21 replies to this topic

[rueda]

Hi,

My brakes needs a little bit more endurance. With RC6 at each wheel and fresh RBF600, I have brake fade after 5 or 6 spirited laps on my VXT.

I will put new belled discs from Eliseparts and boa for fresh air, but I want to improve also other things like caliper piston.

Indeed, they are in aluminium, and with stainless (or titanium) piston, I'm quite sure it can improve a lot.

 

Regelin sells some here, or BOE here, but according to me, it is too expensive for only 4 SS piston, I think I can have Titanium piston for this price.

 

Is there someone who tried this type of mod ?

Is there anyone with a dismounted stock caliper to give me the size of the stock piston. I know it is a 1.75" (44.45mm) of diameter, but what is the lenght ?

I'm quite sure we can find an AP stainless piston (or Ti) of the same size for a cheap price, but I don't know where to find piston size (specially lenght) of the AP parts.

 

Any help appreciated

Edited by rueda, 21 December 2016 - 07:15 PM.

[rueda]

It seems that the original pistons are CP5235-108 (AP ref) and they are 44.45x26.7mm. Anyone can confirm these values ?

 

[oblomov]

The price is probably dictated to some degree by demand, even so, there's quite a difference between Regelin and BOE.

[rueda]

Do you talk about price or quality ?

In term of price, BOE ask me 100$ to send the 4 pistons to France !

 

I'm sure I can find piston at 20£/€, but I need to be sure about the size, but I can't dismount my calipers for now. If I don't find one, I'm quite sure a machinist can do them for less than 200€.

I will continue to dig...

[harboged]

I'm planning to refurb my calipers so I can measure the length. Might take some time before I do it through. However, I could also be interested in pistons if you find something.

[hairy]

Have you got air ducts?

[rueda]

No air ducts, I will put them soon. They are really efficient ?

[hairy]

I don't have them myself, but a lot of people recommend them

[SteveA]

There is clearly something wrong with your brakes. A number of people have run RC6's on vxts for many, many laps without fade. Id check to see if your calipers (both front and rear) are gripping when they are not supposed to. Piston mods and even belled disks should only be needed for proper endurance (6 hours plus)

Edited by SteveA, 28 December 2016 - 10:40 AM.

[rueda]

My brakes are in a really good state. I think it is related to the track (Ledenon) which is really hard for the brakes (not enough time to cool down the brakes), I'm not the only one who had this type of problem on this track. Also, my braking style which certainly don't help... Never had problems on other tracks.

My discs was also at the end of their life, and we were 2 in the car. All of that doesn't help, but I want to be sure not to get the same problem a second time.

[2-20]

Also, in South of France we can see temperature above 35 in summer. Ask Acidpopstar, I think he can confirm...

[cicastol]

Titanium brake pads shims help a lot .

 

https://hardbrakes.com/

[rueda]

I had thought about that too, easier than stainless piston. Too expensive at harbrakes.com, but I think I will make them by myself (or by someone who do water or laser cut)

[2-20]

why not trying one ply or 2 of fiber glass roving bonded with permatex "brake quiet"

[rueda]

I'm afraid of the "sponginess" feeling with glass fiber, like you can have with adhesive shims.

Ti plate is a cheap solution, you can have a Ti Gr5 plate for a nice price. If someone else is interested, perhaps I can do a batch of water or laser cuted shims.

[2-20]

Stainless steel is even cheaper and not far to Titanium wth regards to heat conduction

[2-20]

Fiber glass is not elastic like rubber . It will compress at the begining but it will not come back

[2-20]

By the way, you can perhaps use the Lotus ones:

 

[color=rgb(255,255,255);font-family:Arial, Helvetica, sans-serif;background-color:rgb(51,51,51);]A117J0114H  [/color]Shims, metal, pad front, RH

A117J0115H  Shims, metal, pad front, LH

 

£2.77 each

[harboged]

It seems that the original pistons are CP5235-108 (AP ref) and they are 44.45x26.7mm. Anyone can confirm these values ?  

Yeah, 26.7 mm is correct, just measered mine.

[rueda]