Brake query

[nathanH]

After doing Rockingham the other the week it was apparent after my first two laps that the brakes are appalling!

Pedal went epicly spongy and loads of vibration on hard braking...

now, I like to think I know a bit about cars etc but when slowing up gently there is no vibration through the car so that makes me think the disks arnt warped... The pads are some £35 ktec jobbies a mate gave me for free after he fitted DS2500's, the Fluid was changed the day before for some DOT4 and the if im honest... Im not sure if my disks are HC's or not as I paid £55 from the local factors, they where in a big red brembo box...
Im thinking of just changing the pads and replacing the fluid with 5.1.
(I fitted HC/greenstuff/hoses and 5.1 in my old 172 and that was pretty good on the road)
It says to me the disks are fine so I wont change them, the pads seem the weak point so they need to be changed but will 5.1 make a difference with standard hoses, I dont have a load of cash to spend but need to change them before Cadwell on the 7th.

opinions.

 

[Jonny1*2]

One word for you! Brake pads!!!!

For a good track setup, you want braided lines, HC discs (sounds like you already have these), and pads, hmmmm, there are a few options, but steer clear of green stuff. Fluid wise, castrol super dot 4 is fine. Just make sure you bleed them after the track as the stuff nearest the calipers will deteriorate as the day goes on.

I'm running ds2500's and they are generally ok. Get a bit of glazing though. Mintex 1144's are an ok alternative.
Better pads are carbon lorraine and PF97, but be prepared to go through discs and ruin your paint (both car and wheels)

 

[TimR26]

HCs, DS2500s, Goodridge lines and Castrol Super Response fluid will be fine for the track.

 

[nathanH]

I may have to make do with just pads for now then... Just look at actually how much CL and DS are! ffs!

 

[TimR26]

If you're buying expensive pads it's a waste fitting them to used discs when HCs only cost 60 quid.

 

[nathanH]

Mintex 1144's are only £43, I think they'll be alright for now, I'll see how I get one. I cant afford to splash out on new disks before the 7th tbh.

also, what would the vibration be under heavy braking?

 

[Jonny1*2]

Mintex 1144's are only £43, I think they'll be alright for now, I'll see how I get one. I cant afford to splash out on new disks before the 7th tbh.

also, what would the vibration be under heavy braking?

Cadwell or Oulton? If it's the latter I'll see you there

 

[nathanH]

Cadwell sadly, going with Whitely, foxy and adamanderton if his car is ready in time and a few others

 

[robins]

Mintex M1144 is about as good as OEM on track. Fork out on a good set of pads like some DS3000, you can always switch em back over to standard on the road and not wear out an expensive set of pads (remember to bed them in each time). Juddering will be the disc heating up and then warping due to the thermal stress/expansion. They will cool down and go back to normal again. Thats why racecars have floating discs to avoid this problem

 

[Kam.]

Mintex M1144 is about as good as OEM on track. Fork out on a good set of pads like some DS3000, you can always switch em back over to standard on the road and not wear out an expensive set of pads (remember to bed them in each time). Juddering will be the disc heating up and then warping due to the thermal stress/expansion. They will cool down and go back to normal again. Thats why racecars have floating discs to avoid this problem

what people commonly refer to as warping of the discs is actually due to pad material being deposited on the disc unevenly. This is more common when the pads have gone above their temperature range. The CL Brakes pad range does not transfer any pad material as they are made from sintered metal compounds (unlike other manufacturers) so you will never get this problem if you use their pads..

 

[Fred@BTM]

^they just fall apart instead

1144's are NOT a track pad

 

[Greeny.]

I just bought some CL pads and new discs so looking forward to getting these on as my green stuff's are dog!!

 

[nathanH]

Cheers for all the info guys, ok, I may have to dig deeper. So my disks wont be wrecked then?! and the Spongy pedal will be down to the fluid boiling?...

 

[Soot1e]

The Brembos you had in the red box will be HC discs, so they can stay. I have Ferodo DS pads and ATE Blue Dot 4. to go with them and they were great on the first track day, no spongy pedal or fade. You definitely need a good brake fluid such as Castrol Response dot4 or ATE blue dot4. Some of the dot 5.1 are good and some ain't so good but I don't know about them.

 

[nathanH]

So red box is deffinatly HC then? The Dot 4 fluid I put in was castrol, A friend who works for subaru borrowed a fresh bottle from work. The general consensus on CS seems to be DS2500's.

Also I just got a bargin on four 205/45/16 PE2's, V rated, fitted - £300 love that!

 

[Soot1e]

So red box is deffinatly HC then? The Dot 4 fluid I put in was castrol, A friend who works for subaru borrowed a fresh bottle from work. The general consensus on CS seems to be DS2500's.

Also I just got a bargin on four 205/45/16 PE2's, V rated, fitted - £300 love that!

HCs yes, unless they are grooved discs, then they are Max's.
DS Pads yes.
Castrol Response Yes or Castrol SRF if you are rich. Did you run plenty of fresh fluid through each bleed nipple to flush out the old stuff? I suck out the old fluid from the master cylinder resovoir first then refill with new fluid and bleed each nipple with 1/2litre, just to make sure.

 

[nathanH]

Used a litre bottle and ran it untill it ran clear, the old stuff was very dark.

 

[MarkCup]

If I was you I'd change to braided lines before doing anything else.

No matter how good your fluid is, no matter how fancy your discs are, no matter how capable your race bred pads are, if your standard rubber hoses expand due to heat (which they will!) you will fail to get any pressure pushing the pad onto the disc surface = no braking.

The lines are what transmit the effort from your foot to the suface of the disc...if there's a weak point anywhere in there, money spent elsewhere is wasted.

 

[robins]

Think DS2500 or CL5+ will be ok if you're not planning on being the last of the late brakers into all the corners, otherwise DS3000 or CL6 are what you want if track performance is more important than dust, wear and squeeling issues you sometimes get with them. All these pads are around the £110-£130 mark iirc.

 

[Kam.]

^they just fall apart instead

very rarely. Its only happened to two sets of pads which would have been off the first production run. None have since disintegrated..

 

[Kam.]

the two best dot 4 brake fluids are Castrol SRF and the CL Brakes Race fluid. The CL Brakes stuff is has the highest dry boiling point and the Castrol SRF the highest wet boiling point.

 

[Kam.]

HCs yes, unless they are grooved discs, then they are Max's.

Both the plain discs and the grooved 'Max' discs are HC's (High Carbon) on the RS