I'm with simba on this one. I don't believe the CS vent flows more than a stock scoop at speeds. the only advantage to having one would be for hot air release when your standing still or moving slow.... I see no advantage besides that. And the drag created by th scoop is not nearly as much as it is made to seem as before.
Does CS Hood actually help air flow??
- Thread starter toayoztan
- Start date
JDMGT-4":2lwqh939 said:
Flipping them forward will get more air into the bay, but there's really nothing directly under them that's worth cooling. They were designed to vent hot air out, while the scoop forces it in.
You could flip the drivers side vent to get some cooler air near the intake, but again without an air box or ducting of some sort, it'd be a marginal difference.
Air flow isn't a laminar sort of thing like a liquid. Unless it's going very fast or is constricted by a vent or duct of some sort, it tends not to remain in an organized stream. If you want to get air from one place to another, you need to duct it.
Were kinda comparing apples to oranges here regarding air flow
ATA - the stock 185 hood will win hands down. Even if heat escapes through the scoop, at least its escaping somewhere besides the side vents. I remember talking to a lot of alltracers around here that bought the cs hood but have the ATA Top mount intercooler. They have worse heatsoak problems than regular 185 hoods.
For front mount/WTA, the bumper has more to do with cooling than the hood since the actual cooler is place in the bumper area.
Coefficient Drag wise, Simba is correct. Tha actual numbers: stock .34 vs CS/RC .3
.04 is substantial at higher speeds
CS hood probably vents more hot air stationary since one of the main heat sources (Turbo manifold/Turbo) lies directly under an opening. I'm also pretty sure that the CS hood works similarly to the EVO hood in regards to its purpose. I bet at speeds, the engine bay doesnt have to get rid of as much hot air from the turbo since most of it would be escaping from the center vent.
ATA - the stock 185 hood will win hands down. Even if heat escapes through the scoop, at least its escaping somewhere besides the side vents. I remember talking to a lot of alltracers around here that bought the cs hood but have the ATA Top mount intercooler. They have worse heatsoak problems than regular 185 hoods.
For front mount/WTA, the bumper has more to do with cooling than the hood since the actual cooler is place in the bumper area.
Coefficient Drag wise, Simba is correct. Tha actual numbers: stock .34 vs CS/RC .3
.04 is substantial at higher speeds
CS hood probably vents more hot air stationary since one of the main heat sources (Turbo manifold/Turbo) lies directly under an opening. I'm also pretty sure that the CS hood works similarly to the EVO hood in regards to its purpose. I bet at speeds, the engine bay doesnt have to get rid of as much hot air from the turbo since most of it would be escaping from the center vent.
AlltracAvenger
Member
Hm. I'm speaking from relative inexperience, but the design of the hood on both the 185RC and 205 seem to suggest not actually moving air through the engine bay per se, but reducing underhood heat as to make the ambient underhood temperature much less than what it would be with a full hood. Both cars have W/A intercoolers, and with that there isn't as much of a need of direct airflow to the IC itself(a lot of that work is done by the front radiator; I have had a dramatic improvement in IC temp on my '165 by adding a secondary, and that's with a non-vented stock hood). However, heat soak is a major problem without much way for heat to escape... '165s in particular suffer greatly from this.
From what I see, the 'lip' to the vent creates a low pressure area right above the vent, which would for the lack of a better word 'suck' the heated engine bay air out of the vent when the car is at speed, as well as allow the heat a route to escape while stopped... keeping it away from the TMIC altogether. Now, since A/A ICs need airflow to operate, the RC vent will serve as an airflow restriction to a stock '185 IC. The point is, I think that if you have a RC or '205 IC on your car, then a vent is a very very good thing to have. If you have a stock '185 IC, don't do it, or go for a front mount. As far as mounting a front mount, would a RC hood be of any benefit? I think so; not for the IC per se, but to reduce underhood temps in general, which could reduce heat soak of your intake piping, too.
Sorry if things aren't totally clear here... I'm running on two hours of sleep. If anyone needs any further clarification, lemme know.
From what I see, the 'lip' to the vent creates a low pressure area right above the vent, which would for the lack of a better word 'suck' the heated engine bay air out of the vent when the car is at speed, as well as allow the heat a route to escape while stopped... keeping it away from the TMIC altogether. Now, since A/A ICs need airflow to operate, the RC vent will serve as an airflow restriction to a stock '185 IC. The point is, I think that if you have a RC or '205 IC on your car, then a vent is a very very good thing to have. If you have a stock '185 IC, don't do it, or go for a front mount. As far as mounting a front mount, would a RC hood be of any benefit? I think so; not for the IC per se, but to reduce underhood temps in general, which could reduce heat soak of your intake piping, too.
Sorry if things aren't totally clear here... I'm running on two hours of sleep. If anyone needs any further clarification, lemme know.
alltracman78
Active member
AlltracAvenger":30neb5r6 said:Hm. I'm speaking from relative inexperience, but the design of the hood on both the 185RC and 205 seem to suggest not actually moving air through the engine bay per se, but reducing underhood heat as to make the ambient underhood temperature much less than what it would be with a full hood. Both cars have W/A intercoolers, and with that there isn't as much of a need of direct airflow to the IC itself(a lot of that work is done by the front radiator; I have had a dramatic improvement in IC temp on my '165 by adding a secondary, and that's with a non-vented stock hood). However, heat soak is a major problem without much way for heat to escape... '165s in particular suffer greatly from this.
From what I see, the 'lip' to the vent creates a low pressure area right above the vent, which would for the lack of a better word 'suck' the heated engine bay air out of the vent when the car is at speed, as well as allow the heat a route to escape while stopped... keeping it away from the TMIC altogether. Now, since A/A ICs need airflow to operate, the RC vent will serve as an airflow restriction to a stock '185 IC. The point is, I think that if you have a RC or '205 IC on your car, then a vent is a very very good thing to have. If you have a stock '185 IC, don't do it, or go for a front mount. As far as mounting a front mount, would a RC hood be of any benefit? I think so; not for the IC per se, but to reduce underhood temps in general, which could reduce heat soak of your intake piping, too.
Sorry if things aren't totally clear here... I'm running on two hours of sleep. If anyone needs any further clarification, lemme know.
DING!
He gets the prize.
The hood is designed to vent hot air from the engine. It sits right above the hottest spot in the bay, the turbo.
As for how well it vents at high speeds, the higher the speed, the better it vents. To a point of course.
Someone mentioned Bournellis Priciple.
Bascially, when you have air rushing over a hole, it creates a vaccum. The more air/faster the air travels, the more vaccum.
A carburator works on this principal.
The hood has a VERY large hole in it.
Note the "dam" at the front of the vent. To create more of a defined hole.
As for who designed it, certainly not Carlos Sainz.
He was a driver, not an engineer.
It was probably a team of TTE/Toyota engineers.