I wish to upgrade the brakes on my CAV 51 with 15" wheels. The current set up is PBR calipers and 11.375" rotors. I want to use 310mm discs and wilwood 4 pot calipers. I am not sure whether there is enough space in the wheel to do this upgrade. Has any CAV owner done a similar upgrade?. Any advice on possible set-ups would be greatly appreciated.
brake upgrade
- Thread starter cavgt40
- Start date
Sibbat, good question, have been wondering the same thing myself.
My guess is that a wilwood/brembo 4 pot caliper is going to require a bigger-than 15" wheel. My car is CAV mono #6 and it basically has the brakes off a Ford Mustang Cobra. I know there's a brembo upgrade kit for these Cobra calipers which bolts right on, however, the Cobra mustang has wheels which are larger than 15". Nobody who supplies these kits seems to know about clearance with 15" wheels unfortunately. I imagine that Jean/John at AutoFutura in S.A. or Ian at CAV Canada can advise here with precision so hopefully they might see your post.
My guess is that a wilwood/brembo 4 pot caliper is going to require a bigger-than 15" wheel. My car is CAV mono #6 and it basically has the brakes off a Ford Mustang Cobra. I know there's a brembo upgrade kit for these Cobra calipers which bolts right on, however, the Cobra mustang has wheels which are larger than 15". Nobody who supplies these kits seems to know about clearance with 15" wheels unfortunately. I imagine that Jean/John at AutoFutura in S.A. or Ian at CAV Canada can advise here with precision so hopefully they might see your post.
Your inner rim will need an ID of at least 14.25" for a distance 2" outboard of the disc/rotor c/l and a minimum of 3.00" from disc/rotor c/l to rear or inboard face of the wheel center.
This would give only 0.100" caliper to rim clearance which is borderline and can be risky if a stone or debris gets caught between the two or if any flex is present in caliper mount or stub axle assy.
Jac Mac
This would give only 0.100" caliper to rim clearance which is borderline and can be risky if a stone or debris gets caught between the two or if any flex is present in caliper mount or stub axle assy.
Jac Mac
sibbat2,
I have just completed upgrading to Wilwood Superlite Radial Mount 4 pots within 15" split rim wheels with 310 disc on a DAX40 that uses the Granada uprights. There is sufficient room in a split rim wheel as they use relatively thin aluminium for the rims. Cast wheels might not accommodate a 310 disc, but it is easy to determine what will and wont fit if you measure the inside contour of the wheel. Do a search on my threads as I have posted a fair number of sketches.
I ended up with about 6mm clearance, but clearly the bigger the gap the less likely that a stone will jam and damage something. For info, my internal wheel diameter is 365mm 14.375".
regards
Dave
I have just completed upgrading to Wilwood Superlite Radial Mount 4 pots within 15" split rim wheels with 310 disc on a DAX40 that uses the Granada uprights. There is sufficient room in a split rim wheel as they use relatively thin aluminium for the rims. Cast wheels might not accommodate a 310 disc, but it is easy to determine what will and wont fit if you measure the inside contour of the wheel. Do a search on my threads as I have posted a fair number of sketches.
I ended up with about 6mm clearance, but clearly the bigger the gap the less likely that a stone will jam and damage something. For info, my internal wheel diameter is 365mm 14.375".
regards
Dave
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Hi Syed,
About the brake upgrade, what are you looking to accomplish? The stock PBR aluminum calipers and vented 285mm rotors will suck the eyeballs out of your head if properly set up.
However, the Wilwood Calipers certainly are capable of more total friction and fade resistance if used with slotted rotors.
Properly set up is the issue. Then the brake parts themselves will make a difference. Putting big brakes on the stock car will not significantly improve stopping distances or fade resistance more than simply slotting the stock rotors. That would be the first step.
Secondly, the suspension setup as delivered on pre 100 cars was really meant for normal street driving. It soon became apparent in track testing and certain open road (we can't say where or when) situations that the stock setup needed upgrading.
This has been done by Autofutura on the newer cars, post 100 and we have components to retrofit the earlier cars such as yours.
I've spoken about controlling the contact patch before on the forum, in brake discussions. I'm all for stopping as quick as possible because these cars get up and go really really fast.
On a practical side you have to consider all the costs and effects of changing the brakes. If you increase either the rotating mass or the diameter of the rotating mass of the brakes, there will be horsepower penality. This will cost in acceleration and somewhat ad to the need for bigger brakes in stopping. Also a net increase in weight will effect the sprung to unsprung weight ratio unfavourably, hurting ride quality. But damm those big brakes are pretty!
So to get the car to stop better you have to improve control over the contact patch. Most of the braking power to be gained is in the rear brakes. In the stock car the rear end geometry leaves a lot of room for improvement under high braking loads. This is caused by the lower control arms geometry, lack of adjustability and rubber mountings.
This is also why some owners can't dial out enough rear brakes, they're locking early because the maximum tire contact patch is not being used.
CAVs fitted with our Revised Lower Control Arm Kit have gained stopping power, handling and ride improvements. We also fix the wheelbase at the sme time. There are also geometry improvements in the new Steel Rear Upright that further improve cornering and driver confidence at higher speeds.
The stock front end can produce decent stopping forces if aligned correctly and tires not over inflated. This is straight line braking on smooth surfaces. If you're planning some track days or spirited road driving, then our new Steel Front Uprights will help you out even more.
There are posting in CAV talk about the new suspension bits, take a look at it and give me a call or email.
Cheers
About the brake upgrade, what are you looking to accomplish? The stock PBR aluminum calipers and vented 285mm rotors will suck the eyeballs out of your head if properly set up.
However, the Wilwood Calipers certainly are capable of more total friction and fade resistance if used with slotted rotors.
Properly set up is the issue. Then the brake parts themselves will make a difference. Putting big brakes on the stock car will not significantly improve stopping distances or fade resistance more than simply slotting the stock rotors. That would be the first step.
Secondly, the suspension setup as delivered on pre 100 cars was really meant for normal street driving. It soon became apparent in track testing and certain open road (we can't say where or when) situations that the stock setup needed upgrading.
This has been done by Autofutura on the newer cars, post 100 and we have components to retrofit the earlier cars such as yours.
I've spoken about controlling the contact patch before on the forum, in brake discussions. I'm all for stopping as quick as possible because these cars get up and go really really fast.
On a practical side you have to consider all the costs and effects of changing the brakes. If you increase either the rotating mass or the diameter of the rotating mass of the brakes, there will be horsepower penality. This will cost in acceleration and somewhat ad to the need for bigger brakes in stopping. Also a net increase in weight will effect the sprung to unsprung weight ratio unfavourably, hurting ride quality. But damm those big brakes are pretty!
So to get the car to stop better you have to improve control over the contact patch. Most of the braking power to be gained is in the rear brakes. In the stock car the rear end geometry leaves a lot of room for improvement under high braking loads. This is caused by the lower control arms geometry, lack of adjustability and rubber mountings.
This is also why some owners can't dial out enough rear brakes, they're locking early because the maximum tire contact patch is not being used.
CAVs fitted with our Revised Lower Control Arm Kit have gained stopping power, handling and ride improvements. We also fix the wheelbase at the sme time. There are also geometry improvements in the new Steel Rear Upright that further improve cornering and driver confidence at higher speeds.
The stock front end can produce decent stopping forces if aligned correctly and tires not over inflated. This is straight line braking on smooth surfaces. If you're planning some track days or spirited road driving, then our new Steel Front Uprights will help you out even more.
There are posting in CAV talk about the new suspension bits, take a look at it and give me a call or email.
Cheers
Hi Syed,
You could try some local race shops or machine shops. Somebody can slot your stock rotors. There should be an OEM part available although what disc corresponds is not known at this time. Hmmmmmm The as-supplied carbon metalic pads are darn good btw, I'd use them unless you've glazed them.
Cheers
You could try some local race shops or machine shops. Somebody can slot your stock rotors. There should be an OEM part available although what disc corresponds is not known at this time. Hmmmmmm The as-supplied carbon metalic pads are darn good btw, I'd use them unless you've glazed them.
Cheers
I decided to remove the front right rotor on my CAV over the weekend to investigate the pulling upon hard braking I have been experiencing for some time now. I also intend to machine in slots in the rotor while its out. After removing the adaptor and the rotor it became apparent that 4 of the lug bolts were loose, it seems that the holes on the hub are too big so that splines on the shoulder of the bolts simply rotate in the hub holes. I also noticed that the head of the one good bolt had been welded to the hub at one point. Upon closer examination it became obvious that the heads of the 4 other bolts had also been welded onto the hub and I probably broke the weld joints when loosening the pin drive nuts.
Is it possible that the bolts of incorrect size were used when the car was assembled in South Africa (CAV N0 51) and they simply welded the heads of the bolts to the hub to overcome the problem?.
Obviously the bolts have to be replaced but I do not know how to remove them as there is very little clearance between the hub and the upright. Do I have to remove the hub?.
Also what type of bolts do I need and where can I get them from.
Is it possible that the bolts of incorrect size were used when the car was assembled in South Africa (CAV N0 51) and they simply welded the heads of the bolts to the hub to overcome the problem?.
Obviously the bolts have to be replaced but I do not know how to remove them as there is very little clearance between the hub and the upright. Do I have to remove the hub?.
Also what type of bolts do I need and where can I get them from.
TonyM
Lifetime Supporter
Just as an FYI my car (which I purchased new) also had some of the studs welded to the hub, pics available on request.
Cheers,
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