Brake upgrade

[fsrowsell]

I need advise on which upgrade disc I should use for my brake upgrade on my 92 Stevens… I already have my Brembo Calipers from an AM DB9.

I’m not sure if I should keep the current wheel hubs and us maybe upgraded discs or if I should maybe do it proper and change the wheel hubs to the later model Esprits… that way I would have better choices in disc diameters…

Any thoughts?

[andydclements]

I think Ralph may have some insight for you, he's just doing / done an upgrade.

[SE Owner :-D]

i went for v8 hubs mate...did you turn the rims to get your futuras on?

[fsrowsell]

Andy, did Ralph start a trend on the forum, on his brake upgrade?

Roger, I turned the hubs down when I fitted the S4S wheels... I am leaning towards the V8 hubs I think. This would give me allot more flexibility... I think.

Cheers

Felix

[Jonathan]

If you want to upgrade to larger more versatile discs later then post 93 hubs are the only way to go, you'll need brackets and stuff for the calipers too.

Question of cash really, the original disks are fine for fast road use - bit skinny and not as ventilated but they do the job esp combined with the brembos.

[SE Owner :-D]

felix see if you can talk the limp wristed chutney ferret into v8 hubs for his karlos fandango's

ps.

i need your s4s code...

[ralphw]

Hi Felix

I modified a set of 305mm dia 28mm thick discs to fit on the pre 93hubs and remain within 2mm of the original back face position. Easy job really just had to mod the PCD and open up the centre hole by 10mm. Using Hi Spec 6 pots with green stuff pads. Machined up a ali mounting bracket to take the calipers and used high tesile bolts to hold it together.

Didnt like the backplates, the new discs are bigger, so they have come off and I intend to machine some fillers for the top and bottom arms. extend the bolts and knock up some specific heat shields to protect the rubbers. Just waiting for the FM rep to turn up at work.

Just got some minor tidying to do then take it for an MOT but need a new fan first. Think I might have found a source of brand new fans that could replace the Lucas ones, hope to get some time to dig into this at the weekend. If I am correct they will only need a simple wiring mod. I think I will try to pull out the original dwg of the fan when I get to work tomorrow and compare.

Cheers

Ralph

[Bibs]

Green Stuff pads are useful for Saxo's and Corsa's. Put some proper pads on your car.

[SE Owner :-D]

redstuff

[fsrowsell]

Hiya, Ralph that is great news… The only reason why I was going with the other hubs is because I want at lease 300mm disks. The fans are also good news as will… As for pads, my calipers came with Hawks I do believe...

Ralph, can you share more details with me on your brake upgrade. ie What Rotors did you use. What is the distance between your bolt holes on your calipers and do you have any pictures to share. My home email address is fsrowsell@sky.com

Roger, what code are you referring to, mate? Cheers Felix

Edited August 10, 2010 by fsrowsell

[SE Owner :-D]

Felix,

Have pm'd you mate cheers.

Rog

[fsrowsell]

Ralph, the cars I could find with 305mm disc were Volvo's and Reliant... Is it one of these, that should use?

Cheers

Felix

[ralphw]

Felix

Have e-mailed you.

Bibs

Why, they only wear the discs out quicker. If I have to leave the braking that late or am driving that aggressively on the road then perhaps I might have got something wrong. For track use I would agree.

Cheers

Ralph

[Bibs]

No they don't!

The friction surface is identical thoughout the range, it's the backing material and it's resistance to temperature that changes. Green stuff are good for about 200 degrees so if you brake hard twice on the trot you'll boil your brake fluid. I use yellow which are resistant to up to 800 degrees so I won't boil my fluid, reds are good for 600.

I've spoken with one of the Directors of EBC and he said that no way should greenstuff pads be on any performance car.

[ralphw]

Bibs

Thanks, good info that I for one wasn't aware off. Will go for Red next time. Having said that I alway use a good brake fluid and change it yearly. With my use it wont boil.

I found out ages ago what crap brake fluid is capable of and also how quickly even the good stuff goes off. Never put cheap fluid in and make sure you change it often. When I work for the Met Police, we had data showing a good high performance 270° Super Dot 4 dropping to under 180° in less than 9 months. Just imagine what the crap stuff would be like.

For info I used to have to go out for tender on this stuff regularly and I always had each sample analysed by the forensic science lab to see how performance compared with spec. Since then I have always used the high spec Castrol brake fluids and the data showed it degraded less that most of the other products in the same time frame.

Cheers

Ralph

[fsrowsell]

Cheers Ralph, I look forward to tackling this after I come back from Scotland next week....

Felix

[Jonathan]

Tend to use castrol everything but I have never had an issue with Halfords own Dot 4 shite, came as a necessity because it was miles cheaper to and more important to correctly bleed and flush the system than put £10 / litre 'decent' fluid in.

Before anyone laughs it was still locking those MONSTER V8 AP brakes up from 100mph down the mile straight at CAT driver training on the 2nd run when the disks got so hot they turned blue !

That day (esp the alpine course) was fairly demanding on the brakes and they did not show 1 iota of fade.

I always use the best pad I can afford for road use - as Bibs says green and Esprits don't really go (I ran greens on the Elise and they were fine, whether I'd trust them on my heavier / faster nigh on irreplaceable car of my dreams is another matter) - true weaker pads don't chew the disk up as much hell they don't stop you either

Unless you're doing emergency stops everywhere an aggressive pad won't eat the disk up too much as the added friction co-efficient will just stop the car faster so less effort is needed in the pedal (less wear) to achieve the same braking force. Over 5,000 miles my rears (red stuff) have worn the disk by 0.2mm (checked with my micrometer, cus I service the car myself I record this useless blurb incase anyone challenges it) - by my calcs I still have another 35,000 miles or so left in them.

[Vulcan Grey]

No need to go with new hubs.

Look at the X180-R or Sport 300.

They fitted larger rotors on custom (cheap) flat hats fitted in the standard SE way, behind the hub.

http://picasaweb.google.com/lotusse/LotusAPRacingBrakes#

In the rear, they did use a dished hat over the hub, but then they all do.

You can also go full floating, depending on what rotor you choose.

This is what I am doing

http://picasaweb.google.com/lotusse/LotusBremboRacingBrakes#

and others (Claudius)

http://picasaweb.google.com/lotusse/LotusWilwoodBrakes#

[fsrowsell]

Cheers Travis, very interesting in deed... Right now I'm going to give Ralph's suggestion a try. He suggested to us 305mm disc from a Peaugeot 406 and keep the same hubs...

Felix

[fsrowsell]

Well, I finally got a change to work on my Big Brake Disks to day.

Thanks to Ralph for the tip on the 305mm disks that only require the centre to be enlarged by 10mm and then drill a couple of holes and there you have your disks mounted to the stock bearing hub… Next big thing is to fabricate mounting brackets for the calipers..

Edited August 28, 2010 by fsrowsell

[Mike6]

I'm just pleased that the 20 odd year set up on my carb turbo passed the MOT today but then again living in the crowded South East I can never get above 50 mph. Correction when following Bibs down to Brighton the other week we did hit 90 mph

[fsrowsell]

finally have one bolted on!! It's allot of work, but I'm sure it will be worth it....

Edited September 6, 2010 by fsrowsell

[superdavelotus]

Hi Felix,

That's great work! Is the bracket made from steel the bracket is aluminium? If it's aluminium, how thick was it when you finished cutting it?

Also how did you finish the internal corner, was it a square cut into it? I would have put a fillet in there as this will be a weak point. If bracket was to break it will be at the internal corner and will shear off. Obviously the better route would be a radius to avoid sharp corners but if cutting by hand then this is the next best option. You could even cut the fillet then use a round file to form the radius.

BTW, I am not knocking your work, it's excellent! It's good to see owners getting stuck into new projects. Keep the good work up!

Edited September 6, 2010 by superdavelotus

[Jonathan]

Hmmm I agree with Dave - simply on a safety note, no one wants to hear about someone splashing the car.

Can he not run a lick of weld up the 'Vee' to produce a fillet ?

[ralphw]

Felix

As a general rule of thumb the thread engagement for aluminium should be twice the bolt diameter eg if the bolt is 10mm then the thickness of the plate should be 20mm. Good grades of aluminium can go down to 1.5 times the bolt diameter but you need to be certain of what grade of aluminium you are working with. If it is steel you are using, then you should be able to get away with 1 times the bolt diameter and if it is a stronger grade then perhaps 0.8 times. Again you need to know what you are working with if not, play safe.

I would use the high tensile bolts with a metric fine thread.

I agree with Dave ref the fillet, please be carefull as any vibration created during the braking process will be transmitted into the bracket and a sharp transition will be a prime site for a stress raiser and may result in a fatigue failure.

Nice to see your progress to date, well done.

Cheers

Ralph