your opinions on brake ducting

[foolio2k4]

Ok so I want to get your opinions on brake ducting. Im trying to follow the least costly approach to this.

So this was my idea. Im getting ready for track days this spring/summer so i've already picked out my fluid and pads.

now, i know its a good idea to have ducting to cool the brakes and reduce fade. I have a GT500 front end so what i planned was to have a dual ducting system. Using the traditional lower grill ducting and removing the fog lights and using that as a secondary, larger, ducting system. As for the backing plate, I was thinking of creating 2 holes the size of the duct and then having a shop weld a circular metal to create a bracket to connect the ducting hoses to.

Does this seem like a feasible idea? If its a little confusing to understand and ill try and make it clearer.

something like this. minus the carbon fiber of course haha

 

[SoundGuyDave]

Couple of things... First, there really isn't room in a *stock* Mustang wheelhouse for that much ducting while still retaining full lock capability. Second, most of the "hardcore" racers seem to be making it by okay with just a single 3" duct.

I *THINK* that the name of the game is efficiency rather than quantity. If you can set up a brake ducting system that minimizes the number of bends between the duct inlet and the duct outlet, you'll be in better shape than with one that zig-zags all over the place. After you've worked out a routing (look out for the washer bottle!!), then concentrate on efficiency at the outlet side. Look for brake duct plates that seal against the inner hub of the rotor, so that all that lovely cool air is forced through the vanes, and not just blowing all over the place. Finally, look for inlet efficiency. Try to mount your ducts in a high-pressure area of the front fascia. Oil flow plots are probably the best bet for figuring that out, unless you have other packaging constraints.

Due to class regs, I'm "reverting" to a stock fascia for this season, and had to start over from scratch with the ducting scheme. I'm doing 6"x3.5" rectangular ducts in the fascia, low, under the turn-signal lamps, as close to the corner of the lower grille opening as I can get. Due to an oil cooler, remote-mounted oil filter, and a few other goodies, I can't run the grilles in the corners of the lower grille like everybody else does. I may have to relocate my coolant catch tank and transponder for routing, but that's relatively minor. For the outlets, this is what I'm using:

Fabbed aluminum, nice pieces.

 

[Philostang]

For the outlets, this is what I'm using:

Fabbed aluminum, nice pieces.

Yeah, those are nice...

Of course, if you had a friend with a welder, you could do near the same with the stock dust shields...just saying...if you had one around...

It would look something like this...

foolio, regardless of whether or not you fab your own piece or purchase another, what you're looking for is an outlet that securely aims the air at the center of the rotor.

Sometimes you see outlets that are very large (often made of carbon fiber), and these often have multiple inlet ports. From what I gather, the function there is to get cool air to the caliper as well as the rotor. One or more ducts will aim at the caliper and another will aim for the center of the rotor. I'd say that for the overwhelming majority of us (even those doing some pretty hard-core running), this is not really necessary. Most of us deal with hot calipers by upgrading our fluid to live in that environment, and that takes care of any problems we're likely to encounter. Cooling your rotors is a much higher priority.

Best,
-j

 

[SoundGuyDave]

Yeah, those are nice...

Of course, if you had a friend with a welder, you could do near the same with the stock dust shields...just saying...if you had one around...

So... What are you trying to say? What, like I'm not burying you under enough projects??? Now, go spend time with your wife, so you can come back to my shop and weld some more! (j/k)

foolio, regardless of whether or not you fab your own piece or purchase another, what you're looking for is an outlet that securely aims the air at the center of the rotor.

Sometimes you see outlets that are very large (often made of carbon fiber), and these often have multiple inlet ports. From what I gather, the function there is to get cool air to the caliper as well as the rotor. One or more ducts will aim at the caliper and another will aim for the center of the rotor. I'd say that for the overwhelming majority of us (even those doing some pretty hard-core running), this is not really necessary. Most of us deal with hot calipers by upgrading our fluid to live in that environment, and that takes care of any problems we're likely to encounter. Cooling your rotors is a much higher priority.

Philostang speaks nothing but truth! A few things to consider, things I learned doing planning work for a buddy's Spec944 enduro car... MANY things will change depending on the anticipated use of the car. A lot of the trick, high-tech stuff we see on "real" race cars are geared towards the specific needs of the tracks they run, and the format of the series. As John mentioned, we handle brake temp buildup in the calipers primarily with fluids, but we're also "engineering" our setups for 15-minute Time Trial sessions, 20-30 minute HPDE sessions, or 45 minute sprint races. When you start talking about 3-8 HOURS of constant running, priorities and needs start to change. Caliper cooling (for the most part) is overkill for what we do, and the penalty paid in complexity, cost, aero loss, etc. is much higher than the temp reduction benefit. Start looking at a few hours, though, and suddenly that equation changes. Just like Hoosier A6 tires on the S197 are great for initial fast laps, after about 10-15 minutes of hard running, they're starting to grease up. The R6 tires take 3-5 minutes to start to come in, but they'll hang for quite a while once up to temp. Then you get to the Hoosier GAC (Grand Am Cup) tires, which sacrifice the velcro-like grip of the A6/R6 in favor of a tire that can run for 90-120 minutes without falling off (performance, not physically), and probably run even longer than that. With length increasing, other fluid cooling needs start to crop up... Brake fluid recirculators, trans and diff coolers, larger oil coolers, power steering coolers, etc. all become "interesting," but if you're in a TT or sprint format, they're just not worth the hassle, cost, and added potential failure points.

For what we do, good ducting practices with a single 3" feed is generally plenty. Remember, with race brakes, it IS possible to over-cool them. When I run Road America, I have to partially block my ducts, since the pads get cold enough to start losing grip again.

 

[foolio2k4]

Yeah i dont think i will need to cool my stock calipers anytime soon.

So i will definately have to go back and check clearances on my car for enough space for brake plumbing.

The lower GT500 grill inlet is way to small IMO to be of any effect. hence the reason to go dual and replace the fog lights.

Is it a good idea to have some type of mesh at the inlet to stop larger debris from entering the ducting? Would debris like that cause damage to the rotor?

 

[Philostang]

Actually, to do one up yourself has two main parts, the cut/grind/fit part and the weld part. The weld part I'm offering is easy...and I'm leaving the rest to you. >=)

Seriously, these things are not rocket science. We're talking about a dust shield you already have (unless you Frisbee'd the things out the door one night) mated to 1/2 of a $5 section of exhaust tube. That means it's $5 for both. It's all in the labor...and you're doing most of it. >=)

And if you're wondering why all the mean smilies, wait till you see the curves in the existing dust shield. Still, I think it shouldn't be hard to do this better than I did the first time through, so part of my motivation is revenge.

Best,
-j

 

[ArizonaGT]

Another thing to take into account is the ducting + pad combo.

Running DTC70s, with brake ducts all the way open, I notice less initial bite, but it ramps up quickly if the brake is held down. The more I close the ducts w/ tape, the more initial bite I get.

This is a function of pad operating temperature--so the cliff notes are to understand the operating temp range of your pads, and consequently how cooling will effect this.

 

[FR500GT]

What ducts are those?

Couple of things... First, there really isn't room in a *stock* Mustang wheelhouse for that much ducting while still retaining full lock capability. Second, most of the "hardcore" racers seem to be making it by okay with just a single 3" duct.

I *THINK* that the name of the game is efficiency rather than quantity. If you can set up a brake ducting system that minimizes the number of bends between the duct inlet and the duct outlet, you'll be in better shape than with one that zig-zags all over the place. After you've worked out a routing (look out for the washer bottle!!), then concentrate on efficiency at the outlet side. Look for brake duct plates that seal against the inner hub of the rotor, so that all that lovely cool air is forced through the vanes, and not just blowing all over the place. Finally, look for inlet efficiency. Try to mount your ducts in a high-pressure area of the front fascia. Oil flow plots are probably the best bet for figuring that out, unless you have other packaging constraints.

Due to class regs, I'm "reverting" to a stock fascia for this season, and had to start over from scratch with the ducting scheme. I'm doing 6"x3.5" rectangular ducts in the fascia, low, under the turn-signal lamps, as close to the corner of the lower grille opening as I can get. Due to an oil cooler, remote-mounted oil filter, and a few other goodies, I can't run the grilles in the corners of the lower grille like everybody else does. I may have to relocate my coolant catch tank and transponder for routing, but that's relatively minor. For the outlets, this is what I'm using:

Fabbed aluminum, nice pieces.

 

[SoundGuyDave]

I got them from another member at Corner-Carvers.com, but they came with "Fulltiltboogieracing.com" stickers on them, if that helps.

 

[DusterRT]

I got them from another member at Corner-Carvers.com, but they came with "Fulltiltboogieracing.com" stickers on them, if that helps.

He's on SVT Performance too, which you don't need to join to see threads on, his email is in there somewhere I think..anyway I've got them too, not cheap but nice pieces for sure.

http://www.svtperformance.com/forum...9-front-brake-cooling-ducts-finally-done.html