Hood spacers
07-28-09, 04:10 PM
#26
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A streamer, masking tape and video camera will put all theory aside.
Airflow is all about positive and negative pressures, and each setup (speaking specifically of engine bays) is different. Belly pan or not, fan shourd or not, rear aluminum pan or not. No one mod will affect each car the same.
Tape some tell tales to it and go for a drive. Video tape it and post it up so there's no more debate about whats going in or coming out.
Of course you'll see heat rising out of the hood while stopped. You can see that without hood vents
I think its a neat idea, Aerodyne tried to make adjustable ones back in the day. But to me, it looks like some yahoo didn't know how to fit a panel. But I like neat ideas, top marks on that.
Airflow is all about positive and negative pressures, and each setup (speaking specifically of engine bays) is different. Belly pan or not, fan shourd or not, rear aluminum pan or not. No one mod will affect each car the same.
Tape some tell tales to it and go for a drive. Video tape it and post it up so there's no more debate about whats going in or coming out.
Of course you'll see heat rising out of the hood while stopped. You can see that without hood vents
I think its a neat idea, Aerodyne tried to make adjustable ones back in the day. But to me, it looks like some yahoo didn't know how to fit a panel. But I like neat ideas, top marks on that.
If I can figure out a good way to mount my camera in the car I might actually do the yarn test. I've been really interested to see the effects of the vents. I like the lines of the FC which is why I felt it was better to cut big holes in my hood instead of raising the back up, but to each their own.
07-28-09, 04:17 PM
#27
Apparently since you're messing with the hood, your mounts are weak + will break in an accident shoving the hood through the windshield + decapitating you.....
*(coughicallbullshitcough)*
07-28-09, 04:46 PM
#31
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Wow it always amazes me how people make assumptions and don't think things through. The hood by design rests on top of the firewall ..... I have never even seen a car where the hood sits below the firewall. In order for the hood to come through the wind shield and reach your neck the engine would have to be in the back seat ..... I think at that point being decapitated would almost be doing you a favor...... and this is ignoring the fact that hoods are designed to crumple.
Now assuming the front latch broke and the hinges broke and the hood didn't crumple the hood would still just slide up the A pillars and over the roof, or flip end over end and end up on the roof or behind the car.
And lets not forget all of the car out there with forward opening hoods..... these by design lift at the rear and should in theory be way more likely to decapitate you.
Meh I'm not here to argue the merits of doing this or weather or not it looks good. Some guys wanted to do it, I figured out a way for them to do it and figured the community might appreciate seeing a different way to do something.
LOL fixed it for you
Now assuming the front latch broke and the hinges broke and the hood didn't crumple the hood would still just slide up the A pillars and over the roof, or flip end over end and end up on the roof or behind the car.
And lets not forget all of the car out there with forward opening hoods..... these by design lift at the rear and should in theory be way more likely to decapitate you.
Meh I'm not here to argue the merits of doing this or weather or not it looks good. Some guys wanted to do it, I figured out a way for them to do it and figured the community might appreciate seeing a different way to do something.
07-28-09, 05:00 PM
#33
well i appriate the idea might do something like that myself, ppls negative opinions aside(not really sure y one would read a thread and make a completly one sided remark, life must taste like plain *** cheerios for them if they are so close minded)
wats the cost to make something like that, you may have a buyer
wats the cost to make something like that, you may have a buyer
07-28-09, 07:07 PM
#34
Wow it always amazes me how people make assumptions and don't think things through. The hood by design rests on top of the firewall ..... I have never even seen a car where the hood sits below the firewall. In order for the hood to come through the wind shield and reach your neck the engine would have to be in the back seat ..... I think at that point being decapitated would almost be doing you a favor...... and this is ignoring the fact that hoods are designed to crumple.
Now assuming the front latch broke and the hinges broke and the hood didn't crumple the hood would still just slide up the A pillars and over the roof, or flip end over end and end up on the roof or behind the car.
And lets not forget all of the car out there with forward opening hoods..... these by design lift at the rear and should in theory be way more likely to decapitate you.
Meh I'm not here to argue the merits of doing this or weather or not it looks good. Some guys wanted to do it, I figured out a way for them to do it and figured the community might appreciate seeing a different way to do something.
LOL fixed it for you
Now assuming the front latch broke and the hinges broke and the hood didn't crumple the hood would still just slide up the A pillars and over the roof, or flip end over end and end up on the roof or behind the car.
And lets not forget all of the car out there with forward opening hoods..... these by design lift at the rear and should in theory be way more likely to decapitate you.
Meh I'm not here to argue the merits of doing this or weather or not it looks good. Some guys wanted to do it, I figured out a way for them to do it and figured the community might appreciate seeing a different way to do something.
LOL fixed it for you
But yeah, I completely agree with you. Sorry to argue with the mods, but you're full of crap. I'm 99% sure that a hood won't decapitate you.
07-29-09, 02:20 AM
#35
Dustin Becktold
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bring on the decapitation!!!!!
i have this "mod" on my FC as well, mostly because sitting at ThunderHill in between drift runs my car would remain very hot, even with my e-fan on. it's also 100 plus out there with no shade. now that i've "modded" the hood you can feel the heat pouring out the back of my hood when your sitting there and temps go down a lot quicker, even with the car running. no more pushing my car forward in line with the heat on full blast, windows down, hood up and ignition off.
i have this "mod" on my FC as well, mostly because sitting at ThunderHill in between drift runs my car would remain very hot, even with my e-fan on. it's also 100 plus out there with no shade. now that i've "modded" the hood you can feel the heat pouring out the back of my hood when your sitting there and temps go down a lot quicker, even with the car running. no more pushing my car forward in line with the heat on full blast, windows down, hood up and ignition off.
07-29-09, 02:52 AM
#36
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https://www.rx7club.com/showthread.php?t=323922
Apparently since you're messing with the hood, your mounts are weak + will break in an accident shoving the hood through the windshield + decapitating you.....
*(coughicallbullshitcough)*
Apparently since you're messing with the hood, your mounts are weak + will break in an accident shoving the hood through the windshield + decapitating you.....
*(coughicallbullshitcough)*
07-29-09, 11:00 AM
#38
Engine, Not Motor
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Most carbon fibre hoods will just split apart.
If you look at how the OEM hinges are designed, they are set up to pull and not create a shear point. This keeps the hood attached at the back and caused it to fold at it's weak point (in the middle). Normally this forces the rear of the hood down. Raising the hood up on those hinges (or raising the hinges) creates a shear point. Whether someone has done testing to confirm that it will be dangerous in a collision, I don't know. I doubt the hood would make it through the a-pillars but it is hard to say what happens in a collision. Lifting the back creates a totally different angle and with the weakened hinges it could cause the hood to jam into the a-pillars or travel up them. As the corners are weak, it is possible that the hood could fold a bit and come through the windshield as the hinges no longer cause it to fold down into the firewall but now up into the a-pillars.
If you look at how the OEM hinges are designed, they are set up to pull and not create a shear point. This keeps the hood attached at the back and caused it to fold at it's weak point (in the middle). Normally this forces the rear of the hood down. Raising the hood up on those hinges (or raising the hinges) creates a shear point. Whether someone has done testing to confirm that it will be dangerous in a collision, I don't know. I doubt the hood would make it through the a-pillars but it is hard to say what happens in a collision. Lifting the back creates a totally different angle and with the weakened hinges it could cause the hood to jam into the a-pillars or travel up them. As the corners are weak, it is possible that the hood could fold a bit and come through the windshield as the hinges no longer cause it to fold down into the firewall but now up into the a-pillars.
07-29-09, 12:49 PM
#39
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When I said vent was referring to the ones in the center of my hood, see the picture below.
You make a good point about increasing the pressure in the engine bay, although it's not quite accurate. Hot air rises so at a standstill with the hood raised or vented the air can escape out of the back of the hood, helping prevent heat soak.
At low speed the air will actually flow out of the rear of the hood allowing more air to pass through threw radiator due to less of a restriction.
At higher speeds air is actually drawn/forced through the back of the hood and exits at the lower back of the engine bay. This actually creates a suction effect and helps pull air through the radiator, sort of the same way exhaust scavenging works. This also passes more air over the actual engine cooling the engine itself and not just the coolant.
BTW: Don't worry about directly cooling your engine block with air moving past it, you're engine is watercooled for a reason. It never hurts to indirectly cool the engine by lowering the underhood temperatures.
High speeds are not much of a problem for cooling as there is plenty of airflow through the radiator.
It's at idle and low speeds that the engine bay turns into a furnace. When I stop my car and let it sit for a few minutes, the vents in my hood get so hot that they will sometimes burn you. This is simply from the shear amount of ambient heat escaping through them.
Riz.
07-29-09, 02:08 PM
#40
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This is where I would like to see test results confirming this. This were a result where reality crushes theory, in this specific aplication. However to convince me I would need data. Ofcoarse you don't care about convincing me, so test results probably will never be presented. I guess if you believe/think/know it works then that's fine. You will probably get alot of remarks from smartasses like me though, LoL!
. I see your point of view, although I do not agree. I think if the engine bay was sealed then it would become a high pressure zone and make it that much harder for air to pass through the radiator. Not yet. On my list of things to do has been to find a decent temperature gauge/ thermometer.
07-29-09, 02:26 PM
#41
Dustin Becktold
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about the chopping off of the heads thing, has anyone ever actually heard of it happening in "real life" or is this just theory? i've never heard of it myself and it seems to me that there are a lot of drifters out there with this "mod" and we all know crashing at every possible angle is highly possible in this motorsport. never heard of a decapped drifter.
also, we know ricers copy everything, usually poorly, and i've never read or seen in the news about some ricer rearending someone and losing there top. if anyone has got anything please let us know. would be nice to know for sure.
i would hope that my steal A pillars are stronger then my aluminum hood, i mean, you sit on a hood and it bends, you drop kick a A pillar and nothing happens, it's pretty tough. not saying i know it would never happen, just saying it has to be like 9 million to 1 chance or something.
also, we know ricers copy everything, usually poorly, and i've never read or seen in the news about some ricer rearending someone and losing there top. if anyone has got anything please let us know. would be nice to know for sure.
i would hope that my steal A pillars are stronger then my aluminum hood, i mean, you sit on a hood and it bends, you drop kick a A pillar and nothing happens, it's pretty tough. not saying i know it would never happen, just saying it has to be like 9 million to 1 chance or something.
07-30-09, 12:42 AM
#42
Does anyone done this on a turbo car with the stock TMIC? I've always wondered how it would affect the airflow through the scoop to the IC with the hood at an angle. BTW I don't remember which magazine did it (super street I think) but on a Miata the intake temps dropped significantly when monitored with an IAT gauge before/after. Its funny because the article specifically points out the increased advantage of the mod on an engine that creates a lot of heat, like a turbo rotary. The Miata's air filter is positioned towards the firewall though and it is right above the exhaust manifold.
07-30-09, 02:33 PM
#43
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Sitting in traffic or staging is when you are most likely to over heat. Over heating is death to most engines, especially rotaries. If your car is unmodified then there is little reason to do something like this (unless you run it hard for long periods of time). But as you modify the car to make more power you are also making more heat and it should be dealt with to help ensure longer engine life.
I'm not worried about directly cooling the engine. I should have made that clearer. Any extra ambient air passing over the engine serves as extra cooling on top of the water system. It's a bonus and means you cooling system does not have to work as hard.
True, plenty is not a unit of measurement . I see your point of view, although I do not agree. I think if the engine bay was sealed then it would become a high pressure zone and make it that much harder for air to pass through the radiator.
Good luck with tour research, and make sure to share the data! ;-)
Riz.
08-04-09, 09:42 PM
#46
A jug fills drop by drop.
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http://www.importtuner.com/tech/impp...rop/index.html
hate quoting a Honda tech mag but anyway its got some good info
hate quoting a Honda tech mag but anyway its got some good info
08-19-09, 03:08 PM
#50
As long as you use appropriately graded hardware it should not be any more likely to shear. There is also an argument that can be made that it is less likely to shear due to the extra mating surfaces having more ability to hold the forces .... the same premise as a twin or tripple disk clutch.