wheel design effect on braking

[65up2d8]

I love the look of TTII wheels like many people on this forum. However, I also agree with many others who say that too many people are using TTII's and would like to see something a bit different. I have had a set of 15x7 and 15x8 Centerline Billet Stars on my car since the early 90's, and although I love the look of these wheels on my car, I want to upgrade to 17" or 18" wheels. I don't have a digi cam, so I can't provide pictures of my car at the moment. However, check out this link for the wheels: http://www.centerlinewheels.com/wheels_detail.php?mw_id=1&sw_id=1 (Mustang's Plus ran this wheel on a car they call Ol' Blue for a while).

Now, to my question: I have often read that an open spoke design wheel contributes to brake cooling and, accordingly, brake performance. I am currently running Granada disks up front and a Lincoln Versailles disk brake rear, but I want to go with the mustangsteve's 13" Cobra front brake kit and convert to PBR calipers on the Versailles rear asap. If I go with a fairly closed spoke style 17' or 18" wheel similar to my current wheels in the process, do you guys think the braking will be noticeably affected? Please don't throw me the softball answer of it depends on whether I intend for it to be a daily driver or a race car; I certainly understand that. Suffice it to say that I do intend at times to ride the brakes hard for long periods.

In addition, I have a Shelby R Model style front valance with bumper and side scoops that I could easily plumb and make functional for brake cooling. In particular, do you think I'd see any negativity in braking performance if I plumbed the brakes for fresh air?

Sorry this post is so long, but I felt all of the above factors had to be included to get down to the nuts and bolts of my question. I thank you in advance for any thoughts.

 

[65ShelbyClone]

As long as you have the stock disc brake dust shield with the scoop in it or ducting of your own so the center of the rotor is fed air, I dont think the wheel will affect braking at all. The only way it might is if your tire height is increased or if the rim is really close to the caliper/rotor. Since you'll have at least 17" wheels, that shouldnt be a problem. The brakes really dont get alot of cooling from the outboard side of the wheel.

 

[10secgoal]

Cooling would be better, yes. But it will be harder to stop. Not saying you may even notice it, but just the physics of having a taller tire, will the give the tire more leverage to use against the brakes when trying to stop.

 

[67coupe351w]

But it will be harder to stop. Not saying you may even notice it, but just the physics of having a taller tire, will the give the tire more leverage to use against the brakes when trying to stop.

Which is why you should be scared when you see the homiez with the 22's and the stock brakes. Very bad idea....infact even Jessie James has talked about this so you KNOW its gotta be true.

 

[shotsy]

Sorry to Hijack but I just did the MP front disk conversion on my 70 and the kit didnt come with any shields? What kind of probs would I have running no shields on the front disks?

 

[65ShelbyClone]

Probably none unless you do enough serious and repeated braking to fade them. They will help, but alot of people go without on street cars.

 

[rbohm]

there are a number of things that affect braking in regards to wheels, backspacing, rim weight, rim height, tire width, tire footprint, tread pattern, tread material, and spoke design. all else being equal, open spokes CAN influence airflow through the wheel. poor spoke design can block airflow through the wheel thus holding heat in. wheel design, and wheelwell design allows air to flow from the inner area of the wheelwell to the outer area. the better the design, the better the airflow. you can have two wheels, one with open spokes and one with closed spokes, and depending on the overall design, one will flow more air through the wheel than the other will. sometime open spokes are not the best way to go. all the said, the spoke design has a minor effect usually on brake performance, except in a race situation, and even then brake performance depends less on spoke design than other factors.

 

[65up2d8]

I guess the ultimate reason I made this post, and the question I'm asking is, how would a 17" Centerline Auto Drag (if available) compare with a 17" 2003 Mach 1 wheel in terms of brake cooling, all other considerations aside?