Why are the driving light vents fake?
06-11-2007, 06:35 AM
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Why are the driving light vents fake?
I know one is filled with an oil cooler, but why don't they use the fake ducts either side of the main gill as brake vents?
Just not needed?
Just not needed?
06-11-2007, 07:00 AM
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Yeah I know but ex e30 BMW daily driver had big ducts in the air dam to feed vented disks. I suspect with the diametre of the vented rotors they figure they just don't need the extra air.
06-11-2007, 07:06 AM
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I think the Jap ones came with 2 oil coolers as well but since the aussies get the watered down version, the might have taken it away. As MissyK said, its a good idea to put a second one in if you plan to track heaps or add a supercharger or turbo to the car as insurance
06-11-2007, 07:06 AM
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If you're overheating your brakes to fade out that much on the road, should you really have a license?
The car's been made the way it's been made, you can change it if you want, but it's probably not worth it.
The car's been made the way it's been made, you can change it if you want, but it's probably not worth it.
06-11-2007, 07:23 AM
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(I'm have a little computer trouble so If this posts twice... ignore one.)
I'm not having trouble with the brakes. They put anything not tied down through the window at the mearest touch (see coffee holder reply in The Lounge thread.)
The 2nd oil cooler theory is probably correct. Cheers
I'm not having trouble with the brakes. They put anything not tied down through the window at the mearest touch (see coffee holder reply in The Lounge thread.)
The 2nd oil cooler theory is probably correct. Cheers
06-11-2007, 09:01 PM
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OK - I'm last person to be giving this lecture but the testosterone levels on this forum are getting too high. I suppose we're at that time of the cycle where we're all a bit frustrated and getting aggitated with each other. As usual we get over it and things go back to happy chappy. Breath in guys, I'm off to kick butt at Karate (first lesson back today), so be afraid.. :P 
hugs to all.
hugs to all.
06-12-2007, 03:37 AM
#24
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Guys!
I will set the record straight - none of you have the fact straight.
Yes - the fake plastic next to right fog lights are for the 2nd oil cooler.
and
Yes - Australian RX-8 only have the left oil cooler.
But
No - not all Japanese models have 2 oil coolers, only a selected model and some after market ones.
Certainly Type S has single oil cooler only. MazdaSpeed ver. has twin.
Only American models come twin standard.
And I think MazdaSpeed oil cooler is the same as the American right hand oil cooler.
I will set the record straight - none of you have the fact straight.
Yes - the fake plastic next to right fog lights are for the 2nd oil cooler.
and
Yes - Australian RX-8 only have the left oil cooler.
But
No - not all Japanese models have 2 oil coolers, only a selected model and some after market ones.
Certainly Type S has single oil cooler only. MazdaSpeed ver. has twin.
Only American models come twin standard.
And I think MazdaSpeed oil cooler is the same as the American right hand oil cooler.
06-12-2007, 04:01 AM
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I had a good crawl around under the car and I've made a few observations...
1) The vents behind the front wheel on the outside are real! Hey, go figure. Not that I thought they were fake I just didn't think what they were venting.
2) As they vent the oil cooler around the wheel arch, between the metal fender and the plastic inner skin. It seemed a long path for this air to travel. Why not open the back of the oil cooler area and let the air flow straight through and over the brake disks as well.
3) Can't do it. Here are two reasons why. 1) Warmed air from the oil cooler might not help cool a brake disk. 2) The vents as they are create a venturi effect and pull the air through the oil cooler by creating negative pressure behind it. Vent Strakes might even help a little because they channel passing air between them, there by increasing velocity and therefore negative pressure.
4) If you did open a vent at the back of the oil cooler straight to the disk brakes (as some late series RX7 owners did, some after market noses did have brake cooling vents under and separate to the oil cooling vents) then you'll decrease the air flow through the oil cooler. This was the major problem in constructing the air intakes for the Concorde. You need an air box in front of the cooler to slow the air down. To create an air box you will need to set the oil cooler further back and pit a grill in front. (For those who will point out that the Concorde is a defunct supersonic airliner and the RX8 is a landlocked daily driver... the principle is the same. You need to slow the air down to allow it to pass through the radiator otherwise it forms a kind of shockwave wall. I suspect this is why Mazda didn't put a grill on there to begin with. For them a grill is not just decoration. It serves a function.
5) I resorted a 28 Ford once and they there were always cooling problems with these old cars – even when they used thicker cores. They have no grill and therefore no air box to slow air. Ford got around this by sealing the area around the frame and engine with two long sheets of metal that flared downwards towards the rear. Like reversed scoops. They were to create venturi effect and pull air through the radiator because the air would dam in front of it. Many restorers left these parts out believing that the more space there was around the engine the more it would cool. Not so. It's the speed the air travels over the engine that makes a difference. Creating more space can increase volume but this may not increase heat transfer.
6) Which leads me to the value of the large flat plastic tray that runs from under the nose to behind the engine. As the cars get older and heat begins to make these more brittle and the odd spoon drain takes a swipe at it, it's vital these be replaced. Its part of the cooling system, it creates a negative pressure in the engine bay behind the radiator and therefore has a big role to play in the life of the engine. That goes for the engine cover to I suspect.
So keep cool. Here endith the thesis.
I wait with glee both intelligent and fatuous comment.
1) The vents behind the front wheel on the outside are real! Hey, go figure. Not that I thought they were fake I just didn't think what they were venting.
2) As they vent the oil cooler around the wheel arch, between the metal fender and the plastic inner skin. It seemed a long path for this air to travel. Why not open the back of the oil cooler area and let the air flow straight through and over the brake disks as well.
3) Can't do it. Here are two reasons why. 1) Warmed air from the oil cooler might not help cool a brake disk. 2) The vents as they are create a venturi effect and pull the air through the oil cooler by creating negative pressure behind it. Vent Strakes might even help a little because they channel passing air between them, there by increasing velocity and therefore negative pressure.
4) If you did open a vent at the back of the oil cooler straight to the disk brakes (as some late series RX7 owners did, some after market noses did have brake cooling vents under and separate to the oil cooling vents) then you'll decrease the air flow through the oil cooler. This was the major problem in constructing the air intakes for the Concorde. You need an air box in front of the cooler to slow the air down. To create an air box you will need to set the oil cooler further back and pit a grill in front. (For those who will point out that the Concorde is a defunct supersonic airliner and the RX8 is a landlocked daily driver... the principle is the same. You need to slow the air down to allow it to pass through the radiator otherwise it forms a kind of shockwave wall. I suspect this is why Mazda didn't put a grill on there to begin with. For them a grill is not just decoration. It serves a function.
5) I resorted a 28 Ford once and they there were always cooling problems with these old cars – even when they used thicker cores. They have no grill and therefore no air box to slow air. Ford got around this by sealing the area around the frame and engine with two long sheets of metal that flared downwards towards the rear. Like reversed scoops. They were to create venturi effect and pull air through the radiator because the air would dam in front of it. Many restorers left these parts out believing that the more space there was around the engine the more it would cool. Not so. It's the speed the air travels over the engine that makes a difference. Creating more space can increase volume but this may not increase heat transfer.
6) Which leads me to the value of the large flat plastic tray that runs from under the nose to behind the engine. As the cars get older and heat begins to make these more brittle and the odd spoon drain takes a swipe at it, it's vital these be replaced. Its part of the cooling system, it creates a negative pressure in the engine bay behind the radiator and therefore has a big role to play in the life of the engine. That goes for the engine cover to I suspect.
So keep cool. Here endith the thesis.
I wait with glee both intelligent and fatuous comment.
