Ok this past weekend at VIR guys from Hawk were there for mandatory brake classroom session, and also offered to shot brake temps during one of our sessions. So the classroom was basically a refresh of the stuff I have been reading online. During the session that they offered to shot rotor temps half way through the session I tried for 2 consecutive laps to compress my braking zones and shot into the pits for temps. LF 800deg RF 830deg LR320deg RR 330deg. These temps are well withing the range of the pads I'm running, Cobalt XR3 F and GT sports R. The guys suggested passably some ducting for the future. Also after my last session while swapping tires I see 2 large cracks in the LF rotor. These rotors only had 7 track days on them (I guess that's one too many). Anyway I did cruise the pits looking at others ducting, and have searched this site many time. This setup has me intrigued http://www.sandmracing.com/m_b05_ducts.html . As it was stated in class the guys from Hawk said that ducting should be aimed at the center of the rotor. But many of the ducting setups I have seen on cars and on this site are just aimed at the rotor. I guess my question would be is a 2 or 2.5 inch duct run to the center of the rotor like the linked setup truly any better than the almost standard 3 inch aimed any where towards the rotor or caliper?

Thanx for any input

Oh yeah please dont post the Picard GIF I did search.....

 

You, my friend...will not feel the Wrath of Picard. Not a bad question. Ducting to the center of the rotor should be better for all the reasons you've heard. Internal rotor design would favor that too, the way the vanes are. I think it's less commonly seen on cars here because it is more difficult to set up, being that the axles get in the way. Its also a matter of how effective the ducting needs to be for you. Just a small improvement in cooling, or what? Not much incentive to spend hours upon hours fabbing and busting your knuckles while something infinitely simpler will be adequate.

I've been in the same position as you, where I want to prolong the life of my rotors but am otherwise not having cooling issues. Eventually I'll get around to experimenting some, but it'll be awhile yet. That information could be available elsewhere too.

Edit: One last thought. VIR is not a great judge of how your brake system is doing. Those long straights allow for a lot of cooling off. What kind of experience do you have on a track thats harder on the brakes? BeaveRun and Shenandoah Circuit come to mind, I know there are others.

 

Yes, good question.

Just a data point - seven track days isn't all that bad for front rotors. I generally get 800-1200 track miles to a set of front rotors on the NSX, with 2.5" ducting blowing on the back surface of the rotors. At that point the cracks are significant enough (figure 1/2" long) that I have to replace them. Rears last forever.

 

I just redid mines with 2.5 inch vacuum hose. And a super headlight mod

heres the headlight intake mad half way through



and the ducting thanks to Karl

 

TO A SOLID QUESTION!
as for rotor life, 7 days aint bad. i dont know if ur on street tires or r-comps but thats not bad either way. as for a good set-up for ducting, yes. getting air directed into the center so it exits through the veins is most important. we tried it the other way on the h5 car and...well we went througn alot of brake parts rurring the enduro last year.
another thing that kills rotors is the uneven clamping forces provided by stock rotors. just as an example, h2 itr on stock calipers. the rotors get heat checks in them like everyone else int he world. swaped to spoon calipers-no more heat checks. i'm not saying spoon salipers are the ****. but its the more even clamping force that spreads the load evenly between the 2 sides of the rotor and thus lets it go on getting the chit kicked out of it for a few more weekends.

ps-shane is gonna kick my *** this year!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lo-Buck EF &raquo;</TD></TR><TR><TD CLASS="quote">we tried it the other way on the h5 car and...well we went througn alot of brake parts rurring the enduro last year.</TD></TR></TABLE>

Sweet, good to know. Looks like fabbing time You have any pics of the H5 ducting?

 

those pads were just getting warm.


Take a picture of the cracks so we can see.

 

There are a few tracks I've raced at that really cause the brakes to heat up and I got brake fade. I wasn't too concerned with getting the optimum amount of brake cooling and didn't want to spend a significant amount of time or money to do it. I went off to the Home Depot race shop and bougtht two collector/reducers found in the dryer isle. I then got some brake hose from OG Racing (they sell it at a great price!) http://www.ogracing.com/catalo...METER

The collector/reducer was mounted in the air dam. Then I used two soup cans that would be used to route air to the rotors (each can had a 3" diameter). I simply drilled a hole in each soup can and used one of the existing Honda bolts that was right near the rotor to secure the can. Some zip ties and racers tape finished the job. It was inexpensive and works very well.

Oh, I'd be pretty annoyed if I only got 7 days out of my front rotors. Then again I do have a pimpy brake cooling system. LOL

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stinkycheezmonky &raquo;</TD></TR><TR><TD CLASS="quote">

Sweet, good to know. Looks like fabbing time You have any pics of the H5 ducting?</TD></TR></TABLE>
i do not. they were on my harddrive when it crashed. but the h5 car is getting a new brake set-up when the h2 motor goes in. so hopefully we can make it through the 4 hour enduro w/o changing all the front brake parts (calipers, pads, rotors, lines) durring the event.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stinkycheezmonky &raquo;</TD></TR><TR><TD CLASS="quote">
Edit: One last thought. VIR is not a great judge of how your brake system is doing. Those long straights allow for a lot of cooling off. What kind of experience do you have on a track thats harder on the brakes? BeaveRun and Shenandoah Circuit come to mind, I know there are others.</TD></TR></TABLE>

VIR is the only track I have run thus far.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lo-Buck EF &raquo;</TD></TR><TR><TD CLASS="quote"> TO A SOLID QUESTION!
as for rotor life, 7 days aint bad. i dont know if ur on street tires or r-comps but thats not bad either way. </TD></TR></TABLE>

5 days on street tires the last 2 on full tread RA1's (from the video I shot was running 2:24-2:28 lap times)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">those pads were just getting warm.


Take a picture of the cracks so we can see.</TD></TR></TABLE>

Oh I had no brake fade at all but the air temp was only in the 40's when those temps were taken. Also the carcks are approx an inch long from about the middle of the rotor to the edge where you can see the crack is clean through. No camera right now to take pics

 

suggestion-since your still on a street pad and r-comps your gonna need to upgrade pads to something that'll deal more with the heat generated by braking forces on r-comps.

if i ever get around to making ducts (hopefully before hyperfest) i will put up some pix0rs

 

If you want more info, I have to change front rotors when I change the front pads (Hawk Blue). I get about 4-5 races (1 hour of track time per race) out of the rotors (OEM). This is a full race (track only) setup and it is a relatively heavy car for H4 (2600 lbs).

I have 3" brake duct (industrial vacuum hose) that tries to point at the middle of the rotor. Its not perfect (cause there is no way I am fabricating what that guy in the link did), but it does the job.

 

ive been planning on setting this up for a while, and think i have it all finally figured out. Come spring ill have it done, and ill be sure to post pics.

 

I think I'm going to try to fab up something like the link I origionaly posted. Only because its pimpy and I get metal for free.. Oh yeah and I cant afford to do anything else to the car right now... So maybe my brake ducts will look BALL'IN.. If I do, do this I'll take pics..