Seeking Input on a 'Budget Big Brake Upgrade' kit

[SCOTI]

Allow me to introduce myself: I'm Scot from Texas, & I'm a Chevy truck addict.

I currently own/drive a 74 short fleet that looks like it's worn factory stock w/a severe altitude adjustment. It's got a 350/350 combo w/tilt & a/c as the only options. It still wears the factory "Crimson Red' (which looks amazingly hugger-orangeish after all these years) w/a white top & sports 18/20" TT2's that sit just right w/the 5/7 drop.

Truck #2 is a 'medium-bronze' 68 short fleet that's my 'shop truck/tow vehicle'. It has owner modifed front/rear suspension, 5-lug disc converion, 4whl air-ride, & a 350/700r4 combo. I'm currently completing a suspension re-vamp to go along w/the drivetrain swap (it was a 6cyl/3spd). Truck #3 I've had since 1987. It's a big-block 67 short fleet that's under-going a long-term 'frame-off'..... but it's been moth-balled for a while now as I work on these current projects.

This thread is cut/copied from the 67-72 chevy truck board. I was granted permission to post it here as well just in case there's some that don't get to the other board:

How many people would be interested in a 13" disc brake upgrade 'kit' for your truck that's a less exspensive alternative to current 'kits' & uses the more common PBR 2-piston caliper vs. a custom manufactured caliper?

I've been in contact w/a manufacturer that is considering the 'further' development of a kit for Classic Chevy trucks (think 64 ~ 87) that is based on kits they already sell for GM cars. I state 'further' because they already know what they're doing & have some measurements/dimensions, but have not had the demand to make it more of a priority. Price is up in the air because the work isn't finished.... heck, the design isn't finished. But, this manufacturers other GM kits (that offer the same upgrade) can be had for around $1K (*more or less depending on options) & you modify your own spindles. So the price SHOULD be close. These 'kits' would be a 'limited liability' type, meaning there's a disclosure that they are intended for 'off-road use only'.

But . . ..... the development can be slow if there's not enough interest. So I'm asking you... John Q Public, classic chevy truck owner, is there interest?

*Options on their current 'GM-car kits' range from just brackets w/instructions, to billet hubs, to complete 'kits' w/your choice of rotor (solid, slots, drilled); caliper (standard or upgraded PBR); & pads

[Captkaos]

I cheated and added a poll to your topic.  Wanted to see what people thought that didn't vote.  I am a yes...

[SCOTI]

I thought about the poll here as well but figured just getting the info out there was the main goal.

[Captkaos]

I understand, figured I would add it just in case there are those that don't want to post feedback..

[mikeith]

voted yes! i would LOVE some bigger brakes on a good budget... or not to change the subject but i stunt sportbikes and one of the BEST ways to get better braking is in the master cylinder.... anyone make a better master for our trucks... i mean yeah i would like the look of bigger disks but MY main goal is just some great braking.... any ideas

[VileZambonie]

Bigger brakes means more unsprung weight which = a worse handling bucket of bolts. The fact is factory GM brakes can handle virtually any amoutn of stopping power you could ever desire right out of the box. Most problems were these self energizing duo servo drum brakes can prematurely lock up due to any slight change in suspension or powertrain or tire and wheels size. Either your rear brakes are locking or your front brakes are overworking and fading. The best solution is keep unsprung weight low, use a quick take up master cylinder, and a good metering valve and a good proportioning valve. If you can tune your factory brakes you are way ahead of them game and are saving big$$. The proportioning valve limits pressure to the rear brakes since they are slef energizing when pressure typically exceeds 600 psi. If you find with them properly working and adjusted this is the case get an adjustable proportioning valve. Also your metering valve is used to delay slightly the application of the front brakes to allow the rears to overcome the return springs seat pressure. Adjusting your metering rate can easily overcome brake bias problems. I bet 90% of peoples braking problems are attributed to other problema not associated with their brake system and if they made serious modifications their base brake system can be modified in more efficient ways then going with the bigger is better bs.

I can stop my lifted trucks, slammed trucks and fairly stock trucks quite impressively utilizing factory braking systems.

Study Hydraulics, pascals law, force and mechanical advantages and forget bigger brakes. They are big enogh from the factory.

[SCOTI]

Bigger brakes means more unsprung weight which = a worse handling bucket of bolts. The fact is factory GM brakes can handle virtually any amoutn of stopping power you could ever desire right out of the box. Most problems were these self energizing duo servo drum brakes can prematurely lock up due to any slight change in suspension or powertrain or tire and wheels size. Either your rear brakes are locking or your front brakes are overworking and fading. The best solution is keep unsprung weight low, use a quick take up master cylinder, and a good metering valve and a good proportioning valve. If you can tune your factory brakes you are way ahead of them game and are saving big$$. The proportioning valve limits pressure to the rear brakes since they are slef energizing when pressure typically exceeds 600 psi. If you find with them properly working and adjusted this is the case get an adjustable proportioning valve. Also your metering valve is used to delay slightly the application of the front brakes to allow the rears to overcome the return springs seat pressure. Adjusting your metering rate can easily overcome brake bias problems. I bet 90% of peoples braking problems are attributed to other problema not associated with their brake system and if they made serious modifications their base brake system can be modified in more efficient ways then going with the bigger is better bs.

I can stop my lifted trucks, slammed trucks and fairly stock trucks quite impressively utilizing factory braking systems.

Study Hydraulics, pascals law, force and mechanical advantages and forget bigger brakes. They are big enogh from the factory.

Bigger brakes = increased unsprung weight if the materials used to create each is the same.

Hypothetically speaking (since I don't have parts to weigh), a billet hub w/a 13" 'hat' style rotor would weigh less than or equal to the 1pc. 12" iron GM hub/rotor.  I'm guessing the weights would be close to equal w/the mechanical advantage going to the increased leverage afforded w/the larger diameter disc, & although it has no effect on rotational mass, a PBR 2-piston aluminum caliper is definitely lighter. With a typical GM truck hydraulic brake system functioning properly, switching to 13" diameter rotors up front is not going to decrease the handling abilities

I do agree 100% that installing 13" brakes doesn't do much good if the remainder of the system is not working properly. You brought up some good points about the pre-mature rear drum lock-up issues & 'out of tune' systems. GM's 12" discs did a fine job back in the day when a trucks speed, performance, & wheel/tire diameters wasn't quite up to what's possible today. This is why new trucks come w/13" rotors & larger if the vehicle is work/performance related.

My trucks stop well too. But I'm confident that could be improved upon & I don't like the looks of the smaller 12" rotor behind the window of a 20" wheel. Fixing this requires a larger rotor (w/the benefit of a better caliper).

I'm not interested in the latest high-dollar cross-drilled & slotted brake kit on the market. I just want the opportunity to select proven, affordable, & obtainable parts w/o the marketing & name-dropping.

I do appreciate your honest opinion.

[VileZambonie]

I hope I didn't come off like a jack ass - I had a few drinks last night lol. I see what you are saying though and I'd be interested in seeing how it performs. I was under the impression you were just suggesting larger brakes means better brake performance. Good luck with it

[SCOTI]

I hope I didn't come off like a jack ass - I had a few drinks last night lol. I see what you are saying though and I'd be interested in seeing how it performs. I was under the impression you were just suggesting larger brakes means better brake performance. Good luck with it

No foul, no harm. You did bring up some good points about how overall maint of these hydraulic systems can effect performance & balance w/o upgrading.

[SCOTI]

It's been a while so I thought I would update those possibly interested . . ....

e-mail from 12-17-07
Scot,

Picked up the hubs last Friday and they look good.  I was going to assemble
them with bearings and studs this week and then mock them up on the OE
spindles that we have here.  After proving fitment, we'd be ready to put
them into a real world installation and you're at the top of the list due in
large part to your involvement in getting this project pushed up the
priority list and willingness to give feedback through the development and
installation process.

Given the holidays and such, throw us an email after the 25th or give us a
call and we'll update you on the status.

Happy Holidays,

e-mail received on 1-05-08
Scot,

The holidays were busy but went well...just wish there had been a few more
days off to enjoy as well.

The hubs are done and assembled.  We've just been lacking the time to finish
modifying the spindles and fitting the brackets, but the goal is to get that
done this weekend and get back to you with the results.  Assuming everything
fits up as planned, what's your schedule looking like for putting your truck
back together and having things rolling?  Ideally, we'd like to get the
first set installed and tested out as quickly as possible as there are a
bunch of folks waiting on this kit.  We already have several takers for the
first kit but you've got dibbs at this point and I trust your mechanical
abilities to be better than most and appreciate your input thus far.

Sorry things sort of stalled out over the holidays, but we're back on it and
hoping to make some headway soon.


Good news for those that might be wanting to do this sort of upgrade.

[Captkaos]

I was wondering what the status of this was..  Thanks for the update!

[Captkaos]

Scoti, got any install pics on this?  I still interested...

[joesgarage71]

 Bigger Front brakes would be a nice up grade for my towing truck along with the 14 bolt rear dics brakes (tech section of pirate4X4.com) I plan to install.BUT! not for a $1000.

[SCOTI]

Sorry..... Still trying to get everyone that might be interested some pics ASAP.

[frogman68]

Sorry..... Still trying to get everyone that might be interested some pics ASAP.

Are you guys mind readers ?

Joe I was thinking the same thing.

I (cant find arg) the link (have it bookedmarked at work) but the disc brake set up I saw was less than 400 the backing plate are like 100 dollars then use a 76 K30 Rotor and Caliper (but if you wanted the parking brake the calipers from a 78 Eldorado rear more $$$). Not sure how it would work I was going to post a thread because the 76 K30 use the D52 pads and the Caddy uses D122 I couldnt find the dimensions of the calipers to see if they would fit on the backing plate.

This will be to the experts, Didnt Gm offer rear disc on the early 90's 1 tons? If so wouldnt it be better to just find (might be a pretty penny) the whole rear (would it bolt up??)

Btw I voted yes..