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#1 Mike260LW

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Posted 08 June 2014 - 11:53 AM

OK you technical gurus, are events like Philip Island Historics etc. deemed to be  part of a "National" championship or series?  I ask this in relation to the application of CAMS Schedule J - Safety Cage Structures. To me this is saying if you are running in a National event the structure will be required to incorporate roof reinforcement and windscreen pillar reinforcements (drwg J17) which, in the interest of not adding more steel pipe and weight, I would prefer to avoid. The 5th Category Historic Technical Regulations are pretty vague on the subject.


#2 PZG302

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Posted 08 June 2014 - 12:33 PM

Short answer, no.

Long answer, for me personally, if I was building a cage from scratch make it a well planned explosion of pipe from BHP rod and bar division.

The penalty of extra weight will be negligible when you look at the stiffness being put into the body. The Zeds are 40 years old now and even new were a pretty loose and sloppy chassis.

If you already have a cage in the car and it is log booked then you don't have to do anything.

Easiest way to make sure, talk to CAMS technical people.

#3 Mike260LW

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Posted 08 June 2014 - 03:02 PM

It's a scratch build, so the option, is mine; but nothing neutralises HP like weight! I'll talk to CAMS as you suggest.

#4 dat2kman

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Posted 08 June 2014 - 03:36 PM

You'll go nuts talking to CAMS.
Historic events are not part of any National series.
Comply with the requirement at minimum, add what you want where you want it, for you.
The Z behind the seat makes it a bit difficult to comply, mine is built different to Fletts, you are taller, so that adds more difficulty.
You can, when next passing by lokk at the ones i have here, all comply with 5th Category Historic requirements.

#5 PZG302

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Posted 08 June 2014 - 04:42 PM

Mike, if it's a scratch build and you haven't got a builder yet I would recommend the bloke that did the cage in my S14.

You are more than welcome to come round and have a look at the cage I got built. Ties into suspension mounting points for the rear and ties in the B and A pillars nicely as well as good intrusion bears on both sides.

The extra weight of a well designed and built cage will be more than nullified by the extra stiffness the shell will now have as a much better platform for the suspension to work. And for Group S, you can remove a fair bit of trim so the weight increase will be bugger all anyway.

#6 260DET

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Posted 08 June 2014 - 06:59 PM

It would be interesting to actually know where a S30 chassis needs stiffening, while tying in the strut tops is obviously of some benefit they are long way from the actual suspension pivot points where load is fed into the chassis. A simple way to basically check a chassis would be to jack the car up under one wheel and measure diagonal flex, that would be a start. I wouldn't be going overboard with an elaborate cage unless each extra piece is added for a specific and needed purpose.

#7 Mike260LW

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Posted 09 June 2014 - 09:42 AM

Thanks for the info Matt and Jason, the shell is currently in the capable hands of "Phil the phabricator" who has caged a number of S30s for Tarmac Rallies, so I am persuading him along the "less is more route", rather than building something to bounce off gum trees.
Phil is currently tidying up the shell which has the usual problems of forty years of neglect. New floors both sides; repaired previously botched rust and accident repairs and the usual Swiss cheese around the battery tray. He has also replaced the gussets that tie the front chassis rails to the fire wall in slightly heavier gauge steel. Interestingly, the seam that runs laterally across the floor behind the seats had all but unpicked itself which came to light when a floor section was removed and without some hefty interim bracing, would have been difficult to keep true.
Phil was the one who raised the windscreen pillar support aspect of the cage build.  My intention was for a simple six point as per Drwg J2 with a Drwg J6 diagonal from hoop corner to back stay base to, as you suggest Jason, get the leg room.
Hopefully, once trued, seam welding, gusseting and tying of cage back to the shell will provide the torsional rigidity hoped for. Not being permitted to link the cage to the front strut towers is a big hindrance to rigidity. I agree with you Richard, safety aside, there is no point in adding extra pipe unless it is really countering loads.
On another, slightly off-topic, subject. What's the go with race seats for Sc?  The regs say " in period style". To me no modern race seats are really in period style. My question is can you run with a seat with wrap around head restraint? In the name of safety they have to better. I've seen Group N cars running with them. Your thoughts?

#8 dat2kman

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Posted 09 June 2014 - 10:58 AM

Mike,
Watch the diagonal brace thing.
Drama is, it is required to be contiguous ( in line with) the main hoop.
The interior room makes this very hard. Especially when running main hoop legs down to floor.
A seat belts mount  bar horizontall, can have the diagonal intersect, but it is a real squeeze.
Fit navigator seat belt harness mounts, for future dual use.
Some At Track scrutineers do not like a diagonal running from one top side of hoop, backwards to a strut top on other side, it is not a diagonal. ( Phillip Island race scruts!)
A short vertical strut from tunnel top at rear bulkhead, to horizontal seat belts bar, is a good idea.

Recent CAMS bulketins have allowed "winged" headrests for drivers seat.

Strain guages will show up before and after on body flex




#9 260DET

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Posted 09 June 2014 - 04:15 PM

Allowed to fill hollow sections with structural foam? Makes the car much quieter, good for hearing health  ;) Have heard of sneaky people opening up hollow sections like sills to add structural members, low weight is preferable to high weight too. Anyone drill holes in the rear drums and backing plates? This rule business could be fun.

#10 NZeder

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Posted 09 June 2014 - 05:36 PM

Interesting points Richard. In SC are strut braces permitted?  If yes then are the type that go from strut to strut and back to the firewall allowed? If so then the firewall point could be matched up to a dash bar ;)

All this stuff was done is period as was strut to strut cages so don't get why CAMS don't allow the same today. Anyway I guess those are rules you have to build to so that is what you build to if that is your target grid/class.

#11 dat2kman

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Posted 09 June 2014 - 06:30 PM

Group S, Production spirts cars, as they were manufactured and sold new.
No aftermarket factory optional parts allowed, unless it can be shown and proven, items were fitted to new cars.
No strut braces, no engine bay triangulation.
What goes on or in inbetween panels or inside things, NFI!
Make it look as standard as possible, you get left alone.
The rules/regs allow certain things to he done, added and removed.

While at bare shell stage, seam welding is a good move

#12 260DET

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Posted 09 June 2014 - 07:14 PM

In that case fill the hollow sections with structural foam, now is the time to do all that sort of basic good things that tend to be forgotten about once the car is built. Use epoxy resin and structural foam sheet in the roof to stiffen it up, would help in a roll over and be quite light too. An idea I've had for the solid front rotors is to drill them radially from the circumference in as far as possible, mainly to help cooling. And do the same with the rear brake drums but take the holes right through there.

#13 NZeder

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Posted 10 June 2014 - 06:43 AM

I guess if porka is going to beat you in a class like sc so be it as from the rules it is all about production based racing and lets face it those with the bigger budget usually win. Given a porka cost more than a zed then that is what it is = bigger budget. If it is like some of the classes here in NZ the car is meant to be the star not winning on the track (however who doesn't want to win even if it is getting the better of a porka once and a while knowing you budget could not purchase the special non standard production car)

If you want to win get a bigger budget build what you want (s130 with turbo V6 power - which in my mind any zed without a in line 6 is not a zed which is why even nissan did not really want to id the cars as such and the export cars were ZX) having said that you have chosen the wrong car too as you are limited by it's chassis design and will not win a race with car who's owner has even $$$ to get an even better track weapon.

But that is not why you have built it that way. You have built it as maybe that is the fun for you building something different and having fun. Is that not the same? SC racing is about having older cars as it was as it should and having fun -- winning is not the aim of the game.

If the guy running the grids are anything like here in NZ a porka and zed aren't even in the same class as one has a back seat and can play in the saloon type class and the other has 2 seat and has to play with sports cars aka gt40, lemann specials etc not exactly production based (that is just one or two event a year here NZ that lump the zed in these groups)

BACK ON TOPIC NOW PLEASE. Richard we get it you don't like SC racing it is not your cuppa tea so be it we all know it from your posts.

#14 PZG302

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Posted 10 June 2014 - 10:40 AM

Mike, if allowed definitely seam weld the shell at this stage. Obviously the strut towers to inner guards and the inner guards to chassis rails plus radiator support to inner gurads and rails where they all meet. Or to make easier every seam in the engine bay. And obviously the old inch long weld then inch gap so it can be pulled apart if necessary for repairs.

With the long fronts and rails in a S30 the "legs" of each side move a lot and without a brace will be very hard to stop each side moving around.

A brace from the A pillar to the strut tower on each side can be fabricated and hidden reasonable easy behind the front guards.

With the cage tie into the rear strut tower tops and also if you have the room tie it into the rear suspension mounting points for the control arms cradle, for want of better words.

I used a horizontal member of teh cage to act as a rear strut brace and taxi bar in my old car for the harness.

Also for the intrusion bars, try to keep them as low as possible for entry/egress. My intrusion bars were a single bar at sill height, not possible now with the current Schedule J requirements and something that I wasn't all that happy with, but the cage in the S14 has bars that will allow me to get in and out of not to badly and will provide good protection.

You can sort of see in the photo below the back of my cage in the old shell
Posted Image

The main hoop actually was welded into a flat plate shaped to the wheel well and then into the floor. A diagnaol could have been fitted to the main hoop if starting at the bottom on the driver's side for the seat to fit. And you can see the rear towers were strengthened and the standard braces welded up fully

The front of the cage was built to suit the regs for 3J when it was built hence the front leg coming down in front of the dash, as below.
Posted Image

If I was to redo the front I would have done it like this....
Posted Image
With a knee breaker bar and intrusion simialr rather than the single bar the zed had. That cage was good for the time, late '80's early 90's, but I would really look at doing what I have with the S14 if doing a cage today for a S30, and run the winged seats which are legal in Sc. Also don't forget a window net, the kit i got was dearer than most but required no welding and is built to fit Porsche cup cars but will fit most cars. It gives you plenty of room to get in and out and is easy to operate from the driver seat on your own with gloves on.

Obviously tie the cage into the a pillars from the front legs. If the main hoop sits in the right spot also tie into where the B pillar would go, this will stiffen the shell nicely.

The structural foam may be a light weight way to help stiffen the shell, but for me the small risk of fire and the toxicity of the fumes would stop me, not just for me getting out of the car but for the poor bunnies putting the fire out if the worse happens. I copped a nasty lung full of bad shit at Lakeside putting out the GSR Falcon that Allan Jones drove, I was crook for a while and coughing up nasty shit for a few days. Will aslo make repairs a bastard if you had to replace a sill.

#15 Zedman240®

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Posted 10 June 2014 - 03:38 PM

Useless posts removed...
Can we please keep it to constructive, useful opinions please?

BTW, drilling rotors like that would be suicide.

#16 Mike260LW

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Posted 10 June 2014 - 05:48 PM

Thanks one and all for the feedback and advice.


Some At Track scrutineers do not like a diagonal running from one top side of hoop, backwards to a strut top on other side, it is not a diagonal. ( Phillip Island race scruts!)




Jason, I get really nervous when I hear things like this as it seems it is one little man in a uniform's opinion versus another! Copped a similar thing at Classic Adelaide with a scrutineer insisting we change the tie-back angle on the crotch straps.  This car had previously been scrutinised by Targa officials and other CAMS stewards in Qld and interstate and never been an issue.  Other competitors copped the same requirement.  It was just this guy's thing for this event.

I've read and re-read the General Requirements for safety cages and the J5 (across and in-line with the hoop) is an "and/or" for J6 (hoop top to backstay). Our Tarmac Rally cage is configured this latter way and we have not been pulled up on it yet.

Richard, I've heard the expanded foam thing used in gravel rally circles.  The Zed doesn't have much in the way of large and continuous hollow sections where foam would add a great deal of structural rigidity.  I tend to agree with you Matt, i think the downside of fire fuel, difficulty for future repair and being a water trapping rust risk outweigh the possible benefits.

As for other weight saving measures, when you consider the mass of the shell and hanging panels (which must remain unaltered), engine, drive train and suspension - none of which you can drill holes in, there is not a lot left to save weight in! Be assured, however, I will be trying! I will post photos of the finished cage, but don't expect anything "revolutionary" - just well built and hopefully well thought out.

#17 PZG302

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Posted 10 June 2014 - 06:07 PM

Mike, my car was 960kg wet ready to race with steel guards and hatch. I did the plastic windows, glass screen and stripped interior fibreglass single skin bonnet and removed bumper bars.

The front guards were lighter than fibreglass, every time they needed work they were beat into shape and then the rasp bought out to make the high spots match the low spots  ;D You couldn't lean on them. Also helped all trim was removed where allowed.

I calculated another 15kg could be removed from the car with fibreglass hatch and rewiring the car to cover the bare minimum needed to operate within the rules. Also helped was a light 240 shell and I ran an R180.

If you want another set of eyes to have a look in the next couple of days let me know. Every bit helps in getting the weight down and a well thought out cage will make the suspension work really well.

#18 Mike260LW

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Posted 10 June 2014 - 07:48 PM

I agree Matt, not much weight saving on fibreglass vs steel guards. Sc says all original hanging panels, but the plastic windows are a big weight saving. bumpers will get the flick and as a '74 260 (light shell) can run a R180 too. Also like the idea of minimalistic wiring.  Once Phil D'phabricator has eradicated the rust he will start on the cage. Will solicit comments before fabrication.  Thanks.

#19 260DET

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Posted 10 June 2014 - 10:02 PM

I guess if porka is going to beat you in a class like sc so be it as from the rules it is all about production based racing and lets face it those with the bigger budget usually win. Given a porka cost more than a zed then that is what it is = bigger budget. If it is like some of the classes here in NZ the car is meant to be the star not winning on the track (however who doesn't want to win even if it is getting the better of a porka once and a while knowing you budget could not purchase the special non standard production car)

If you want to win get a bigger budget build what you want (s130 with turbo V6 power - which in my mind any zed without a in line 6 is not a zed which is why even nissan did not really want to id the cars as such and the export cars were ZX) having said that you have chosen the wrong car too as you are limited by it's chassis design and will not win a race with car who's owner has even $$$ to get an even better track weapon.

But that is not why you have built it that way. You have built it as maybe that is the fun for you building something different and having fun. Is that not the same? SC racing is about having older cars as it was as it should and having fun -- winning is not the aim of the game.

If the guy running the grids are anything like here in NZ a porka and zed aren't even in the same class as one has a back seat and can play in the saloon type class and the other has 2 seat and has to play with sports cars aka gt40, lemann specials etc not exactly production based (that is just one or two event a year here NZ that lump the zed in these groups)

BACK ON TOPIC NOW PLEASE. Richard we get it you don't like SC racing it is not your cuppa tea so be it we all know it from your posts.


No problem with Sc racing at all but I like driving powerful cars because of the challenge and the fun although it would be easier to build and drive a Sc Zed. Getting the last bit of performance out of a Sc, rather than build just another also ran, would be a real challenge which is why a bit of thinking outside the box and looking at using modern ideas where allowable comes in. To each his own of course, although it does no harm to discuss what might be possible I would have thought.

EDIT: To add to a previous comment on drilled rotors, following is a link which sets out the advantages of cross drilled rotors over plain. I seem to recall seeing a Sc Zed that did not have cross drilled rotors, amazing http://www.ebay.com....05243690/g.html Took five minutes to find.

#20 dat2kman

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Posted 11 June 2014 - 08:37 AM

Clearly the regulations set in place for Historic Production Spirts cars as set down by CAMS, are not being read.
Ignore the immediate above incorrect information.

If anyone was stupid enough to follow that, you would be in for a rude shock at your first event, and told to go home.




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