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Old 23-09-2007   #1 (Post Link)
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8 PISTON Brake upgrade for Alfa GTA !

Or HOW to challenge a Lamborghini for 100 -0!
Or Beat the super cars not on 0-100 but on 100-0 !

The photos are from my car. These are the calipers that Lambo is using on both Murcielago and Gallardo. They are very hi-tech, made by Brembo. They are huge but they have some unique specs.

About 2.9 kilo each from special aluminum-magnesium materials.
They use 4 small pads for every caliper and not 2 big like 4 or 6 pot calipers. That make them more accurate and easy to respond even
on small brake pedal movements.
But since we have 4 pads driven by 2 piston each- one small and one big- when you push the pedal more the bigger pistons take action and give very firm braking power.
And this happens plus 4 times for the 4 pads plus 2 times for the 2 calipers. So you can have a very progressive braking and also very
powerful when you needed. Thats called depth on braking.

Braking is not only if you can stop or not for that distance, Or how
to make it shorter. Is more . Is also how deep can you brake in a big
turn. How late can you brake? And in which position can you place
the car before start to accelerate?





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Old 23-09-2007   #2 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Yes beautiful indeed - very impressive. Looks like a very tight fit, even behind those 18" wheels.

I would hate to think of the cost but if you have the power then big brakes are essential
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Old 23-09-2007   #3 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Pacs,
An easier fit than you can imagine, using the correct rim offset that is. I drove the car, the braking performance is fantastic & very confidence inspiring. I managed to carry some very high speeds into long sweepers on the main Attika highway. Me GTAFAN & 2 passengers, cruised through there between 210-240km/h, continuous.

Some tasty mods to his car, nice coil overs, strut braces,brakes,18" rims, Q2 LSD & yes the by now infamous Monster TB,BMC CAI kit, Supersprint decated exhaust & remap. His car is great but next time I drive it he will have my old stage 4 Glenwood Motors 3.7L V6 in it, now then it should really be exciting.
Should be able to give a Lambo a run in the 0-100km/h dash then instead of the 100-0?????
Monstro3.7
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Old 23-09-2007   #4 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Nice one! Any photos of the whole car with the brakes. I like to how standout it is!
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Old 23-09-2007   #5 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Very interesting topic.
Sounds like the calipers are not that heavy, but how about the discs ?
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Old 24-09-2007   #6 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Have you fitted a brake bias proportioning valve ?

Your front to rear balance should be changed fairly radically by that mod.
Have you taken any measures to keep an optimal balance?

Cheers,
TB
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Old 24-09-2007   #7 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

TB, he has big Brembos on the rear too
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Old 24-09-2007   #8 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Gents,

There is no brake proportioning valve in the car as per some competition type set ups that I've run.

GTAFAN can ellaborate on the details but the tech that did the work in Greece is 1st class.
Changes within the system MUST exist, I never got into that. I drove the car at some pretty high speeds, we spoke technical until my wife, who was with us got a little board with our persistent shop talk. You know how it is????

What made the system impressive was the progressive brake feel & balance, far better than what I've experienced with the MOV'IT system.

So I would like to know some details & I plan to have the car fitted out with the same kit when I move it to Greece in 08'. It's that impressive!!!!!

So lets hear what GTAFAN has to say.
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Old 24-09-2007   #9 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Originally Posted by Trailbraker View Post
Have you fitted a brake bias proportioning valve ?

Your front to rear balance should be changed fairly radically by that mod.
Have you taken any measures to keep an optimal balance?

Cheers,
TB

Yes, it would be interesting to hear about the changes made to the system.. I can not understand why the brake bias is not adjustable..It must mean they either pre-balanced the system, or just slapped on some Bling Hardware..

Particularly intersted if the ABS software was modulated, and how(scan tool)..Is the Master brake cylinder running on standard sized pistions? Has the brake lines ben upgraded? What are the total surface area of the 4 small pads mentioned, and was the 8 piston calipers originally made for 365mm disc?

What about the car itself.. is it optimized for this type of extreme braking system? What tires are used.. Is it corner weighed, and to what values front to back? How was the suspension set up to optimize the brakes?
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Old 24-09-2007   #10 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Peter,
I will be interested to hear more details as well from my friend GTAFAN. I can tell you what I have observed, from checking it out, obviously as much as is possible without getting the car on a lift. The balancing of the brakes is definitely in the system. Details we can get from GTAFAN, although I suspect that the brake tech will be the one who knowns all the details.

The calipers are engineered for 365mm discs as per fitment to the Lamborghini. The discs & bells on the car were made up by AP Racing.

It's definitely NOT a bling system & I drove the car 65km on the main Attika highway at seriously high speeds.....no fade..fantastic balance.
I've had some serious brakes on my cars, especially the forced induction M3's. This has been the best system that I've experienced on the road ever.
Monstro
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Old 24-09-2007   #11 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Sorry Peter,
GTAFAN's car has Intrax adjustable coil overs which look I must say identical to the Autodelta Sport Corse adjustable coil overs fitted to my 147GTA.
These are adjustable but again he will have to tell us how it's set-up. The present set-up is definitely a good road track compromise. He has strut braces & then an interesting rear re-inforcement engineered for the rear.This was custom, done by the Greek techs who set the car up. It does work though.
Tyres at present fitted to the 8.5X18 BBS CH rims are Yokohama Parada 2's but his tried various brands from Pirelli's to Michellins. I don't think he gets much more than 10000km's from tyres, not at the speeds he is driving.
It's one of the first GTA's produced & he has had it for many years, it's covered 132000km but it's a very clean car, well maintained. When I first saw the car & I'm really fussy, it looked like a car that's covered around 35-40000km.It's that clean.
GTAFAN has had alot of experience with the GTA, over a long distance.His had a couple of suspension set-ups, tyres, wheels etc.Good feedback for other members in this regard.

Like us his an enthusiast, he has had his share of being robbed by some tuners & the like.
I just wish there were not such vast distances seperating us all as it would be great to get together with our cars. So I look forward to The Ring in 2008.
Regards,
Monstro
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Old 24-09-2007   #12 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Like my friend Monstro said there is no proportioning valve in the car .
Our ABS reads automatically the Difference and cuts out the rear system every time to keep balance.

But I should start from the beginning my brake story, because I have
done many changes that most of the people wouldn't imagine that could be done.

With the GTA I first started with sport pads and metal hoses, just to
give a better feeling. But that was not enough. The GTA is very heavy
front car and 240km is very easy to have. So I was looking for something Better.
Just about that time I met a very enthusiastic brake technician. I was crazy to see some photos from his work. That was
improving brakes on Ferrari's, Porsche's,evo's, sti's and a lot of racing stuff. So I asked If we can do something in to my car.
He explain to me that even the 330mm alfa upgrade was not so big improvement, because : The bigger caliper is not so big finally. Why?
is using the same piston diameter 38-42 as the small one. just have
a bigger body to be able to take the 330mm disk. The only improvement is the bigger pads, and the bigger disks that has 32mm space between instead of 28mm the old 305mm. BUT this gain is not
so big, because 330mm disks are heavier(10,5 kilos) and much heavier than 305mm(5,5 kilos). So the same size pistons have to stop a double weight disks.
So I had to find a lighter disks , and decided to go for 2 piece with aluminum bells. But said to me that he could place an even bigger
4piston caliper from a Ferrari Maranelo 575 !!! Is that possible? Yes.
And I got my first Ferrari braking system in my Alfa. These calipers
are from the biggest 4 piston. They use 38-46mm pistons with special ceramic hats. And are a bit lighter than Alfa's 330 calipers! We placed 2 piece disks 330mm with alu bells- 5,5 kilos each!
So that was an improvement !!!
Much more progressive, much more powerful and at the same time much more lighter than the OEM.

I have some photos from that to see before we speak more about braking...


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Old 24-09-2007   #13 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

GTAFAN,
Even I'm suprised, never knew about the Ferrari set-up. You have done with brakes what I have done with big bore Alfa V6's it seems? Tried all sorts of set ups.
Monstro
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Old 24-09-2007   #14 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

I do agree the 330mm is heavy. I still remember when I picked the parcel (2 calipers and discs). I almost dropped the box and it needs to be handled by 2 people.
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Old 24-09-2007   #15 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Originally Posted by Pascs View Post
TB, he has big Brembos on the rear too
Sadly that doesnt even out the score..not even close..The 147/156 GTA is very nose heavy with centre of gravity far out front. While the longer wheelbase of the 156 is a destinct advantage, you are always fighting the physics during hard braking. In the end brakes dont stop the car, Tires do.. so you really need those rear tires in play if you want ultimate brake performance.

My own 3.2 is a good example of what happens when you got too beefy brakes. The original system can't cope with the bias ratio, too much is allocated to the front, physics act, and the rear goes light..... So you are sometimes left with the limit of adhesion of basically two tires and not four..Brakes still bite like a Motherf....and everyone that rode Pax with me commented on them.. but it's mostly held together by the sticky tires, and brakw torque is still nothing compared to properly biased brakes on a properly track oriented car. Trailbrakers car is a good example..156 Challenge Race cars on stock 285mm system with Adjustable brake bias are another.. you can brake shorter and more precise. You really need to experience different 156's braking at maximum before you can compare Apples to Oranges.

In my case I am going three ways to solve the brake bias problem. First i must get a brake porporioning valve or perhaps adjustable brake bias system. Secondly will have to upgrade the coilovers to KW III or similar and get it cornerweighed..Making it possible to adjust the compression should hopefully weed out some of the issues. Thirdly I may have to see if it's at all possible to fit the GTA master brakecylinder to the system. From Eper it doesnt look promising..but anything is possible i guess..Just worried the ABS software will get even more confused, and hardly anyone knows how to access and revise ABS software.. All this is done to in an effort get the proper brake Bias. Proper brake bias and proper suspension balance means more Rubber has contact with the surface More rubber in contact with the surface means you can stop the car quicker.. In the end the tires are the single most important factor on a high performance car.

Unless the guys who fitted that impresive looking Lambo system did some drastic moves to optimize balance, not only of the brake bias, but balance of the whole car, then I am willing to bet the pink slip of my GTA that overall brake torque is drastically reduced compared to a well proportioned stock 330mm system like TB's.

In any case, knowing that the 330mm system easily outperforms the limit of adhesion for any street tire with just upgraded pads and brake lines, it all seems a bit pointless to me to sticking on those huge exotic brake caliper and discs.. It looks great, but apart from weight saving which is always great, and improved pedal feel, which is also great, it's pretty much Bling unless you really really went to town on the engineering and track testing side of things... Money is imo better spent on upgrading the stock system, fine tuning suspension/balance of the car, and practising your driving & braking technique on track.

If those 330mm Cabon discs didn't cost silly money, i'd say there was a significant overall performance gain waiting.... Especially if you add lightweight 17" wheels and high end Semi Slicks like Pirelli Corsa's..
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Old 24-09-2007   #16 (Post Link)
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Re: 8 PISTON Brake upgrade for Alfa GTA !

Just saw a lot of post was made since i started writing the above last one.. Am working right now to was sort of typing 10 min on 20 min off, and wasn't looking for new posts meanwhile..... looks like a lot of information was posted, so cheers for that.. I'll look it over later tonight when i have more time.
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Old 24-09-2007   #17 (Post Link)
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