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Finding a racing class for the L34


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#21 dalee

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Posted 13 November 2013 - 04:43 PM

its a 2.8 that what it says on the engine block!  :-X


not fair to all those you are racing against, but can't imagine that you would be the first



#22 d3c0y

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Posted 13 November 2013 - 04:57 PM

They're all cheating so it doesn't matter :P


So Z-Gs, where does 2B stand on them? Cause technically it's a specific model not aftermarket parts just added to the car.

#23 PZG302

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Posted 13 November 2013 - 05:29 PM

No problems to run the ZG nose in 2B, plenty have in the past as the panels were listed in the homologation papers with the part numbers.

Best bet is to ring or visit CAMS office and get a copy of the FIA homolagation docs. But, ask for a set that has not had the ineligible parts for PRC covered up as you need it for sports car racing not rally, or you may get a copy from europe or direct from FIA. I know they cost a few dollars now. I have a set of S30 papers but all the really good bits are covered with a note saying "not eligible for PRC".

In regard to the block, some events it was worth me saying I had a stroker when I had the 2900 in to bump me up a capacity class where I was faster.....

#24 d3c0y

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Posted 13 November 2013 - 05:41 PM

After a quick search I came up with these and hopefully this is a good start.

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#25 d3c0y

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Posted 13 November 2013 - 05:47 PM

Can anyone read french :/ ?


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#26 260DET

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Posted 13 November 2013 - 06:55 PM

Can't see anything in the rules that prevents the use of a front diffuser, in fact it looks like two could be used, one each flowing into a front wheel well which is quite a common device these days and made as part of the front undertray. Sticking the usual Z front and rear spoilers on is not good enough if serious.

#27 d3c0y

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Posted 13 November 2013 - 07:11 PM

What about the full undertray in the FIA docs above.  Or do the cams rules overrule fia homologation?

#28 dat2kman

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Posted 13 November 2013 - 08:32 PM

What about the full undertray in the FIA docs above.  Or do the cams rules overrule fia homologation?

I have the variuos sets of FIA papers, for each of 240,260 and 280z, some papers do make reference to certain items as " not for PRC" this refers to Australian Production Rally Cars.
To comply with 2F Sports, the finished car must be in strict accordance with what the FIA papers indicate.
The next class up, 2B, allows for a lit more modifications, as per CAMS manual, so f the CAMS manual says you can do this, you can do that, this is free, this is not, for 2B you are fine.
Re the undertray, the Z came with it std, you may remove or retain, as to material, read the rules.
2B allow a front splitter that can only extend back to a certain point, i think, it is a centreline between front wheels.
A smart cookie would integrate the front splitter with a factory undertray, ad two components but for airflow advantage.

As far as front airdams, and rear spoilers, the 2B rules have certain requirements, these are superior to the FIA approved front and rear spoilers.
2B should allow the 3.4 John McKeons 240 on injector bodies and Haltech runs 3.2, he has had me drive it for him in race events, a bit of suspension tweaking had me at 1.5 secs a lap fadter than John, we used my qually time for a better start pos on an ProdSports series of events a few years back.
The 2B rules, on interpretation are quite liberal for the Z cars
McKeon runs 10's with flares, slicks are good, but he has more often run semis, due to cost, they are well cheaper, and almost as good!

Dont get bogged down in the FIA papers !

Edit,,,, maybe with flares and 10" rims McKeon's could be 2A, have to check?

#29 d3c0y

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Posted 13 November 2013 - 09:44 PM

Is that car still for sale?


Also how does he get away with running 10" rims in 2B? I thought it was a 100mm extra track in total, which would be the total over both sides, or have i read the rules wrong?

Do you know what times it runs at Lake Side?

#30 PZG302

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Posted 14 November 2013 - 06:53 AM

Is that car still for sale?


Also how does he get away with running 10" rims in 2B? I thought it was a 100mm extra track in total, which would be the total over both sides, or have i read the rules wrong?

Do you know what times it runs at Lake Side?


The S30 was homologated with 10" rims, so that's how they get away with it. John McKeon's car was originally built by Stewie Wilkins in Sydney in late '97 and it debuted in the "98 NSW State championships. It is and was built as a 2B car.

Don't know what it ran at Lakeside, but when I raced against that car when originally built it was doing around 1:45's around Eastern Creek and I was doing 1:48's to 1:50's in the green car.

Don't worry about 2F, your car won't ever fit in that category, you only have to worry about 2B rules.

As for the 2B aero, this is whatt kills off good front aero:

3.3 Front air dam: It is permitted to fit an airdam to the front of the car, subject to the following restrictions:
(i) No part extends forward of the foremost point of the original vehicle.
(ii) It may be no wider than the coachwork as measured above the centre of the front wheel hubs.
(iii) Undertrays may be installed, including a splitter, and be used as an aerodynamic aid. No part of the undertray/
splitter may extend further rearward than the leading edge of the front tyres, it must not project any further
forward than the original bodywork and no wider than the outer edge of the tyres at the wheel hubs, be no
lower than the lowest point of the bodywork and remain parallel with the sills. (Tyres must be inflated to a
minimum of 1.8 bar of pressure.) Any material which supports or locates the undertray/airdam which extends
further rearward that the leading edge of the front tyres must be perforated with minimum 50mm diameter
holes with centres no more than 150mm apart.
(iv) On vehicles where the front bumper/fascia is integrated with the coachwork, the airdam may replace the
original bumper/fascia provided that the original mounts are retained.

You can only go the leading edge of the front tyres across the whole undertray, and only as far forward as the leading edge of the bonnet, though you may push it to front edge of bumper if you tried hard.

Rear aero is limited to:

3.4 Rear aerodynamic devices: It is permitted to fit a rear deck spoiler or wing provided that either:
(i) It was supplied as a factory option for that particular model of vehicle or another model of the same family
of vehicle, provided it complies with paragraph (iii)(a) below. It is permissible to replace one rear aerodynamic
device with another complying with the present article, or
(ii) It is within 150mm of the coachwork at all points, and no part extends forward of the rear axle centreline; or
(iii) It is a rear wing assembly subject to the following constraints:
(a) It extends no further rearward than the original bodywork (diagram 2B-1, measurement A).
(b) It extends no further forward than 400mm beyond the rear most point of the original coachwork
GROUP 2B - MARQUE SPORTS CARS
2B-1, measurement B).
© There is only a single wing element having an overall front to rear measurement of no greater than
300mm when measured horizontally (diagram 2B-1, measurement C).
(d) The overall width of the wing assembly shall be no wider than the widest part of the coachwork at the
forward point of attachment.
(e) 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
(diagram 2B-1, measurement D).
Drawing 2B-1
Notes on Aerodynamic Devices: Any specific part of the car influencing its aerodynamic performance fitted as
specified in 3.3 and 3.4 above:
• May not be used for mounting any additional devices or performing any alternative functions other than the
channelling of air for cooling purposes.
• Must be rigidly secured to the entirely sprung part of the car (rigidly secured means not having any degree of
freedom).
• Must remain in its entirety immobile in relation to the remaining sprung parts of the car. Where an original
airdam incorporates a moveable component, such component must be rendered inoperative and be fixed into
position.

#31 dat2kman

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Posted 14 November 2013 - 09:30 AM

Front splitter/undertray, as above, to comply, than the standard Z engine undertray, as fitted to std car, does go back a little ways, it all helps!
The front steel bumper, re-made in a light thin fibreglass or carbon, extended ever so slightly forward, to then allow bottom of front splitter lip to be vertically in line.

Rear aero, the Mazda RX7 Group C touring car with wrap around sides ( Birdbath!) is legal, when trimmed on mount edges and made to fit rear body work
I have an original f/glass mould for one of these, if required!
Add a Gurney lip to rear top edge.
Can confirm, homologation papers allowed 10" rims.

#32 d3c0y

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Posted 14 November 2013 - 09:43 AM

So you can choose between Homologation papers or Cams rules, just which ever is the more beneficial right?





#33 PZG302

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Posted 14 November 2013 - 11:13 AM

So you can choose between Homologation papers or Cams rules, just which ever is the more beneficial right?


Nope, they have to be read in conjunction with each other, makes it difficult.

An example is the standard steel undertray, you can run it as it was standard, but then as per the 2B rules you must cut 50mm holes in it at 150mm centres behind the front edge of the tyres to be legal.

RX7 birdbath to be legal has to be modified so it is only 150mm within the coachwork at any point. You need to trim about 50mm off the height and then it is still touch and go whether it is legal due to the wording. I know this because my car was originally fitted with one that I still have, but not trimmed. I was going to get a spoiler made up similar design to a bird bath but based on an escort rear spoiler that was a lot closer to the right height.

Front aero was going to be limited to a MKII spoiler that I had with an undertray across the front to the radiator support to strengthen the spoiler. Too much aero becomes a pain to remove for access or for loading on and off trailers. can also present problems if you damage it on another car or running off the track, which you will do. I prefer to have a car pretty insensitive to aero for the reason of damage, you want the car to be almost as fast with no front on it compared to the full kit.

An example was the 50th anniversary meeting at Lakseide where the car got written off. On the Friday I ran wide at Hungry and the front spoiler ended up in about 100 pieces, Gavin didn't have another one, so I ran without any front aero and thought it would be horrible, It wasn't, it was a little more foaty through the kink, but nowhere near as bad as a standard car as I had the radiatir support panel and radiato acting as a dam, and not the standard valance acting to provide lift. In our second race of the day I got into the low 61's on tyres showing canvas on the edges. If I had a WATC type aero that is very sensative to change my times would have been way off and/or teh car undriveable.

My front spoiler had two bits of square tube that slid into to bit of square tube welded to the radiator support and then a 10mm bolt into the front guards at each side with the 10mm nut to hold in place. 30 seconds to fit and remove and made it a lot easier to move the car around the shop, or once up here my garages.

At this stage I would be more concerned with working out what you want to do with the car, targa, hill climbs, sprints or door to door and build the car to least compromise to the discipline you would prefer to do.

#34 260DET

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Posted 14 November 2013 - 04:58 PM

We need to be careful with the terminology here, the under panel added to the 260Z is not an undertray in the aerodynamic sense as that word is usually used. I should have one somewhere around here, no way would it add any aero downforce. Perhaps it could be used to either support or allow the extension of a proper aero undertray though. There is only one S30 that I know of which has a proper undertray with diffuser, initially it worked so well that the force generated sucked it down off it's mounts onto the track, the car laps PI in the 42's now which is damm quick for any road registered car. Only effective aero enables this.

Because the S30 has a sloping back, the air coming off the back of the roof should come down enough so as to work a wing quite effectively. Really, for a S30 to compete with modern cars it needs modern aero. It is that simple.

#35 NZeder

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Posted 14 November 2013 - 05:53 PM

Not sure if anyone answer the question about the undertray with the big cross through it. That was the part factory fitted to the PS30-SB aka Z432-R that was sold to the general public for use on public roads - however these were only JAF homologation and only required 25 models to be produced in 1 calendar year. Much like the PS30 aka Z432 which again homologated under JAF classes only required 250 units to be produced and a total of 500 (I have seen the figure of 480 Z432 getting build and not sure how many Z432-R but given they were a special version of the Z432 maybe the 25+ were including in the total to get over the 500 units produced)

Anyway that undertray was therefore a factory part and was made available on the sports option list. You might also note that 3023 is the homologation number for the HS/RS30 aka export models with the L24/L26/L28 engines (with the later models/engine extensions to the original papers). A number of the sports options items were permitted under the Group 4 aka GRIV you see on the top of the paper - the crossed out parts were for GRIV only so can't be used on GRIII (Group 3). The 240/260/280z (3023 homologation) is slightly different to the JAF stuff as the FIA required more production numbers for their classes/groups.

IIRC Group 3 is for standard series production sport/gt cars much like Group 1 is for standard series production saloons (aka 2+2 configs Escort, Porsche etc). Then Group 2 and 4 were like groups again for saloons (group 2) and sports/gt (group 4 aka 2 seaters). Both these later groups 2&4 allowed for prototype/non standard series production items that were homologated ie that undertray, larger 4 pots calipers, over fenders (or bubble arches for the Escorts). Some cars were homologated under both group 1 and group 3 ie a saloon when in 2+2 and the manufacture made/sold the same car in 2 seater only version removing the rear seat. However having read the FIA Appendix K I am lead to believe that if a car was like that ie same model homologated in Group 1 and 3 then it can only run in group 1 form today.

Porsche made and sold to the public in 1967 a 911R which was a lightweight, more power, larger wheels, bigger brakes 911 much like the Z432-R is to the Z432 however as Porsche was running in Europe it would have been under FIA production number requirements so they get over the line. We however don't as the Z432-R was JAF and only 25 units were required made/sold the general public with FRP bonnet, plexiglass windows, 100l fuel tanks, lighter body, cut down interior etc and of cause the S20 engine not the L24/26/28 series so that rules them out for us unlike the Porsche guys. I believe the 911R also have flared arches factory with 7" rim on the rear and 6" on the front.

There are a number of cars that are running today that will have larger cc engines that what the rules allow - ie Pinto RS2000 or RS2000 replicas with 2300cc or larger engines due to cosworth cranks/rods and even alloy blocks painted to hide they are alloy. So what is the difference to an L34 aka L28 that is what is states on the side of the block just like the Pinto or 911 boys will say about the over cc engines (yes my 911 is the factory 2.4 BS 3.1 more like- sure some might be still running a 2.4 2.7 more likely)

All race classes around the world have these rule bender/breaker in them and until they enforce the rules on all, and I repeat all, competitors then they will always be there. We know zeds and what parts were in the sports options lists and what was run in period - Big Sam was raced at FIA events with CAN-AM Brakes of the day but does that mean you can run with CAN-AM brakes today? Well that does depend on the class rules. If the class rules states "Production based parts only" then CAN-AM/AP brakes can't be fitted - end of.

In the USA AirHeart/Hurst, AP and MK63 were all offered to any 240z/260z/280z owner from selected Datsun dealerships via the Datsun Competition Department of the day. However if the class rules you run under today state standard series production brakes then all these are out as they were optional parts dealer fitted ie not standard series production just like the bubble flares on Escorts - not a standard series production item.

Fun and games these rules and what can and can't be done. If you read the FIA Appendix K rules you have a lot of scope when building a period 240z ie you can build a full Group IV replica with MK63 front and rear, big overfenders, larger 15" x 10" rims with L28 engines running triples and you could get HTP papers for such a car. However that does not mean you will be allowed to run it locally in AU under a given race meeting. Even the FIA state themselves that if someone holds an International FIA Appendix K (Historic) race meeting then your HTP papered 240ZG Group 4 replica is eligible to enter but that does not mean acceptance by the event organizer as it is still at their discretion who will be accepted to race.

Got to love the rules and bias views that might come into play in classic/historic racing.   




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