03-06-2007, 12:21 AM
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Join Date: Nov 2004
Posts: 22
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Ready?
 Quote:
Originally Posted by juultje
So my projectcar is deliverd at the paint shop. They are also going to put new floorpans in in.
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03-06-2007, 06:50 AM
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Join Date: Feb 2006
Location: Rijsbergen, Holland
Posts: 60
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The floorpans are normally available. If you need them sent me the details of you're car and i'll make you an offer,
My car is painted in primer waiting for the paint-job. Work for customers has kept me busy so i'am a little behind schedule.
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03-06-2007, 08:05 AM
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can you post some pictures as I always like to see good cars like the Giulia GTV coming to shape.
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04-22-2007, 02:32 AM
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Join Date: Jul 2005
Location: Utrecht - Netherlands
Posts: 84
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Quote:
Originally Posted by Berlinista
Well, of course everyone is free to have his opinion, but as being experienced in Alfa racing for about 10 years now, I think ventilated discs are Bull$h!t.
And especially on a street car. you will never get the pads or discs up to temperature. We tired it on several cars over the years, but never got much profit out of it. that's with 200 HP serious racing alfa 105's.
anyway, if you do want that, take a montreal disc.
Or several Audi discs. you will have to machine a spacer behind the disc, to get the right offset.
But hey, try the normal disc first, with a GOOD pad, like somthing from SBS or Hawk, they do street/racing compounds. Forget ferodo, that's racing only, for example DS 2500 or DS 3000. Do NOT buy sh*t like Green Stuff. Invest in a GOOD pad, Goodridge brake lines, fresh master cilinder etc. there you go. Or Stop.......
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After having been in 2 GT's with the Alfaholics 4 pot caliper & Vented disk setup at Castle Comb racetrack(UK) last weeked...I have gone for this kit!
Engineering is beautiful and massive stopping power...it really impressed me how good these brakes are and how they last during a trackday session.
Think about investment...a good GTA replica (or Trackday Super/Spider) is worth a lot of money nowadays...we are only talking a few hundred euros difference here vs. a brandnew Brembo TS/Tarox Disk setup. I think the Alfaholics kit is just so much nicer and will increase overall value of your car once you mount them. Stopping power is simply fantastic.
Now...this is interesting. The 4 pot setup doesn't wear out EXPENSIVE brakepads (and disks) like a 2 pot Brembo setup does. The pads on the 4 pot last a lot longer. Over the years the inventment+running cost will be almost identical between both setups...
In this case for me there's only one route...
Last edited by hagen111; 04-22-2007 at 08:17 AM.
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04-24-2007, 02:26 AM
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Join Date: Sep 2004
Location: Devon, UK
Posts: 526
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Quote:
Originally Posted by Berlinista
4 pot calipers are too much on a 105 even with an increased booster.
You cant really dial in your brakes when nearing a turn. Its all 100% or nothing. I personally do not like that. In my experience, the TS brake mod is by far best. That it is also far cheaper is only an added bonus.
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The number of pistons do not increase power. The piston surface area does. More pistons just allows you to use a bigger pad - more fricton material equals more brake power. Bigger discs also increase brake power but they also increase feel. Our race car runs 6-pots, it has the same piston area as our 4-pots, so has no more braking force, but it enables us to run an even longer pad for extra bite and also enables us to run uneven piston diameters to ensure the pad wears evenly. You see the problem with small pads is not only the fricton area available, but they also run at higher temperatures, when they run at too high temperature they become more prone to 'wedging' (wearing more at the top than the bottom in a leading caliper fitment). This causes the pistons to rock in the caliper slightly and causes a longer brake pedal. When we ran Brmbos on our race car we were changing pads after 30minutes of tracktime - Ferodo DS3000s (the best race pad IMO) were coming out like a wedge of cheese and crumbling away. This is why you need long pads, to distribute the pressure evenly, to do this efficiently you need more than two pistons. Whether you increase piston area or not is up to you, if you do you get more pressure, if you don't you get the same pressure, just over a larger fricton area.
Maybe your brake snatching comments are due to poor pad choice, how much development have you done with pad materials?
I would also invite you to a passenger ride on our roads here in my car, I think you will realise that 198BHP is more than capable of getting the brakes up to temperature on the roads! Again, maybe yiou are making the wrong pad choices?!
GTV-GR - problem with drilled discs in vented format is that they are very prone to radial hairline cracks - this is not a nice thing to have! The problem with vented discs is that the heat is constantly moving round the disc, when it reaches a hole, it can't go anywhere, this extra heat causes it to crack. This does not seem to happen with cross drilled solid discs, there seems to be enough thickness for the heat to disipate somewhere else.
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[COLOR=Blue][URL]www.alfaholics.com[/URL][/COLOR]
1966 2.0 Sprint GT race car, 1967 T/S GTA Replica, 1965 FIA App.K 1600 GTA, 1965 1600 GTA Stradale RHD, 1965 1600 GTA Stradale LHD, 1966 1600 Giulia GTC, 1991 S4 Spider, 1967 1600 Duetto, 1999 2.0 916GTV (soon to be sold!) and now replaced with 2002 3.0 V6 24v 916 GTV
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04-24-2007, 02:30 AM
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Location: Devon, UK
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p.s. as you may be aware, my trackday GTA Replica was originally built with Brembos - they stayed on the car 2000 miles, then i threw them in the bin because I couldn't stop my car in a way that matched the rest of the performance the vehicle had. As a result we developed a proper braking solution.... 4-pots, the ones we offer to clients.
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[COLOR=Blue][URL]www.alfaholics.com[/URL][/COLOR]
1966 2.0 Sprint GT race car, 1967 T/S GTA Replica, 1965 FIA App.K 1600 GTA, 1965 1600 GTA Stradale RHD, 1965 1600 GTA Stradale LHD, 1966 1600 Giulia GTC, 1991 S4 Spider, 1967 1600 Duetto, 1999 2.0 916GTV (soon to be sold!) and now replaced with 2002 3.0 V6 24v 916 GTV
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04-25-2007, 07:12 AM
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Join Date: Nov 2005
Posts: 29
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Quote:
Originally Posted by Max Banks
A bit of physics here:-
- more fricton material equals more brake power.
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04-25-2007, 08:13 AM
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Join Date: Jan 2005
Location: Melbourne, Victoria, Australia
Posts: 79
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Quote:
Originally Posted by elderly
From the Stoptech Site:- "A bigger pad of the same compound in the same location as a smaller pad will not yield shorter stopping distances. The amount of pressure applied, pad friction coefficient, and the diameter on the rotor at which that pressure is applied, determine the torque reaction, or stopping force."
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It is is obvious that if you just increase the pad area and all else stays the same , the piston presure will spread across the greater area and the total friction will stay the same.
The question is, in real world applications, what is the limiting factor, the amount of pressure that caliper can apply or the area of the friction material. Anyone knows the answer here ?
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Branko Gjuro Turk
1968 (105.59), 1968 (105.31), 1970 (105.31), 1970 (105.31), 1970 (105.45)
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04-26-2007, 07:13 AM
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Join Date: Feb 2006
Location: Rijsbergen, Holland
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Quote:
Originally Posted by chfu
can you post some pictures as I always like to see good cars like the Giulia GTV coming to shape.
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04-26-2007, 07:37 AM
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Join Date: Jul 2005
Location: Utrecht - Netherlands
Posts: 84
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Berlinesta's car has come back from the paintshop...
His project-topic on the dutch bulletin board. |
04-26-2007, 03:23 PM
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Location: Devon, UK
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Quote:
Originally Posted by bgt_veloce
So, if you maintain the presure per unit of area then you have greater braking. I think that was the point that was being made earlier but witout pointing out that detail.
It is is obvious that if you just increase the pad area and all else stays the same , the piston presure will spread across the greater area and the total friction will stay the same.
The question is, in real world applications, what is the limiting factor, the amount of pressure that caliper can apply or the area of the friction material. Anyone knows the answer here ?
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[COLOR=Blue][URL]www.alfaholics.com[/URL][/COLOR]
1966 2.0 Sprint GT race car, 1967 T/S GTA Replica, 1965 FIA App.K 1600 GTA, 1965 1600 GTA Stradale RHD, 1965 1600 GTA Stradale LHD, 1966 1600 Giulia GTC, 1991 S4 Spider, 1967 1600 Duetto, 1999 2.0 916GTV (soon to be sold!) and now replaced with 2002 3.0 V6 24v 916 GTV
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04-26-2007, 06:37 PM
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Location: Canberra, Australia
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From a purely engineering viewpoint looking at a brake itself in isolation, the amount of torque a brake can exert on a wheel is totally independant of the contact surface area. It is a function of the mean diameter of the friction surface, the force exerted and the friction coefficient of the contact area. By increasing any of the coefficient of friction, the pressure or diameter, you can increase the torque and therefore the braking effect on the wheel.
Of course throw so many variables (that I will not even try to comprehensively address) in there to a whole braking "System", and you have the reason that this all can seem like a "Black Art" (a term, as an engineer I deplore).
Such as, the fact that the coefficient will change with temperature, the hydralic ratio, balance, feel etc.
The other thing to remember is that what a braking system is actually doing is converting energy. That is, it converts kinetic energy into heat. The capacity of the system to convert this energy into heat is a limiting factor. All that power you are putting to the ground in accelerating the car has to go somewhere... and in a race car, an awful lot has to be dissipated through the braking system, hence the need for lots of ventilation. So I would say that design requirements aside (maintianing uniform pressure across the pad, etc), the biggest limiting factor with a braking system given the intended usage, is its ability to dissipate heat.
Having said all that, back in '97 when I built my GTA replica (first with a 180 bhp Nord engine, and then with a 165 bhp TS engine), I went the full 75 brake setup on junior stub approach. For road use, I never once came close to the braking potential of this setup.
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04-27-2007, 02:17 AM
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Location: Devon, UK
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Quote:
Originally Posted by Clayton105
From a purely engineering viewpoint looking at a brake itself in isolation, the amount of torque a brake can exert on a wheel is totally independant of the contact surface area. It is a function of the mean diameter of the friction surface, the force exerted and the friction coefficient of the contact area. By increasing any of the coefficient of friction, the pressure or diameter, you can increase the torque and therefore the braking effect on the wheel.
Of course throw so many variables (that I will not even try to comprehensively address) in there to a whole braking "System", and you have the reason that this all can seem like a "Black Art" (a term, as an engineer I deplore).
Such as, the fact that the coefficient will change with temperature, the hydralic ratio, balance, feel etc.
The other thing to remember is that what a braking system is actually doing is converting energy. That is, it converts kinetic energy into heat. The capacity of the system to convert this energy into heat is a limiting factor. All that power you are putting to the ground in accelerating the car has to go somewhere... and in a race car, an awful lot has to be dissipated through the braking system, hence the need for lots of ventilation. So I would say that design requirements aside (maintianing uniform pressure across the pad, etc), the biggest limiting factor with a braking system given the intended usage, is its ability to dissipate heat.
Having said all that, back in '97 when I built my GTA replica (first with a 180 bhp Nord engine, and then with a 165 bhp TS engine), I went the full 75 brake setup on junior stub approach. For road use, I never once came close to the braking potential of this setup.
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I agree that heat is the biggest issue; naturally, thus if you try to put all that heat through a small pad you toast it, hence the bigger the pad the better.
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[COLOR=Blue][URL]www.alfaholics.com[/URL][/COLOR]
1966 2.0 Sprint GT race car, 1967 T/S GTA Replica, 1965 FIA App.K 1600 GTA, 1965 1600 GTA Stradale RHD, 1965 1600 GTA Stradale LHD, 1966 1600 Giulia GTC, 1991 S4 Spider, 1967 1600 Duetto, 1999 2.0 916GTV (soon to be sold!) and now replaced with 2002 3.0 V6 24v 916 GTV
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04-27-2007, 04:18 AM
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Join Date: Jun 2006
Location: Sydney, Australia
Posts: 207
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Quote:
Originally Posted by Clayton105
From a purely engineering viewpoint looking at a brake itself in isolation, the amount of torque a brake can exert on a wheel is totally independant of the contact surface area. It is a function of the mean diameter of the friction surface, the force exerted and the friction coefficient of the contact area. By increasing any of the coefficient of friction, the pressure or diameter, you can increase the torque and therefore the braking effect on the wheel.
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Looking at extremes to demonstrate the principle...... Will the total frictional force of a brake with a pad the size of your finger tip be identical to the force applied over the area of a football field even if the two brakes are made of the same material? No. The multi-pot, large surface area brakes have more force applied to the pads which increases the braking. There are materials limits, hydraulic limits (most likely to be met first), and other factors you mention but the pr | |
