DIY Brake Ducts for a Series II - Page 2 - RX8Club.com



Series II DIY DIY projects specific for Series II RX-8s

Reply
 
 
 
Thread Tools Search this Thread Rate Thread
Old 06-27-2017, 10:12 AM   #26
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
When I bought my Miata last summer, I said to myself, "Self, if you have 2 sports cars, 1 will always be ready to go to the track. This idea is brilliant!"

The reality is, that 2 sports cars are always on jack stands, instead of just 1. RX-8 still has no hubs. Broke an end link on the Miata and heat cycled the tires out of service last Saturday. No cars ready to go to the track.
Steve Dallas is offline   Reply With Quote
Old 06-27-2017, 11:01 AM   #27
Registered
iTrader: (38)
 
9krpmrx8's Avatar
 
Join Date: Jan 2007
Location: San Antonio, Texas
Posts: 33,004
Thanked 90 Times in 80 Posts
I still have the ducts that are made to go in the S1 bumper if anyone is interested, I was going to use them for something else but never installed them.
9krpmrx8 is offline   Reply With Quote
Old 06-28-2017, 08:33 AM   #28
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
Minor update to this thread.

1. Hubs finally came in, car is back on the ground on its stock wheels.

2. No signs of rubbing during the drive to work this morning. I'll visually inspect it tonight.

3. The sound of wiffel ***** tells me the rotors are receiving air pressure.

4. I believe my track wheels (255s on 17x9s) will rub at full lock. I have that "problem" with my Miata, too.
Steve Dallas is offline   Reply With Quote
Old 06-28-2017, 10:42 PM   #29
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
Minor-er update.

Pulled the front wheels tonight. No signs of rubbing with the stock wheels, and I tried to make it happen.

I'm still pretty sure my track setup will rub under full lock, but #supernicegrandtouingfivepercenterracecar.
Steve Dallas is offline   Reply With Quote
Old 07-09-2017, 05:30 PM   #30
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
I have some data. Unfortunately, I do not have good comparison data against the Miata photo above, because I ran a different track configuration this morning, and the session times were different.

Let's talk about that track configuration. I ran the 1.3 mile track on the left side of this photo. You'll notice it has no long straights. It also has mostly low speed corners. Those two things together make it absolutely brutal on brakes. I normally dry boil fresh 600 fluid after about 15 minutes on this track. The Miata temperatures were shot after a session on the 1.7 mile track on the right side, with its long straights and sweeping, high speed turns. Totally different animal. This morning's sessions were 30 minutes long, and the Miata sessions were 20 minutes long.




Here's a video of me driving that track last year.



I shot brake pads temps after sessions 2 and 3. I was able to run a full cool-down lap at the end of session 2. I managed only half a cool-down lap at the end of session 3.

These photos are of the right side brake pads, which get the hottest on a CCW track.

Session 2:




Session 3:




So, low 500s. I was hoping for a little better cooling performance, but this certainly is not terrible. Previously, my pyrometer would not even measure this, as it maxes out at 800F, and my pad temps were higher than that on every track configuration. This is definite improvement. I am not displeased.

The other consideration has to do with robbing air from the radiator to cool the brakes. That seems to be OK. I don't have any new data for very high ambient temps to compare to my old data (see radiator thread linked above), as the ambient temps for session 2 and 3 this morning were 86F and 90F, respectively. No idea what a 95F or 100F session would look like, and I no longer care to find out.

These charts don't look too far out of line. I may have lost a few degrees of cooling capacity, but the difference is not dramatic.

Session 2:




Session 3:





Wait. What happened there in session 3? The answer is, I ran up on a Miata that would not let me pass. So, I backed off to give him half a lap of space. Then I caught him again. Then the session ended. Some people.

.

Last edited by Steve Dallas; 07-10-2017 at 07:29 AM.
Steve Dallas is offline   Reply With Quote
The Following User Says Thank You to Steve Dallas For This Useful Post:
wankelbolt (07-09-2017)
Old 07-10-2017, 06:02 PM   #31
Registered
 
Join Date: Feb 2017
Location: Austin, TX
Posts: 399
Thanked 47 Times in 38 Posts
800F+ down to 490-510 is pretty amazing. The coolant temps are fine compared to a lot of your older charts. It might not be the fairest of comparisons, but it would seem like the smaller slower track would exacerbate these problems if anything.

Last edited by Reoze; 07-11-2017 at 09:12 AM.
Reoze is offline   Reply With Quote
Old 07-11-2017, 07:11 AM   #32
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
Agreed on all points. I tried to stress that the track drives up brake and coolant temps due to its layout.

I take turns 1 and 2 in 4th gear. The rest of the track consists of bouncing off the rev limiter in 2nd and 3rd, so RPMs are unusually high nearly all the way around. Otherwise, there is lots of hard braking with little opportunity to cool the brakes back down. This track is basically a torture test. Not displeased at all.
Steve Dallas is offline   Reply With Quote
Old 07-28-2017, 03:18 PM   #33
Registered
 
Join Date: Mar 2017
Posts: 18
Thanked 0 Times in 0 Posts
By no means was I trying to be confrontational in the other thread about pads. Hope you didnt take it that why. Figured Id bring the discussion here though. Did you check temps with different pads before or after you installed the ducts? Curious if Hawk pads were running at different temps than your carbotechs.
300zxsteve is offline   Reply With Quote
Old 07-28-2017, 03:42 PM   #34
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
No worries. You were right. I was causing the discussion to meander.

I don't have hard temp data on different pads. I did shoot Hawk pad temps now and then, and I remember them being similar to Carbotech temps. I know I was eating those too. Hawk's pretty powder coating didn't last through 1 track session.

The main reasons I quit using Hawk pads were rotor wear, pad wear, ungodly loud noise, and poor modulation. Carbotech pads cost more, but brake parts last at least twice as long, noise level is lower, and pedal feel is very linear.

EDIT: For data points, the Hawk pads I used on track were HP Plus, Street/Race, DTC-30, and DTC-60.

.

Last edited by Steve Dallas; 07-28-2017 at 03:51 PM.
Steve Dallas is offline   Reply With Quote
Old 07-28-2017, 03:49 PM   #35
Registered
 
Join Date: Mar 2017
Posts: 18
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Steve Dallas View Post
No worries. You were right. I was causing the discussion to meander.

I don't have hard temp data on different pads. I did shoot Hawk pad temps now and then, and I remember them being similar to Carbotech temps. I know I was eating those too. Hawk's pretty powder coating didn't last through 1 track session.

The main reasons I quit using Hawk pads were rotor wear, pad wear, ungodly loud noise, and poor modulation. Carbotech pads cost more, but brake parts last at least twice as long, noise level is lower, and pedal feel is very linear.
Interesting. And you mentioned youre just using any low cost off the shelf rotor? In the interest of weight and heat dispersion is there a reason why you don't have a two piece rotor where you could just replace the ring?

FWIW I ask because the stock brakes on my newly bought rx8 are all but trash.
300zxsteve is offline   Reply With Quote
Old 07-28-2017, 03:55 PM   #36
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
At the time, I was buying OE rotors from Mazdaspeed Motorsports Development. My RX-8 is currently wearing StopTech Sport slotted rotors, because they were on clearance somewhere online.

I use any old cheap rotors on my Miata, on which I installed brake ducts immediately. I will probably do that on the RX-8 going forward, now that it is ducted.

I don't use 2 piece rotors on the RX-8 mainly because of cost. IIRC, Racing Brake may be the only option, short of a BBK, and there are "issues" with RB and pad selection. I haven't gone to a BBK, because I don't need more stopping power. I only need more heat dissipation capacity, which a BBK would give me, but ducting is more effective and much less expensive.

Last edited by Steve Dallas; 07-28-2017 at 03:59 PM.
Steve Dallas is offline   Reply With Quote
Old 07-28-2017, 04:44 PM   #37
Registered
 
Join Date: Mar 2017
Posts: 18
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Steve Dallas View Post
At the time, I was buying OE rotors from Mazdaspeed Motorsports Development. My RX-8 is currently wearing StopTech Sport slotted rotors, because they were on clearance somewhere online.

I use any old cheap rotors on my Miata, on which I installed brake ducts immediately. I will probably do that on the RX-8 going forward, now that it is ducted.

I don't use 2 piece rotors on the RX-8 mainly because of cost. IIRC, Racing Brake may be the only option, short of a BBK, and there are "issues" with RB and pad selection. I haven't gone to a BBK, because I don't need more stopping power. I only need more heat dissipation capacity, which a BBK would give me, but ducting is more effective and much less expensive.
Thanks for the help and insight.
300zxsteve is offline   Reply With Quote
Old 07-28-2017, 06:40 PM   #38
Registered
 
sinkas's Avatar
 
Join Date: Oct 2002
Location: Fremantle, Western Australia
Posts: 303
Thanks: 0
Thanked 8 Times in 7 Posts
Hey Steve, what do you use to record the track footage? Harrys lap timer and a smartphone?
sinkas is offline   Reply With Quote
Old 07-28-2017, 06:59 PM   #39
Registered
 
sinkas's Avatar
 
Join Date: Oct 2002
Location: Fremantle, Western Australia
Posts: 303
Thanks: 0
Thanked 8 Times in 7 Posts
Hey Steve, what do you use to record the track footage? Harrys lap timer and a smartphone?
sinkas is offline   Reply With Quote
Old 07-28-2017, 09:21 PM   #40
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
Yes. Exactly that. I also have a GoPro that I use sometimes. I wish data overlays were easier with the GoPro. That leads me to use Harry's on my phone, which is out of sync and just not very good on Android.
Steve Dallas is offline   Reply With Quote
Old 07-28-2017, 09:25 PM   #41
Registered
 
sinkas's Avatar
 
Join Date: Oct 2002
Location: Fremantle, Western Australia
Posts: 303
Thanks: 0
Thanked 8 Times in 7 Posts
Quote:
Originally Posted by Steve Dallas View Post
Yes. Exactly that. I also have a GoPro that I use sometimes. I wish data overlays were easier with the GoPro. That leads me to use Harry's on my phone, which is out of sync and just not very good on Android.
Sorry to hijack thread, but what mount for you use for your phone? ?RAM?
sinkas is offline   Reply With Quote
Old 07-28-2017, 09:28 PM   #42
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
I'm using an Encased mount for a Galaxy S5. It doesn't suck too badly after liberal application of glue. A Ram mount would probably be better, but much heavier.
Steve Dallas is offline   Reply With Quote
Old 08-02-2017, 07:56 AM   #43
Water Foul
Thread Starter
 
Steve Dallas's Avatar
 
Join Date: May 2013
Location: Republic of Texas
Posts: 1,753
Thanked 61 Times in 44 Posts
In the spirit of confusing this thread a little more, here is a photo of my left front brake rotor and pad on my Miata. This is Centric's cheapest blank and a Carbotech XP10 pad. These brakes were ducted from the beginning and now have 13 track days over 6 months on them. A few of those track days were at least partially wet, and two featured my son driving as a novice, so let's call it 8 or 9 real track days.

The rotors show very little wear, and the pads have roughly 70% life left in them.

Cheap rotors + gentle pads + ducting = winning combination.

Steve Dallas is offline   Reply With Quote
 
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 02:49 AM.


All content Copyright 2017 by Internet Brands, Inc.