Jump to content
Impact Bumpers
Wingnonut

Master cylinder. Which?

Recommended Posts

Aftermarket 3.2 £70

ATE 3.2 £160

ATE 930 £200

Is there any really benefit of the 930 master cylinder over a 3.2 (and is it a straight swap) and is the ATE one any better than an aftermarket?

Thanks in avance

Richard.

Share this post


Link to post
Share on other sites

If you are running standard brakes the standard master cylinder is fine.

The 930 MC has an increased bore size to work with the bigger brakes.

Aftermarket VS ATE - your choice. Sure both will work fine. I would always go with the higher quality part.

Share this post


Link to post
Share on other sites

£160 for an original fit ATE part doesn't seem that bad considering the cost of other items these days.

It's probably the same part used on a VW camper van or something similar.

Share this post


Link to post
Share on other sites

I’m with Foxy - don’t feck about brake components 

Share this post


Link to post
Share on other sites

Cheers chaps. Agree on the ATE point but half expected for someone to say the aftermarket were made by them any how. 

I am guessing the 930 unit with the bigger bore will give a firmer pedal? Got the impression it was a popular upgrade 

Share this post


Link to post
Share on other sites
1 hour ago, Leicestershire said:

Firmer pedal but less power.

Only an upgrade if you have larger diameter pistons at the other end (brake calipers) to maintain the hydraulic force ratio.

👍

Share this post


Link to post
Share on other sites
1 hour ago, Leicestershire said:

Firmer pedal but less power.

Only an upgrade if you have larger diameter pistons at the other end (brake calipers) to maintain the hydraulic force ratio.

+1

Works well when using Boxster front calipers, not with std setup.

Mark

Share this post


Link to post
Share on other sites

Not sure on the ratio theory reasoning as to my mind, the bigger the differential between the master cylinder and the calliper piston, the greater or lessor the force. A small master operating a large calliper piston displacement would necessitate a greater force as it would be spread over a larger area? By contrast, a large master cylinder operating a small calliper would require less force to achieve the same effect, I.e. the displaced fluid would be pressing down on a smaller area thus increasing the effect? It’s the stiletto effect, a woman of moderate weight would have a much more devastating effect if she stood on your foot with a stiletto, than a much larger woman wearing trainers! An elephant treads lightly on massive feet despite weighing 5 tons......now if it wore stilettos, or am I missing something?....I await to be corrected!

David. 

Share this post


Link to post
Share on other sites
13 minutes ago, David Gander said:

Not sure on the ratio theory reasoning

If you put a larger MC in the std system the pedal travel will decrease (larger piston moving more fluid per unit of travel) and the foot pressure needed will increase as you have less leverage due to the shorter travel. A shorter travel and stiffer pedal will make it harder to modulate braking in the most effective/safest way.

Putting larger pistons in the calipers (e.g. fitting Boxster front brakes) increases the pedal travel and reduces the foot pressure needed, this also makes effective brake modulation more difficult. Adding the larger Turbo MC restores the balance to get nearer to the optimum hydraulic force ration for best brake modulation.

Mark

Share this post


Link to post
Share on other sites
8 hours ago, David Gander said:

Not sure on the ratio theory reasoning as to my mind, the bigger the differential between the master cylinder and the calliper piston, the greater or lessor the force. A small master operating a large calliper piston displacement would necessitate a greater force as it would be spread over a larger area? By contrast, a large master cylinder operating a small calliper would require less force to achieve the same effect, I.e. the displaced fluid would be pressing down on a smaller area thus increasing the effect? It’s the stiletto effect, a woman of moderate weight would have a much more devastating effect if she stood on your foot with a stiletto, than a much larger woman wearing trainers! An elephant treads lightly on massive feet despite weighing 5 tons......now if it wore stilettos, or am I missing something?....I await to be corrected!

David. 

You have the right idea but it's just the wrong way around.

Small master cylinder gives more force but more travel.

Small master cylinder fitted to a system with big piston calipers gives huge hydraulic power with lots of master cylinder travel (very little travel of the brake pistons).

 

Share this post


Link to post
Share on other sites

Its not Force, this stays the same,but the magnification of the Pressure, relative to the volume of the cylinder /caliper bucket.

 Not luck enough to have driven a 930, my guess would be that the internals of the Master Cylinder  will differ from 3.2`s, to allow for different brake bias.

 

 

   

Share this post


Link to post
Share on other sites
1 hour ago, angusb said:

Its not Force, this stays the same,but the magnification of the Pressure, relative to the volume of the cylinder /caliper bucket.

 Not luck enough to have driven a 930, my guess would be that the internals of the Master Cylinder  will differ from 3.2`s, to allow for different brake bias.

 

 

   

A 930 has a 23mm diameter master cylinder. SC & 3.2 have a19 mm diameter master cylinder.

Add the sizes of of all the caliper pistons up and a 930 has a greater piston surface area. 

Is force not equal to pressure X area?

Share this post


Link to post
Share on other sites

I remember talking to Paul at Tuthills about the 930 ms after I had fitted the Carbon 12 brake kit. 

I think he said something along the lines of that in isolation it didn’t add much to the braking, but in done in tangent to altering the rear brake bias then therevare benefits to be had.

Share this post


Link to post
Share on other sites

Tuthills also do their own adjustable pedal box which replaces the servo on our cars

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...