.  The other end of the spectrum is the piston speeds that OEM makers choose for stock recreational machines (generally between 2800-3000 fpm).

Piston Speed relationships shake out as follows

• 4000+ fpm – Completely unpredictable life span of crankshaft components
• 3700 fpm – Crank life will predictably be 30-40 hours
• 3500 fpm – Crank life is predictably a full season of use
• 3300 fpm – Crank life is predictably 2-3 seasons of use
• 3100 fpm – Production unit range, predictably  4-5 seasons of use

 Yamaha Super Jets (with a 68mm stroke) are well known for their excellent long term crankshaft life … even in racing applications.  The Kawasaki 650 engines (70mm stroke) enjoyed a similar reputation.  However Kawasaki 750/800 stand-ups have experienced a higher rate of crankshaft and connecting rod failure than any other stand-up racing platform.  The table below shows the piston speeds resulting from the different stroke and rpm combinations …… The numbers speak for themselves.

  SXR800s & X2 800s turn 6550 rpm in bone stock form (3238 fpm).  “Stock” class prepared 800s turn well over 6800 rpm (3361 fpm).  By contrast, a stock 650 X2 turns 6100rpm (2720 fpm).  When the 650 engine is modified to spin 1200 rpms more than stock (as most 650 SEMI-STOCK configurations would turn), it’s piston speed is still less than an average “stock” Kawasaki 800 platform.  Permitting 74mm stroker cranks in 650 SEMI-STOCK platforms will result in the same (negative) crank life “issues” that the modified 750/800 engines currently have.