Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

THE Ducting / Heat Transfer Thread

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 07-27-2007 | 10:24 AM
  #26  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 38
From: macon, georgia
i am hitting a little over 130 on the back straight, really can gain on people in that braking zone. we are turning 1:46's or so. Stock pads are probably contributing a lot to your problem. Sounds also like you have a lot of wheel energy to burn off!
my track tire and wheels and lugnuts only weight 40Lbs apiece
Hope to see you at RA sometime--our group will be there Aug 11/12--come on down!
olddragger.
Old 07-27-2007 | 11:31 AM
  #27  
Red Devil's Avatar
Registered User
 
Joined: Jun 2002
Posts: 3,086
Likes: 1
From: Misinformation Director - Evolv Chicago
Originally Posted by olddragger
i am hitting a little over 130 on the back straight, really can gain on people in that braking zone. we are turning 1:46's or so. Stock pads are probably contributing a lot to your problem. Sounds also like you have a lot of wheel energy to burn off!
my track tire and wheels and lugnuts only weight 40Lbs apiece
Hope to see you at RA sometime--our group will be there Aug 11/12--come on down!
olddragger.
+1 for the XP8/Bobcat combination.

I suspect that some are also experiencing brake fade because they aren't using their brakes properly. In other words, they are riding them too much, and not squeezing them on and then getting off of them...or frankly are overusing them by slowing before corner entry way more than they should be. At various points, and dependent on track, I'm sure I'm guilty of some if not all of the above.

And great idea for a thread. I wish I could contribute to oil and water cooling, but have a low level grasp of the theory behind this stuff...
Old 07-27-2007 | 11:39 AM
  #28  
Michael's Avatar
Thread Starter
Registered
 
Joined: May 2005
Posts: 456
Likes: 0
From: Houston
Originally Posted by Red Devil
+1 for the XP8/Bobcat combination.

I suspect that some are also experiencing brake fade because they aren't using their brakes properly. In other words, they are riding them too much, and not squeezing them on and then getting off of them...or frankly are overusing them by slowing before corner entry way more than they should be. At various points, and dependent on track, I'm sure I'm guilty of some if not all of the above.

And great idea for a thread. I wish I could contribute to oil and water cooling, but have a low level grasp of the theory behind this stuff...
My gauges should be sitting at my front door right now [I'm at work at the hospital], and I will hopefully be purchasing adapters next week.

Then we'll be able to see differences [if any] the REVi duct makes, as I'm running a REVi without duct, and Joe RX-8 so graciously gave us temps with the REVi. I figure it's going to rob at least a little airflow from the radiator, but we shall see.

I'm for sure purchasing [new or used] the RB oil pressure/temp adapter, but I'm trying to warrant the price of the water temp adapter if a brass t-fitting from Home Depot or Lowes would accomplish the same thing...
Old 07-27-2007 | 11:49 AM
  #29  
Joe RX-8's Avatar
zoom-zoom
iTrader: (1)
 
Joined: Dec 2004
Posts: 139
Likes: 1
From: Johns Creek, GA
Originally Posted by olddragger
Sounds also like you have a lot of wheel energy to burn off!
my track tire and wheels and lugnuts only weight 40Lbs apiece
Hope to see you at RA sometime--our group will be there Aug 11/12--come on down!
olddragger.
Yea, I am still running on the stock rims, which gets expensive as I tend to chew through a half of a set of "max performace" street tires every day on the track. Been looking at the Enkei RP-F1 18x9.5 that seem to be popular, but haven't hit the lottery yet. If I go back out this fall, I'll bite the bullet and get something. What rims/rubber are you running?

What is going on at RA Aug 11/12? I didn't see anything on their schedule. I'll be in Florida that weekend, however.
Old 07-27-2007 | 01:30 PM
  #30  
Robbie's Avatar
Registered
 
Joined: May 2007
Posts: 29
Likes: 0
From: Pueblo
If I read this correctly, there is no duct for the oil coolers into the wheel well? If this is so, the efficiency of the oil coolers will go up is some sort of duct work or by venting the inner wheel well to allow air to move out of the oil cooler area. Otherwise pressure will just build up and airflow through the exchanger will be very small.
Old 07-27-2007 | 02:25 PM
  #31  
Michael's Avatar
Thread Starter
Registered
 
Joined: May 2005
Posts: 456
Likes: 0
From: Houston
Originally Posted by Robbie
If I read this correctly, there is no duct for the oil coolers into the wheel well? If this is so, the efficiency of the oil coolers will go up is some sort of duct work or by venting the inner wheel well to allow air to move out of the oil cooler area. Otherwise pressure will just build up and airflow through the exchanger will be very small.
If you look closely in this picture, you can see the itty-bitty vents:



If I ever get around to "fixing" that, I'd be more inclined to leave the plastic as is, but buy a 7" fan and some tubing to suck heat out from behind the cooler, over the wheel, and into the fender where it can exit out of a gutted gill or something, instead of opening the wheel well up to the elements+venting to the already hot wheel/calipers.
Old 07-27-2007 | 02:31 PM
  #32  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
I am in the middle of configuring my oil coolers for 6" fans. The cooler lines need to be re-fabbed (to clear the cooler instead of lay across it) and a new bracket is in order, but that is simple.
As soon as I figure out what the OE connectors are in thread and size, I can put this all together.
Old 07-27-2007 | 05:47 PM
  #33  
Michael's Avatar
Thread Starter
Registered
 
Joined: May 2005
Posts: 456
Likes: 0
From: Houston
Originally Posted by MazdaManiac
I am in the middle of configuring my oil coolers for 6" fans. The cooler lines need to be re-fabbed (to clear the cooler instead of lay across it) and a new bracket is in order, but that is simple.
As soon as I figure out what the OE connectors are in thread and size, I can put this all together.
That's wonderful news! I trust you'll share your findings with the world, as usual?

How far are you from Melbourne [Fla]?
Old 07-27-2007 | 06:32 PM
  #34  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
About 3000 miles.
I'll publish up whatever I figure out.
Old 07-27-2007 | 07:33 PM
  #35  
shaunv74's Avatar
Power!!
 
Joined: Feb 2004
Posts: 4,412
Likes: 3
From: Sunny See attle
I think there is definitely something to be had with ducting airflow out of the oil coolers and out of the engine compartment in general. Either out the top through a vented hood or out the bottom through some ducting downward. If you put a cowl around the oil cooler and angle it down to exit out the bottom of the car I would think that should help instead of the tiny slits into the wheel wells. You'll want to keep the total cross section equal so you don't lose airflow.
Old 07-27-2007 | 07:40 PM
  #36  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
The OE oil coolers are not only pathetically small, they are also blocked on their exit side by a bracket (covering the middle 1/3 of the cooler directly) and the inlet and outlet lines (covering nearly another 1/3 completely). After having 2/3 of their surface area blocked, they are expected to eject the hot air through some small slats on the wheel well dressing.
I don't know if there is a low pressure region in front of the wheels, but there is no real path for air at low speeds where most overheating occurs.
I am going to plumb the lines so that they exit the cooler perpendicularly (there is a ton of room) and then remove the OE bracket, replacing it with a 1700 CFM fan that will act as the bracket when attached.
I'll probably remove the slatted area of the wheel well and replace it with a mesh similar to what is present in the grilles of the MS nose.
Old 07-27-2007 | 11:02 PM
  #37  
Razz1's Avatar
Mu ha.. ha...
 
Joined: Aug 2004
Posts: 14,361
Likes: 3
From: Cali
CAn ja do a DIY or at least postr some photo's MM?
Old 07-28-2007 | 12:01 AM
  #38  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
When I finally build it, everyone will have a front seat.
Old 07-28-2007 | 09:54 AM
  #39  
Paul_in_DC's Avatar
Rotary Public
 
Joined: Dec 2004
Posts: 1,512
Likes: 2
From: Northern Virginia near DC
Originally Posted by MazdaManiac
The OE oil coolers are not only pathetically small, they are also blocked on their exit side by a bracket (covering the middle 1/3 of the cooler directly) and the inlet and outlet lines (covering nearly another 1/3 completely). After having 2/3 of their surface area blocked, they are expected to eject the hot air through some small slats on the wheel well dressing.
I don't know if there is a low pressure region in front of the wheels, but there is no real path for air at low speeds where most overheating occurs.
I am going to plumb the lines so that they exit the cooler perpendicularly (there is a ton of room) and then remove the OE bracket, replacing it with a 1700 CFM fan that will act as the bracket when attached.
I'll probably remove the slatted area of the wheel well and replace it with a mesh similar to what is present in the grilles of the MS nose.
Careful though. Remember how much stuff flies off those tires just in normal driving (rocks, sand, etc.) not to mention the amount of water they throw off on rainy days.
Old 07-28-2007 | 10:07 AM
  #40  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
We don't have rain.
The likelihood of rock being thrown forward is fairly slim, though I have been known to do a little backwards drag racing.
Old 07-28-2007 | 10:23 AM
  #41  
Kane's Avatar
Illudium Q-36 Space Moderator
iTrader: (1)
 
Joined: Jan 2007
Posts: 6,364
Likes: 43
From: PCB
Hey MM, have you ducted the fender vents at all?
Old 07-28-2007 | 09:41 PM
  #42  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 38
From: macon, georgia
one thing that hurts our oil temps that I dont see talked about much is that the oem oil coolers are not very efficient. Just put your hand on one after u have driven a while. Should be much warmer.
olddragger
Old 07-28-2007 | 10:08 PM
  #43  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
Originally Posted by olddragger
one thing that hurts our oil temps that I dont see talked about much is that the oem oil coolers are not very efficient. Just put your hand on one after u have driven a while. Should be much warmer.
olddragger
While I agree that the coolers as employed aren't up to snuff, that test would be meaningless.
In fact, if the coolers were very efficient, they would seem cool immediately after you opened your door.
The coolers themselves are not receiving maximum temp oil. Just tracing the line to the coolers shows this.
However, I'd say they are adequate just by measuring the temp difference between the two coolers, which is usually at least 20°F.
Old 07-29-2007 | 12:26 AM
  #44  
shaunv74's Avatar
Power!!
 
Joined: Feb 2004
Posts: 4,412
Likes: 3
From: Sunny See attle
Are the coolers in series?
Old 07-29-2007 | 08:10 PM
  #45  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 38
From: macon, georgia
tes the coolers are in series. While hand on cooler may not be exact--but your have on a fluidyne oil cooler and then put your hand on ours. approx same oil temp in both cars and if i remember correctly Jeff Goldburg(forgive me if I have the name incorrect) installed a 3nd cooler(fluidyne) in between the 2 oem ones. Guess which one was warmer --to the touch. To me logic says that if the cooler is warmer it is handling /dispensing more heat. I am a simple man---when ever I can be.
It will be an interesting project--let us know the difference in the temp of the oil being delivered to the 1st cooler and then the temp pf the oil and it returns to the engine if possible?
olddragger
Old 07-29-2007 | 11:36 PM
  #46  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 26
From: Under my car
Its MadDog (Tim) that has the third Fluidyne cooler between the two OEM coolers.
Old 08-03-2007 | 01:08 AM
  #47  
Silver_Surfer's Avatar
I4NI
 
Joined: Jun 2006
Posts: 833
Likes: 2
From: Hawaii
Michael:
Awsome Heat pics! Any chance of retaking these pics with a big fan blowing into the front of the vehicle? My reason is I(my 2 cents) belive the fender vents must work to a certain amount. Heck if you look under the hood at both approns you can see through the square holes at the fender side vents. How can they not work? Also from the front view the ac condenser & radiator was cool(dark color). The best way I think to retake these pics is when the vehicle is on a dyno at full throttle. I know this is asking alot but I would really like to see that!
Old 08-03-2007 | 03:27 AM
  #48  
Flashwing's Avatar
3-wheeler
 
Joined: Dec 2005
Posts: 2,734
Likes: 0
From: Phoenix
A previous trip to Tortilla Flats here in Phoenix gave me the opportunity to test my cooling upgrades since installing them. I'm currently running a Koyo Radiator and the Greddy oil pan.

I won't bore everyone with technical details of the drive...needless to say the environment is pretty harsh. We were experiencing air temps of 101 degrees and I was driving mostly in 2nd gear between 7 and 9k RPM's for several minutes.

Water temps held steady and climbed as high as approx 230 degrees but would quickly fall. The oil system held up for half of the trip but the system became heavily saturated and due to the low speed the coolers did little to get rid of the heat in an already hot climate.

Even if a low pressure are existed behind the coolers, the limited vent capability means most air hits plastic...

Having the high speed 6 inch fans means forcing air through the coolers which would be a huge benifit at low speeds as MazdaManiac pointed out.

I'm eagerly awaiting the arrival of these fans...I feel this would be a good alternative to a 3rd cooler though I am exploring this option as well.
Old 08-03-2007 | 11:10 AM
  #49  
Michael's Avatar
Thread Starter
Registered
 
Joined: May 2005
Posts: 456
Likes: 0
From: Houston
Originally Posted by Silver_Surfer
Michael:
Awsome Heat pics! Any chance of retaking these pics with a big fan blowing into the front of the vehicle? My reason is I(my 2 cents) belive the fender vents must work to a certain amount. Heck if you look under the hood at both approns you can see through the square holes at the fender side vents. How can they not work? Also from the front view the ac condenser & radiator was cool(dark color). The best way I think to retake these pics is when the vehicle is on a dyno at full throttle. I know this is asking alot but I would really like to see that!
They're not mine. Two sets have been taken [that I've seen] and been posted on this forum. Just search "thermographic" and both sets should come up.
Old 08-03-2007 | 07:42 PM
  #50  
Silver_Surfer's Avatar
I4NI
 
Joined: Jun 2006
Posts: 833
Likes: 2
From: Hawaii
Originally Posted by Michael
They're not mine. Two sets have been taken [that I've seen] and been posted on this forum. Just search "thermographic" and both sets should come up.
Thanks for the quick reply!! Just a thought.


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: THE Ducting / Heat Transfer Thread



All times are GMT -5. The time now is 05:50 PM.