30 replies to this topic

[joshua]

Anybody know if the non-servoed Elise S1 master cylinder fits the VX? Are the pedal boxes the same ?

[siztenboots]

nope. non servo assisted brakes on S1. Pedal box is extruded ally

[N17VES]

nope. non servo assisted brakes on S1. Pedal box is extruded ally

Bit of a vague answer, but correct.

The S1 and ealier S2(rover engine cars) have a different pedal box (extruded alloy), and don't come with servo assitance or abs.

The master cylinder could be swapped, but the abs module will need to be removed and possibly the brake lines might need to be modifed slightly, or S1 lines used. It may well be plug and play, but until you start its all guess work. Having done brake lines on a kitcar and realising how easy they are to join and bend etc, I actually don't think this would be particulary hard.

The main problem will be the pedal box. I think the S1 has a push rod for the brake pedal, I'm not sure how the vx220/later S2 compares, but it would be need to be compatible with the S1 master cylinder.

[The Batman]

there is a second hand master cylinder for the vx on ebay at the moment £60

[joshua]

Thanks for the replies - I suppose almost any dual circuit master cylinder which picks up the current servo holes will do, if I can keep the reservoir ports facing up. Most are just a pushrod from the pedal I think. Or perhaps the original cylinder can be adapted to operate with servo removed?

[N17VES]

nitron might be worth a call - they've fitted a balance bar to their N2 project. http://nitronracing....ess.com/page/2/

[Steffe]

I am picking up on this thread as I am also interested in modifying my brakes. I think it would be lovely to be able to remove the ABS and servo sh**, just having the mastercylinder like the S1 Elise. Is there a difference between a mastercylinder working without servo (like Elise S1) and a master cylinder designed to work with a servo (VX220), except the mechanical interface? My father is a mechanic and can make any type of aluminium adapter plates and such stuff. What's worries me is if there would be other issues. Case 1: Remove servo (and ABS) from VX220 mastercylinder, making an adapterplate. Would that work out well? Would it be very hard to brake? Case 2: Remove master, ABS and servo replace with S1 master and adapter plate. What will happen will the brake balance between front and back be OK? Can it be adjusted? Case 3: Other solutions... (not to expensive please) Why? Because MClaren F1 has it and the ABS is sh**.

[techieboy]

This might give you an idea of what's needed - Hofmanns ABS delete kit.

[Steffe]

I am also adding two pictures showing the clean (early S2) braking system: http://deroure.com/d...&SMO=0&ST=&SC=0 Compared to servo/ABS system: http://deroure.com/d...&SMO=0&ST=&SC=0 Master cylinder + brake fluid bottle would be 155 + VAT. I have looked at the Hofmanns solution. It looks like they are actually using the original master cylinder and have just replaced the servo with an adapter plate. Also adding some braided hoses, those could rather be substituted with cheap Cu-piping. Cost for making this could be almost zero, except the adapter plate. Or am I missing something...

[techieboy]

a new master cylinder plunger of the correct length

[Steffe]

Do anyone what ratio and size that the VX220 and Elise S1 mastercylinders have? How much of the braking power goes to the front wheels compared to the rear wheels? I also saw that Elise SI master cylinder can be bought for 72£ at: http://www.elisepart...aster-cylinder/ If I use the VX220 master cylinder it would also be great to plug the brake fluid bottle straight to the master cylinder, not using the piping. Do anyone know if there are any bottles from another car that would fit? Or in other words, what car is the VX220 master cylinder coming from? Regards Steffe

[NA Jimbo]

Do anyone what ratio and size that the VX220 and Elise S1 mastercylinders have?

How much of the braking power goes to the front wheels compared to the rear wheels?

I also saw that Elise SI master cylinder can be bought for 72£ at:
http://www.elisepart...aster-cylinder/

If I use the VX220 master cylinder it would also be great to plug the brake fluid bottle straight to the master cylinder, not using the piping. Do anyone know if there are any bottles from another car that would fit?

Or in other words, what car is the VX220 master cylinder coming from?

Regards
Steffe

It is fitted to a lot of left hand drive VWs and some skodas

[Steffe]

I have now researched the science behind braking systems The master cylinder gives the same pressure to both front and rear wheels. In our cars there are no proportional valve regulating pressure to the rear wheels. So the brake balance between front and rear axle is created by having different diameter (area) of the brake calipers. So changing to larger brakes in front (or rear) will upset the brake balance Otherwise it does not seem very complicated to make this switch. More news later.

[joshua]

The VX does have a proportioning system known as DRP (direct rear proportioning). It's in the ABS. This works like a traditional proportioning valve but acts on various inputs such as system pressure, rate of pedal application etc. Previously oblivious to this I fitted a proportioning valve in line to the ABS rear circuit. This made cock all difference to the balance with it's knob screwed right in or screwed right out, the line pressure was still being controlled by the DRP. In fact I screwed it in and out so many times the knob and it's shaft eventually fell out of the valve soaking my left foot and carpets with fluid... (cheap Ebay valve) When the ABS is switched off the DRP defaults to almost no pressure at the rear, which is ok as long as you're using sticky tyres. I was looking to reduce pedal travel so to move more fluid opted to install a Subaru WRX sti 28mm master cylinder mated the original servo. The OEM master cylinder is 23mm, of doubtful quality and apparently contributes to poor pedal feel in the VX.

[Steffe]

Thank you very much for the information! So it is an electrically controlled valve in the ABS, that explains some. One thing that I have noticed is that when I drive backwards and step on the brake pedal, it sounds like some valve is activated or something. That sound might come from the ABS-unit? When I looked at the drawings of the Elise S1 system it seemed to be without any proportional valves though. I wonder what diameter the Elise S1 master cylinder has, it might be a better idea trying to copy that system. I think the front brakes are the same, but I am not sure about the rear brakes.

[cnrandall]

http://www.hofmannso...vo-deletion-kit Price is wrong, it's got a fair bit cheaper than that (will update friday). Works brilliantly.

[Steffe]

http://www.hofmannso...vo-deletion-kit

Price is wrong, it's got a fair bit cheaper than that (will update friday). Works brilliantly.

How do you adjust brake balance with your solution as you have removed the ABS-unit?

[Aerodynamic]

From with year model does this Subaru master cylinder comes from?

The VX does have a proportioning system known as DRP (direct rear proportioning). It's in the ABS. This works like a traditional proportioning valve but acts on various inputs such as system pressure, rate of pedal application etc. Previously oblivious to this I fitted a proportioning valve in line to the ABS rear circuit. This made cock all difference to the balance with it's knob screwed right in or screwed right out, the line pressure was still being controlled by the DRP. In fact I screwed it in and out so many times the knob and it's shaft eventually fell out of the valve soaking my left foot and carpets with fluid... http://www.vx220.org..._DIR#/laugh.gif (cheap Ebay valve) http://www.vx220.org..._DIR#/angry.gif When the ABS is switched off the DRP defaults to almost no pressure at the rear, which is ok as long as you're using sticky tyres. I was looking to reduce pedal travel so to move more fluid opted to install a Subaru WRX sti 28mm master cylinder mated the original servo. The OEM master cylinder is 23mm, of doubtful quality and apparently contributes to poor pedal feel in the VX.

[The Batman]

holy thread resurrection batman robin!

[Aerodynamic]

Its nize. 😆