Ok all, lets talk about Z car breaks!!

[Mr.G]

I've been reading articles on how the breaks can be a little spongy on our early Z cars. Anyone else experience this??

One article that was quite interesting was by R Sime from Planet Z, I'll reproduce bits of it so I can share some of the points made with you. (I printed the article some time ago and now cannot get the link to work or I would have linked to it.)

There are a couple of routes to go down the brake improvement path.

1) Go for the Toyota 4 x 4 calipers.
2) Put race car pads on.
3) Race car calipers
4) Service exisiting system (original) ie, Bleed system, change pipes, replace master cylinder.

Toyota 4 x 4 Calipers
Pretty much a bolt on piece of kit and yes they will make your Z car stop on a dime. The disadvantage is the extra weight of the calipers. They need to be to stop a 4000 pound vehicle. Since Unsprung weight is the most important to eliminate the author is not in favour of the extra weight as he also states that the brake bias that the Datsun engineers set up is also upset.


Race car pads
When these are fitted on street driven cars they will not only reduce the braking performance but will wear the rotors very quicly and while the pads are cold will perform very poorly.


Race car calipers
The author agreed that he cannot arguw about weight in this instance but on a street driven car they will cause more problems. They are not sealed against most of the everyday things street cars drive through. How often do you check your brake caliper bores for rust and how often do you bleed the brakes?? This set up needs frequent bleeding.


Service Existing System
In the authors opinion stock brakes, reconditioned and in good operating order are more then adequate. For an uprade it is adeqaute to use modern pad material such as semi-metallic or carbon metallic intended for street use.

What he says makes good sense to me what does everyone else think??

 

[datty240Z]

I find the braking performance more than adequate for everyday use on both 240Z and 260Z 2+2.  In fact the brakes on my 260Z 2+2 are by far superior to the 240Z, contrary to popular opinion.  Both have been fully reconditioned and the 240 has a new master cylinder.  The brakes on the 300ZX TT are another matter entirely.  Mine has only approx 40,000 miles, I have changed pads front and rear for genuine Nissan ones(Expensive) and replaced fluid and still performance remains poor.  Certainly does not inspire confidence.

Does any one have experience of brake performance probs with 300ZX TTs?

Andrew.

 

[zedhead260]

I tend to agree that stock brakes work fine for normal road use. This is provided they are well maintained, i.e - Seals in master cylinder are in good condition, and calipers are applying the same force and not pulling to one side.
There are a few minor mod's you can do to improve matters without spending shed-loads of money. The most obvious is a better quality brake pad. You can also fit braided hoses for a better pedal feel. It's a good idea to use a semi-synthetic brake fluid too.
Something else I have done to my car is fit a bigger servo from a 2+2. This doesn't actually improve the brakes as such, it just inspires a bit more confidence when having to brake hard. I have also fitted a bigger bore master cylinder from a 280ZX so it displaces more fluid.
The latter is really for when I do go for bigger calipers. I have some Lockheed 4 piston jobbies from a Range Rover to fit along with a bigger diameter vented disc. But you'll need at least a 15 x 7" wheel for this. It's the same set up as Big Sam had in the early days (I think). I'll let you know if an adjustable brake bias control will need to be fitted, but I have it on good authority that it will be ok with the larger master cylinder.
This will however, increase my unsprung weight. I can justify this because my car has slightly more performance than stock and I have started using it on track days. It's when you get on the track you start to feel the limitations of standard brakes. They do cope to an extent though, providing the whole system is in good order (and this includes tyres and dampers).
Of course, you can still have big stoppers without dramaticly increasing unsprung weight. You just needs lots of cash to afford them. It's all well and good being concerned about unsprung weight, but how many people consider this when fitting bigger/ wider wheels and tyres ??
It's all about compromises. Bigger wheels = sharper steering response. Wider tyres = better traction. Big brakes = able to drive like a complete looney and still be able to stop the second time you brake hard.

 

[Zed2k]

I am trying to uprate my front brakes on my 240 and have some calipers from a Ford transit which seem to bolt straight on, I will try out the mod very soon and find out if it is a viable upgrade and may be alot cheaper than trying to get hold of 4x4 Toyota ones.
I personaly haven't really had any probs with the standard set up they seem up to the job on a standard car.

 

[pmac]

I run a set of Toyota Calipers on my fairly standard 71 240Z.
I bought them from a Toyota breaker for £150. They had just been fully reconditioned and only done one  very short trip on the Hi lux before it was broken for spares. It seemed a relatively cheap and easy upgrade. My original calipers were in need of an overhaul.(At what cost??).
I find the result is a modest improvement and was well worth the money to me.
Technical stuff like unsprung weights dont mean much to me personally. I just get in the bloody thing and press the pedals!
Peter Mac

 

[zedhead260]

I did consider going down the route of Hi-Lux four pots as they bolt straight on and you can keep the stock discs. My major concern was whether the life span of the discs would be reduced due to warping because of the extra heat generated. If this turned out to be a problem I suppose cooling ducts could be added. I'd be interested to know how you get on with them. Are you using standard pads ? or is there an aftermarket performance option ?

 

[pmac]

I probably dont drive quick enough or often enough to stretch this mod to its full extent. At the moment the pads are the ones that came with the calipers, probably brand XYZ from India or Taiwan. I also have a spare set of pads I bought at Billing last year for a Fiver from one of the dealers.. I have at least one set of s/h discs on hand. So this lot will probably see out my days as a Z driver

 

[status]

had my 260Z for about 17 years now,always had a problem with brake fade at about80 mph,changed my discs about 5 years ago and has more or less done away with it,another thing is good tyres,if you buy cheap poo you dont stop,so it is worth buying decent tyres,havnt really tested my 240 brakes yet

 

[ben240z]

be very careful using carbon metalic pads. Go faster shops will try to sell them to you but they will destroy your discs in no time at all. You might even get to the stage where you replace the discs every time you replace the pads. This advise comes from personal experience as I run them on the race car.