Brakes?

[AL001]

The M400 I recently bought had new discs/pads all round only 4 months ago yet was awful in this department at Spa due to judder and the fluid boiling after only 4 laps - not impressed. It's running factory M400 set-up except more aggressive DS2500 pads at front.

Anyone else suffering similar? Gone down another route? Added cooling ducts to brakes?

I'm reluctant to go for the factory set-up if this is the norm I can expect.

Stability under braking was very impressive though and there's obviously a lot of potential with a decent set-up.


P.S. I ran an Exige and Radical for about 10 trackdays each - neither ever warped their discs.

[obes]

Paul has made some cooling modifications by adding some ducting. There's some pics on his photo pages...

http://paulcundy.smugmug.com/gallery/359222/6/33660305

[paulcundy]

obes said:

Paul has made some cooling modifications by adding some ducting. There's some pics on his photo pages... http://paulcundy.smugmug.com/gallery/359222/6/33660305

That's the central tunnel cooling. Here are the brakes;

http://paulcundy.smugmug.com/gallery/359222/1/14277022

Rgerads
Paul C

[joolski]

I have had the same modification done to my car.

I've not tested it on the track as yet, so i can't say how effective it is, but I've never boiled the brakes on my car even on heavy track usage.

--Jools

[AL001]

Neither have I. Not sure what brake fluid the factory use or if it was changed at last service. I was very surprised to see my brake fluid container doing a good impression of a kettle on lifting the clam.

[obes]

oops, so it is. Sorry !!
I knew they were on there somewhere !

[chillidog]

AL001 said:

The M400 I recently bought had new discs/pads all round only 4 months ago yet was awful in this department ...

After a dozen track days I've had no issues with them on the M400 using the standard pads. I always do 1 lap or 2 (if it's a short circuit) to cool them down. I'm on my second set of standard pads.

DOT 5.1 is the fluid that should be used for the M400 btw.
--
Richard

[paulcundy]

forgive me for asking but;
You are sure it was the brake fluid? I've never heard of anyone's actually boiling before.
The power steering can bubble but its at the other end of the car.

Regards
PauL C


>> Edited by paulcundy on Tuesday 11th October 16:52

[AL001]

Actually, now I think about it, it was the coolant that was bubbling. Sorry. Because the brake was also getting increasingly spongey had added 2 plus 2 and got 5. Doh!

Had gaffer taped below the PAS reservoir vent hole but that was OK - Spa not a tight circuit to affect the PAS much.

Do Plans look after your Noble Paul? What spec are the discs/pads you're using?

[chillidog]

Ok that makes sense ... boiling brake fluid!!! ... I had visions of some very severe braking being carried out!
--
Richard

[robp]

Coolant bubbling is pretty well OK - brake fluid isn't. Glad that was sorted. I also get brake judder at high speeds with hot discs - never got this with my 3R and the brake spec is supposed to be exactly the same for the M400. Found a 'greasy' residue on outside front discs (not on the inner discs or either of the rears) and I originally thought this was the problem. But no. So it's currently being looked by NL whilst car is in for 6K service.
Other than the judder (which I find annoying, but dosn't affect braking)how did you find Spa in the M400?? You still over there with BaT?

[AL001]

M400 was ok at Spa but nowhere near as good as driving it last year in my Radical I'm afraid. Perhaps not fair comparison though as one more of road car.

Brake judder spoiled it quite a bit but I don't think the M400 engine is that charismatic when stretched on the higher speed parts and also doesn't pull that hard over 120mph (or the aerodynamics at least). Gearbox works against the driver too at higher rpms. Tbh, I'd rather have been in my old GT3 Mk1 there with it's fantastic engine. Handling was great though and very predictable.

Covered 2,000 miles in one week with nothing major going wrong. Very pleased with it mostly.

[chillidog]

Rob's posting reminds me that you can also apparantly reduce the judder if you clean out the venting holes in the disks.
--
Richard

[robp]

AL001 said:

M400 was ok at Spa but nowhere near as good as driving it last year in my Radical I'm afraid. Perhaps not fair comparison though as one more of road car.

Frankly, no GT sports car is going to go round Spa like a Radical!

AL001 said:

Gearbox works against the driver too at higher rpms.

Did you try just keeping a higher gear in some of the corners and then use the torque to exit? I've found that gives me much more fluid/rapid progress eg Old Hairpin at Donington in 4th.

[AMG Merc]

This makes me wonder, I have the solid brake pipe upgrade on my car - does the M400 have this as standard?

[barroom_spert]

AL001 said:

M400 was ok at Spa but nowhere near as good as driving it last year in my Radical I'm afraid. Perhaps not fair comparison though as one more of road car. Brake judder spoiled it quite a bit but I don't think the M400 engine is that charismatic when stretched on the higher speed parts and also doesn't pull that hard over 120mph (or the aerodynamics at least). Gearbox works against the driver too at higher rpms. Tbh, I'd rather have been in my old GT3 Mk1 there with it's fantastic engine. Handling was great though and very predictable.

What speed were you doing at the end of Kemmel before braking for the right -left and what was your max through Blanchimont? Just gives an idea of the breaking effort for those corners.

[robp]

AMG Merc said:

This makes me wonder, I have the solid brake pipe upgrade on my car - does the M400 have this as standard?

Yes - but all else is the same AFAIK

[joust]

I've not had too many issues with the M400. I did go through a set of discs after about 6 track days, but at <£1k all in fitted for pads and discs that isn't bad.

New discs revolutionise the braking and fix any judder - mine have just started a very very slight judder after 4 track days since the last one, and I can "feel" they are now not running 100% straight.

I think if you track the M400 (given it's not Lotus Elise light) then discs are a bit of a consumable like tyres.

If you are a dab hand at a spanner than you can change discs and pads for <£800 yourself - me I'm too lazy!

J

[DanH]

I was always suspicious that the judder wasn't due to what aren't particularly expensive pads depositing material on the disks. Can you get any pagids that fit e.g. RS29s?

[paulcundy]

Has anyone looked with a magnifying glass at the holes in the discs? Plans will not fit drilled discs to any of their cars because they all start to crack around the holes. They only ever fit grooved ones. On saturday we took the discs off an Elise and lo and behold virtualy every drilled hole had a small but definite crack radiating from them.

Would these cause shudder?

Apparently AP do a replacement fit for the Noble caliper that is of a better material, more moly in them, and are grooved.

Note these would probably be only for "serious" petrolheads.

Regards
PauL C