Help Needed on Monte Brakes

[Terry W]

My Series 2 Monte had Tarox Discs on the back when I bought it but standard on the front and I have been unhappy with the brake feel. I have now fitted Tarox on the front as well and there is now more "bite" at the front, but a serious stab on the middle pedal locks the back brakes. Chad (Monte Hospital) suggest removing the balance valve at the rear. He should know - but I would value other opions.

Secondly - I have badly damaged the front caliper rubber piston gaiters and the Monte Hospital can't supply. Anyone know who supplies these (preferably in the UK).

[Will]

That thing on the rear firewall, if the Monte is like the US Scorpion, isn't a balance valve at all, it's a differential pressure switch that reads a drop in pressure in one brake circuit by sliding a spool a very small distance to close a switch to the "brake" light. In which case, removing it won't do much.
Chad will know the Monte, I don't. If you had a scorpion, the first thing to do would be to lose the brake booster, I don't even know if the Monte incorporates this, but if it does, and it only boosts the front, lose it.
On a scorpion (don't know on a Monte) it is possible to remove the booster and re-plumb the system using the existing brake lines with nothing to buy. I do know chad sells (or used to) a kit for bypassing the booster, this would probably yield a neater appearance and is relatively cheap, as I recall.
Depending on how you drive, you also might want to try a set of the Hawk blue pads. Do stay away from silicon brake fluids as they make for a softer pedal and require the removal of ALL old fluid, which is next to impossible. Chad and others sell mondo-performance brake upgrades, but get ready to throw some serious cash down.
Above all, good luck and exercise caution, both in the brake fitment, and to protect your paint while doing the work.
-Will

[Otto-valvole-per-tutte]

Terry has a series 2 so that shouldn't have brakebooster.

Only series 1 Montecarlos had brakebooster on the frontwheels.

The series 2 had bigger discs, 251 mm on the front and the back 8O .

Cheers, Pieter

[Bazza]

My Series 2 Monte had Tarox Discs on the back when I bought it but standard on the front and I have been unhappy with the brake feel. I have now fitted Tarox on the front as well and there is now more "bite" at the front, but a serious stab on the middle pedal locks the back brakes. Chad (Monte Hospital) suggest removing the balance valve at the rear. He should know - but I would value other opions.

Secondly - I have badly damaged the front caliper rubber piston gaiters and the Monte Hospital can't supply. Anyone know who supplies these (preferably in the UK).

If your rear brakes are locking up then the problem must lie with the front circuit. As you have damaaged rubber seals in the front calipers, I suspect that your problem lies there. It shouldn't be too difficult to find a seal kit - they are the same as almost all of the early FIATs with front disc brakes.

[Wallace]

Agree with Baz. With the same type of discs front and back, the front should definetly lock up first; the worst scenario is to fit Tarox on the front ONLY - I had this for about 2 days before I fitted them on the back as well - it will lock up VERY EASILY otherwise !!!

I personally would not remove the limiter - in fact it might be this component at fault. Locking up the front will at least keep the car in a straight line. Locking up the rear will result in a spin. Lancia knew what they were up to fitting a limiter in the rear circuit.

Just my two penneth worth. .. . . . . ... .

[Will]

OK, your brake system is different than ours, I think we established that- but how can the gaiters cause a failure?
If water got in there and froze up a caliper maybe, but those are just dust seals- at least on our cars. What am I missing?
-Will

[Wallace]

Yeh Will - but you're forgetting the amount of rain and damp we get in this *^$£-hole of a country !!

The pistons are only chrome platted and can and do rust .. . .the rubber seals have got to be over 20 years old as well if they havn't been replaced.

The wedges holding calipers in place often stick up for much the same reason - rust ! I've often thought of getting them re-nikel platted to smooth them off a bit - shouldn't cost more than a couple of notes each.

[Will]

Wallace;
Zinc chromate actually works better than nickel for anti-rust, i use electroless nickel and it takes a pretty good build to be rust-proof. Zinc chromate is faster and cheaper. Available from many places, I use Caswell.
I know a lot of the UK cars spend a lot more time in the elenents too, I would think a plating setup would be a necessity for you guys.
I know you do a lot of machining/fab work already. I'm sure you would find it easy by comparison.
-Will

[Wallace]

Just thinking that nickel is tougher . . so wouldn't wear off so quick .. .I've had a go at platting - but the results were always a bit patchy (just me I guess .. .) - I tend to get someone else to do it or usually make the thing out of strainless !

[Bazza]

Just thinking that nickel is tougher . . so wouldn't wear off so quick .. .I've had a go at platting - but the results were always a bit patchy (just me I guess .. .) - I tend to get someone else to do it or usually make the thing out of strainless !

Wallace - it wouldn't be too difficult to make some brake pistons from stainless steel - I know it would be more expensive but at least it would be virtually everlasting.

[monte_giallo]

[quote="Wallace"]
The wedges holding calipers in place often stick up for much the same reason - rust ! quote]

Nothing a sharp blow with a hammer can't usually move :wink: Personally, I use Copaslip on reassembly.

[Terry W]

Thanks for input on this one, but just to clarify - I only damaged the rubber on re-assembly after installing the front Tarox discs - my own stupid fault - but my point is that there was no time for any muck to get in and the front are definitely working. Indeed the front are biting better now I have the Tarox fitted, BUT the rear still lock on hard breaking.

Can we just go back to exactly how that limiter thing works. Does it react to the car nose diving under braking or does it just limit the pressure to the rear all the time? Can someone advise?

Also - can anyone be more specific about which Fiat has the same rubber dust guards?

Thanks - Terry

[Bazza]

Can we just go back to exactly how that limiter thing works. Does it react to the car nose diving under braking or does it just limit the pressure to the rear all the time? Can someone advise?

Also - can anyone be more specific about which Fiat has the same rubber dust guards?

Thanks - Terry

The seals are the same as: Panda, 127, 128, 131, 132, early Uno all types except Turbo & Diesel and X1/9 (and probably a few more that I have forgotten).

The limiting valve on S2 Montes is the same as fitted to early Pandas - it limits rear braking by an internal weight which slides forward under g force to reduce the rear braking. Having said that - I have never heard of rear brakes locking up on S1 cars with the servo disabled which have smaller front brakes and these cars have no rear brake limiter.

[Wallace]

Don't think so ! . the limiter is just that - it limits the pressure hitting the back calipers with a heafty spring/piston arangement. There's a graph in the manual showing input vs. output pressure. I't's equal up to a certain pressure, then it reduces it - theres nothing fancy in terms of compensating for deceleration etc.

At least I don't think there is !! :wink:

[Bazza]

Don't think so ! . the limiter is just that - it limits the pressure hitting the back calipers with a heafty spring/piston arangement. There's a graph in the manual showing input vs. output pressure. I't's equal up to a certain pressure, then it reduces it - theres nothing fancy in terms of compensating for deceleration etc.

At least I don't think there is !! :wink:

Well I stand corrected then! Unfortunately I don't have any literature on the subject so I am just going from memory.

[monte_giallo]

Racing my S1 Monte I have to retain the standard discs (rotors) and calipers. My standard pedal/master cylinder (no booster) is absolute rubbish and even dangerous. Using fairly sticky Yokohama tyres I need more brake pressure, but I also need less pedal movement so I can heel and toe.

I am therefore thinking of replacing the master cylinder with Mk II Golf MC and booster, piping some vacuum up to the front. If I lock up the front or the back too soon, I will fit a pressure device to equalise braking effort.

Anyone tried this, or have any ideas why it wouldn't work?

Thanks!

[Wallace]

Dunno. But what IS possible is to make up a new pedal box to take twin mc's with a bias bar - it's now all built and tested - and getting powder coated this week before final assembley. As I've now fitted big, Wilwood 4 pots all the way around I needed more fluid displacement - roughly 1.5 times. so I've used twin 1" master cylinders. The ratio of fron' to back caliper piston size is pretty much the same as standard - just more of it !! I think this IS important. Just fitting bigger calipers front or rear is going to ruin the balance of all - unless you vary the size of the mc's to compensate.

Clutch mc is 3/4" as original.

What would be amusing is to get a couple of Montes (sereis 1 and 2), try braking in the wet on a skid pan somewhere with the servo and bias valve connected/bypassed respectively. .. . any takers ??

[monte_giallo]

The ratio of fron' to back caliper piston size is pretty much the same as standard - just more of it !!

Sounds very tasty, Wallace (& ABS too, I dare say!).

You must have 2.66 times the original caliper piston area with your Wilwoods? How does your system compare with Ken Haven's?

[Wallace]

Han't actually installed and bled them yet . . . but - the pedal box fits in the same place, pedals are actaully monte ones so from the outside nothing's changed - i.e. they don't need any bodywork mods - just a straightforward swap.
Ken's uses the Tilton brackets which needed a bit of cutting up of the front bulkhead to fix. And I'm not sure how he's done the accelerator. It IS a tight fit though. The mc's need to be milled down to make them narrower AND there's no room to put the clutch MC on the left - it has to go on the right with the central pivot now acting as the actuator .. . .but you know how I love a challange !

[Bazza]

Wallace - I think you may have gone a touch too big with the master cylinder bores. Integrale Evos have Brembo 4 pot calipers with 44/38 mm. pistons and they use a 7/8" master cylinder.

[Wallace]

Possibly - but I had to start somewhere - and at least I can change them !!! And I know everyone says it's not a good idea - but I'm using (or will be) silicon which is more compressable. And there's the extra plumbing with the ABS.

I did work out the ratio of the standard brake piston area to the wilwood ones - and 1" mc's were the the closest to give the same ratio as the 3/4"standard mc (if you follow me .. . . ).

If it's too big, too small, doesn't work, whatever - I'll tell everyone !!!

[Otto-valvole-per-tutte]

Barry,

Shouldn't the HF4WD brakes be a direct swap with the Monte front ones?

:idea:

Cheers, Pieter

[monte_giallo]

I can understand the techie pleasure of massive, ventilated, cross-drilled discs with 4-pot calipers and the rest, but actually (to be boringly realistic for a moment) in a season's racing I haven't yet had a problem with the discs and calipers themselves. I've got little series 1 discs and am using Mintex 1144 pads.

The only time I've ever had any brake fade at all was at Cadwell Park, described as the English Nordschleife (i.e. twisty and very hilly) when the throttle jammed open for the last five laps and I had to hold it on the brakes. At the end of the back straight on the long circuit things went very soft and I went a bit sidways. I still managed to finish. It's the MC I hate.

Of course, with two people and full luggage, coming down the Rockies/Alps might be more testing.

[Wallace]

You probably dead right ! I just "fancied" them - that's all ! And if THAT engine works - I'm going to have a smidge more BHP than your engine .. . .

I also want to permanently "cure" the handbrake. But that's another story. :lol:

[monte_giallo]

A smidge more: I'll say. Twice mine, I expect!

Though, to be boring again, you'll only need better brakes if you translate that into significantly higher top speed: 970kg at 130mph is the same whether it has 140 or 240bhp. Can you get higher axle ratios?

I don't know how Montes are above this speed. I would expect some front lift - I don't want to see you doing a Le Mans Mercedes down the A1!

[Wallace]

It's got a volumex diff. - so yes - it should go a bit faster for the same revs. I've had the thing up to 130 and it felt fine - but the noise from the engine is something else - you really do start to wonder if you remembered to tighten up all those bolts correctly . .

I suppose I had had to justify them, it would be that there's a velocity squared thing in there somewhere if you work out the amount of heat the brakes are going to dump. So the top wack doesn't have to be a great deal more to seriously increase the heat (not that I'll ever do those speeds anyway . . ). And all the Porsche boxsters have big 4 pots, so why not mine ???

To be really honest - it probably is total overkill/overspend .. .but since when did any Monte/Scorp owner ever do otherwise ??? (something Mike said about sinking 10,000 bucks in a car worth 2000 . . . ).

[Bazza]

Barry,

Shouldn't the HF4WD brakes be a direct swap with the Monte front ones?

:idea:

Cheers, Pieter

Short answer is I don't know Pieter but they are similar to but larger than Uno Turbo brakes which are almost a straight fit on an S1 Monte so maybe they would be easy to fit on an S2.

[Otto-valvole-per-tutte]

Barry,

Some studying 8) on :

http://www.tarox.com/Product_Listing/Fiat/fiat.html

makes me think that 257x22x51 brakes from Fiat (Croma) or Alfa (164) can be used :twisted: .

The Fiat Coma even has 14" wheels so fitting the caliper will be no problem.

I think that moving from standard size 251x11x51 to 257x22x51 and ventilated will be a nice improvement. Shall monday at work dig some info up from what mastercilinders are used on Croma's and 164's. Also curious about the calipers being used.

Cheers, Pieter

p.s. does anyone overhere know the sizes (diameter) in mm's for headmastercilinder and brakecaliper pistons front/rear for a Montecarlos S2?

[Terry W]

This discussion on brakes is interesting - accept that it is demonstrating that I am in a very different league to some of you guys in both knowledge and ability!

Just to close off the issue that I started this discussion with- ie my problem with rear brakes locking on a series 2 (no servo).

From what Wallace has stated - the limiter SHOULD reduce pressure to the rear and prevent them locking up. Thus removing the limiter will only make things worse. It seems to me if anything that I should try replacing the limiter (truth is I will get someone else to do that job!). Is the other alternative to fit a variable limiter such that I can fiddle with it until front back seems about right. However - as I have only just fitted the front Tarox discs - presumable I should give it a few miles for the front discs and pads to "bed-in" as that will increase the front braking and thus the problem may right itself. However the Monte is not going back on the road for a while so we shall have to wait and see.

Lastly - one other thought. As my car has been modified quite a bit, I have 225/50R15s on the back and 195/50R15s on the front. I was pondering as to whether the fact that the back tyres are wider than the front would mean that the bigger "foot-print" of rubber on the road would equate to less weight per sq cm and thus make the wheels more likely to lock. Is my logic sound or am I talking out my rear end?

[Will]

Terry, I'm sure it would save you a great deal of effort to plumb in a proportioning valve if you are changing several factors. With this fitted, you can do just about any mods you like and still be able to adjust to compensate for them.
Some of the discussions I see on this thread regarding ratios of MC cylinder area vs. pot cyl area are really not terribly relevant, as it translates into a few ounces more or less of pedal effort.
Pedal effort IMHO is a negligible factor, particularly since a slightly small MC which requires a bit more pedal effort will also tend to make the pad pressure easier to control. You might get better feedback from a bigger MC, but you are also more likely to lock the brakes...ooops!
In my opinion, getting all four wheels to come close to the limits of grip at the same time is a lot more important. Since you want to run the same pad compound at all four corners to avoid the balance changing as the brakes heat up, the easiest way to balance the system is with a proportioning valve. Dual cylinders that use a balance bar work as well, but I have yet to see one where you don't have to stand on your head to adjust it. Also, these systems (at least some of them) tend to bind if you pump on an open cylinder, which can make bleeding a real pain, as you will probably have to do both circuits at the same time. the trick is to get proper adjustment of the heim joints on the bar- no easy task in that position.
I'll also mention that if you do go this route, Tilton makes (or used to
) a remote cable and knob for adjusting bias.
You should read the HP Books' "Brake Systems- OEM and racing Brake Technology", I think you will find this to be an invaluable reference as to the types of choices available to you. I know Wallace did ABS, which is covered here as well if you are interested.
Good luck with it, post the pics when you do it!
-Will

[Wallace]

I think Will's right (mostly .. . !) - getting the balance right is moost important. Fitting larger calipers up front, whatever which DON'T keep more-or-less to the original piston area front to back ratio (I think about 1.6 to 1) results in buggered brakes. I know 'cos I've done it.

The only other thing to make sure of is that you have enough fluid displacement in the mc's to be able to jam the brakes on - with a standard Monte mc, there simply isn't enough fluid to lock the wheels hard on without the brake pedal hitting the floor with Wilwood 4 pots fitted all round - and that's an MOT failure for a start. Hence the seperate mc pedal box I've built. It does aalso have a bias bar and the option of fitting different diamter mc's - but this wasn't the main reason for building it. If I could have brought a larger diameter "standard" one - I would have !!(I did toy with the idea of borring it out - but decided against it in case it leaked/failed at an inconvenient moment . . . . .).

Fitting a bias valve to a standard pedal box is quite easy - I've uploaded a photo of the one I did a few years ago in my photo section. The only thing to be aware of is the lack of clearance on the left hand side (on UK right hand drive montes). If you bolt it on the left - the heater valve won't clear which makes for chilly motoring ! Bolt it on the right !!!!!

ABS is something else altogether - when I finally finish of EVERYTHING else and the car actually runs . . . . . . .

[Otto-valvole-per-tutte]

Wallace,

Tried to mail you but your mailadres didn't work :cry: .

Got another one?

Cheers, Pieter

[Ken H]

I've got the remote bias adjust on my Tilton pedal box which for an extra $50 is the only way to go - allows adjustments, even while driving if you're brave. I do suggest you first check the total number of turns so that if you get all messed up while driving that you have some way to get back to a 50/50 ratio.

One thing to keep in mind (that I actually forgot - oops!) is that with a pedal box like the Tilton that has a balance bar and two separate master cylinders, the force applied to each MC is only 1/2 as much as with the stock MC. You will need to adjust the MC area downward to compensate. As Wallace said, with a standard pedal box you have a zillion size options so it's easy to change if you're not happy.

Personally I think pedal force is a big concern, because there is a limit to how much force your leg can apply, and you want it to be comfortably more than what it takes to lock 'em up. I remember an experience driving a big '70s American car down a hill and having the engine die and power brake vacuum run out. Not something I want to repeat! Pedal force and fluid volume and pedal travel are all linked together thanks to basic physics. I based my MC size by starting with the original system, and comparing both the original pedal leverage and MC/caliper piston ratio to the new pedal leverage and piston ratio. Theoretically I should still have the same pedal force as I did before (assumes the same rotor size and pad friction, as these also enter the equation if they've been altered). It's still theory though until tested, something I hope to be able to do before summer.

- Ken

[Wallace]

Ken - I keep telling myself I'll have my car running by the summer - just not sure which one :wink:

[monte_giallo]

As Wallace said, with a standard pedal box you have a zillion size options so it's easy to change if you're not happy.
- Ken

That's interesting, Ken. I need to improve my brakes for racing in two ways:

1. I want more braking force, as with sticky tyres I can hardly lock up, which I sometimes need to do (if I spin, for example!)

2. I want _less_ pedal travel, so that I can heel and toe.

These things are mutually incompatible without a servo, so I am planning to fit a big MC with a servo and load proportioning valve. I was planning to fit a Golf MC, which would involve a lot of fabricating. Do you know what MCs would fit the standard pedal box and have larger pistons?

I guess I would have to fit a remote servo if I use the standard pedal box? Or two servos?

[Will]

I'd suggest grippier pads before a servo, especially on a race car.
The problem with a servo on a racer is twofold. First, there's the extra weight. Second, assuming that it is a vacuum servo, if you get jammed at WOT you will effectively have no brakes, even in situations like staging, unless you have a line lock, your brakes will fade off. Mind you this is the front circuit we're talking about.
Remember guys, in addition to MC sizing, and caliper sizing, if you are fabbing from scratch, you can also change the lever geometry to get more or less leverage on the MC.
Irrelevant in most cases, but overlooked in others.
-Will

[monte_giallo]

I'd suggest grippier pads before a servo, especially on a race car.
I've already got Mintex 1144 pads, which are a pretty grippy competition pad. Also don't forget, I want less pedal travel, not the same travel.
The problem with a servo on a racer is twofold. First, there's the extra weight. Second, assuming that it is a vacuum servo, if you get jammed at WOT you will effectively have no brakes, even in situations like staging, unless you have a line lock, your brakes will fade off. Mind you this is the front circuit we're talking about.
Weight is not a problem: I'm already at the minimum weight limit.
WOT is a potential problem, but if I have two servos, it would be reduced, also I could fit an extra vacuum tank.
Not just the front circuit: I'm talking about servos on both circuits, which, if remote, I guess would mean two servos?

Remember guys, in addition to MC sizing, and caliper sizing, if you are fabbing from scratch, you can also change the lever geometry to get more or less leverage on the MC.
Irrelevant in most cases, but overlooked in others.
-Will
Using the same pedal box, the only geometry change would be a longer pedal, which would mean more pedal travel, which is the opposite of what I am trying to achieve.
Come on, Will, I thought you liked thinking out of the box!

[Ken H]

I've already got Mintex 1144 pads, which are a pretty grippy competition pad. Also don't forget, I want less pedal travel, not the same travel.

The main problem with the Scorp/Monte brakes for track use (esp. with higher HP) is thermal capacity. Those stock rotors are pretty darned small, and drilling and slotting and pads can only do so much. I'm a big believer in larger diameter vented rotors (front AND rear), allows you to really use the brakes hard which equals faster lap times. Ask my passengers about their racing harness bruises!

More HP = more braking capacity needed. If you think of it in terms of energy it makes sense. That hopped up engine will put a lot more energy into your car as you go down the straights, and it all has to be dissipated by the brakes. I've never had any fade with 10" vented rotors front and rear even on tough tracks like Laguna Seca. Vented rotors 1) cool faster and 2) have more mass so they heat slower.

When I said earlier that "with a standard pedal box you have a zillion size options" I meant a standard Tilton/Wilwood/etc. racing setup, not the stock Scorp/Monte. Sorry for any confusion. I don't know of a bolt-in larger MC that will fit the stock pedal box, and would be surprised if one existed.

One more thought: I'm guessing that a good bit of your pedal travel is from caliper flex. You may find that with stiffer calipers and larger rotors that you won't need a servo. Seems like overkill for a 2100# car.

- Ken

[monte_giallo]

The main problem with the Scorp/Monte brakes for track use (esp. with higher HP) is thermal capacity. Those stock rotors are pretty darned small, and drilling and slotting and pads can only do so much. I'm a big believer in larger diameter vented rotors (front AND rear), allows you to really use the brakes hard which equals faster lap times. Ask my passengers about their racing harness bruises!

More HP = more braking capacity needed. If you think of it in terms of energy it makes sense. That hopped up engine will put a lot more energy into your car as you go down the straights, and it all has to be dissipated by the brakes. I've never had any fade with 10" vented rotors front and rear even on tough tracks like Laguna Seca. Vented rotors 1) cool faster and 2) have more mass so they heat slower.

One more thought: I'm guessing that a good bit of your pedal travel is from caliper flex. You may find that with stiffer calipers and larger rotors that you won't need a servo. Seems like overkill for a 2100# car.
- Ken

Actually Ken, I have never had any problems at all with fade at any UK track, although our ambient temperatures are probably lower than yours. Funnily enough, I am very happy with the rotors and calipers, which is just as well, as (and I should have told you) in HSCC racing in the UK we are obliged to retain the standard Monte Series 1 rotor. I believe they can take a good bit more load! Mind you, I don't take a passenger ;-).

Certainly some of the travel is push-rod slack, plus flexing in the pedal box. No one (not even Chad) has had much luck altering the pedal box. If I can't get a higher capacity MC, I'll look at a new design of MC altogether.

Do you have a view about possible lack of vacuum problem due to WOT conditions in racing that Will expressed?

[Wallace]

Actually - I have ! Or rather built a new one around the exisiting pedals. Reasonably straightforward and works (on the bench at least) a treat.

Basically copy the standard one, bolt the brake mcs to the outside with the clutch mc on the right. you'll need to mill off the Tilton mcs to the minimum as well.

Chad's after a look so he can bash them off !!!!

Paul - if you WANT a spare power steering pump, come and get it !

[Ken H]

Do you have a view about possible lack of vacuum problem due to WOT conditions in racing that Will expressed?

Not a problem in my experience. I don't race but I do a lot of track days, currently in a twin turbo Audi with power brakes. I'm using WOT as much as any racer, and I've never had a problem. The booster maintains enough vacuum for several full stops, so unless you're constantly dabbing the pedal while holding WOT, you should be fine. And if you did have problems, a vacuum reservoir (or worst case a vacuum pump) would be an easy cure.

- Ken

[monte_giallo]

Not a problem in my experience. I don't race but I do a lot of track days, currently in a twin turbo Audi with power brakes- Ken

Audi & Monte is a good combination: I have a UR quattro turbo (MB) as a road car.

[monte_giallo]

Actually - I have ! Or rather built a new one around the exisiting pedals. Reasonably straightforward and works (on the bench at least) a treat.
Paul - if you WANT a spare power steering pump, come and get it !

Thanks for the offer, Wallace. I'll check mine when I delve into the rack problem on the Beta.

I'd be interested to see pix of your new MC layout too!

[simon_fdl]

Here's an old post of mine from egroups. The brakes still work fine,

Hi All,
Regarding brakes.
I have two S2 Montecarlos - daily driver and race car. As far as road use
is concerned, the standard brakes (without booster) are adequate. I have
experienced front wheel lockup several times - typically during emergency
or near emergency braking from low speeds (less than 60km/h).
There are two causes:
1. The weight distribution is rear biased, and at low speeds, there is not
enough forward weight transfer.
2. 'Economy' tyres which give good mileage just don't have enough grip
bearing in mind the lack of front end weight. I now use the best tyres I
can afford - I agree with Chris' comments - tyres are what ultimately stop
the car.

I am the consortium leader for Montecarlos in the Lancia Club of South
Africa, and almost all our dead Montecarlos met their end in low speed,
front end collisions.

Road use:
1. Good quality (soft) tyres. Go too wide and you reduce tyre/road contact
pressure.
2. Braided steel hoses.
3. Ferodo or ATE pads. Anything really as long as quality is ok. EBC greens
are too soft for race use.

Now for race use:
The standard setup is not good enough.The brake fluid boils and the brakes
fade. I have also experienced the hard-soft-hard pedal.
My current setup has solved the problems - it must have, I won last time
out. (Ok, I broke handicap time, but who cares :-)
Current setup:
Goodridge braided steel hoses - use them on the road as well because 20+
year old rubber brake hoses are beyond their service life.
Fiat Uno Turbo front discs and calipers. The disc diameter is 5mm (or so)
less than stock, but the Uno Turbo discs are ventilated. This setup will
bolt straight onto S1 front hubs. I had to get Fiat X1-9 front hubs.
Why the Fiat Uno setup - I can't afford Tar-ox or Wilwood.
Good quality brake fluid - I'm using Motul Race fluid. 600 degrees
non-silicone.
Air ducts onto front calipers.
With a complete spare pedal box assembly and the complete brake pedal from
my race car, I was able to do some bench testing and find the cause of the
hard-soft-hard pedal.
The S2 pedal assembly differs from the S1 and Right hand drive differs from
Left hand drive. In South Africa we drive on the left - ie right hand drive
cars.
The S2 brake linkage at the top of the pedal has a kind of parallelogram
structure - as far as I can see, designed to maintain a straight push on
the M/C piston throuhout the pedal travel. Bench testing was done with the
M/C outlets plugged, but with some fluid in the M/C. I felt that
compressing the air in the M/C duplicated (to some extent) M/C behaviour
under normal circumstances. Anyway, this is what happens when the pedal is
pressed :
First the pushrod starts to move the M/C piston. (Hard pedal)
Then the parallelogram linkage "collapses" onto the cam section
nylon/teflon bush that the brake pedal pivots on. The pedal moves during
this phase, but there is little or no M/C piston travel. (Soft pedal)
Once the "collapse" is complete, pedal travel results in M/C piston travel.
(Hard pedal)
The solution to this problem was twofold
1. Increase pushrod length - I couldn't believe how sensitive the system
was to changes in pushrod length. I'm sure Chad's kit for the S1 would be a
great help here. The M/C dual port front circuit conversion is also worth a
look.
2. Stop the linkage "collapse". After some trial and error, I found that if
I locked the linkage in the "almost collapsed" position that the push rod
maintains an almost straight push. This lockup was managed by welding some
3mm plate onto the top of the pedal assembly and bolting this to the holes
in the back part of the parallelogram linkage - where the anti-rattle
spring normally fits.
It works for me anyway. Three 30 min practice sessions, a 15 min qualifier
and a 10 lap race, no brake fade, no soft pedal, no problems at all.

I have used drilled discs - did improve things, but not much.
Drilled/slotted discs - be careful here - I was given a set which had holes
in two rows on the same radius and I split a disc on the racetrack. The
slots also co-incided on the inner and outer of the disc - they were
showing signs of cracking there too.

Lose the booster, but make sure that there is minimal (2-3mm) free play
before the pushrod starts moving the M/C piston.

When driving slowly, make sure you leave enough room for braking - if you
don't believe me, compare the low speed steering effort with a FWD car with
no power steering.

Cheers, Simon - racing next weekend at Phakisa racetrack (where the South
African round of the MotoGp is held)
Useless fact - the first time I went to Phakisa, I stayed over in a guest
house (it's a small town, ok) and they gave me Valentino Rossi's room.
Whoo-Hoo!

[Snakeman]

Simon,

Dmake any modifications to your rear brakes when racing, or do you keep it standard :roll:

S

[simon_fdl]

Hi,
Rear brakes are standard.
Cheers, Simon

[Will]

....if that's the case, a softer spring, or shorter spring (snip) might do the trick. The major problem I see with that is there is bound to be a major difference between wet and dry braking. Unless you are figuring the discs are wet also, therefore same pressure can be applied?
Hmmm.....