Discussion
Having driven with both stock brakes and AP brakes, there is a noticable & reassuring difference under normal driving conditions (and an enormous difference on the track I would expect).
However, I wouldn't say that the stock brakes are woeful, and mine served me well in a couple of emergency situations. If you like to drive quickly on B-roads with lots of on-off braking, I can see why they would be at the top of the upgrade list though.
The cost of AP's is significant though. It was mentioned to me at MF that a new kit might become available soon, which might be a bit less costly.
However, I wouldn't say that the stock brakes are woeful, and mine served me well in a couple of emergency situations. If you like to drive quickly on B-roads with lots of on-off braking, I can see why they would be at the top of the upgrade list though.
The cost of AP's is significant though. It was mentioned to me at MF that a new kit might become available soon, which might be a bit less costly.
Lewis,
I wouldnt get too hung up about the brakes just due to a wee power increase! After all, the work the brakes have to do is a function of the weight and the speed of the car (E=0.5m x V^2 and all that....) and not directly due to whats coming out at the flywheel.
I have had a CV8 since the start of 2005, which got Wortec Sport Pacced soon after - It still runs on stock brakes, and I agree with Stig that the stock brakes are more than fine for road use.
Whilst there is no doubt that changing the brakes may give you more stopping power, there really is only a marginal connection between engine power and stopping requirements in most circumstances.
For example, 2 Monaros, one 328 BHP, one 390 BHP. Both driving along the public road at 60 mph. Both have to pull up in an emergency on stock brakes. Both sets of brakes do exactly the same work as the cars weigh the same and are going at the same speed. Both cars take off again at full pelt. The 390 BHP car gets to the national speed limit a tadge faster than the 328 BHP car, but after that, they are equal again, and if they had to repeat the stop, conditions would be the same!
OK, consider a far more onerous scenario. A private track comprising 1/4 mile straights with incredibly tight corners, necessitating the car to almost come to a stop, before accelerting at full tilt for a 1/4 mile again, before going hard on the brakes. In this scenario, the 390 BHP Monaro will hit the end of the straight at about 6 mph more (give or take a bit!) than the 328 bhp one. Accordingly the brakes have to dissipate about 11.6% more energy. Not an awful lot, and bear in mind unless you are on the track, its unlikely you'll be doing repeated 1/4 mile take offs with hard stops time and time again!
On the road, in realistic situations, the differential will be much less than 11.6%. When I changed my CV8 from 328 to 390 or whatever the Sport Pac claims, I cant say I noticed any additional requirements for braking over stock, despite having enough fun to only get 8K out of a full set of tyres!
Someone on here wrote that AP's would be good for 1000 BHP. Would they? How would they cope with stopping a 250 tonne heavy haulage truck, travelling at 90 kmh, yet only pulled by a 600 hp tractor unit? They wouldnt, as they would have to dissipate over 150 times the energy of a Monaro going at the same speed... OK, its an extreme comparison, but you get the point!
If you want more braking power, then sure, look at uprating the brakes. Sticking on more powerful brakes will change any car, irrespective of the power output. But dont dismiss the stock brakes just because your going to up the BHP a little! Try it first and see what you think! Maybe you'll agree with Codefaster, Stig and myself that the stock ones are not as bad as many folk make out!
I wouldnt get too hung up about the brakes just due to a wee power increase! After all, the work the brakes have to do is a function of the weight and the speed of the car (E=0.5m x V^2 and all that....) and not directly due to whats coming out at the flywheel.
I have had a CV8 since the start of 2005, which got Wortec Sport Pacced soon after - It still runs on stock brakes, and I agree with Stig that the stock brakes are more than fine for road use.
Whilst there is no doubt that changing the brakes may give you more stopping power, there really is only a marginal connection between engine power and stopping requirements in most circumstances.
For example, 2 Monaros, one 328 BHP, one 390 BHP. Both driving along the public road at 60 mph. Both have to pull up in an emergency on stock brakes. Both sets of brakes do exactly the same work as the cars weigh the same and are going at the same speed. Both cars take off again at full pelt. The 390 BHP car gets to the national speed limit a tadge faster than the 328 BHP car, but after that, they are equal again, and if they had to repeat the stop, conditions would be the same!
OK, consider a far more onerous scenario. A private track comprising 1/4 mile straights with incredibly tight corners, necessitating the car to almost come to a stop, before accelerting at full tilt for a 1/4 mile again, before going hard on the brakes. In this scenario, the 390 BHP Monaro will hit the end of the straight at about 6 mph more (give or take a bit!) than the 328 bhp one. Accordingly the brakes have to dissipate about 11.6% more energy. Not an awful lot, and bear in mind unless you are on the track, its unlikely you'll be doing repeated 1/4 mile take offs with hard stops time and time again!
On the road, in realistic situations, the differential will be much less than 11.6%. When I changed my CV8 from 328 to 390 or whatever the Sport Pac claims, I cant say I noticed any additional requirements for braking over stock, despite having enough fun to only get 8K out of a full set of tyres!
Someone on here wrote that AP's would be good for 1000 BHP. Would they? How would they cope with stopping a 250 tonne heavy haulage truck, travelling at 90 kmh, yet only pulled by a 600 hp tractor unit? They wouldnt, as they would have to dissipate over 150 times the energy of a Monaro going at the same speed... OK, its an extreme comparison, but you get the point!
If you want more braking power, then sure, look at uprating the brakes. Sticking on more powerful brakes will change any car, irrespective of the power output. But dont dismiss the stock brakes just because your going to up the BHP a little! Try it first and see what you think! Maybe you'll agree with Codefaster, Stig and myself that the stock ones are not as bad as many folk make out!
Your argument is valid, although your calculations are a little flawed.
Velocity increase and decrease are a function of V squared.
Double your speed, quadruple the energy required to either get there or stop.
6mph at speed is a huge differential, I needed an additional 150bhp to see that type of increase over 1.5 miles.
So braking would require a similar increase in power.
Whilst the brakes are reasonably good at stopping they are bound to generate a lot of heat which will need to be removed before they can be used again, if you don`t then you`l cook them and that will cost plenty.
Having max braked from nearly 180mph 4 up recently with no problems I was most surprised when I cooked my AP`s solo braking from 175ish.
Only difference was tarmac temps.
With regard to more powerful cars not needing bigger brakes that`s a new one on me, and certainly not one the car manufacturers agree with.
If you are driving around at the limit of your brakes what`s the point of extending the performance of the car.
Awesome stopping power can be just as impressive as HP by the way.
Velocity increase and decrease are a function of V squared.
Double your speed, quadruple the energy required to either get there or stop.
6mph at speed is a huge differential, I needed an additional 150bhp to see that type of increase over 1.5 miles.
So braking would require a similar increase in power.
Whilst the brakes are reasonably good at stopping they are bound to generate a lot of heat which will need to be removed before they can be used again, if you don`t then you`l cook them and that will cost plenty.
Having max braked from nearly 180mph 4 up recently with no problems I was most surprised when I cooked my AP`s solo braking from 175ish.
Only difference was tarmac temps.
With regard to more powerful cars not needing bigger brakes that`s a new one on me, and certainly not one the car manufacturers agree with.
If you are driving around at the limit of your brakes what`s the point of extending the performance of the car.
Awesome stopping power can be just as impressive as HP by the way.
Lewis07 said:
Thought about a track day at Brands. Did one in my Cossie Sierra last year on th GP circuit and it was awsome. Anyone trashed their Ro around Brands? Or similar?
I did the Brands Indy circuit in a std VXR with standard brakes and after a couple of laps they went to mush.
Always been a bug bear of mine as they're simply up to the job of stopping 2t of Ozzy metal from high speed...Go the AP route...awesome stopping power, but not cheap
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