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Group Sc Brake Problems


260DET

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Dave,

 

You will enjoy Sb with 1600 roadster.

 

I've been thinking / planning for a few years. Had the cars for many more years and been acquiring parts since then. All that's left to do is build it.  :-[

 

 

 

You two need to get a room  8)

 

"Two men enter, one man leaves" ??

 

thunderdome5.jpg

 

 

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We're a tiny bit more civilised than that.

As a FYI,, the other Gp S cars that the Dato Z's are up front with are running four wheel discs, and ventilated.

They do not have any overheating concerns, unlike the solid rotor front/drum brake rear Z's that are mxing with them.

We have come up with a vented rotor, same OD as stock, and a modification/addition, to the stock caliper, that will straddle the rotor.

We dont have a major issue woth pads, and are using various top f range  froction co- efficient pads,,, it is the heat build up in the rotor, hib, wheel centre and caliper, that causes the issue.

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Gday Guys,

Just thought I should poke my nose into the conversation. Having raced GpS for a few years now, I have found by using quality rotors, Brembo, and Pagid RS4 for sprint races 30km and Pagid RS29 for our 100km race have worked ok. However, if I just pull into the pits after a race the rotors will warp. I must stop the car on the clutch so not to clamp the pads to the rotor, and jack up the car and keep turning wheels until they cool down to a point where they won't warp. You also need to make sure your rear brakes are adjusted up for every race. Less load on front brakes = less heat. I will also bleed the brakes once or twice over a weekend or as required. Up until now I have been using Castrol SRF but am trying a new combo at the moment. If you don't warp a rotor you will get up to 4 meetings out of a set of pads and rotors. The rear shoes will only last 2 meetings but at $30 who cares, as long as you don't trash your drums. I have tried trick drum linings but don't work. Unfortunately after 4 race meetings the rotors are no good any more as they will be bent not necessarily warped. The friction faces will look great but if you put a straight edge across the back you will notice the outer edges of the rotor will be bent inwards. this is caused by the "ring" of extreme heat and the much cooler hub area. If you machine them you would loose about 1.5mm off thickness but am more worried about shattering one in use as they try to bend again.  If you fit new pads they will need to bed in to a taper to conform and create loads of pad knockoff. Also If you race in the rain and go through a puddle you will warp a rotor.

Over the years I have had many success and failures and still I have to keep developing the car. My current problem is I am on my last set of Brembo rotors and they are no longer available worldwide. I have been in contact with RDA who told me there product was not suitable for racing.  Where to now? Chinese rotors??? also drums haven't been made for years. Chinese drums are hopeless and dangerous. My car hits 220 down the straight at Eastern Creek and is a big stop into turn 2. Will they work lap after lap?

I like the concept of the GpS rules, and don't like watering them down, but our cars have come a long way since the rules were written. While running std SUs it made us make them work instead of just bolting on some Webers Mikunis etc. With the brakes its the same theory, but when suitable safe parts aren't available???

  I would like to see a vented rotor off a Peugeot or similar allowed with a spacer of about 8mm or so in the caliper but getting this through CAMS might not be so easy. I think it would be safety issue if we were to run sub standard parts.

  Where do we go from here?

James

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and also don't worry about the Porkers with there 4 wheel discs The Zeds have L series power. Just blow em off down the straights n hold them up around the back  ;D

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My current problem is I am on my last set of Brembo rotors and they are no longer available worldwide.

 

  Where do we go from here?

James

 

James,

 

Apparently tirerack still sell them

 

http://www.tirerack.com/brakes/brakes.jsp?make=Brembo&model=Replacement+Rotor&group=Replacement+Rotor&partNum=B25082&autoMake=Datsun&autoModel=260Z&autoYear=1974&autoModClar=

 

 

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Good to see some positive comment particularly concerning brake management, to provoke constructive discussion was the whole idea of this thread :)

 

StopTech in the US sell S30 front rotors and their gear is good, while on the subject of the US I'm fairly sure that the well known early racing successes of the S30 there included the SCCA C/production class which if I'm right was allowed some engine but no brake upgrades. And now moving to the subject of upgrades, it may be said that we are fortunate in being allowed to use the current front and rear aero, as far as I'm aware the front spoiler was never a production item.

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Good to see some positive comment particularly concerning brake management, to provoke constructive discussion was the whole idea of this thread :)

 

StopTech in the US sell S30 front rotors and their gear is good, while on the subject of the US I'm fairly sure that the well known early racing successes of the S30 there included the SCCA C/production class which if I'm right was allowed some engine but no brake upgrades. And now moving to the subject of upgrades, it may be said that we are fortunate in being allowed to use the current front and rear aero, as far as I'm aware the front spoiler was never a production item.

Excellent work, to see you have solved our braking concerns!

And now on to solve our "aero"!

What is specified in the CAMS Group S specs sheets along with the FIA Homologation papers, in conjunction, as what is permitted.

Noting some items are valid/invalid for PRC. ( Austrlian Rally only from 1988 onwards, we built a 260Z that complied, and eventually won the NSW State Rally Champs)

 

It matters not that the Aero were never a "production" item, the front/rear spoilers were applied for many many years ago, based on the mid 1970's useage of these items on the then Production Touring Cars, at the time, only here in Australia, it was this that got them accepted, and only certain specific designs and sizes.

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Yep, Jason can start an aero thread :)

Absolutely pointless!

We know what the requirements are, and work within those!

 

I have just been sent a whole magazine,Austrlian Sports Car World, 1973, by a member here, Andrew, and it contains fair

Y detailed information in the road registered cars, as built by Nissan, that were sent out here under Carnet De Passage.

This, and further pictures, parts catalogues, and other material, will be used in a submission.

The crucial thing is that we need a letter from Nissan advising that there were a number of cars built, new, that had the items fitted.

 

It is this detail that will be submitted to CAMS. G

The fact that they were built by the factory, to be registered ( transport approved) on public roads, is sufficient requirement, as advised by Bruce Richards.

 

Alan Thomas, do you have contacts at Nissan Japan?

Does anyone have a possibly sympathetic to our cause, person at Nissan Japan?

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Alan Thomas, do you have contacts at Nissan Japan?

 

Yes I do, but in this particular case I recommend you start at the front desk and let them guide you through the system to the person they think will be most qualified and authorised to deal with the request. Short-circuiting the system can be a hindrance.

 

If it's really as simple as getting Nissan to testify that they built and used such cars (something that we already know, and something that could be demonstrated in any number of ways - including the period Australian magazine articles) then it should be pretty easy... 

 

 

 

 

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Alan, we have tried the mathod of approach to the "contact us" section of Nissan Japan's website, on both ccaisions the reply was " we do not have records that date back that far, sorry"

And that there was no person at their website able to assist.

 

Back to square 1.!

 

I did meet Kazuo Hioki at Zama, but have no contact detail for him direct.

He very fondly recalled his time spent in Australia, and recalled the Group C Bluebird turbo race cars, as well as the very unique rally car Nissan Australia built for George Fury.

Kazuo even asked if I would lile to donate that car for it to be displayed at Zama.

But, that was 5 years ago, and, as above, I have no contact for him.

 

Do you think he may be able to assist in obtainng a "letter of confirmation of manufacture"?

 

 

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I did meet Kazuo Hioki at Zama, but have no contact detail for him direct.

 

Hioki san is a friend of mine, but he has now left the Nissan group and works for JAF. I don't think he'll be able to help you.

 

Honestly, I think you need to get old school on this. Forget e-mails. Nissan receives thousands of random e-mails every day and you're unlikely to get past the first few people who filter such correspondence. My advice would be to start through Nissan Australia (going over their heads may be seen as a snub) and if no joy there start writing letters (on paper) to Nissan in Japan.

 

The guys who curate the collection at Zama (Safari Motors) really ought to be able to help with this kind of thing, but - in my personal experience - the top dog there doesn't know his arse from his elbow...

 

 

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OK, so they overheat, what then has been done to counter that, front and rear.

 

Had a brief chat with Switzer yesterday, apparently the Zed's head gasket was leaking but he was going to push on. Don't know what happened to Mike, he was gone early arvo today. Adler in his Porker two bloody seconds clear of everyone, WTF were the rest of them doing  ::)

 

Sorry I missed you Richard at MP on Sunday.  I had a "character building" weekend which wasn't helped by torrential rain on Friday with the resultant bog in the marquee pits.  I went up to do my Observed Licence Test in the regularity.  Clutch master cylinder failed putting the car on the trailer so had to replace (not an easy one man job) and bleed clutch and brakes in the mud.  Went out in practice and qualifying on road tyres - wrong choice. Had a good first run on flogged out race tyres battling with a couple of Porsches then motor went off-song for the second round. Securing bolt for carby choke fell out allowing choke to rattle around and block jets.  Normally safety wired but had work done on Carbies and not replaced.  Didn't feel like pulling airbox and carbies off in the mud.  CAMS officials very accommodating, said they'd seen enough and signed off paper work.  Packed up and went home to dry off!  Stan Adler was doing 1:28s, for what it is worth.

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Consider yourself extremely lucky to have gotten signed off on your OLT, in a Regularity grid!

It s supposed to be done in a Race grid!

But dont go telling everyone, or we may ( i hope we do!) get an influx f Southerners turning up for the July Historics doing their OLT's!

 

Ask tye question of the HRCC f you can run as "Invited car" with the ( usually!) low grid numbers field in Group S for the July meet. Gove Stan a call and ask him for acceptance, of your heavy spec (???) Tarmac rally car, on treaded type tyres,,,,,

They've let McKeon run the slck shod car, in past!

 

 

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Yeh it was muddy where you were Mike, someone told me you had an off and that's why your tyres were muddy :)  So how's the Sc coming along, you realise that the hopes of the Q S30 community are riding on your shoulders to pip Adler. Or else do a Jason on him  ;D

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Yeh it was muddy where you were Mike, someone told me you had an off and that's why your tyres were muddy :)  So how's the Sc coming along, you realise that the hopes of the Q S30 community are riding on your shoulders to pip Adler. Or else do a Jason on him  ;D

and what would "doing a jason on him " be?

 

Mike will get up to speed just nicely at the Qld tracks, the task will be to keep Andy Wilsons very quick little 105 Alfa at bay.

 

 

This is fun!

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  • 2 months later...

I found one of my brake issues was with the Master Cylinder leaking. Although not ideal the group S brake situation is a bit more under control now.

 

James Flett gave me his secret pads and fluid to use and a mission to try all different replacement rotors so that we can have good alternatives to the end of production of the Brembo.

 

I bought these discs from the USA on ebay where they had really reasonable freight charge and before the AUD tanked.

http://www.stoptech.com/products/rotors/centric-premium-rotors

I can report that these discs are holding up quite well.

 

As for what pads to use you need to ask James, I've sworn to secrecy :)

 

 

 

 

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