Lotus Sport/AP replacement rotors

[dmh]

The prototypes are in testing and I am now trying to gauge the size of a production run. If you are interested please contact me.

****** 308mm/26mm ******
2-piece floating rotor::$500
Replacement rotor::$250
Replacement hat::$250
Replacement hardware set::$125

Developed in conjunction with Girodisc.

:: Braking Performance :: The thirty directionally curved vanes act as a centrifugal air pump and actively move cooling air through the rotor as it rotates, helping to shed heat quickly and reduce brake pad fading. The cast iron discs are heat-treated for thermal stability and also slotted, allowing a maximized contact at the interface between pad and disc as the edges of the slots continuously clean and refresh the pad surface.

:: High Quality Materials :: The hat is 2024-T3 billet aluminum with a grey color Military spec type III hard anodized finish. The disc hardware consists of 10 cadmium plated high strength alloy steel drive bushings which take the load from braking actions while maintaining the float between the hat and disc. Girodisc manufactures these components in the USA to our own specifications, which are higher than that of the factory parts. The Girodisc drive bushings have a Rockwell hardness of 26 C, which is much higher than the AP bushes. The corresponding washers are hardened alloy steel and the cap screw is grade 12.9.

:: Value :: Compare these professional race spec rotors and hats to the equivalent from a Lotus dealership and not only is the cost savings apparent, your braking performance will be too.

[EdHahn]

Can you post a photo of the backside of the rotor? Interested in seeing how the disc mates to the hat. Thanks!

ed

[Uncle Sam]

Don't need rotors now, but if I did I would get these. The sales potential for these wearable items is going up with the age of the cars. I would prefer slotted to drilled anyday. Good Luck with your product.

[dmh]

Originally Posted by EdHahn

Can you post a photo of the backside of the rotor? Interested in seeing how the disc mates to the hat. Thanks!

ed

See: http://girodisc.com/pdf/assembly.pdf

[elise/europa]

The kit is for the fromnt and rear?

If yes, how you deal to increase the rear disc diameter?

If no, just for the front. The actual front disc is 288 OD, running with 50 mm depth pad, for a effective diameter of 288-50 = 238 mm. This mean that rotor of 308 mm will have an effective diamter of 258. This gives a difference of 8.4%, affecting the front and rear distribution. And since the actual distribution is already not perfect with already too much brake in the front, is it a good idea to increase the front diameter.

[dmh]

Originally Posted by elise/europa

The kit is for the fromnt and rear?

If yes, how you deal to increase the rear disc diameter?

If no, just for the front. The actual front disc is 288 OD, running with 50 mm depth pad, for a effective diameter of 288-50 = 238 mm. This mean that rotor of 308 mm will have an effective diamter of 258. This gives a difference of 8.4%, affecting the front and rear distribution. And since the actual distribution is already not perfect with already too much brake in the front, is it a good idea to increase the front diameter.

This kit is a direct fit for the Lotus Sport/AP BBK; it is not a stock replacement. Nor is it a replacement rotor for the aftermarket AP BBK.

We are going to try and work with Sector111 as they have an exclusive on the Girodisc rears. DMH specs different rotor and hats than does Sector111.

[ace10]

Originally Posted by dmh

2-piece floating rotor::$500
Replacement rotor::$250
Replacement hat::$250
Replacement hardware set::$125

each? set of two? set of four?

[elise/europa]

To dmh,

If you are doing a kit for the stock replacement, I really think that heavier in mass should be a good idea for the front. The diameter don't affect the capacity to take heat, it just affect the torque, and stock, the torque is not bad; and for racing, typically the friction is higher giving more than required torque. Of course, with full racing pad, the actual weight is good enought since the disc temp can be as high as 1400 F. Actually, I am overheating my Pagid R4-2, which are good for only 900 F.

Since the center of the two pieces is made in aluminum, it is cool to add this weight to the disc itself to be able to run cooler during the braking. The temperature is proportional to the weight, and material heat capacity. For the same mass, it is better to have smaller disc to reduce the inertia if the required brake torque is acheive.

Also, it very easy to enlarge the front disc by adding spupid spacer into the caliper since the oil is passing by an external tube. For 28 mm disc, it is just required to shim 2mm. Those shim are easy and cheap to produce by laser cut. For 1 1/4 disc, which is more common in USA, the shim should be around 1/4, still easy to build, but I am not sure if the external tube needs to be replaced or not.

Of course, this was just my opinion. In my case, I will install Alcon disc of 295mm X 28mm at the front.

[EdHahn]

Originally Posted by dmh

This kit is a direct fit for the Lotus Sport/AP BBK; it is not a stock replacement.

OK, you shoulda made that point in the initial post.

ed

[R T]

... it's in the title, isn't it?

[ace10]

Originally Posted by R T

... it's in the title, isn't it?

that this is not a stock replacement was not clear to me.

[Dmbrown34]

What is the difference between these and the Sector 111 rotors?

http://www.sector111.com/products/pe...disc-front.cfm

Sector 111 also uses Girodiscs to construct the rotors for them and Sector 111 is a bill cheaper.

[R T]

apples vs. oranges?

[dmh]

Originally Posted by Dmbrown34

What is the difference between these and the Sector 111 rotors?

http://www.sector111.com/products/pe...disc-front.cfm

Sector 111 also uses Girodiscs to construct the rotors for them and Sector 111 is a bill cheaper.

Sector 111: stock replacement, zinc plated not heat treated rotor, 6061 T-6 aluminum hats, anodized gold

DMH: Lotus Sport/AP replacement, heat treated not zinc plated rotor, 2024-T3 aluminum hats, clear hard anodized (looks dark grey)

The DMH/Girodisc is the same setup you'll find used by professional race teams...the different materials used accounts for the price difference

[vyuen]

Is there any weight reduction compared to the AP rotors?

[jkolb]

Is there a source for the calipers and any adapters that might be required to run these discs?

Jerry

[dmh]

Originally Posted by vyuen

Is there any weight reduction compared to the AP rotors?

None to speak of as they are the same size and type (iron rotor and aluminum hat).

[dmh]

Originally Posted by jkolb

Is there a source for the calipers and any adapters that might be required to run these discs?

Jerry

I think Lotus might be the only place you can currently get the kit (analogous to Yoko A005s). However, they are nothing more than AP CP7600 calipers, Pagid pads, adapters, rotors, and stainless steel lines (front and rear). If the demand is there I can put a kit together. Please let me know if you are interested.

[cr_craig]

I'm interested, since the drilled rotors on my cup 255 are already cracking . . .

Thanks,
Robert.

[fins0619]

I would be a buyer as well.