Need Your Input on G2C Conversion, Please

ultrastang

ultrastang

Founding Member
Feb 26, 2002
1,092
2
37
Arkansas
#1
I went to a local machine shop here in Camden, Arkansas that does extensive work for the government/military where they produce components for rockets, missles, bombs, etc. All the metals and alloys they deal in are strickly high quality grades that meet strict military specifications (stringent compliance --no junk stuff!).

I took them a rough drawing and a mock up of my Granada spindle along with the 13" Cobra rotor and Bullitt caliper, to explain to them and to show them what I was wanting to do to adapt these components onto the Granada's spindle.

They looked it over and said they could produce the brackets. My initial proto-type set is going to cost me $500 dollars to cover the CAD time and for the machining and material costs of just the initial 2 brackets themselves.

For a production run of X-number of sets, after my proto-type brackets are made, my up front out-of-pocket expense is going to run me about $3,000.00 dollars to have the rest of the brackets machined.

From my preliminary estimates at this time, It looks like the brackets will cost the customer ~$295.00 dollars for (2) billet aluminum brackets, (2) machined aluminum rotor centering rings, the necessary fasteners and shipping would also be included in the cost. --This is an estimated cost, mind you. I won't know until I have everything in hand to know exactly what the actual cost will be, but I will try to keep the cost around this figure.

6061-T6 aluminim would be plenty strong enough to do this conversion with, (since it has the same strength properties as 836 cold-rolled carbon steel), but I'm going to have the brackets machined out of stronger 7075-series billet aluminum just for added safety in strength without the added weight of steel.

I'm already commited to the $500 it will cost me up front to have the first proto-type G2C (Granada-to-Cobra) conversion brackets made, but I would hate to spend another $3,000.00 dollars on top of that for a production run of conversion brackets if no one else is interested in this conversion.

My question is, how many of you that are running Granada spindles on your Mustangs or related Fords would honestly be interested in purchasing a conversion bracket like this, that you allow you to mount the SN-95 13" Cobra rotors and Cobra calipers onto your Granada spindles?


Thoughts or comments?

Thanks in advance,

--Steve (ultrastang)

http://img99.imageshack.us/img99/2061/g2cconversion002aj2.jpg

www.ultrastang.com
 
#2
I like it, but (and you can try to convince me until you're blue in the face and you still won't succeed, even if you are right) I'm not going to use an aluminum bracket to hold brakes on my car, nor will I use a welded steel bracket. If it was a machined steel bracket, I'd probably buy it. I don't think the weight is that big of a deal, if I'm so concerned, I'd likely be buying Brembos or some other high $$$ brake. Big thing on my street car I'd worry about is fatigue over a period of time.

Just my .02 Steve, you do great work.
 
#3
1320stang said:
I like it, but (and you can try to convince me until you're blue in the face and you still won't succeed, even if you are right) I'm not going to use an aluminum bracket to hold brakes on my car, nor will I use a welded steel bracket. If it was a machined steel bracket, I'd probably buy it. I don't think the weight is that big of a deal, if I'm so concerned, I'd likely be buying Brembos or some other high $$$ brake. Big thing on my street car I'd worry about is fatigue over a period of time.

Just my .02 Steve, you do great work.
Click to expand...

The brackets I'm having made are starting out as 2" x 2" 7075-T6 aluminum bars, so they won't be constructed out of some weenie, paper thin, metal. In all reality, whether I make a production run of these brackets or not, I'm having this proto-type set made for my own personal use that I'll install on my own '68 Mustang. I definitely wouldn't run a compromised part on my own stuff, and I for sure wouldn't pass something off to someone else that was a compromise.

It does take more mass with aluminum to equal the same strength of steel of a lesser mass but at the end of the day, physics and mathmatics are constants that never change. A steel bolt that's rated at 150,000 lbs. of shear strength is no stronger than an aluminum bolt that's also rated at that same amount. They will both break at the same given amount of force that they are rated for. True, the aluminum bolt will likely be much bigger in diameter than the steel one, but the steel one will still not be any stronger if they equal the same rating.

I've tried to do extensive research on the web to see if there was any info out there on brake failures related to using aluminum as a mounting medium, but I couldn't find any articles/reports anywhere on this. However, I did find instances of spindle failures related to the thinner '65-'69 Mustang spindle designs where the spindle pins broke at the point where it attaches to the spindle upright/steering arms.

This is another reason why I chose to do this conversion on the heavier-constructed Granada spindles, which is an almost identicle part to the '70-'73 Mustang spindles.

I appreciate you taking the time to reply and give some of your thoughts on this conversion.

--Steve
 
#4
im interested in it, as i have granada discs on my car. but my main concern is the 1" spacers i have to use right now for my Bullitt rims. would i still be needing this spacer? is there anyway to implement the spacer into the design? i saw one company making a kit with a "hub spacer" i think...
 
#5
Mustang steve is doing pretty good on his conversion kit for drum spindles... I think it would be nice to have a upgrade kit for stock disc spindles. with the reproduction of granada spindles, I think it would be an affordable way to do it. For marketing though, you need to find a way to make sure the kit with buying spindles will be cheaper than any ssbc or wilwood kit
 
#6
PJx5x said:
im interested in it, as i have granada discs on my car. but my main concern is the 1" spacers i have to use right now for my Bullitt rims. would i still be needing this spacer? is there anyway to implement the spacer into the design? i saw one company making a kit with a "hub spacer" i think...
Click to expand...

What I have: 1968 Mustang that had 4-wheel non-power drums from the factory. In 1990, I converted the front brakes on my '68 to '75 model Granada front discs --11" rotor with single-piston cast-iron Granada caliper.

Recently: I bought some new '70 Mustang rotors and removed the hubs from them and pressed new, longer wheel studs into the hubs. I purchased some SN-95 Cobra drilled & slotted rotors and a pair of '01 Bullitt Mustang aluminum twin-piston calipers (same calipers as Cobra or Mach1).

The Cobra rotor's friction surfaces are pushed away from the Granada spindle's upright/steering arm by about 1-inch more than where the original 11" Granada rotor's surfaces were located. If the spacer was mounted on the back side of the Cobra rotor (mounted on a Granada spindle), it would push the rotor even further out, which means the bracket would have to be extended even more in a perpendicular plane relative to the spindle. I believe in this instance, the more you move the rotor away from the spindle, the weaker the caliper mounting bracket would be, unless you bulked the bracket up more to offset the leverage that would be placed on it the more you move it outward.
 
#7
PJ, the brackets are for the calipers and the spacer is a hub adapter as the hole in the disc is of a larger diameter than the diameter of the hub. The Mustang is a hub-centric designed vehicle and I take it this spacer fits the disc and allows the wheel to be centered on the hub rather than relying on the lugnuts for sole support.
 
#8
xoxbxfx said:
Mustang steve is doing pretty good on his conversion kit for drum spindles... I think it would be nice to have a upgrade kit for stock disc spindles. with the reproduction of granada spindles, I think it would be an affordable way to do it. For marketing though, you need to find a way to make sure the kit with buying spindles will be cheaper than any ssbc or wilwood kit
Click to expand...

I wouldn't mind making an adapter bracket for a '70-'73 Mustang drum brake spindle, but I'm not going to touch the '64½-'69 drum/disc brake models. There's just too great a risk of spindle pin failure with them. This is why Ford upgraded the spindles to a beefier design starting with the '70 Mustangs, because they knew the spindle pins were the weak links on those models.

Regardless of what or who's brake system you install on your vehicle, ANY used spindles should be taken to a machine shop and magnaflux-checked for stress cracks BEFORE you put the new brake components on --especially if you plan to road race your car.

Just because your spindles "were working just fine" before you made the conversion does not mean that they were free from defects or stress cracks. It's better to have them checked so you will KNOW they are good, rather than assume they are good, only to be proved wrong.


www.ultrastang.com
 
#9
ultrastang said:
I wouldn't mind making an adapter bracket for a '70-'73 Mustang drum brake spindle, but I'm not going to touch the '64½-'69 drum/disc brake models. There's just too great a risk of spindle pin failure with them. This is why Ford upgraded the spindles to a beefier design starting with the '70 Mustangs, because they knew the spindle pins were the weak links on those models.

Regardless of what or who's brake system you install on your vehicle, ANY used spindles should be taken to a machine shop and magnaflux-checked for stress cracks BEFORE you put the new brake components on --especially if you plan to road race your car.

Just because your spindles "were working just fine" before you made the conversion does not mean that they were free from defects or stress cracks. It's better to have them checked so you will KNOW they are good, rather than assume they are good, only to be proved wrong.


www.ultrastang.com
Click to expand...

I totally agree when using big brakes on something it was not designed for. I think if you can keep the costs down and possibly hook up with a supplier of granada repops and sell them, a full kit would be nice. The niec thing about cobra brakes is the fact you can get pads at any parts store and rotors are cheap.
 
#10
xoxbxfx said:
Mustang steve is doing pretty good on his conversion kit for drum spindles... I think it would be nice to have a upgrade kit for stock disc spindles. with the reproduction of granada spindles, I think it would be an affordable way to do it. For marketing though, you need to find a way to make sure the kit with buying spindles will be cheaper than any ssbc or wilwood kit
Click to expand...

If the bracket design for the G2C conversion actually makes it into production, I hope I will be directly responsible for sending a lot of business to Degins for the new Granada spindle castings he's producing now.

I didn't just sit down a couple of days ago and decide I would throw something together in a hurry in order to get this rotor and caliper to mount onto the Granada spindle. This is a project I've been trying to work out for a number of months now that's envolved a lot of my time as well as a good deal of my money going into this.

I looked at spindle designs and ruled out the pre-'70 models because of their thinner, weaker designs. This pretty much only left a small segment with the '70-'73 Mustang drum/disc brake spindles, which percentage-wise, is not a lot in relation to all other Mustangs.

Since I already had Granada spindles on my own '68, and the fact that there are probably thousands of others who have adapted them to their Mustangs and related Fords, it only made sense to go with the beefier Granada spindles --especially now that Degins make brand new Granada spindles. :-)

www.ultrastang.com
 
#11
1320stang said:
PJ, the brackets are for the calipers and the spacer is a hub adapter as the hole in the disc is of a larger diameter than the diameter of the hub. The Mustang is a hub-centric designed vehicle and I take it this spacer fits the disc and allows the wheel to be centered on the hub rather than relying on the lugnuts for sole support.
Click to expand...

http://vintagevenom.com/fdk.htm

theres the one i mentioned. it looks like the spacer is mounted behind the rotor
 
#13
Ultrastang, I am interested as this conversion was already something I had been jones'ing for from Mustang Steve, but I already have the Granada fronts and no longer have my original drum spindles and/or hubs on my '65. However, I do have the following questions:

1. I did the Granada conversion before I had ever heard of the bump steer and Ackerman problems on a '65 with Granada spindles. What, if anything, can I do to correct these problems if I keep the Granada spindles? Will the Baer Tracker and/or Pro-Motorsports bump steer kits correct these problems, or do those kits only work with stock spindle geometry?

2. Do you have any answers to the hub dilemna yet?

3. If I do this conversion, will it be compatible with a TCP front coilover and rack and pinion system and/or Randall's rack, RRS, etc?
 
#15
65up2d8 said:
Ultrastang, I am interested as this conversion was already something I had been jones'ing for from Mustang Steve, but I already have the Granada fronts and no longer have my original drum spindles and/or hubs on my '65. However, I do have the following questions:

1. I did the Granada conversion before I had ever heard of the bump steer and Ackerman problems on a '65 with Granada spindles. What, if anything, can I do to correct these problems if I keep the Granada spindles? Will the Baer Tracker and/or Pro-Motorsports bump steer kits correct these problems, or do those kits only work with stock spindle geometry?

2. Do you have any answers to the hub dilemna yet?

3. If I do this conversion, will it be compatible with a TCP front coilover and rack and pinion system and/or Randall's rack, RRS, etc?
Click to expand...

If you pretty much leave the front suspension as is (no Shelby drop, no lowering springs), you shouldn't have too much problems with the Granada spindles on a '65/'66. If you still have wandering problems with the Granada spindles, have your front end aligned to these specs:

0 to .5 neg. camber and 2.5 deg. pos. caster with 1/8" toe in.

If the companies you listed designed their products to work with the Granada spindles, then there should be no problems there. I didn't change anything about the spindle itself, only the rotor and caliper that's being installed.

I'm still looking for a source for the hubs --as opposed to buying complete rotor/hub assemblies to get them from.

In reference to the R&P setups, if the companies making them designed them to work with the Granada's spindles, there shouldn't be any problems.

Probably the best thing you could do is to contact these companies, tell them what you have or are planning to install, and see what they say about it.

www.ultrastang.com
 
#16
LMan said:
Would this kit still require a 16" or larger wheel?

Im running PBRs on an 11" wheel, and would like to move up to 13", without the expense of the MS kit....
Click to expand...

I believe the Ford 16" wheels (designed for a late model Mustangs) MAY clear without problems, but I know for sure the Cobra, Bullitt, or Mach 1 wheels will work since all three of these models use the same brake setups.

I'm kinda anxious to get the brackets back so I can bolt the stuff up on the '68 and take one of the wheels off my '03 Mach 1, put it on the '68, and see how the setup looks through the spokes of the Mach 1 wheel.:nice:

www.ultrastang.com
 
#17
Steve, correct me if i'm wrong here but don't the caliper brackets for 69-73 mustang disc brakes bolt on the same as a granada spindle? in other words i think you can interchange the 69-73 caliper brackets with the granada bracket for both spindle designs, correct? if so you would have a slightly bigger market if the your caliper bracket would fit 69-73 spindles AND granada spindles. i'm pretty darn sure the brackets are interchangeable.


on that note what i'm really looking for is a bracket that will let me use the 99-04 caliper on a stock 69-73 disc spindle or even a drum spindle (i have both) so i can keep my 15" wheels. i don't really like the look of 17" wheels on a classic, call me old school i guess. even a 12" rotor and 99-04 caliper that would allow the use of my 15" wheels would be cool too, maybe even preferable.

i have seen people use a 12" crown vic rotor but i can't remember what caliper was used and i also can't remember if it cleared a 15" wheel or not. i had planned on going that route but i would have to have a caliper bracket fabbed up and for a single set of brackets it would be cost prohibitive for me.

any ideas or suggestions?
 
#19
bnickel said:
Steve, correct me if i'm wrong here but don't the caliper brackets for 69-73 mustang disc brakes bolt on the same as a granada spindle? in other words i think you can interchange the 69-73 caliper brackets with the granada bracket for both spindle designs, correct? if so you would have a slightly bigger market if the your caliper bracket would fit 69-73 spindles AND granada spindles. i'm pretty darn sure the brackets are interchangeable.


on that note what i'm really looking for is a bracket that will let me use the 99-04 caliper on a stock 69-73 disc spindle or even a drum spindle (i have both) so i can keep my 15" wheels. i don't really like the look of 17" wheels on a classic, call me old school i guess. even a 12" rotor and 99-04 caliper that would allow the use of my 15" wheels would be cool too, maybe even preferable.

i have seen people use a 12" crown vic rotor but i can't remember what caliper was used and i also can't remember if it cleared a 15" wheel or not. i had planned on going that route but i would have to have a caliper bracket fabbed up and for a single set of brackets it would be cost prohibitive for me.

any ideas or suggestions?
Click to expand...

It actually goes back a year earlier than that. 1968 was the first year the disc brake equipped Mustangs switched from the K/H 4-piston fixed-mount caliper to a single large piston floating caliper.

I'm pretty certain the '68-'73 mounting points on the spindles are the same on the '68-'73 disc brake spindles as the mounting points on the '75-'80 Granada/Monarch & '74-'77 Maverick/Comet spindles.

However, --for me, I'm staying away from the pre-'70 model spindles with their thinner spindle pins. I can't keep someone from putting the adapter brackets on a '68/'69 disc brake spindle. All I can say is you've been warned.:nono: I'm more interested in a safer assembly than turning a fast buck. I don't make a big income at my job, but I'm not so desperate for money that I would push this conversion off on someone with a spindle that's really not up to the task.

All Mustang spindles (drum or disc brake) from '64½-1969, have a thinner, weaker design than the '70-73 drum or disc brake spindles. In 1970, Ford beefed the spindles up on both drum and disc brake equipped models, because the spindle pins of the pre-'70 Mustangs have a weaker design that can break off at the upright/steering arm.

In a street application, the '64½-'69 spindles MAY run without incident. If you are racing opentrack though, it will just be a matter of time before disaster strikes. --So to me, I just prefer to stay away from them and not chance it either way.

In ANY case, whatever you have or setup you're running, if your spindles are used, take them to a machine shop and have them magnaflux-checked for stress cracks prior to putting the new brake system on.

I wouldn't mind making an adapter bracket for a '70-'73 drum brake spindle. What year model is the drum spindle you have?


www.ultrastang.com
 
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