Big Brakes

[Fin]

With a view to upping my engine power in the future, I'd like to sort my brakes out first.
I've found a couple of products out there
One by Ultimate engineering for Porsche calipered brakes at £695 for the kit and an additional £400 on top for second hand calipers.
Also found a set up by FutBus for £845 which isn't as big a setup but a little more reasonably priced.

These look like the best bet at the moment.

Has anyone upgraded thier brakes?
Can it be done better or cheaper?
I was looking for some fast road pads and braded hoses as a kind of inbetweeney stage
but I'm unsure weather this is (a)possible or (b) worth the bother

I'm running a T25 pickup by the way - so I'm not lugging beds cookers etc, just want to make it stop for when the engine eventually goes in
Any advice would be much apreciated.

[R0B]

what engine are you proposing to put in your pickup.

[Fin]

Worst case a G60 out of a Corrado as I used to have a Golf Rallye and know the motor inside out

Best case a Subaru conversion of some sort

[R0B]

quite a few have scooby engines and run on standard brakes.

[CycloneMike]

I have a Subaru powered camper, fitted with an early fixed caliper brake system.
Before I put it on the road, I completely overhauled the braking system.
This included new drums, shoes, backing plates and wheel cylinders all of which are standard spec at the rear.
At the front I had my calipers reconditioned and fitted with Brickwerks uprated pads.
I replaced all the flexi hoses with braided hoses (also from Brickwerks)
I have also since fitted with a new master cylinder because I suspected my pads were dragging.
Yes all of this cost money and many on here will consider it lavish, but I did it because I wanted to be confident it would stop when I needed it to and now I don't have any problems with my braking system slowing or stopping the van even from speed when fully loaded.
In addition to knowing all the parts are in good condition, I believe a big part of the stopping performance is due to the uprated pads.
The Achilles heal of the braking system on these vans is the solid front discs, which are also small by today’s standard. Under heavy braking approximately 60-70% of the work is done by the fronts. As has been mentioned on another thread solid discs are not as good as vented disc for repeated hard use because they get hot and don't then cool again very quickly. With standard pads this is likely to lead to fade when they reach and exceed their max continuous working temperature. I haven't experienced any fade with the updated pads. However you don't get something for nothing and I (subjectively) believe that the disc wear is much faster than it should be, but I can live with that as long as the van keeps stopping.
Having said all of this I do think the Futbus kit looks very good and is the obvious upgrade to properly improve your brakes if you have the money to spend, its what I would do next time.
This is just my opinion but I think the Porsche stuff is unnecessary and I would only buy it if you are wanting to do it for fashion reasons. When it comes to brake design capacity, high speed stopping puts a much greater demand on the braking the system than the weight of the vehicle, which is why the Porsche stuff is so much larger. (kinetic energy = ½ mass x velocity squared)
Even with a G60 engine in your bus you still won’t be doing Porsche speeds!
Regards,
Mike.

[Fin]

Thanks for the info guys, I think the Futbus kit will more than do the job.
I'll save my pennies and just do the full monty, I want to be sure that the old girl will stop once I've got her rolling.
It's more the hills down here that have been worrying me, with the Bus loaded with kit, the brakes tend to fade at the bottom of a steep hill.
I think I'll do a fluid change in the meantime just in case

[hairyuk]

my brakes were crap and i wanted to upgrade them the same as you but i went to van fest and there was a german guy there refurbished 10" servos for 50 quid so i purchased one thinking it would be a cheap step in the right direction ready for when i upgrade the rest.
well it's a pain in the ass to fit, dash out, pedal assembly out, and needs to be adjust correctly before fitting it all back together, but now my brakes are so "pooh" hot i don't need to upgrade anything else. i'm now thinking of putting some nudge bars on the back of my van to stop people crashing into the back of me when i gently nudge the brake pedal. i'm not sure about brake fade as i'm not using it on a race track but for road use they're ace.

[ricicles]

my local veedub garage had an early bay in fitted with a more powerfull motor, rather than fit a disc setup they fitted twin servo,s to the og drum brakes, apparently it worked very well, better than an aftermarket disc setup.

[bennwedge]

you can pick up porsche calipers much cheaper than £400. i bought mine recently for £100 off another vdub nut . ive found vented discs for £300 but will only fit the later type front stub axles which i still have to get. so hopefully my brake upgrade will come under £500 ben

[silverbullet]

The big servo was / is the most important modification, as I have been told by "those in the know". Oettinger used to add this to the standard sliding calipers and 16mm disc on the (memory test...) low compression 3.2 WBX6 and that was 170 bhp? It was deemed adequate and the brakes could safely be worked harder by the 10" servo. Considering some of these engines went into very heavy Carats ~1800kg before passengers, why would you need more? The big 3.7 got the special vented discs and BMW calipers up front IIRC.

[ianboydsnr]

futbus is having a sale in December 10% off

[CycloneMike]

A bigger servo will not increase the heat capacity of your brake system, but it will make your brakes feel more effective because it will give you a greater clamping pressure at the brakes for the same driver input effort at the pedal.
Its similar to using a bigger amplifier with the same old little speakers, you might be able to turn them up louder more easily but they still have the same limits
Brakes explained.
Your brake discs in addition to providing the primary retardation force to slow the van also act as a heat sink to collect then dissipate the energy of the moving van.
If energy cannot be created or destroyed only converted from one form to another, then when we have a moving vehicle (kinetic energy) and we apply the brakes until it stops by creating friction between the discs and pads, the kinetic energy of the van has been converted to some other form of energy ...... which is heat (and some sound). This is mostly absorbed by the brake discs / drums.
Stopping an 1800kg van from 60mph will produce enough heat to boil a kettle full of water and does this in about 5 seconds. Keep doing this repeatedly and you can understand why brakes get hot. Bigger discs have more mass and can absorb more heat, vented discs cool quicker because they have a larger surface area and draw air over it to take the collected heat away. A T25 van by today’s standards has comparatively small and solid discs, the worst of both worlds. They heat up quickly and cool slowly.
Brake force generated = clamping pressure at the caliper x coefficient of friction between disc and pad x radius of force (distance caliper from centre of wheel)
The problem is the stuff that creates the friction will only work in a certain range of temperature. If you get the brakes too hot then the brake pads break down and can no longer contribute to providing the same braking force. Despite how much pressure you can apply at the caliper with your foot helped along with the bigger servo, if the co efficient of friction between the disc and pad has been lowered, then consequently so has the braking force.
It is a slight misconception that vans need bigger brakes because they are heavier. Yes weight does place a load on the brake system but not as much as braking from speed. The kinetic energy of a moving object is half its mass times by its velocity squared. So if you double the weight you double the energy the brakes have to absorb. But if you double the speed you increase the energy by 4 times. Hot hatches generally have bigger brakes than a Transit van for example, because they can accelerate faster and may need to repeatedly brake from higher speeds.
In summary, a bigger vented disc will always be a better upgrade than a bigger servo.
For those who wonder, amoungst other things, I spend a lot of my professional life examining potentially failed brake systems. I also do a lot of vehicle testing and research. About 6 months on an off this year on brakes.
And if your brakes are in good condition and well servied but still can't cope with your drving style, then you could always consider driving more sedately.

[v-lux]

If its any use, ive got a full front and rear Futbus kit and i'm very pleased with it.

[hairyuk]

cyclone mike makes a very good point about brake disks heating up and brake fade due to that
i'm not saying dont go for bigger vented disk multiple pot calipers braded lines etc..........if you can afford it but i think you should start with the 10" servo and go from there.
I think the improvement in braking force from just that modification is more than enough for most road users.
It surprised me and it will surprise most others.
If anything it might make you start to think about abs as they're so good and sharp you might start worrying about locking your wheels up under heavy braking

[silverbullet]

Well said Mike, thanks for the applied physics refresher. An appreciation of what you are driving and taking it's limitations into consideration, will do more for your vehicle and occupant's long term prospects than trying to drive like it's a brand new Impreza, scooby engine or not!