Brake fitting in 15" wheels

[trackrat79]

You guys mite want to look at circle track supliers. Many of the local region racing series run chassis based on production parts if not just modified factory chassis. They have spindles, hubs, arms calipers that are all design around 15" dia wheels because thats what they have to run. It is how I found aluminium hubs, slip on rotors and solid mounted calipers for my truck. It took some digging though some different catalogs and talking to several people but eventually found something that will work. Now it is just a matter of saving up the money. It also helps that I had several suppliers in the area that I could go to in person and take parts with me that I had to use and see what would and would not work before buying anything. A place that has a lot of stuff ishttp://lefthanderchassi.com

[Karch]

Critter, others, do you actually like the Howe 2-piston calipers, or would the GM single piston be better?

I have a Tall B-body and 1LE setup that I am planning on installing later this month, and I just picked up a LS1 rear setup.

I like the idea of the twin piston caliper, and the lighter weight, but when I called Howe to inquire about street use the guy was very elusive....just didn't want to talk about it. I would have signed a waiver if that's what he wanted???

Thanks

[chicane67]

Guldstrand years ago welded a bracket on F/B spindles to take a Vette 4 piston caliper.

I have a set of these if anyones interested........

[Karch]

Anyone want to chime in on my above question about the Howe calipers?

Also, what size piston should I go with if I do go this route?

Thanks.

[PonchoJohn]

Skip,
You might try reading about Cheap Big Brakes on chevelles.com
I seem to remember there was a guy (I think he called himself Bill C.??) who used Suburban parts to make a H/D braking system that would fit in a 15" wheel. From what I remember, the rotors were 1.25" thick, so they can take some abuse.
John

[BonzoHansen]

Anyone want to chime in on my above question about the Howe calipers?

Also, what size piston should I go with if I do go this route?

Thanks.

I'd be curious on input regarding the Wilwood GMIII calipers. I have been told they work for the 1LE 12" setup on b-body spindles that is common on 2nd gens. And they fit better - I think the Howes are bigger and can cause clearance issues on some 15s. IIRC.

Also, I know guys on NastyZ use D61 pads, which have a larger pad area. Sometimes they fit under stock calipers, sometimes they do not. When they don't, they use a caliper for mid 70s Chevy van. Same mounting points, just wider (and larger banjo bolt on the line)

[Bandit]

Skip, I am currently installing Wilwood 12.19" Big Brake rotors and 4-piston calipers on my car. When I am finished I will test fit the stock 15" snowflakes to see if they fit with those brakes. (Now that you have my curiosity peaked) I will report my findings to you.

Paul

[Skip Fix]

Let me know!!

[Bandit]

Forgot to mention, my stock rims are the wider 8" snowflakes, I don't know if that would make a difference over the 7" ones as far as BS or whatever.

[Skip Fix]

All mine are 8" snowflakes.

Interesting note on stock caliper drag. My 81 TA has the "low drag" calipers and they do have less drag thran the stock 78 TAs calipers. But today I spun the 2004 GTOs and there is basically no drag at all on those calipers.

[andrewb70]

All mine are 8" snowflakes.

Interesting note on stock caliper drag. My 81 TA has the "low drag" calipers and they do have less drag thran the stock 78 TAs calipers. But today I spun the 2004 GTOs and there is basically no drag at all on those calipers.

I think many modern calipers (I believe the GTO calipers are made by PBR) will retract the pistons.

As a side note, please be careful when using circle track parts. Some of these parts are not designed for heavy street use and they are not designed to be used on heavy cars. Just a word of caution.

Andrew

[trackrat79]

I have never had a problem. I have seen parts last multiple seasons before needing replacment.

[critter]

Sorry, gone for a while and don't post here a lot.

Karch, yes, I like them but should have done more homework before doing it. The smaller piston size would work better than larger. Now I know.

If I do it again (and I will) it will be the 1LE with a test fitting of the Howes. If they don't work I'll go with the Wilwood GMIII.

Andrew, while I understand where you're coming from, what do you think is more stressful, track or street? How much do we really drive our toys? See my point?

[Skip Fix]

Andrew the Wilwood aluminum GM caliper is the "spec" caliper used on many Late Model Asphalt cars on all 4 corners, although with a 1.25" rotor. These cars aren't that light, pretty sure they are definitely over 3000lbs. and I would bet stress the brakes as much or more than aggressive street driving.

I beleive the 1LEs are closer ot a 1" diameter, not sure if they have Wilwood single piston or Howe dual GM types for that thickness, I thought just .81 or 1.25.

What was the issue with the Howe's and larger pistons, not enough master volume to use them as good?

[critter]

Yeah, Skip. When I pulled the rear drums and replaced them with 79TA rear discs the pedal has a TON of travel and not much feel. Brake feel was great and stopping was very good with the rear drums.

After doing my homework I found that I had too much piston volume for the MC. Swapping to the smaller piston Howe's is a cheap fix if it works. I might try that if I find an extra couple of hundred laying around.

[Karch]

Thanks Critter.

Correct me if I am wrong, but you are saying the large pistons don't give you decent pedal feel?

I spoke to Howe about their calipers, a second time, and they said to go with the largest of the three offerings, when combined with the LS1 rears.

I am right now in the midst of the change from 10-1/2" to 12" 1LE changeover, and I just found my m/c to be leaking. I am going to get a new 1-1/8" replacement tomorrow from CPP. I just bent a new 3/16" line, hooked up a line lock, and the Wilwood adj. prop valve. (I think fluid regulator is a better term?).

[critter]

Yes, that is correct. The larger pistons require a larger volume of fluid. I used a 79, WS6 master cylinder and I "think" that's a 1 1/8 inch master. When talking with the brake experts they all seemed to think that the combination of the big, single pistons on the rear (79 WS6 disc brakes) and the large pistons in the front were too much. Solution? Bigger MC (not possible) or smaller total piston area to be applied.

You do know that the Howe dual pistons are not a direct bolt on, right? I had to do some judicious grinding on back of the spindles for clearance.

[Karch]

I actually wasn't entirely aware they weren't a bolt on deal. I do remember seeing someone had to grind away some areas, but I either thought it didn't apply to the tall spindles, or I just simply allowed myself to blissfully forget there would be any issues...and we know how that always turns out.

I do think there are some m/c's out there that are 1-1/4", maybe even a 1-3/8", just in case you are interested, but I do see your point.

I'll give the iron ones a go for now, and see how well it works. I still need to add the rear discs. I have 2 setups. One off the Elderado's, similar to what you have, with the problematic calipers, and one set off an LS1 type camaro. I have to be sure they'll clear my 15" wheels. While I do want to get a set of 17's, I want to keep the 15's for drag racing.

Thanks again. CPP is having a sale that ends soon. They have new (not rebuilt) m/c's for $42. That's where I am off to.

[BonzoHansen]

I beleive the 1LEs are closer ot a 1" diameter, not sure if they have Wilwood single piston or Howe dual GM types for that thickness, I thought just .81 or 1.25.

I'm told you use the #5861 GM III calipers with the 1LE swap. 1" disc width.

The GM III for 1.00" width rotor is machined and fitted with OEM type slide pin vibration dampeners for a direct OEM caliper interchange.
http://www.wilwood.com/Products/001-...-GM3/index.asp

[Skip Fix]

I thought the factory single piston cast iron had a bigger piston than that Wilwood, hench more potential clapping torque. So othe than lighter I don't know what you are gaining. Often the cast iron is more rigid also nad less flex in the caliper. Maybe the III is better than their older ones.


Critter if you used the stock single stage booster pedal instead of the 4WD pedal that could have been some of your issues. It has more leverage so easier push less MC travel than the 4WD pedal hole.