Drill and slotted disc's

[John L]

I presume these have to be fitted on the correct sides, but I'm sure in which direction they should be fitted, or doesn't it matter?

John

[john.r.davies]

And I presume you have already bought them, so my advice will fall on stony ground.

 

Don't.

Drilled discs crack, slotted ones only wear your pads quicker.

A vented disc is the best mod.

 

John

[Guest ntc]

And I presume you have already bought them, so my advice will fall on stony ground.

 

Don't.

Drilled discs crack, slotted ones only wear your pads quicker.

A vented disc is the best mod.

 

John

Well I have read some **** on here but for road use that is a load of bol!!!!s

[Mark Frith]

Well I have read some **** on here but for road use that is a load of bol!!!!s

[Mark Frith]

-+ 1

[Guest ntc]

John

the curve goes from the center and backwards the same as if the car was going forward.

[john.r.davies]

A picture worth a thousand worthless words

 

 

and if you think that those cracks just happen to go through the holes:

 

 

or that if once hey are started, they won't continue:

 

 

But why should you believe me? Don't it's your choice.

 

John

[Guest ntc]

I don't they are not tr discs used on the road.

Edited February 9, 2016 by ntc

[Alec Pringle]

I'd suggest that you wouldn't have to spend too long in an MoT bay before you'd see the odd car with cracked discs of the sort John's photos illustrate. Certainly I've clocked a few, and on a variety of cars.

 

Hard driving and cold water splash can all too easily cause cracks to emanate from drilled holes, as can holding the brake pedal down stationary, it's not exactly an uncommon occurrence - albeit, perhaps less common than drilled discs used in anger on the track for example.

 

Difficult to see the benefit for the average TR - which benefits from relatively large discs for the pad friction area, excepting perhaps the Wedges which offer a good deal less by way of disc diameter - especially as the average TR tends not to be pedalled that hard anyway . . . . .

 

Any weight saving is pretty much irrelevant in the context of the overall unsprung weight hanging off the front corners of a TR.

 

If improved braking really is required for a speedy machine, I for one would be looking at vented discs rather than drilled solid discs, the modest weight increment isn't sufficient to be of concern.

 

Slots may indeed have a beneficial effect under really quick motoring, but no free lunches and there is a penalty to be paid in terms of wear rate . . . . .

 

Cheers

 

Alec

[John L]

I haven't actually ordered any yet, I do have some drilled ones fitted currently and always thought they were on the wrong way round, confirmed now. Haven't had any problems with them though, but I have only done about 10000 miles in my ownership, and not done any really spirited track days. I'm also using Mintex pads.

One good thing they are useful for is locking the disc to take the wire wheel adaptors off!

John

[TriumphV8]

What can be better like this choice:

 

 

 

They are wonderfull and reliable vented discs that became necessary

due to the more than doubled power.

Best is from outside they look like stock.

 

Anyway I drove drilled discs on the Porsche 964 what I believe could

be bought ex works, too.

Mine never cracked or failed. I simply had to change them due to

becoming too small after lots of miles.

Seems to be a problem of the disc quality and maybe drilling a

cheap Charly can not be recommended.

 

EBC offers a slotted and dimpled disc set both vented and not vented

for the TR6 and like my Porsche these discs are prone to making some

noise both in the pedal and to be noticed under hard breaking.

As I do not drive in the wet I found it not necessary to drill my TR discs.

[GT6M]

Well I have read some **** on here but for road use that is a load of bol!!!!s

 

Yip just gotta agree on this, its total bollocks by the bloke woe said total bollocks

 

They will go , evan on mild road use, ask me how I know.

prob never seen discs like that,bar a picture. prob never ran drilled discs,

prob never run drilled discs ona big bike either, cos they go v v fast if water hits em when hot.

 

I had 2 sets go v v fast untill i gave up and went 35mm thick 315 dia,and vented

solved all the probs i had before.

 

And it dont matter whether they are TR discs or not, if they drilled discs, they will go. simple as that full stop end of argument.

And if they are TR discs just drilled, then forget it altogither,

they will go evan faster than the bought drilled type.

 

Really expensive drilled discs fitted to v v expensive cars have a diff make up of the disc metal, the cheeper type dont, hence they crak.

 

My advice, same as Johns, dont fit em

get some solid vented,ns if yer wanting to stop quicker.

butt, bigger better brakes will be limited by yer skinny non stikee tyres

 

Also, grooves and holes ina disc will reduce frictionee area

make a lott of noise and lotts moer dust and wear yer pads oot faster.

Good pads have slots in em for this purpose of disposing of trapped gas / dust.

 

M

Edited February 10, 2016 by GT6M

[Denis]

I agree with everything Alex has said...unless you're motor racing your TR the standard disc does the job!

[John Bracher]

The answer to the directional question seems to vary according to manufacturer!

Have a look at some of their marketing/advertising pictures, many of them do not fit as per their own instructions.........

 

The noise generated does change according to direction of slots relative to 'forward' direction though.

 

Best improvement I found was Mintex 1144 pads!

The slots and dimples/holes definitely wear the pads quicker than plain discs.

[john.r.davies]

Well, there you are ntc.

On this matter there is you, and then unless Mark agreed with you, I can't tell, the rest of the world.

 

I'm always glad to hear counter arguments to my opinions, especially if evidence is offered, but "bol!!!!s" is neither argument nor evidence, just abuse.

 

John

[Guest ntc]

John

I have fitted 4 cars with the above from TR Shop,some have had hard use and some now high mileage NO issues with any of them

[jerrytr5]

I hesitate to enter this debate, however for what it is worth I enter my thoughts for consideration.

The intention is to reduce or prevent brake fade.

A vented disc conversion will be the most efficient, also the most expensive.

Drilled &/or slotted discs with upgraded pads will suit most road-going TR's and is economical.

I use RTR drilled & slotted discs, Hawk pads, DOT 5.1 fluid and Racetorations directional air scoops.

This is effective at reducing brake fade on track days & Nurburgring forays.

I have not noticed any excessive wear on pads or discs, neither have I experienced discs cracking or any additional noise.

I don't believe there is a 'right' way round of fitting a disc unless specified by the manufacturer.

Jerry

[john.r.davies]

I think that the purpose of holes and slots isn't usually to reduce fade, as that word describes diminished braking effect due to overheated brake friction material.

Holes are said to vent 'gases' that prevent the pad biting the disc, although how this occurs is beyond me, as both ends of the hole are closed at the same time.

Slots are said to prevent glazing of the pads, by constantly 'shaving' them, although glazing is something that the late, great Carrol Smith considers a Myth: http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

 

If you experience fade, there seems to be a consensus that a good way to minimise overheated discs is to use a vented disc.

The other factor is the pad, and every brake friction material manufacturer offers a selection that operate in different temperature ranges.

These are usually termed 'road', 'fast-road' and 'racing'.

The down side is that 'hotter' pads work indifferently when they are colder than their operating range, and many boy racers have fitted hotter pads, only to slide into the wall at the end of their road

John Bracher endorsed Mintex 1144s for road use and I agree, but if you do use your brakes hard, then they also offer 1155, 1166 and even 1177 pads, with ascending heat ranges. The last is strictly race, and you would meet the wall if they aren't warmed up before significant use, but I find that 1155s are perfectly good in all situations, from 'pootling' in town to racing.

 

Since using 1155s on my Capri venteds, I have never, ever faded.

 

John

Edited February 10, 2016 by john.r.davies

[RogerH]

Hi John,

blanking both sides of a vent hole off at the same time does not stop the hole from removing the/any gases.

Air/gas is very compressible and after the pad passes by the hole the pressure is relieved.

Drilled discs do work as do slotted and vented - one has to decide where they are appropriate.

 

As for the language on this thread my red pen has been hovering. Please, all of you control yourselves.

 

Roger

[Guest ntc]

Roger

Sorry next time I will use tosh but to condem is wrong imho

[john.r.davies]

Thank you, Roger!

I did not appreciate that point.

John

[Steves_TR6]

As you can see I have the TR shop supplied 'drilled and slotted' disks.

 

I don't think they are actually drilled right the way through?

 

No issues in 12k spirited road miles.

 

By way of comparison all the ducatis that I've owned have had drilled disks as standard, and with some hard track day usage no issues there either.

 

I wonder if it's about the quality of the drilling?

 

Steve

[GT6M]

its no so much the drillings, its the metals discs are made of, and / or the temperings when med.

 

In one of me own on the standard disc, it went cos the disc stopped a blue colour and the brakes lost stopping ability cos the faces oft disc had been re tempered to something they wer,nt supposed to be, they got v v hard, and also got spiders cracks all over, all radiating frae the wols int disc.

 

Flywheel clutch faces get similar spider web cracking too.

all due to heat build up. As ye can see its got blued in spots too.

 

On the Motocross bikes, cheep discs with hard pads they would be cracked withing a race if disc got v v hot, then got wet,or ..dunked.

 

butt, bung in v soft bitey pads, and they lasted ok,

 

even top cars and OE stuff goes wrang,

this of a Merc I was working on a while back.

bloke said his wheel bearing gone, awfull noise.

but it wer,nt as ye can see int pics

 

Also, eva look here.

https://www.google.co.uk/search?q=images+of+cracked+brake+discs&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi71OTvsu7KAhXsFZoKHRvcC1sQsAQIHw&biw=984&bih=597&dpr=1.25

 

M

[oldtuckunder]

IMHO and very humble at that.

 

The big question seems to be are you trying to improve your braking, or are you trying something for fun, because you can, and its one more thing to add when describing your car "I have fitted ????????"

 

An enlightenment for me after complaining about the brakes on the Vitesse when using xyz's coloured pads etc. was to follow a recomendation on this forum to try some decent pads (mintex 1144 as it happens) and to bed them in correctly, and to not abuse them by holding the car on the footbrake after getting them hot. The information that good brakes work by adhesion not friction altered my mindset a lot.

 

Suffice to say that even bedding them in almost physically made me sick (and I have no servo), I was pulling deceleration that I had never seen before and this was on plain rotors. Since then what was a continual moan about the brakes that had me considering lots of upgrades has gone away. I now know that if the performance goes off I have probably done something stupid to destroy that adhesion layer, like gently trailing the brakes, or if I get a judder that I held it on the brakes when they were hot and thus stripped a patch of sticky on the disk. And the solution is simple, wipe the discs clean and go out for 5 mins again and bed them in.

 

So if you looking for better braking IMHO first try some decent pads, and bed then in properly and see what you get. The advantage of this approach is that plain discs are a dime a dozen and most of them are decent (you could replace a set a year for minimal cost). If you find that you are still fading the brakes under heavy usage after this, then one you really are working them hard, and you probably need to look at going the full vented route as anything else is really just tinkering.

 

I have no opinion on slotted or drilled discs, other than I would love an organisation like the TR Register to say, OK members we are going to take a standard TR and a whole bunch of different discs, pads etc to somewher like Castle Coombe for the day and try them all and publish the results so you don't all have to individually piss around trying things and making subjective comments. Now that I would call a valued service for my TR Membership. But we know it would never happen :-)

 

Alan