vette75406

Who has non stock style calipers and what did you replace them with?

norvalwilhelm

I am running the stock calipers that were drilled and lightened 3 pounds each. The front were replaced about 15 years ago and the back are still the originals,
This is a stock original. his shot doesn't do it justice. It is in perfect shape
Double click to enlarge

Twin_Turbo

Drilled calipers? I guess it's early and you mean rotors right? :)

vette75406

I really like alot of the stuff you have done to your car , I am in the process of duplicating some of it , as in the frame reinforcement, and hydro boost. btw you said that you took one of your boosters from a van , was that a astro type or a fullsize , also would it be possible to Im me a link to a list of parts you used for the conversion.

427V8

I think you mean you drilled the rotors...

see this thread
http://forums.corvetteforum.com/zerothread?id=794985

BTW, Norval obviously doesn't run his car very hard. No one I know that runs their brakes hard has a set of rotors last more than a couple of years, and no one uses drilled rotors since they crack faster than non-drilled rotors.

BTW, some of my friends are running race prepped Porsches and have used factory rotors with cast ( not drilled ) rotors and still have cracking problems.
The non drilled rotors last longe and perform better.

The second reason not to drill rotors is that the removed mass is exactly what the car does not need. The brakes are undersized as it is and making them smaller does not help at all.
Of course they do look cool for gentle street driving, but not an option for the track.


[Modified by 427V8, 7:49 AM 4/9/2004]

norvalwilhelm

said that you took one of your boosters from a van , was that a astro type or a fullsize , also would it be possible to Im me a link to a list of parts you used for the conversion

It is early. Just got up. I don't recommend drilling calipers :lol: :lol:
I took my hydroboost from full size vehicles. A full size van and then another from a 94 one ton truck. As for parts other then hydraulic lines there were no parts required. I used the existing ones.

I only run organic Wagner pads and replace them every 2 years and the rotors look brank new each year. No I don't use my brakes hard. I just like to drive fast and don't often need to make panic stops. I have not yet found a single crack and my drilled rotors are more then 10 years old.
Guys say what you want, I have no problems with cracked rotors , the back are still the original ones and my brakes are strong. I don't run on a track and drive normal stop and go. I do like to run very fast but that doesn't require alot of braking. I did cut 12 pounds from the unsprung weight and until I find out different through personal experience I will continue to run drilled rotors and organic pads.
One summer I ran Performance friction pads but they started to eat the rotors so I took them off.

flynhi

Norval, what difference did you note in suspension performance with the reduction of unsprung weight by 12lbs?

big632

The rotors I run for drag race are slotted and or drilled. They can crack after heavy braking and street driving with heavy on off stops without cooling. They were not designed for that kind of driving and are perfect for drag race where every once of rotating weight is reduced.10 pounds of rotating weight is the same as loosing 100lbs off your car. As far as corvette rotors they are massively built and can be drilled with no problems with cracking as norval has said.Im sure if you roadraced your car at its limits you could manage to crack them if you tried,but normally would not be an issue. regards mike

flynhi

So, let's see: with drilled rotors-
lose 10 lbs and
get the effect of a 100 lb reduction in car weight
get improved suspension response due to less unsprung weight
no rotor cracks in typical street use

What's not to love about this?

Twin_Turbo

lotsa work no?? :) still, you're right, it will work just fine. Norval could improve his unsprung even more with some light calipers (mine are only 5,5lbs) so Norval, not only do you have to drill the rear aluminium bumper, you also need lighter calipers :D .. get cracking :)

norvalwilhelm

The second reason not to drill rotors is that the removed mass is exactly what the car does not need. The brakes are undersized as it is and making them smaller does not help at all.
Of course they do look cool for gentle street driving

I don't understand why I need all that mass, unsprung at that. The rotors are bolts solidly to a large chunck of alumimun , called a rim. This would disipate heat better then the small area I lost with drilling holes. They are even using Carbon Fiber rotors to reduce unsprung weight.
As for braking power with the hydro boost there is absolutely no problem totally locking up the brakes is I desire.
No one on this forum takes things apart more then me. All 4 or my rotors are taken off every winter , inspected and put back on, remember the backs are still original and the holes were drilled in the 80's some time. I do not have a single crack yet.
Some will say that I don't drive hard enough? I regularly drive very fast, fast but smooth. I do not race the car on a track or on public roads but that doesn't stop me from regularly running at 100 plus and I have filled the interior with smoke from a couple of 100 mph panic stops just to see how things are working.
Just because I don't wear out my tires yearly, destroy the rotors yearly, beat on the motor daily doesn't mean I don't like to drive fast and feel the power of the motor and the brakes. I am just easy on equipment.
My wife's Bonneville cost about $43,000 with fantastic brakes and compared to my vet they are weak. I am always comparing her car's smoothness at high speed and brakes to the vet and I have her beat in both cases.
My ride is smoother, she has 245x 17 tires all around with a performance suspension and large anti lock brakes.
For a 29 year old car to say it is faster, smooth and can outbrake that says alot. I know the supercharge Bonneville certainly doesn't set an performance standards but it is a beautiful, fast, smooth sleek car capable of effortless running at 100 mph.
It's the only thing I drive regularly to compare with.

427V8

Thermal mass that is.
Run your brakes hard on a road course and you will understand.

Thermal mass evens out the temperature spikes, venting lowers the mean temperature.

When I say the rotors need more mass I mean for MY application. I cannot guess what your application is. If you really want to lower mass go for smaller / thinner rotors. Smaller first, thinner second. Since rotational intertia is what the square of the raduis?

Drag racers commonly use 1/4" thick solid rotors on aluminum hubs and tiny calipers. They only have to work once ...

Road racers ue big ol rotors with venting. They also measure the temp of the rotors and optimise for the smallest possible size, often changing depending on the track. Street performance guys use huge rotors cause they look cool...

Twin_Turbo

smaller diameter rotors greatly reduce brake torque

norvalwilhelm

I was looking at a new vet today and I was totally shocked to find the rotors were full of holes, not grooves but holes :eek: :eek:
We should inform GM that holes will cause cracking and they have no business putting rotors with holes on their new vets.
All kidding asside the rotors were full of holes and if that causes cracking then they are subject to alot of warranty claims.

427V8

Yes, but the torque delta is a linear function of radius while the rotational intertia delta is the square of the radius.

427V8

"I do not race the car on a track "

But they look cool and people think they work. Just like big wings.

Wrecked82

Mistake not to include VBP O-rings initially. Alot run them here.

Twin_Turbo

I know, it was just a little thing to keep in mind.

While I do agree with you that you want mass in your rotors to keep the temps from spiking (acting as a buffer) most of here don't even use their brakes to the point where they come near the point where the rotor temps start to spike badly because of overheating that can be reduced with more mass so drilling holes won't be a problem. Also, you could force air cool your rotors too if things got out of hand. I won't drill my rotors since I probably have to replace mine regularly (I did some simple math and my rotors are cheaper than my caliper pads so I got some anorganics that are hard on rotors...cheaper in the long run) and it's too much work. I don't see me sitting at the drill press for hours drilling all those holes, being carefull not to drill straight through the vanes, weakening the rotor badly. Gotta give Norval credit for at least his patience and it looks good. If it works for him it's a 1000% success IMO.

turtlevette

could you elaborate on that!

big632

IN a acceleration test. Rotating weight is at 10 to 1 ratio versus curb weight. every 100 lbs equals 1 tenth quicker, every 10 pounds of rotating weight equals 1 tenth quicker. Other examples are 1000lbs lighter is one sec quicker with the same power. Or 100 hp increase is one second quicker,up to app 600hp, than you need more power per gain as you get quicker past say 10second zone in a 3000lb car,