114 replies to this topic

[Ratspants]

The supposed 1144s functioned OK but not as well as the SBS in my view when first installed and absolutely not as well as reports from others would suggest.
...
They shriek, scream, yell, grate and grind unless you really lean on them. I mean they are noiser than you would believe possible. Then a lot worse than that.

Gotta be something wrong there. I fitted my own 1144s and they did squeal a bit when first fitted, after a few hundred miles they don't squeal at all and only make a slight rubbing hiss when gently applied....which I'm pretty sure my OEM ones did too. Sounds like they were badly fitted/wrong ones?

Sorry to hear they are giving you so much greif. These wheels and hubs on the other hand are SOOOOO tempting



Ben

[speedyK]

I think all pads can make noises. I'm on OE pads and, after negotiating an alpine pass yesterday, the squeal from (only) the front right pad was driving my wife and I nuts. On the german forum last year, they were all going on about pad squeal and saying that it was some kind of design problem that GM should sort out – seems to have gone a bit quiet now – though I don't know if that's because people are learning to live with it... The hub/wheel/tyre combo sounds fantastic!

[cyberman]

Yes, its very odd. I have now checked and the pads are 1144s and still clearly marked as such. The disks look absolutely clean and beautiful. The main problem arose Friday when I was in London all day cruising around in traffic with light brake use every few seconds. The problem, whch was particularly bad as one came to rest i.e. in the last 10-12 mph before rest, just built up and up and up till by the end of the day (maybe 40-50 miles of this) I was fit to set fire to the thing...... Trying to be analytical I suppose it would start on one corner and build up to 3 or four. Dependent on speed each had its own tone. One would groan, another would shriek and another would grate or grind as if there was sand in the interface. Then I would stomp it to a halt. It was all very unpleasant. Yesterday I took it out around Henley and down to the outskirts of Reading and it was quite well behaved. Only one or two corners were complaining after warm-up and these were a mild squeal which had to be provoked by careful pressure selection. No grinding or grating and everything seemed to work well. Today I will take it out and give the brakes a very controlled thrashing. Maybe 4 ABS fast stops from 100 mph and then see what happens. Basically I assume its got to be some sort of resonance effect between the grooved surface of the disk and the pad causing the pad to vibrate / oscillate in some way. The speed and pressure sensitivity both lend themselves to that as a view. Hrrm. Maybe one can damp oscillations? Starts pondering about glueing weights on pads..... I have just talked to Eliseparts who say they ship little sticky caliper shims with their after market pad kits in order to stop pad rattle in the caliper. A further line of investigation here. I'll report again. Ian

[Jase_MK]

I have just talked to Eliseparts who say they ship little sticky caliper shims with their after market pad kits in order to stop pad rattle in the caliper. A further line of investigation here.

I've fit 1144s front and rear to two VXs and all sets came packaged with adhesive shims/pads that go on the back face of the pad (where you'd normally put some grease/coppaslip or whatever it's called).

I assume yours came with these?

[cyberman]

Yes, apparently they did and they were fitted. As was loads of copperslip on the pistons et al. Very strange. Time for the severe disciplining session.

[Pidgeon]

Ian just put some Pagids on it. 14's all round were convincing, I will know more about 14 front, 15 rear after the weekend. I have no trouble stating Pagids are vastly superior to any other pad available.

[garyk220]

I have no trouble stating Pagids are vastly superior to any other pad available.

I've got RS14s on the Elisepart discs, and apart from the very occasional low speed squeel when pulling up in traffic, they have been great. The same pads on my previous discs (EBC grooved and dimpled discs) were much noisier, but still stopped well.

[cyberman]

Well, I'm not sure I've fixed them but I've definitely frightened them into a temporary silence. At first going out they were much as yesterday, quiet to begin with, then individually starting to squeal at low speed as they warmed a little. Eventually I found a nice straight empty piece of road down by Benson RAF base and did 5 * 60 -> 15 stops at full bore one on top of the other. ABS active on 3 of them. Slight smell of busy brakes but nothing untoward. Then 1 mile later heading downhill did 3 * 100 -> 15 stops at full bore one on top of the other. ABS activity on all of them. Strong smell of busy brakes and possible slight smoke seen but nothing untoward - or at least other than caused by the ABS. No immediate sign of fade although I did have a soft pedal which recovered on the third stroke and has been good since.... The caliper was not particularly hot although the disk was radiating nicely. Since then they have been as good as gold. Not a squeal has been heard. I have to say, even though they have now quietened down, I don't find them exceptional. The remarks from most using the 1144 has been as they are reported to act almost like a force amplifier and really grab those disks. I don't find quite that. They do work, no problem with that, but they seem somewhat flat in response. They do work from cold, no problem with that. I wonder if they are as consistent at higher pedal pressures and when hot? They are lots better than the OEM no question. Anyway, as yet, I don't feel I know as much about the new braking system characteristics as I would like. Maybe the feedback will now settle down and I will learn more. I'll leave them for a week whilst I work that out. Then I think I will have the SBS part-worns put back in so that I can do a back to back comparison. Now that will be interesting because a I rated the SBS in combo with the Pagid 16 groove disk. I suppose if I got one of those accelerometer thingies it might make the comparison all a bit more meaningful.

[Pidgeon]

My recollection is that the 1144 enthusiasts were mainly in N/A's. Do not understand why you want to waste more time? Just fit the best.

[cyberman]

I see the advice about RS14s which I appreciate. I think the only way to resolve these comparative issues has got to be by controlled testing. I will a: get the accelerometer thingie b: after the SBS trial will stick in a set of RS14s and compare those as well. As its only brakes all we need is the same piece of nice smooth tarmac and we should be able to mock up a convincing comparison.

Edited by cyberman, 04 April 2005 - 02:31 PM.

[Jase_MK]

I'm sure I've said this plenty times before, but..... IMO a brake setup needs to give you the following - enough power to take the tyre beyond the point of lockup in dry grippy conditions, enough feel to modulate the braking and hold the tyre on the point of lockup, resistance to fade. I'm happy with my 1144s as they provide ample power (once you've locked the wheels you are then applying too much braking force anyway), plenty feel and controlability to threshold brake without too much pedal pressure and I've not experienced fade yet (I did with the standard pads). A grippier pad will require less pedal force to achieve the same braking, but IMO this leads to an over-servo'ed feeling and makes things like H&T and general modulation harder. That's only a personal preference thing though. I know people rave about other more expensive solutions and I'm certain they are great, but the potential deccelerative force of the car is dependant on the grip available from the tyres, not the brakes (provided they meet the criteria above). Someone was chatting about 4-pot brake conversions a while back and how amazing the deccelerative forces were - I can see the benefits, but again maximum decceleration whilst threshold braking is down to how much grip is available from the tyres. Has anyone used both Mintex and Pagid and is able to give an objective, technical comparison? (as opposed to "they are awesome!" )

[cyberman]

That is well argued and your question is a very valid. You will have inferred from my comments that the Mintex has enough grip to cause ABS activity with the A048R rubber. The SBS achieved this in spades with the Bridgestones but we have no comparison here. I will endeavour to rectify that in the next week and will try to do the RS14s thereafter.

[garyk220]

IMO a brake setup needs to give you the following - enough power to take the tyre beyond the point of lockup in dry grippy conditions, enough feel to modulate the braking and hold the tyre on the point of lockup, resistance to fade.

Absolutely agree Jase Pagids have best resistance to fade (coupled with very low wear) of the pads I've tried.

Doubtful that a back to back braking efficiency test will demonstrate much more than cold and hot stopping distances on each pad type. However, I'd be very surprised if anything gets close to the Pagids after 30 minutes of hard driving on a track with a few heavy stops from 120mph+ Especially on a turbo - the NA is less sensitive to brakes IME.

[cyberman]

Anybody who has two pennorth to contribute to a braking test specification which a: can be performed in parts on different days b: doesn't involve hiring a circuit and taking a full crew, is very welcome to chip in and help specify it. I had sort of assumed that we might do maybe 12 braking runs working up in 10 mph increments from say 30 mph to 150 (or whatever the venue can manage). The simple rule would be to try to drive the unit into ABS activity, if that can be shown to give consistent performance, and stabilise the disk temperature between runs (I have a nice IR pyro). We should then get a deceleration curve for each initial speed which should be revealing. I wouldn't have an issue with a "temperature stabilisation" which involved ramping it up by run which may help meet some of the objections mentioned. I may even be able to offer a venue if no one else has one: I'll have to ask my neighbour.

[alanoo]

I have had a reply from Dymag (carbon/magnesium wheel). They don't have the sizes to suit us now but they do plan to do wheels which will in the next 12 months. They have full safety certification for road use and quote chapter and verse on compliances.

I have asked them some subsidiary questions e.g will they do Elise hubs only and can they give us a weight estimate for the 7J*16 and 8J*17. Here, to wet the appetite, is a picture of one of their wheels:



Regards - Ian

Bump from hell

Did they do some of these in 17 and/or 16 ?
On their website there is still only 18's+ ...