Brakes

General General Lotus Talk
1

Roy and I used the same datalogging at Oulton Park and aside from analysing ourselves to death one very interesting point came through.We have the same brake setup except for pads - roys with Pagids can pull around -1g under braking - I can only pull -.8 with my Mintex pads. I’m sure loads of you are going to say that was always going to be the result but there’s the proof.Also noteworthy is the fact that his dics need relacing at 16,000 miles and mine don’t at 20,000 miles.Pagids grip better - not many benny!!Mike

2

If both of you can lock your brakes then the pad material has nothing to do with the difference in braking G’s… The tires can only give you so much friction before locking so I think the difference is down to tire wear/pressures/geo settings/driver…IMHO

3

Not entirely true The force required to lock and maintain a locked wheel is less than that required to hold the wheel at maximum retardation.Something to do with dynamic v. static friction…Thus a superior pad will be able to provide more retardation before the pedal pressure forces it to lock the wheel completely.Or I may be spouting again, but worth a thought.Hat, coat, exit stage left…Chris

4

neither of us locked up!!!Peddle pressure required to do so on hot tyres is incredible - haven’t got a clue about the science but neither he nor I could stop any quicker without locking up.I’ve driven the car and there is more bite with the pagids - they just seem sharper and the data supports thisMike

5

just reread Chris’s comments and I think he’s spot on so he’d better take his hat back off!!!

6

Erm ok…hat,coat, stage left for me instead… [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]

7

Just taking a breather from analysing the Data, my brain is beginning to hurt…As far as the braking is concerned and looking at the plots from Mike’s and my laps there is a definite and consistent harder deceleration in my car, It’s tempting to think this is just driver :smug-grin: [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image] but I’m sure this is not the case…Mike and I have done a quick Exige swap to compare brakes, and my impression was that his car needs more pressure to get the same braking, having experienced standard pads, EBC greens, Pagids and now Mintex 1144 in Mikes car. I am convinced that the Std Master cylinder/calliper/disk arrangement is just plain not up to serious track use.The -1g was into knickerbrook , and was definitely one of those ohh-s**t moments. I misjudged the braking point and even getting �1g still ended up �going in to fast�. Well into the braking area I had to stand on the pedal using much more force than would have allowed me to modulate the pressure if the brakes started to lock. I think this is the key problem. The data logger shows that �1g is within the limit of the tyres (which I suspect could probably manage �1.2g or even more). Without legs of steel the force required is to high to allow fine control near the limit; well for me anyway.Being a Southern softy my legs give up after chasing the secretary for a couple of laps around the Mineral water cooler, I suppose the Northern lads have a bit of an advantage, being used to yumping ooop hills and doon dales with a family of Ferets in their Trowsers [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]

8

quote:Originally posted by X111GED:Being a Southern softy my legs give up after chasing the secretary for a couple of laps around the Mineral water cooler, [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]“Mineral water cooler” wats one uv them then? Still pullin it up frum yon well int back yard up ere int North… [image]http://www.exiges.com/ubb/NonCGI/images/icons/confused.gif[/image]

9

Well? yard? - surely health and measurement have nothing to do with any of this.Is a back yard when you reverse approximately one meter?Confused south of the Watford Gap

10

quote:Originally posted by Mike T:Is a back yard when you reverse approximately one meter?Eh? no a meter is what posh northerners put sixpences in furt lights. Myself am still on gas…

11

Just curious - which model Pagids are we talking about? E.g., RS14 Black, RS19 Yellow (Endurance Racing), or RS421 Black and so on. I am considering the 421’s or the Ferodo DS2500/DS4003’s.Incidentally, I never would have considered the Ferodo’s, but that’s what an AP Racing engineer suggested I look into them.

12

RS14’s

13

BetoI made some enquiries about Ferodo pads myself last month and this is the reply I got from Ferodo"Hello Tim,Sorry Ferodo do not list pads in the aftermarket for your Lotus Exige.However you may try Circuit Supplies UK Ltd Tel 01525 385888 who maybeable to help, they are the UK agents for sports/track supplies on Ferodoproducts."Although I haven’t got round to ringing them yet.Cheers, Tim

14

Very interesting info Tim. I inquired through NorthAmerican Raceparts in the States (you know, that place where the football team advanced just as far as your team :0), and they were certain the DS2500’s can be located. I’ll know more tomorrow.Here’s: the message from AP Racing, which by no means says it’s a sure thing; however, it’s interesting he did not mention Mintex:Pagid RS421 is an excellent road pad and in a light car such as the Lotus will probably work well on the track. You may also consider the latest Ferodo pad material DS2500 (not sure if it has been used on a Lotus yet) which is about to become the standard pad supplied with our performance road brake upgrade kits (though not our OE supply where we tend to use Ferodo 3432F material). This material is excellent on the road and would work well on the track. We recently acquired a second hand BMW M5 which is now fully equipped with data logging equipment and one of our brake kits so we can evaluate pads for road and track day use and at 700�C DS2500 showed no signs of fade or noticeable increase in pedal effort. For information the Ferodo front pad ref is FRP219H where H = DS2500 material, and the rear is FRP3056H AP Racing numbers are Front CP3345D44-xxxx rear CP5119D50-xxxx where xxxx = material such as DS2500, RS421 etc. Not sure who supplies Ferodo in Chicago area but you could always try www.federal-mogul.com for more info.Regards,Simon Ellis

15

Beto said - "(you know, that place where the football team advanced just as far as your team :0"Hmmmm…thought football was what what the Bears played in your neck of the woods - Walter Payton, William Perry and all that [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]Hope you beat the Germans on Friday though - I’d settle for an England v USA final [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]The Ferodo factory isn’t too far from me - hence my interest in what pads might be suitable for the Exige. Cheers, Tim