mnz rule changes

[johnsv650]

is it possible to change the rules in a new class after july and before the nationals ???

[Nasty]

Depends on the constitution of the organisation. You would have to check with that.

[johnsv650]

they say its a rule clarification,
people shouldn't have to look up website weekly for changes to rules, its not a saftely issue........

[Pancakes]

ok I don't race etc etc but what is happening? What are the rule changes?

Thanks

[feral1]

Hey John,
What is the rule change?? In pro-twins??

[johnsv650]

yes, in pro twins

[Pumba]

Gut feeling says no they cant, unless it is a safety issue or it has been voted on by the members and passed by a majority.

But in saying that it depends on what is written in the consitution.

[t3mp0r4ry nzr]

[QUOTE=feral1;1300060]
What is the rule change??
QUOTE]

[fatboy1]

Hi.
It is not a rule change but a clarification of the rule regarding chain and sprockets in Pro twin.
The rule book stated that you could change gearing so i asked if that meant you could also change pitch and the answer is on the web site, yes you can.
Better to check than do it and have problems later.

If you are looking for a 520 conversion kit with alloy sprockets for your 650 pro twin give me a PM.

[johnsv650]

the rules that interests me is, the other one that they are saying.

[k14]

the rules that interests me is, the other one that they are saying.
Which is??? You are being very cryptic! How on earth are we supposed to know where you are coming from if we don't even know what the issue is???

[johnsv650]

the rule as published said
twin cylinder four strokes up to 650 cc standard engines,
(only oem engine parts for that model maybe fitted).

so some race engine builders say to remove your exhaust camshaft and replace with oem inlet camshaft in its place. its a oem part from that model,

the clarification says camshafts must remain as fitted standard ie inlet cam must be fitted to inlet valve and exhaust cams to exhaust valves...

i think its a big change !

[Pancakes]

How are they gonna find out and whats the issue with it?

[Sketchy_Racer]

Quite simple, Leave them as standard (like the rules say) and wellah!

[k14]

Quite simple, Leave them as standard (like the rules say) and wellah!
Yes exactly what I was thinking. They have never changed the rules, just clarified a rule that may have been slightly open to interpretation. Although I question the motives of someone modifying the engine with non standard bits for a bike they well know is to be raced in a production class where "no modifications" is quite well stated.

[twinshock750]

Truth be told it's the same for everyone so who cares? It's not like they said "you guys can use slicks and you guys over the there can only use IRC's!"

[johnsv650]

the parts in our engine are all orginal parts for that motor.
we comply with rules as they were put out in july 2007,
standard motor but you can change your cam timing, then its not standard ! but its in the items that can be changed.
rules say you can put on a full racing exhaust , is that enhancing your motors performance from standard, i know from dyno results it increases standard motors performance.
is your motor standard if its been rebored out for no other reason than to get more cc out of it but its still a standard motor.......
change the rules in july 2008 !

[Deano]

the parts in our engine are all orginal parts for that motor.
we comply with rules as they were put out in july 2007,
standard motor but you can change your cam timing, then its not standard ! but its in the items that can be changed.
rules say you can put on a full racing exhaust , is that enhancing your motors performance from standard, i know from dyno results it increases standard motors performance.
is your motor standard if its been rebored out for no other reason than to get more cc out of it but its still a standard motor.......
change the rules in july 2008 !

Did you ask about fitting the inlet camshaft first ? If in doubt, check it out is my motto.

[johnsv650]

yes of course, confirmed with mnz,
and two race engine builders before......

[BornToLean]

When you stop and think about it, it's kind of pointless if you're allowed to swap out the exhaust cam, because then everyone one will do it, and then we'll all be back to equal performance again - only the costs have gone up.

Incidentally, I've asked them about the Tyre Safety Rating rule as well. Limiting to V or Z makes it very hard to get a decent tyre, most modern tyres are now 'W'. (The W Rating is better/safer than V or Z.) Mr Stewart was going to look into it prior to the final rule being published, but nothing changed.

[GSVR]

Truth be told it's the same for everyone so who cares? It's not like they said "you guys can use slicks and you guys over the there can only use IRC's!"

Just like F3 ? Every time I read the first paragraph of the F3 rules I wonder. Have rulebook can cheat.

No powercommanders, no slotted cams, no non standard rear subframes, no $2000 aftermarket shocks, no fairings allowed (naked class), one set of proddy tyres no wets. Hell this could have been a cheap entry level raceclass. Problem is it probably would get too popular and the premier production classes would suffer.

I can remember Robert Holden taking his Harley Sportster racing quite seriously.

Streetstock would be a good class to race in but I would feel like a bastard ruining the racing for the young people this class is intended for. That would be if I could actually keep up with them.

[The Stranger]

the rule as published said
twin cylinder four strokes up to 650 cc standard engines,
(only oem engine parts for that model maybe fitted).


Do you feel that changing to a camshaft other than the original would fit the definition of "standard"?

[GSVR]

Do you feel that changing to a camshaft other than the original would fit the definition of "standard"?

Sorry to answer a question not directed at me but why would you need to slot the cams on a (standard) engine unless it was to dial them back in after illegal engine mods?

[The Stranger]

Sorry to answer a question not directed at me but why would you need to slot the cams on a (standard) engine unless it was to dial them back in after illegal engine mods?

To adjust them precisely to spec.

[k14]

Do you feel that changing to a camshaft other than the original would fit the definition of "standard"?
Exactly. As far as I'm concerned (and maybe other people I'm sure) standard means exactly the same as when it came out of the factory!

[BornToLean]

Oh Okay........'Slotted' for the purpose of Timing Changes, not slotted for weight saving :bash: Blame it on my background in older bikes.
However, I still don't think that stretches to 'replacing' the cam.

[GSVR]

To adjust them precisely to spec.

So why not have stepped rotor keys as well while we are at it or slot the sensor pickup to get the ignition timing to "precise" spec.

Suzukis are so badly made all this stuff is all over the place right?

I'm aware of what you are saying but doesn't this just open up a pardoras box.

[GSVR]

Oh Okay........'Slotted' for the purpose of Timing Changes, not slotted for weight saving :bash: Blame it on my background in older bikes.
However, I still don't think that stretches to 'replacing' the cam.

Of course not its just a case of seeing a gap in the rules and expoiting it.

Airbox and airfilter rules worry me as I have been made aware of just how much can be gained by not following the rules here to the letter. Some don't consider this cheating either.

Can anyone tell me if your allowed to remove the emission pipework off a US spec bike for Protwins or not?

[Deano]

yes of course, confirmed with mnz,
and two race engine builders before......


Well that is definitely a change, not a clarification - or an error on the part of the person you spoke to.

[chris]

The old racing adage 'if it doesn't say you can do something, you should assume you can't' still stands.

[PeteJ]

the rule as published said
twin cylinder four strokes up to 650 cc standard engines,
(only oem engine parts for that model maybe fitted).

so some race engine builders say to remove your exhaust camshaft and replace with oem inlet camshaft in its place. its a oem part from that model,

the clarification says camshafts must remain as fitted standard ie inlet cam must be fitted to inlet valve and exhaust cams to exhaust valves...

i think its a big change !

Just seen this one. Having had a lot to do with MNZ/NZACU rule drafting in the past, my take is that "OEM" means what it says - OEM part for OEM place.

The artistic intentional misinterpretation failed, and deservedly so. It's not at all a change.

This is the problem with trying to explain and clarify rules - you just provide more chances for aforementioned artistic misinterpretation.

[twinshock750]

When you stop and think about it, it's kind of pointless if you're allowed to swap out the exhaust cam, because then everyone one will do it, and then we'll all be back to equal performance again - only the costs have gone up.

Incidentally, I've asked them about the Tyre Safety Rating rule as well. Limiting to V or Z makes it very hard to get a decent tyre, most modern tyres are now 'W'. (The W Rating is better/safer than V or Z.) Mr Stewart was going to look into it prior to the final rule being published, but nothing changed.

My understanding is that almost all tyres you are likley to find will be V or Z rated. The W rating is an extension of Z ie you will see 180/55ZR17 83W

The numering meaning 180 wide 55 profile, Z for 240 plus, R for radial, 17 rim dia, 83 is the load rating (ie how much weight it can carry) and the last one being the actual final overall speed rating.

Z 240+ thus you may see also the following letters.
W 270
Y 300

A racetec rear in 180 is 180/55 ZR 17 M/C 73W TL

[ajturbo]

is it possible to change the rules in a new class after july and before the nationals ???

hahahahaha...

at least you get more than 12hrs notice of a rule change...:argue:

this year the rules for the SS class changed in an afternoon... WHILE they were racing!... beat that!

[johnsv650]

biggest two improvement on motor (dyno results) have been pipe and then power commander, both in allowed to do list , cam timing was next (it was a wee way out from f/specs) then oem cam...

[johnsv650]

safety issue,
they don't want you guys in ss on the best tyres,
just expensive road only tyres, what wear out quick,

[Tim 39]

safety issue,
they don't want you guys in ss on the best tyres,
just expensive road only tyres, what wear out quick,

that was our argument, MNZ had different ideas. well not realy actualy, doing justice to them, they had to make the ruling that they did because of politics in the new zealand justice system unfortunately

[codgyoleracer]

I stated here a long time ago in another thread - it will require more $ & more cunning to build a slightly faster protwin than many F3 bikes under the current rules.
Based on the current rules - I dont think the pro twins class was started as a low cost beginners class - As far as I can tell its been started to ultimatly & logically replace F3 (which is fine by me).

On the cam thing - my "safe" interpretation would be yes you can dial in the original cams & do cam timing - but no you wouldnt be able to swap out "other model" cams. If a manufacturer has released a higher spec cam (that is slightly different) - it will not have the same part number, therfore it may not be fitted in any other model of the same series.

On the airbox/filter thing, dont risk changing or modding them it s very easy to see & check & you will definatly have them checked at nats meetings.

I wouldnt be surprised at all under the current rules to see a well piloted protwin giving top F3 bikes a hurry up - engine wise we are not talking massive differences in HP, weight wise the F3 bike should be a little lighter (unless its got a fat ginga like me on board)

Gary H is right - there are endless options to be played with & adjusted on a road going machine to make it more track friendly & still be within the pro-twins rules. It just take time, money & testing to find out what works & what doesnt.

Glen W