[simon_komo]

Hi Guys

TW research development

For those who have a S2 Exige and a 4pot AP upgrade, many will be aware the bigger brakes offer fantastic "hit your face on the windscreen" braking performance. but there has been one drawback is that there is a tendancy for the rear brakes to lock up. Tony has come up with a GT adaptor that allows the original 2pot front AP calipers to be fitted to the rear. The original rear calipers are kept for hand brake usage.

I had this fitted last saturday and brake feel and modulation has improved significantly.... A great mod by TW.... well done Tony !! Once the weather improves I will drive her a bit more and give everyone more comments

simon

 

[Bender Unit]

WoW, 2 calipars at rear.

 

[simon_komo]

the original rear caliper is no longer connected to the brake hose, just used for handbrake function

 

[Bender Unit]

:up:

the original rear caliper is no longer connected to the brake hose, just used for handbrake function

you answered my brake hose question before I ask rotfl

 

[9and3]

Same size rotor, increased unsprung weight... I don't get it. :shrug:

 

[alanoo]

Simple : when you fit stupid and badly tuned 4 pots at the front, you have to make even more stupid stuff at the rear to get the good balance back rotfl

 

[xtn]

My factory brake calipers work good. No big brake kits for me. :shrug: I've got "hit your face on the windscreen" performance already.

xtn

 

[40mmBrakes]

Bigger front brakes cause rear lock up? Hopefully that's a typo.

Anyway, another option now is a re-machined rear brake caliper; more clamping force but same caliper body. Comes in 40mm, soon also 38mm piston diameters from OEM size of 36mm.

40mmBrakes Home

 

[dfa2100]

Wouldn't your total braking force tend to be limited more by your tires than your brakes? If you can already lock up your tires, you're not going to stop any quicker with bigger brakes, from what I understand. Though if you were tracking it and had a problem with brake fade or some other braking problem I could see the advantage of a different brake setup.

 

[vsop]

Wouldn't your total braking force tend to be limited more by your tires than your brakes? If you can already lock up your tires, you're not going to stop any quicker with bigger brakes, from what I understand. Though if you were tracking it and had a problem with brake fade or some other braking problem I could see the advantage of a different brake setup.

if you lock up a tire prior to the other tires reaching the max stopping load then you are wasting braking force. There is a reason race cars can adjust bias, its so they can get the max braking force as well as control how the brake force is applied to control how the car handles while braking

 

[shay2nak]

i guess you'd have to use this kit on the stock rear rotors and could not be used on the ultradiscs. (smaller rotor)

 

[xtn]

if you lock up a tire prior to the other tires reaching the max stopping load then you are wasting braking force. There is a reason race cars can adjust bias, its so they can get the max braking force as well as control how the brake force is applied to control how the car handles while braking

dfa was commenting on whether there was any benefit to be had fitting the larger front brake kit in the first place.

If the 4-pot front kit upgrade results in a tendency to lock up the rear end first... that tells me the 4-pot front kit upgrade is actually reducing braking torque at the front compared to stock.

 

[ozracer]

I thought there was an AP Master Cylinder upgrade to compensate for this. Im sure I have seen a post on seloc

 

[Noel]

You mean a brake bias valve? Simon, did you fit one after you got this kit?

 

[xtn]

I see Simon hasn't returned to this thread.

Kind of odd to praise a product for being a goofy fix for the pitfalls of another goofy product.

xtn

 

[ozracer]

Noel no I didnt mean a bias valve? I didnt think you could run them with abs fitted?

I though there was a motorsport AP master cylinder with an increased bore size to compensate?

 

[Noel]

Yes you can use this with ABS, you don't require a brake bias valve or master cylinder change. This has been confirmed by TW Racing.

The AP master cylinder is for non-ABS cars. Which in this case is not applicable.

 

[simon_komo]

Sorry Guys, was in Miami the entire week with a conference and hadn't had time to be on forum.

Back in HK now and the weather has dried up. I will have more road test and comment. So far, brake feel is very very good and modulation when braking is very progressive. just give me added confidence. Will update !

 

[simon_komo]

Yes, no need to add a valve for brake bias. TW has had a 2-11 in Zhuhai testing this setup prior offering the road version. Heard they are racing in the Superlight Series, again I will update how the brakes perform when I hear more

 

[Arno]

To at least shed some of the weight gain with this setup you could ditch the OEM cast-iron caliper and fit an aluminum handbrake-only caliper sold by BREMBO. Part number: 22.5882.11/21

Bye, Arno.