Roomster front brake upgrade

[Julian Edgar]

This is a repeat of the Roomster brake upgrade mentioned in another thread but rather buried.

About 3 months ago I fitted new front brakes - 312mm slotted RDA discs, Audi TT calipers, Audi TT caliper mounts, EBC 'red' pads. (This conversion needs 16 inch wheels - I used ones from a VW Vento).

This brake change is basically the "312 mm upgrade" often mentioned in VW Polo and Mk 4 Golf threads, but with grooved discs and better pads.

Old:



New:







The brakes continue to work excellently. As a comparison I can drive a standard vehicle every day of the week - my wife's Roomster.

The car with upgraded brakes has a lighter pedal feel (yes, lighter!) and stops far better, with the brakes really 'biting home' in longer, harder stops.

In a really hard drive through the twisties the Roomster braking is surpisingly capable. It's sure no Evo or Sti, but it still stops damn' hard.

Unfortunatey it's my wife's car that has the towbar, but I also think that this brake upgrade would be excellent if the Roomster towed a heavy trailer or something like a camper trailer.

Apart from the costs (which certainly can add up, taking into account also the larger wheels and tyres), this conversion has no practical downsides.

[dru]

Nice little write up. Did you do the swap over yourself?

Clean calipers beneath the rims look very nice

[Julian Edgar]

Yes I did the swap myself.

[Julian Edgar]

6 month update.

The modified brakes are very good!

I can drive my wife's std Roomster whenever I feel like it and I always notice that in her car the pedal effort is higher and that I need to concentrate when braking because her car's brakes never really 'bite home'.

The EBC 'reds' work very well - they seem to have bedded to the discs better as time has progressed.

Apart from cost and higher unpsrung weight, this is a conversion with no downsides and very clear positives.

[kaanage]

Apart from cost and higher unpsrung weight, this is a conversion with no downsides and very clear positives.

If you've increased the unsprung mass with the larger discs and wheels, then you've also increased he rotational inertia. Do you notice overall inertia increase (rotational and basic mass) reducing acceleration and mileage?

I'm wondering how much of the benefit comes solely from the pad material rather than the leverage increase with the larger discs.

For towing and racetrack use the larger/slotted discs will certainly give more power and fade resistance but I wonder if it is any benefit for normal road usage (if not driving like a maniac/hooligan on mountain switchbacks)

[Julian Edgar]

If you've increased the unsprung mass with the larger discs and wheels, then you've also increased he rotational inertia. Do you notice overall inertia increase (rotational and basic mass) reducing acceleration and mileage?

No difference noticed. What I noticed was the change in ride quality (already had the larger wheels and lower profile tyres fitted, so it was just the change in unsprung mass from the brake swap that I am commenting on).

I'm wondering how much of the benefit comes solely from the pad material rather than the leverage increase with the larger discs.

I would expect that EBC 'Reds' would result in a higher pedal effort, not lower - so I think the extra diameter and leverage is helping here.

[kaanage]

so it was just the change in unsprung mass from the brake swap that I am commenting on.

Sure, but the larger rotors would make up most of this increase so this also increases the rotational inertia (granted, it's far smaller in diameter than the wheel rims and tyres so the increase is less for the same amount of mass added compared with these other items) and I was interested if this had any effect on non-braking performance, in retrospect.

I would expect that EBC 'Reds' would result in a higher pedal effort, not lower - so I think the extra diameter and leverage is helping here.

The EBC site says that their 'Red Ceramic' pads will

brake like an alligator right from cold (as good as Original pads or better) and just get better as they heat up

as well as

has been proven to stop a passenger car/sedan/sport compact/hot hatch 13 metres quicker than OEM pads from 100mph/160kph

so it would be interesting to compare the pads with the OE calipers/rotors IF the size was available