Pagid Rs42's

[Conan]

Originally Posted by Elise 323

Last summer I replaced the stock brake pads with Pagid RS4-2 "blue" pads. Brake feel was improved. I then replaced the rubber lines with Goodridge stainless steel and teflon-lined brake lines. Pedal feel was further improved. Changing the lines is challenging up front. Be sure to bleed the brakes under pressure by pumping, or other means, tipping the calipers upside down to remove any trapped bubbles in the caliper.

In part the brake pedal feel is improved because the Pagid pads are less compressible than the stock pads or most other after market pads. The friction coefficient is also higher.

Here is why there is so much confusion over the correct Pagid part numbers for the Elise/Exige. The shapes of brake pad backing plates is common across several automotive applications. In the case of the rear Elise Brembo caliper the shape of the backing plate is the same as a Dodge Viper. The pads do NOT interchange. The Viper application has thicker pad material and will not fit the Elise Brembo brake. The shape of the backing plate for the front is the same as a Mistubisi EVO but once again has thicker material and will not fit the AP Racing caliper (from memory).

Pagid has RS4-2 "blue" and RS-14 "black" pad material for Elise/Exige applications. The RS4-2s have performed well for me. In discussions with Pagid USA there was concern on a cold sub-freezing Midwest morning that that the RS-14s would not stop the car reliably.

Pagids cause much less rotor wear than Hawk.

Thanks! Great info.

I think I'm going to get RS4-4 compound. Bit more bite and torque.

[Buz]

Any more reviews on the RS4-2 pads?

[mark.r]

Good information in this thread, but I am still pretty confused as to what I really should buy????

[rnr]

Originally Posted by Conan

They list a slightly different pad for the rear than the 1587 -- the 2593.

I have the U1682 on my rear brakes

[rnr]

Originally Posted by Buz

Any more reviews on the RS4-2 pads?

I have Pagid Blue RS 42s on my car and have mixed feelings. I've heard many stories of dramatically better stopping ability and was expecting many things when I put them on the car. As far as I can tell the stopping ability seems to be about the same. What I do like is the feel of the pads - I can sort of feel the pad friction through the pedal which makes me feel more confident in the brakes. However I dont know if this feel is due to pad or merely removing the backing plates.

They do squeak a bit and give off about the same (or possibly less - I cant really tell) amount of brake dust as the stock pads. I have now done about 7-8k miles (including 5 track days) in them and am reasonably happy with them. I am not sure if they are worth the $$$ and might give the Porterfields or Hawks a try when it comes time to change the pads (still deciding which way to go).

Edit: Added the quote I was replying to

[Conan]

Originally Posted by rnr

I have the U1682 on my rear brakes

Ok, now I'm confused. Based on the shapes I posted, the 1682 looks like the front pad and the 2593 looks like the rear pad.

[Conan]

Originally Posted by Conan

Ok, now I'm confused. Based on the shapes I posted, the 1682 looks like the front pad and the 2593 looks like the rear pad.

I'm an idiot. I just looked at the brake system service bulletin and clearly the 1682's are rear brake pads and the 2593's are the fronts. I'll correct my earlier post.

fwiw: My StopTech system I had on the 350Z used rear pads shaped like the 2593's and fronts closer to the 1682's

[rnr]

Originally Posted by Conan

These are also the racing pads, not the sport pads which they don't seem to have the our cars.

I would assume that by 'race' pad they are refering to RS1-4 with the RS4-2 being a sport pad. Do you know if the blues are available in the 2593 size?

[Conan]

Originally Posted by rnr

I would assume that by 'race' pad they are refering to RS1-4 with the RS4-2 being a sport pad. Do you know if the blues are available in the 2593 size?

I don't know. I would guess, "yes," since the compound is listed under the race pad tab. Maybe they make them on a request basis.

[xtn]

Originally Posted by rnr

U1587 pads are the only ones that Pagid sells for our cars. I double checked tha part numers with EliseParts.com

U1587 pads are NOT the only ones sold for our cars.

So far I have been sold the U4705 which are too thick to fit, and the U1587 which fit but are not right. I guess I'll try the U2593 next. Gotta say I'm getting pretty frustrated.

Until I can get some U2593 pads to try, I'm having the U4705 pads milled down from 16.5mm to 15.0mm thick.

xtn

[chrisp993]

xtn

The shape of the Pagid pads are shown in the diagrams:

Pagid Part#1587 http://www.braketechnology.com/1580-1678.html

Pagid Part#2593 http://www.braketechnology.com/2488-2685.html

And you can see that the differences are tiny: 0.1mm in width and 0.5mm in height, combined with the small radius on the inner circumference of the part#1587. Is this enough to conclude that Part#1587 are "not right" ...... it wouldn't drive me to the trouble and expense of machining Part#2593

Anyway, hope the diagrams are helpful

Chris

[mark.r]

Perhaps another brand that does HAVE a pad the without a doubt fits the Lotus is the way I will go. Quite frankly, for a car that spends as much time being driven in such a sporting manner, it should not be this hard to find the the absolute without a question correct pad.

[Conan]

Porterfield claims they will custom make ANY pad to order if you provide the dimensions.

Note: We can make any pad from these compounds if a listing is not shown we would need the year make and model. If it is a pad for an after market caliper that we do not show a listing for we would need a tracing of the pad with the length, height, and total thickness (including backing plate) desired. Most pads can be made and shipped on the same day ordered.

[xtn]

I'm not concerned with the dimensions of the backing plate. As you state the differences are inconsequential.

The 1587 is not right because it of the radiused edge on in inner circumference. Because of that radiused shape, the pad does not sweep the entire disk surface. It leave the inner 8mm (approx) unswept. This is indeed enough for me to conclude that the 1587 is not right.

The 2593 pads are probably perfect, but since I've got 4705 pads on hand, I'm going to machine THOSE down to the 2593 pad thickness. Essentially, I'm going to convert my 4705 pads (too thick) to 2593 pads, since I've already got them and can't wait for a shipment if I just ordered actual 2593 pads.

Originally Posted by chrisp993

xtn

The shape of the Pagid pads are shown in the diagrams:

Pagid Part#1587 http://www.braketechnology.com/1580-1678.html

Pagid Part#2593 http://www.braketechnology.com/2488-2685.html

And you can see that the differences are tiny: 0.1mm in width and 0.5mm in height, combined with the small radius on the inner circumference of the part#1587. Is this enough to conclude that Part#1587 are "not right" ...... it wouldn't drive me to the trouble and expense of machining Part#2593

Anyway, hope the diagrams are helpful

Chris

[xtn]

Originally Posted by mark.r

Perhaps another brand that does HAVE a pad the without a doubt fits the Lotus is the way I will go. Quite frankly, for a car that spends as much time being driven in such a sporting manner, it should not be this hard to find the the absolute without a question correct pad.

Oh it's not hard. You can go straight down to your local Lotus dealer and get stock pads.

A lot of people have touted the Pagids, so I want to try them. If it takes some effort, so be it. Next time I'll try something different.

xtn

[chrisp993]

xtn

The swept area isn't really relevant - within limits - the braking force applied by the brake pad to the disk is proportional to (1) the pad material's coefficient of friction and (2) the force exerted by the (caliper) piston - it is independent of the contact area. This is provided the contact area isn't so small the pad digs into the disk or melts etc.

Check: http://hyperphysics.phy-astr.gsu.edu/hbase/frict3.html

By the far the biggest variable as people swap to different pads is the coefficient of friction, esp. at different temperatures, of different pad materials.

The exact brake pad shape isn't the big deal you think, but maybe I'm missing something - someone can jump in to correct me I'm sure!

Chris

[mark.r]

The 2593 pads are probably perfect

So are these the correct pads for front AND back calipers???

[Conan]

Originally Posted by mark.r

So are these the correct pads for front AND back calipers???

No. The calipers are completely different between the front and back. 2593 is for front only.

[mark.r]

Originally Posted by Conan

No. The calipers are completely different between the front and back. 2593 is for front only.

That what I though as you can see simply by lookin at them. All these part numbers requires a secretary to keep track. So it is thought that 2593 is good for the fronts, although rnr's earlier post says that they are for the rear. What is the correct rear part number 1682?

[Conan]

Originally Posted by mark.r

That what I though as you can see simply by lookin at them. All these part numbers requires a secretary to keep track. So it is thought that 2593 is good for the fronts, although rnr's earlier post says that they are for the rear. What is the correct rear part number 1682?

Ok, I'm attaching images from the Lotus service manual/bulletin. Note the pad shapes. Here are the part numbers from the Lotus parts list:

Brake Pad Set, rear B117J0085S
Brake Pad Set, front B117J0084S