Grooved discs - just plain dangerous??

[ryan]

Just returned from Scotland, and found a worrying characteristic of my new TaRox G88 front discs. They are the grooved type, and were 200 quid a set of two, so not cheap!
Anyway, the weather was really bad on the way up to Scotland, really bad rain etc. When I needed to apply the brakes however, after doing around 10 miles without braking, all I got was this horrible lack braking. It honestly felt like brake fade, but could n't have been that as I hadnt exactly hammering the brakes

After two applications of the brakes, I was back to normal, but then a few miles down the road, again pi$$ing it down, it happened again, and it was really frightening, as a lorry pulled out on me, and I had to slam on big time!
I noticed it at first after washing the car, which is quite normal, but these discs, even then, take far too long to dry off. I guess the grooves are harbouring water?

Notable brake mods are : Pagid fast road pads, braided hoses, and the said TaRox discs up front. Anybody considering these discs would be best of not bothering IMO

[AM TUNING]

i dout its the discs is probly the pads just getting to cold ,, other cars ive had pagids in did the same

[ryan]

i dout its the discs is probly the pads just getting to cold ,, other cars ive had pagids in did the same

Thing is, I had the pagids on my old discs which were also grooved (on it when I bought the car), but there were less grooves, and they'd worn down a bit. I didn't get the problem with them

[Leon.]

Maybe they need to wear in a bit?

[Dave Goodhand]

The grooves wouldn't harbour enough water to push the pad off the disc.

I would say its the pads being cold, as they are fast road use, which usually mean they need to warm up a lot before you get optimal use, and if you're warming them up a bit, and cooling them right down again (not using the brakes) they will be terrible. This is just how they work, as it has been VERY cold even in the south and if you don't use the brakes at all they would probably cool down to a very very cold temperature (Which may well infact be outside of the optimum operating temperature of the pad)

As for the discs... you bedded them in yet? They will take a while to "seat" properly, could just be this.

[Patrick Gray]

would they not be the same as any disk that fades after a good soaking i.e when you drive through puddles you are recommended to try your breaks or when you wash the car it takes a moment or two for the brakes to bite properly.I have drilled and grooved discs on the front with green stuff pads and occassionaly i experience the above.

[pizza boy]

Tis why I always buy stock pads no warm up needed.

[Baker]

Tis why I always buy stock pads no warm up needed.

good point i reckon. keep to stock and you'll be fine. and save money

[Dan_DCDezign]

Don't think it is the discs mate. I had the same discs as you on my teg ... and they were nothing short of stonking!! wether wet or dry ... and the fact that the wheels spin at such velocity, any water in the groves would be spun out in fairly short order. I would certainly recommend a pad upgrade.

Dan

[Mista Weava]

personally, i would agree with most of the comments about the brakes getting cold.

however, if you have not bedded the pads in propely, then you may find that they will behave in this way. be honest, did you give thema good toasting before they bedded in properly? if the answer is yes, the you may find it takes a time for them to come good.

i had this on the last set of pagids for my imreza. they were on pagid 8 groove discs and i was forced to get a serios shift on after about 30 miles of the new pads being fitted - cooked thema treat. it took about 200 miles to come good. the previous two sets of discs and umpteen sets of pads have all been fine, with me having bedded them in for 100-200 miles, before thrashing them.

[Chris \'aka rustboy\' Amm]

i had so called 'semi-race' pads on my old mk1 fitted by a mate and they were great in the summer for the back roads, no fade and worked really well but in the winter they were damn right dangerous, i was literatly riding the brakes when i set off to get some heat in the damn things.

i say stock pads and switch to fast road if your gonna do a track day or something.

[Mista Weava]

although i am new to the mr2 scene (being an impreza boy! ) i must say that i think the mr2 std brakes are very good! the std impreza brakes on the other hand are rubbish, they are spongey, fade easy and warp discs with hard use - uprating is essential. rev 2 brakes seems pretty good to me and the pedal feel is very firm. i would stick with std unless you are packing serious power orintend to do track days.

[ryan]

Think you might be right guys, forgot my pad were 'fast road' and may need warming up