mx5cartalk.com

Surely the CAMS manual is the place to start unless I am missing something:

2B and 2F specifics found in the race section:

http://www.camsmanual.com.au/02_race.asp#2nd

You will probably be referenced to the General Requirements section to:

http://www.camsmanual.com.au/10_gen_req.asp

deviant wrote:Surely the CAMS manual is the place to start unless I am missing something:

2B and 2F specifics found in the race section:

http://www.camsmanual.com.au/02_race.asp#2nd

You will probably be referenced to the General Requirements section to:

http://www.camsmanual.com.au/10_gen_req.asp

Yeah, but is it clear on what can be modified? Ie can I change any aspect of the engine? I will have a look, but I'm always wondering if I can't find the word XYZ in the manual, is it right to assume I'm free to change it however I like?

G

evil_weevil wrote:
AASA Mate.

Im interested, signing up now!
depending on the costs for entry and whats needed for pit crew and for the pit stop im extemely keen.

Yeah i got that. I was saying these are the reasons I probably wouldn't do the Cams Cue series and why this really stacks up for me. Like you....where do I sign

Well my build will make the car 2B (ITB's, piston size and rear wing) so this will push it from C class to B. I'm sure that based on the last weight of the car (1,100 kg inc driver) it will not make more than 220 hp (160 more than likely) so it fits under the power to weight ratio.

Time to put CAMS log book back on the agenda.

One suggestion is to provide a list of where the approved dynos and weight stations are, as well as the parameters that the dyno needs to be set with. At least this rule will not be encouraging people to use a dyno that overstates the HP plus it will solve some of these overstated values being thrown around. It would also be a bonus if the weights and HP of all entrants was advertised.

Again looking forward to 2014.

gslender wrote:Yeah, but is it clear on what can be modified? Ie can I change any aspect of the engine? I will have a look, but I'm always wondering if I can't find the word XYZ in the manual, is it right to assume I'm free to change it however I like?
G

yes, it lists what is allowed, and if it ISN'T listed you CANT do it.....

Otherwise the doc would need to be 5000 pages long to cover every single possible scenario that people come up with. (can I fit rocket launchers to the back for press to pass ability..)

Magpie wrote:Well my build will make the car 2B (ITB's, piston size and rear wing) so this will push it from C class to B. I'm sure that based on the last weight of the car (1,100 kg inc driver) it will not make more than 220 hp (160 more than likely) so it fits under the power to weight ratio.

Time to put CAMS log book back on the agenda.

One suggestion is to provide a list of where the approved dynos and weight stations are, as well as the parameters that the dyno needs to be set with. At least this rule will not be encouraging people to use a dyno that overstates the HP plus it will solve some of these overstated values being thrown around. It would also be a bonus if the weights and HP of all entrants was advertised.

Again looking forward to 2014.

What part of the rules allow ITBs? Having read them, I can't see where it says you can freely change the intake manifold and TB?

G

I have to agree with rascal in that the CAMS manual is written from the point of what you can do and if it is not specifically nominated it is excluded.

For an MX5 (in my reading of CAMS for naturally aspirated) you become 2B when you change the throttle body to ITB's, or put on a big wing (however, no part of the wing assembly shall be higher than a horizontal plane located 250 mm above the point on the coachwork along the longitudinal centre line of the vehicle, vertically below the wing leading edge) or a splitter (however it must not extend past the front of the car and remain parallel with the sills).

Based on my current rear wing it may need to be lowered to meet the 2B rules and I do not have an issue with that, however I know that a splitter if installed will be lower than my sills so I may need to reconsider this plan (at least for CAMS race meets).

With respect to the Jenvey ITB's that I'm using, the 2F rules state "The inlet manifold may be modified by the removal of metal provided the original component is able to be identified" and the Jenvey completley replaces the inlet manifold. If you can put ITB's on the original inlet manifold then you it could be 2F depending on other mods.

The wording in the 2B of "Save for the restrictions imposed in Articles 1.4, 4.2, 4.3 and 4.4, the remainder of the engine assembly and associated systems are free." therefore as the inlet manifold is not mentioned in 1.4, 4.2, 4.3 and 4.4 it is free, hence ITB's are allowable.

The rules for a 2B engine do allow for a fair bit of scope and are not as strict as for 2F.

The rules fora 2B engine are:
4. ENGINE
4.1 General: Engine capacity for reciprocating engines may be varied within the limits of the recognised or replacement block; save that the maximum permitted capacity of the engine is 6000cc. Save for the restrictions imposed in Articles 1.4, 4.2, 4.3 and 4.4, the remainder of the engine assembly and associated systems are free.

4.2 Reciprocating engines:
(i) The cylinder head/s must be those that were standard for that particular model. The cylinder head/s may be modified only by the removal of metal.
(ii) The cylinder block may be replaced by another of the same family of block, which is deemed to be one that:
• is from the same manufacturer
• has the same cylinder bore spacing and general configuration.
• retains the same cylinder head bolt positions.
(iii) The cylinder block may be modified only by the removal of metal, whilst retaining the original configuration.

4.3 Rotary engines: The rotor housings and end and intermediate plates must be those that were standard for that particular model. The inlet ports in the end and intermediate plates may be modified by the removal of metal, including bridge-porting, but the original O-ring seals must remain unmodified and in their original location.

4.4 Supercharging:
(i) Supercharging is not permitted unless fitted as standard to the particular model.
(ii) If supercharging is recognised as standard production for the model, the production inlet manifold and supercharging device must be retained as per the manufacturer’s design specifications. The boost pressure may be altered. The drive pulleys of a mechanical supercharger may be modified to alter drive speed.

4.5 Oil system: Dry sump systems are permitted. The oil tank must be situated in the luggage compartment where possible or otherwise fully shielded from the cockpit. Oil lines may pass through the cockpit provided they are insulated and there are no joins save those at the front or rear bulkheads.

4.6 Exhaust: For turbosupercharged vehicles the exhaust manifold and turbosupercharger must remain as standard. The complete exhaust system is free downstream of the exit from the turbo housing. For other engine configurations, the exhaust is free from the cylinder head exhaust port. The original exhaust mounting brackets may be removed and additional brackets may be fitted, provided that their sole function is the location of the exhaust.

4.7 Engine mounts: Engine mounts, being components fitted between the cylinder block and chassis/crossmember/bodyshell, are free. The engine may be moved within the constraints of the existing bodywork. Where the engine block fitted is other than the original block or where it is relocated, a scattershield complying with Schedule M (refer “General Requirements for Cars and Drivers”) must be fitted.

gslender wrote:What part of the rules allow ITBs? Having read them, I can't see where it says you can freely change the intake manifold and TB?
G

I'd imagine the highlighted bit below...


Excerpt from Cams manual .

Specifications of Automobiles – Group 2B
http://www.camsmanual.com.au
GROUP 2B - MARQUE SPORTS CARS
4.
ENGINE
4.1
General:
Engine capacity for reciprocating engines may be varied within the limits of the recognised
or replacement block; save that the maximum permitted capacity of the engine is 6000cc. Save for the
restrictions imposed in Articles 1.4, 4.2, 4.3 and 4.4, the remainder of the engine assembly and associated
systems are free.
4.2
Reciprocating engines:
(i)
The cylinder head/s must be those that were standard for that particular model. The cylinder head/s may be
modified only by the removal of metal.
(ii)
The cylinder block may be replaced by another of the same family of block, which is deemed to be one that:
•
is from the same manufacturer
•
has the same cylinder bore spacing and general configuration.
•
retains the same cylinder head bolt positions.
(iii)
The cylinder block may be modified only by the removal of metal, whilst retaining the original configuration.
4.3
Rotary engines:
The rotor housings and end and intermediate plates must be those that were standard for
that particular model. The inlet ports in the end and intermediate plates may be modified by the removal of
metal, including bridge-porting, but the original O-ring seals must remain unmodified and in their original
location.
4.4
Supercharging:
(i)
Supercharging is not permitted unless fitted as standard to the particular model.
(ii)
If supercharging is recognised as standard production for the model, the production inlet manifold and
supercharging device must be retained as per the manufacturer’s design specifications. The boost pressure
may be altered. The drive pulleys of a mechanical supercharger may be modified to alter drive speed.

So this goes to my point where it isn't clearly outlined what is allowed, so rocket powered pistons would be ok.

G

Also, so in 2B I could try and run with a 2.5 litre engine block, assuming I bore the std block and keep the stock head etc. assuming this would work, it would be allowed.

G

gslender wrote:Also, so in 2B I could try and run with a 2.5 litre engine block, assuming I bore the std block and keep the stock head etc. assuming this would work, it would be allowed.

The max oversize piston for a NB 1.8 is 85.5mm (equates to about 1,950 cc) and only if you sonic test the block. The max cc (that I know of) for a NB is by using the Maruha 85.5mm pistons and crank, this equates to 2.1cc . I'm not sure if you could get 2.5 out of an NC motor.

gslender wrote:So this goes to my point where it isn't clearly outlined what is allowed, so rocket powered pistons would be ok.

I think rocket powered pistons, if installed, CAMS compliance would be the least of your worries. How would you refuel your rockets? Is the fuel used in your rockets on the CAMS approved fuel list?

Let me start by saying motorsport is a technical sport and we are governed by rules. I suggest you take the time to read the below rules thoroughly. For Modern Sports Cars we have adopted the CAMS 2F (Production Sports Cars) an 2B (Marque Sports Cars) rules with some very minor exceptions.

The CAMS 2F (Production Sports Cars) rules can be found here - http://www.camsmanual.com.au/pdf/02_rac ... 2013-1.pdf

The 2B (Marque Sports Cars) rules can be found here - http://www.camsmanual.com.au/pdf/02_rac ... 2013-1.pdf

There are two key concepts that a competitor needs to understand for both sets of rules:

1. Unless it the rules specifically say you can do something then you cannot change that component. Ie only the listed modifications can be done to a standard vehicle. For example: if the rules do not say you can put holes in the bonnet then you can't put holes in the bonnet.

2. If an component is listed as Free then that component and only that component can be replaced or removed. For example under the 2B rule the inlet manifold is free therefore the existing manifold can be replaced by independent throttle bodies.

Thanks mx5racing that is how I have read the rules. It is the reverse to how I normally have to operate at work reading Contracts (if it is not specifically excluded then it is deemed to be included) but the logic is still the same.

Now I just have to sort out my roll bar (it is a MX5 Plus single diagonal) and if I get the 50mm head clearance. However the car will still be classed as a 2B there is no way it could be passed off as a 2F. I made this decision ages ago when I went to ITB's knowing that it would fall outside of 2F, I just like the sound of ITB's more than sticking with 2F.

Once I know the final HP of the engine build and the weight I can see where it will sit, with the currents mods it will be moved from C to B and if the power is between 122 and 157 it can stay in B. But if it makes more than 158 (and the weight remains the same) I guess it would have to move to group A. Then it will be a case of getting the HP as high as possible to match it with the A class cars, so be it. This is not for sheep stations

Or you build a 200hp motor and tune it to make a flat 157 or whatever to stay in class b, but you wont peak at 157 you will have a flat top at 157 and be faster than a car that JUST peaks at 157.

Dann

Curiously, how do these rules stop people from installing duel tune systems and Dynoing the car on tune A at 150hp and then in the race (in certain sections even) turning on tune B (200hp) and having an unfair advantage?

I mean, how thorough are the checks and assessments of the cars and engines?

G