Re: 1993 Quad4 GTZ: Project WTF
Posted: Sat Jul 16, 2016 11:40 am
$1800 USD!!!! you can buy a house in canada for that much
Official Chevrolet Beretta Owners Forums
https://beretta.net/forum/
Hi Woody,woody90gtz wrote:Which usually add up to less piston diameter than double or single big pistons...and reduced brake force...
Remember a six piston fixed would only be like a 3 piston floating. And they have to make the pistons smaller to fit them in the caliper.
Just for s&g I did the math on the stock Beretta single piston caliper vs the Wilwoods:
3.88" area - stock single piston 92 Beretta caliper
3.54" area - Wilwood 4-piston Cav/Beretta kit (9% reduction vs stock)
4.04" area - Wilwood 6-iston Camaro kit. (4% increase vs stock)
So you'd actually be better off with a stock caliper on a bigger rotor than the Wilwood kit. Which means the N-body calipers is probably even better...
4.37" area - Nbody single piston (12% increase over stock Beretta, 19% increase over Wilwood kit)
Hydraulics are all math, and the numbers don't lie. So the upgrade people feel when they swap to the Wilwood kit is the leverage on the bigger rotor (and/or pad friction). So a stock caliper with a bigger rotor would be an even better upgrade. Hmmmmm
You can't use that or most of the F-body kits because it uses brackets attached to the 4 hub mounting bolts.DanteGTZ wrote: John, you need something like this -- http://wilwood.com/BrakeKits/BrakeKitsP ... Brake+Rear
Another factor I'm not sure your considering entirely is the floating/fixed caliper. A fixed caliper has a much higher efficiency than that of a floating. That being said, I wonder if the 9% discrepancy in your figures can be made up in efficiency in the fixed caliper. Those calculations represent maximum potentials, which aren't directly translated to real world operation. Thoughts?woody90gtz wrote:Which usually add up to less piston diameter than double or single big pistons...and reduced brake force...
Remember a six piston fixed would only be like a 3 piston floating. And they have to make the pistons smaller to fit them in the caliper.
Just for s&g I did the math on the stock Beretta single piston caliper vs the Wilwoods:
3.88" area - stock single piston 92 Beretta caliper
3.54" area - Wilwood 4-piston Cav/Beretta kit (9% reduction vs stock)
4.04" area - Wilwood 6-iston Camaro kit. (4% increase vs stock)
So you'd actually be better off with a stock caliper on a bigger rotor than the Wilwood kit. Which means the N-body calipers is probably even better...
4.37" area - Nbody single piston (12% increase over stock Beretta, 19% increase over Wilwood kit)
Hydraulics are all math, and the numbers don't lie. So the upgrade people feel when they swap to the Wilwood kit is the leverage on the bigger rotor (and/or pad friction). So a stock caliper with a bigger rotor would be an even better upgrade. Hmmmmm
Oh agreed on pads. I underestimated how much a friction change makes a difference. A friend on NastyZ game me a spreadsheet several years ago that lets you calculate actual brake torque. And pad CoF made a bigger difference than rotor diameter...nocutt wrote:IMHO Tires, Tires, Tires...pads, pads, pads...did I mention tires? lol Often enough after doing a brake kit...you are more than likely getting tires...the feel is actually very quantitative imo, so is pad selection. If the Wilwood allows for better class of pads with enough surface area and good compound tires then I will have to disagree with the bolded statement above...
I have also read fixed is more efficient than floating, but I've never seen numbers. I'd love to find out what it actually is. A good functioning sliding caliper loses very little compared to a fixed, but you have to keep it maintained. Most OEM calipers are sliding because of how they conform to flex (knockback). Fixed calipers have more of a problem with pad knockback on an axle that has any flex (ie spindle pin or sealed wheel bearing) because they flex pushes the pistons back in their bore and the next step on the pedal has to overcome that distance and then apply pressure, so you get a pedal that's a lot lower. Very common in autocross with heavy lateral-Gs.DanteGTZ wrote:Another factor I'm not sure your considering entirely is the floating/fixed caliper. A fixed caliper has a much higher efficiency than that of a floating. That being said, I wonder if the 9% discrepancy in your figures can be made up in efficiency in the fixed caliper. Those calculations represent maximum potentials, which aren't directly translated to real world operation. Thoughts?
For my money, the Wilwoods feel and respond fantastically. When we drove the Cherohala Skyway in '14 my stock brakes were almost unable to stop the car on some of the longer downhills. Brake fade was horrible. I literally had to stand on the pedal to get only marginal performance. The same trip with my Wilwoods was a joy. Absolutely no brake fade and the harder I pushed, the harder the brakes clamped.
For the amount of fab/machine work you'd have to do to get a factory caliper mounted on a larger rotor, I'm not sure it's worth more than the Wilwood kit. Plus being able to keep a 5x100 pattern on all 4 corners is appealing to myself. Same thing with the axles - being able to run factory L-body axles with the Wilwood kit keeps things simple to those that don't need anything more stout. JMHO, but the rotor material, caliper construction, and overall detail given to the Wilwood kit gets my vote. Geoff has proven the kit can be had for sub $800.
Not dogging the N-body setup at all, I'm just extremely happy with my purchase.
Jon, you're talking about pedal travel vs master diameter I'm guessing? Because the extra stopping power of the Lumina 24mm vs the Beretta 22mm is not from the piston diameter, it's from the extra pressure out back. A bigger bore master actually reduces line pressure for a given input force. (PSI - Pounds per Square Inch). So 100lbs of force divided by less square inches (smaller bore) = more PSI. A bigger bore master will bring the pedal higher off the floor though if yours is really low due to bigger pistons.3X00-Modified wrote:Oh and btw, My Camaro caliper that bolts directly to the N-body Knuckle is the 2000 era caliper, so the 94 one is not compatable. They do have a few Willwood kits for the 2000 Camaro but they are HUGE and expensive. My desired result is to find a 12" Camaro rotor that is lighter than 20lbs that I can run, I say that because I know I can fit this setup behind my 15" drag wheels... Any larger of a caliper/rotor combo and it wont work.
Second to that I'm researching and trying to find a way to get a 1" bore master in my car vs the 24mm... Yeah i know not a huge difference but going from original of 22mm to the Lumina 24mm was a big change so I think going from 24mm to 25.5mm may be just that little bit I'm missing.
It would be a one and done if I deleted the ABS... But I'm not about to do that
I have seen people complaining about pad knockback in the Pro-Touring world.woody90gtz wrote:I have also read fixed is more efficient than floating, but I've never seen numbers. I'd love to find out what it actually is. A good functioning sliding caliper loses very little compared to a fixed, but you have to keep it maintained. Most OEM calipers are sliding because of how they conform to flex (knockback). Fixed calipers have more of a problem with pad knockback on an axle that has any flex (ie spindle pin or sealed wheel bearing) because they flex pushes the pistons back in their bore and the next step on the pedal has to overcome that distance and then apply pressure, so you get a pedal that's a lot lower. Very common in autocross with heavy lateral-Gs.
bonecrrusher wrote:I have seen people complaining about pad knockback in the Pro-Touring world.
Would the pad knockback with a solid rear axle be more noticeable then an IRS?
Reason I ask - is because with the Fixed C6Z brakes and IRS in the Vette - I have never noticed it while autocrossing, on the road course, or in the twisties.