Any recommendation on Carbon Fiber Hood
12-19-07, 10:39 AM
#76
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Look directly forward over the hood from the front - this is what the air "sees" when you're driving around.
You still can see the base of the windshield from this angle...
Also, stare at that profile pic very carefully...
Notice that the stock turbo scoop is located in a LOW PRESSURE AREA.
-Ted
12-19-07, 11:22 AM
#78
You can argue that the angle of the windshield plays a role in the "vortex" you mentioned but the same principle applies. The hot air will still get sucked out.
The main problem here is that most people want a vented hood to lower car temps, look cool or just to have something not stock. In reality you want the hot engine bay to expel the heat so your sensors and your wires don't get all brittle and cause any possible problems due to broken wires. I'm looking for other examples and I invite you to do the same. I think this is important and we should come to a bonafide conclusion so we all at least know what IS and ISN'T GOOD.
We really need someone who has taken fluid dynamics engineering in here to settle this.
~Mike.........
12-19-07, 12:53 PM
#79
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No, not significantly.
Look directly forward over the hood from the front - this is what the air "sees" when you're driving around.
You still can see the base of the windshield from this angle...
"Also, stare at that profile pic very carefully...
Notice that the stock turbo scoop is located in a LOW PRESSURE AREA."
-Ted
Look directly forward over the hood from the front - this is what the air "sees" when you're driving around.
You still can see the base of the windshield from this angle...
"Also, stare at that profile pic very carefully...
Notice that the stock turbo scoop is located in a LOW PRESSURE AREA."
-Ted
Notice that the stock turbo scoop is located in a LOW PRESSURE AREA."
^^does this mean there not much force pulling the hood upward for turbo 2 hood
12-19-07, 12:57 PM
#80
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OK, it is your reading comprehension that sucks. I made no mention of any "vortex" in reference to the hood or windshield at all. Just the canards which are little winglets placed on the front bumper covers in front of the wheels on race/rice cars. You want your expert, well here I am. I've worked here at NASA for over 10 years and have been in countless tunnels and designed several aircraft. I'm surrounded by the brightest daily and like it or love it, am constantly bombarded with aero DAILY. You discount my post here, but then only 1 post later you back off as being an expert only to admit you don't know jack. Ever notice that EVERY CAR has its climate control, heat, A/C intake ducts RIGHT AT THE BASE OF THE WINDSHIELD? Because its a high pressure zone. Even with the fan in the OFF position, you still get air coming out of your vents inside the vehicle because these INTAKE VENTS are so effective at using that HIGH PRESSURE zone to effectively force air into the cabin. That rear vent, doesn't "vent", its marketing BULLSHIT. Only the front portion vents, which is fine and effective and more then adequate for high powered Rx. The rear vent though not functioning like the little animated picture wont hurt anything. For the last time. Its just a freakin hood for a street car. Who's driving the 800 HP 24 hour full throttle endurance car in here?
~Mike.........
~Mike.........
Originally Posted by stylEmon
i really wish someone made one like the VIS hood, but simple-er. with just one lrge vent instead of 4-5.
12-19-07, 01:08 PM
#81
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ONLY DRY CF will get down to 5-6 lbs
http://kognitiondesign.com/
they can do a custom dry cf hood, if you wnat to pay for the weight savings.
the FG/CF and FG, and CF hoods are not as strong as oem metal hoods, you should always use hoodpins.
http://kognitiondesign.com/
they can do a custom dry cf hood, if you wnat to pay for the weight savings.
the FG/CF and FG, and CF hoods are not as strong as oem metal hoods, you should always use hoodpins.
12-19-07, 08:32 PM
#82
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"believe the reason for the hood pins is that because of the weak nature of the CF vs steel or alum"
WOAH, thats news to me. i didnt know that................
basically what you just said is sooooo counter intuitive, it blew my mind out of my ear.
are you joking me, cf is by far one of the strongest man made materials. if it werent as strong as it is, why would super cars be made of it, why would lemans cars be running shells and BRAKE ROTORS made out of it, why would drag boats be using cf or even carbon-kevlar instead of aluminum or steel.....................
let me see, if i do remember right, i do believe that CF has something like 15x the tensile strength of steel, 10x that of aluminum, oh and weighs 1/100th that of steel, and 1/50th that of aluminum.
if that were the case mike_merryguy, then why would the pagani zonda be made of carbon-kevlar and aeronotic aluminum? same as the farrari enzo, lamborghini mercialago lp640, and the bugati veyron?
god damn, facts man, facts.
peace
p.s. no, you cant get in trouble for having hood pins, only gives cops more reasonable suspicion of having a modded engine.
WOAH, thats news to me. i didnt know that................
basically what you just said is sooooo counter intuitive, it blew my mind out of my ear.
are you joking me, cf is by far one of the strongest man made materials. if it werent as strong as it is, why would super cars be made of it, why would lemans cars be running shells and BRAKE ROTORS made out of it, why would drag boats be using cf or even carbon-kevlar instead of aluminum or steel.....................
let me see, if i do remember right, i do believe that CF has something like 15x the tensile strength of steel, 10x that of aluminum, oh and weighs 1/100th that of steel, and 1/50th that of aluminum.
if that were the case mike_merryguy, then why would the pagani zonda be made of carbon-kevlar and aeronotic aluminum? same as the farrari enzo, lamborghini mercialago lp640, and the bugati veyron?
god damn, facts man, facts.
peace
p.s. no, you cant get in trouble for having hood pins, only gives cops more reasonable suspicion of having a modded engine.
you are trying to compare **** ***** to diamonds here...
and also coming from my cop friends mouth, a hood pin gives no suspicion unless you are already driving like an idiot, just more reason to make you pop the hood
I don't think I have ever heard of someone getting harassed for a modded engine just because of hood pins...
Actually, it's the two-stage locking mechanism that's required.
I dunno if it's a federal law that covers all vehicles in the USA, or if it's a local (i.e. state) law, but down here they will nail you for just hood pins...no matter how many you have on your car.
The two-stage locking mechanism is to prevent you from accidental knocking the hood release and causing the hood to fly off the car during vehicle movement.
Hood pins cannot do this.
-Ted
I dunno if it's a federal law that covers all vehicles in the USA, or if it's a local (i.e. state) law, but down here they will nail you for just hood pins...no matter how many you have on your car.
The two-stage locking mechanism is to prevent you from accidental knocking the hood release and causing the hood to fly off the car during vehicle movement.
Hood pins cannot do this.
-Ted
Stage one - remove pins
Stage two - pull latch inside car
Stage three - pull latch outside
If a cop makes you pop a hood with those steps required and you still get a ticket then you need to take that **** to court b/c he is a ******* retard, If the law states "A two stage locking mechanism is required" then a three stage setup has that covered plus one (math for dumb cops there)
12-19-07, 09:06 PM
#83
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Maybe I mis explained what I was referring to, with a stock latching system, you have 2 stage, remove that and put pins on only 1 stage, but still kinda hard to hit the pin while driving you may run yourself over, don't know how that is possible but I am sure someone can figure it out... LOL but seriously what I meant was adding the pins to an already stock latching system, now you have a 3 stage locking mechanism
Stage one - remove pins
Stage two - pull latch inside car
Stage three - pull latch outside
If a cop makes you pop a hood with those steps required and you still get a ticket then you need to take that **** to court b/c he is a ******* retard, If the law states "A two stage locking mechanism is required" then a three stage setup has that covered plus one (math for dumb cops there)
Stage one - remove pins
Stage two - pull latch inside car
Stage three - pull latch outside
If a cop makes you pop a hood with those steps required and you still get a ticket then you need to take that **** to court b/c he is a ******* retard, If the law states "A two stage locking mechanism is required" then a three stage setup has that covered plus one (math for dumb cops there)
That should not get you a ticket, and the cop is an idiot.
If anything, it's a theft deterrent (if you use locking hood pins).
-Ted
12-19-07, 11:42 PM
#84
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Originally Posted by RETed
Notice that the stock turbo scoop is located in a LOW PRESSURE AREA.
12-20-07, 12:02 AM
#86
diagram posted before bugs me because everyone throws it out there without explaining what they're seeing/SHOWING .
Is it possible that the low pressure (where the arguments is: "air would get sucked in") is caused by the air exiting underneath the car via vaccuum at the end of the underbelly tray (by the tranny?).
Is it possible that the low pressure (where the arguments is: "air would get sucked in") is caused by the air exiting underneath the car via vaccuum at the end of the underbelly tray (by the tranny?).
Last edited by phoenix7; 12-20-07 at 12:10 AM.
12-20-07, 12:01 PM
#88
diagram posted before bugs me because everyone throws it out there without explaining what they're seeing/SHOWING .
Is it possible that the low pressure (where the arguments is: "air would get sucked in") is caused by the air exiting underneath the car via vaccuum at the end of the underbelly tray (by the tranny?).
Is it possible that the low pressure (where the arguments is: "air would get sucked in") is caused by the air exiting underneath the car via vaccuum at the end of the underbelly tray (by the tranny?).
~Mike........
12-20-07, 02:40 PM
#89
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The car has been over 130mph at the track without any pins too. I had to replace the stock latch spring to a much lighter one to get the hood to latch though.
The hood has a fiberglass "skeleton" and although it does weigh less than my old aluminum T2 hood I dont think it is less than 10 #'s.
[IMG]
[/IMG]
Last edited by aram; 12-20-07 at 02:54 PM.
12-21-07, 05:47 AM
#90
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An alternative to the almost non-existent CF hood
I have been looking for a CF hood for the RXX-7, since I want to lower underhood temperatures and increase the airflow through the radiator. As has been noted in this thread, there aren't any good choices available.
Here's my "Plan B":
I have a hood from a Mitsubishi Lancer Evo. When time and money permit, I plan to graft the vent from the Evo hood into the RXX-7 hood. That will get me a low-profile vent near the front of the hood.
Comments?
Here's my "Plan B":
I have a hood from a Mitsubishi Lancer Evo. When time and money permit, I plan to graft the vent from the Evo hood into the RXX-7 hood. That will get me a low-profile vent near the front of the hood.
Comments?
12-21-07, 06:15 AM
#91
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I have a hood from a Mitsubishi Lancer Evo. When time and money permit, I plan to graft the vent from the Evo hood into the RXX-7 hood. That will get me a low-profile vent near the front of the hood.
12-22-07, 05:17 AM
#92
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No, I wouldn't make a mold. The expense of having a custom hood created (estimated at $600, including final painting) precludes going beyond that. I'm not looking for weight savings nor for cosmetic appearance of a CF hood, simply for the heat removing functionality of the vent slightly behind the radiator.
12-25-07, 05:44 AM
#94
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12-25-07, 08:22 AM
#96
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For looks I would say maybe 5 CM's closer to the front, for efficiency (what counts) maybe alot further to the front. It don't look as bad as I thought, but do you realy wanna cut up 2 hoods for it?
Riz.
Riz.
12-26-07, 02:20 AM
#97
NZConvertible caught it. Its marketing bullshit. Yeah sure the front vents actually VENT, but the rears near the windshield is going to have air going into those vents, not hot air comming out. Guys, just buy the hood style you like, be it smooth n/a stock, stock TII, or some other chopped up creation. What matters is you like the style.
~Mike.........
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/want-cooler-engine-bay-without-changing-hood-530715/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/removing-seal-b-w-firewall-hood-bad-engine-temp-330649/
But here's my question...
Yeah, like he said ^^ Ofc, the front of the windshield is a high pressure area, but if you were to duct the front big vents, so it would strictly vent the intercooler (on a VMIC), I could see that ~maybe~ the pressure in the enginebay could built up, and be bigger than the outside pressure (front of windshield). It would work then, possebly only at higher speeds. But those are if's and when's, what's important and fact is that it's not a very good place to vent you enginebay.
Riz.
Riz.
Now the interesting question is, assuming that it can be ducted well enough so surrounding air in the engine bay can't escape those front vents, could the rear vents then actually end up venting air in the engine bay (simply for lower engine bay temps, ie greater longevity of the underhood plastic components, etc, cuz that's really the only benefit of venting the engine bay air anyway...)? And if so then how come removing the weatherstripping on the FD (mentioned above) did NOT achieve this? IIRC, the testing was carried out on a stock hood, to technically the theory was intact (no other vents for the air to escape through), so the air *should* have escaped through the rear "vent"... Comments? (I PMed you on a separate matter btw).
So far as I know, the only two hoods on the planet that offer great aero for FCs are the RE-A GTC hood, and the Sexy Style hood. RE-A is expensive and hard to come by, and Sexy was discontinued...I think. RacerXtreme7 called it best, style is king, and while I like the one Phoenix tossed out I'm more of a fan of R-Magic.
TIA,
~Ramy
12-26-07, 05:04 PM
#100
Mike, I completely understand & agree w/ what you're saying. We had someone in the 3rd Gen section who was claiming that removing the weather stripping along the top edge of the firewall would drop engine bay temperatures by 10 degrees. So we tested it, and sure enough, like you said, air was being sucked INTO the engine bay near the windshield, NOT out. No (outward) venting going on there whatsoever, and engine bay temps actually went UP.
https://www.rx7club.com/showthread.php?t=530715
https://www.rx7club.com/showthread.php?t=330649
But here's my question...That's EXACTLY the route I was thinking of pursuing, but I wasn't sure if it would work. The V-mount IC would be vented (tightly) to the main front scoops in the hood, effectively sealing it off, decreasing the pressure behind the IC, in hopes of increasing flow as well as cooling.
Now the interesting question is, assuming that it can be ducted well enough so surrounding air in the engine bay can't escape those front vents, could the rear vents then actually end up venting air in the engine bay (simply for lower engine bay temps, ie greater longevity of the underhood plastic components, etc, cuz that's really the only benefit of venting the engine bay air anyway...)? And if so then how come removing the weatherstripping on the FD (mentioned above) did NOT achieve this? IIRC, the testing was carried out on a stock hood, to technically the theory was intact (no other vents for the air to escape through), so the air *should* have escaped through the rear "vent"... Comments? (I PMed you on a separate matter btw).
TIA,
~Ramy
https://www.rx7club.com/showthread.php?t=530715
https://www.rx7club.com/showthread.php?t=330649
But here's my question...That's EXACTLY the route I was thinking of pursuing, but I wasn't sure if it would work. The V-mount IC would be vented (tightly) to the main front scoops in the hood, effectively sealing it off, decreasing the pressure behind the IC, in hopes of increasing flow as well as cooling.
Now the interesting question is, assuming that it can be ducted well enough so surrounding air in the engine bay can't escape those front vents, could the rear vents then actually end up venting air in the engine bay (simply for lower engine bay temps, ie greater longevity of the underhood plastic components, etc, cuz that's really the only benefit of venting the engine bay air anyway...)? And if so then how come removing the weatherstripping on the FD (mentioned above) did NOT achieve this? IIRC, the testing was carried out on a stock hood, to technically the theory was intact (no other vents for the air to escape through), so the air *should* have escaped through the rear "vent"... Comments? (I PMed you on a separate matter btw).
TIA,
~Ramy
~Mike...........