Front brake upgrades - a techincal look.

[Kozy]

So I've been doing a lot of research on brakes over the last 6 months or so, and after someone mentioning that some kind of comparison between different setups could be useful, this week I came to a few conclusions which I thought might be of interest to you guys.

I've boiled down a pretty thorough theoretical analysis of the entire braking system into four basic aspects which define braking performance, then compared some common front upgrades in these aspects to see how they compare.

Up on the table we have:
Stock EK9
EP3
ATR
NA1 NSX
NA2 NSX
Spoon twinblocks
282mm Wilwood kit
298mm Wilwood kit

Conditions:
High performance road tyres.
Dry tarmac.
Stock EK9 + driver.
The only things changed are the caliper and rotor, for fair comparison.
Simulated with 'Robodriver'. He can brake perfectly, every time.

Points of interest:
Pedal force to achieve threshold braking (lbs)
Front bias at threshold (%)
Minimum stopping distance from 60mph (meters)
Rotor temperature after 10x 80-40-80mph cycles. (°C)

Results:

Just some raw info for you there, make of it what you will.

 

[M!chael]

Surprised at the stopping distance with the wilwoods! Strange that they excel in every other aspect.

 

[Kozy]

Pedal force, bias and stopping distances are all closely linked, more power equals more front bias and more front bias equals longer stopping distances.

 

[Bucc-i]

What about in comparison to the ITR. Is the the same or better?
Someone suggested I change out my EK9 brake booster for a ITR one for a shorter stopping distance. And you know what, it worked! Are ITR brakes better than EK9 brakes?

 

[Kozy]

As far as I was aware EK9 and 98spec DC2 had the same components, or at least the same size.

 

[Lee s]

Thought will woods would have better stopping distances than ek9 brakes.....

 

[TheBooosh...!]

So by the looks of this na1 nsx setup seems to be a pretty good choice?

And even though the wilwood 298mm kit is the biggest kit its also got the longest stopping distance, therefore a waste of money???

 

[Kozy]

Double post

 

[Kozy]

Thought will woods would have better stopping distances than ek9 brakes.....

They may do in real life if they allow better modulation, or perhaps allow a driver to hit threshold who couldn't in the stock car, but I can't account for the driver.

With 'Robodriver' however, who can brake perfectly every time, then the stopping distance is purely down to how much of the available grip is used. If you are front biased then you are not using all the available rear grip and the stopping distances go up. More front bias is needed when you go to stickier tyres, but that was held constant for this.

And even though the wilwood 298mm kit is the biggest kit its also got the longest stopping distance, therefore a waste of money???

On a stock car perhaps if stopping distance is your only consideration. They would work well on a lightened car, with the weight distribution moved forwards, running on sticky tyres. You need more front bias then.

I'm not here to say what's best necessarily, just posting some numbers so people can have an idea of what different brakes will do, and whether they are suited to their application. Someone running 250bhp in a fully loaded car on street tyres, braking between 80-40mph is going to have different requirements to someone with only 200bhp in a 950kg car running slicks at the track and braking from 110-60mph.

 

[Lee s]

Interesting!
Well I've got just over 230 bhp in a stripped out 9, and I think the std brakes with ds2500 are more than enough.

 

[clockwoRk]

Is this using some sort of simulation software or did you have to, one by one, test all the different setups with some sort of measuring equipment on board? Not challenging it or anything, just curious.

 

[Kozy]

I am writing simulation software. Well the maths part anyway. I need to learn coding to write a proper program/app.

 

[Darragh]

Dont know what to make of that : /

 

[Topher-EK9]

The ATR brakes stay very cool. seems the ek9 brakes get very hot...

How this increases or decreses braking forcw i have no idea but the difference between the 2 is vast..

 

[Kozy]

Dont know what to make of that : /

Take it with a pinch of salt, I know I would if anyone else posted it. I am confident that those values are a fairly accurate representation of actual braking systems, but I'm not going to disclose the guts of it due to how much work was involved, so it's pretty much a case of whether you believe in this kind of stuff and trust me to know what I am doing. I know a lot of people won't and that's cool, but for the ones that do, well there's my findings.

 

[Kozy]

The ATR brakes stay very cool. seems the ek9 brakes get very hot...

How this increases or decreses braking forcw i have no idea but the difference between the 2 is vast..

They're not that hot, that's a decent running temperature and matches the power, grip and weight of the car well. In comparison the ATRs do run very cool, probably too cool on a road car, but if you find that you're overheating the stock brakes either through higher speeds or increased power, then you would be good to choose these over some of the other options.

 

[Darragh]

Take it with a pinch of salt, I know I would if anyone else posted it. I am confident that those values are a fairly accurate representation of actual braking systems, but I'm not going to disclose the guts of it due to how much work was involved, so it's pretty much a case of whether you believe in this kind of stuff and trust me to know what I am doing. I know a lot of people won't and that's cool, but for the ones that do, well there's my findings.

I have faith in you Kozy , just I would have thought the results would be different lol

For the wilwood 298mm did you factor in the 32mm width discs ?
Also wonder how much bias could be pulled back from using a better rear pad ?

 

[Kozy]

The results are not absolute, but a good representation of the differences when absolutely everything else is held artificially constant.

Yep, 298s are on 32mm thick discs.

Using a better rear pad would certainly bring the bias back quite well, but woud still require you to use a weak pad up front, which would be a bit counter productive...

 

[boro_andy]

Could you work it out for any set up?

Ie. I've thought about pairing a set of oem twin blocks (ATR, legend or NSX) on the rear to my 282 wilwoods up front.

Be interested to you know the efficient nature of such a set up and if it would be worth looking at.

 

[Kozy]

I can assess any combination of pretty much anything on the car. I would not put ANY front brake setup on the rear regardless of what front brakes you run though.
Firstly, even the most weedy front caliper will be so far overpowered on the rear that it would be dangerous to drive, and second, there would be no handbrake!