observable engine temp change with vented hoods?
03-15-03, 01:41 PM
#26
WOW these are some good insights! and i'm interested in investing in one in the near future! and yeah i've talked my to friend who has a civic, a while back and he says it makes a huuuuuuge difference on the cooling down process, but he didn't mention anything about cooling while driving! I guess it does make somewhat of a differece though!
03-15-03, 01:54 PM
#27
Blow up or win
Originally posted by rpm_pwr
The best cooling mod you can do is put a 99 front bar on the car. Mazda had an SAE paper saying that they saw >100% improvement in cooling efficiency in the rad and closer to 150% imporvement for the oil coolers.
The same cannot be said for vented hoods since nobody has done the research. But since the stock rad is so choked of airflow (particularly on the series 6 and 7)that it would have to have a decent effect. Not to mention the reduction of heatsoak and the benefit that would have for the lifetime of the hoses etc in there.
PWR calculated that their 72mm core radiator had a whopping 5% improvement over their 42mm core on an FD. Having a front mount only magnifies the problem by throttling airflow even more.
-pete
The best cooling mod you can do is put a 99 front bar on the car. Mazda had an SAE paper saying that they saw >100% improvement in cooling efficiency in the rad and closer to 150% imporvement for the oil coolers.
The same cannot be said for vented hoods since nobody has done the research. But since the stock rad is so choked of airflow (particularly on the series 6 and 7)that it would have to have a decent effect. Not to mention the reduction of heatsoak and the benefit that would have for the lifetime of the hoses etc in there.
PWR calculated that their 72mm core radiator had a whopping 5% improvement over their 42mm core on an FD. Having a front mount only magnifies the problem by throttling airflow even more.
-pete
Since I've got a 99 spec bumber on the way, would you happen to know where I can get a copy of the SAE report? Not only would I like to read it, but it might make the $2,000 expense a little easier to swallow, knowing that I am "doing the right thing".
Thanks!
Ron
03-15-03, 04:36 PM
#28
No Cup Holder Racing
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are you referring to this?
"The third-generation RX-7 had come off Mazda's rigorous development test programs on the bench and on the demanding Global Road Circuit section of the Miyoshi Proving Ground with flying colors. Yet, there was one arduous test left undone. When the car was taken to a race track near Tokyo known for its tight turns requiring short bursts of speed followed by fierce deceleration, the pride of Mazda's rotary rocket team quickly cooked its powerplant when pushed to the limit. Subsequent investigation revealed that air temperature at the entry area had risen as high as 50 C (122 F). Fresh air for the engine's consumption was taken from the single intake that also fed to the air-to-air intercooler. On wide-open driving, air flow reversed its course from the intercooler and went straight into the engine's intake. The intercooler was acting as an inter-heater! In the updated RX-7 with a designed fascia, fresh air is taken through a separate, dedicated duct guided by a newly installed air-guide. Air temperature at the engine's intake entry area has been halved to about 25 C ( 77 F), which adds about 7 kW (10bhp) to the output.
The front-end's opening areas have also been increased by factors of 2.1 for the radiator opening, 1.8 for the intercooler duct, 1.8 for the oil cooler, and 1.6 for the front brake cooling duct intake over the previous RX-7. The radiator's core depth has been increased to 27 mm (1.1 in.) from the previous one's 25 mm (1 in.). The 209 kW (280 bhp) engine had its fin-pitch changed from 1.1 mm (0.04 in.) to 1.3 mm (0.05 in.). Twin cooling fans' blades have also been increased, one from five to seven blades and the other four to five blades, while the high-speed electric motors' consumption has been changed from 160W to 120W."
http://robrobinette.com/sae_article.htm
"The third-generation RX-7 had come off Mazda's rigorous development test programs on the bench and on the demanding Global Road Circuit section of the Miyoshi Proving Ground with flying colors. Yet, there was one arduous test left undone. When the car was taken to a race track near Tokyo known for its tight turns requiring short bursts of speed followed by fierce deceleration, the pride of Mazda's rotary rocket team quickly cooked its powerplant when pushed to the limit. Subsequent investigation revealed that air temperature at the entry area had risen as high as 50 C (122 F). Fresh air for the engine's consumption was taken from the single intake that also fed to the air-to-air intercooler. On wide-open driving, air flow reversed its course from the intercooler and went straight into the engine's intake. The intercooler was acting as an inter-heater! In the updated RX-7 with a designed fascia, fresh air is taken through a separate, dedicated duct guided by a newly installed air-guide. Air temperature at the engine's intake entry area has been halved to about 25 C ( 77 F), which adds about 7 kW (10bhp) to the output.
The front-end's opening areas have also been increased by factors of 2.1 for the radiator opening, 1.8 for the intercooler duct, 1.8 for the oil cooler, and 1.6 for the front brake cooling duct intake over the previous RX-7. The radiator's core depth has been increased to 27 mm (1.1 in.) from the previous one's 25 mm (1 in.). The 209 kW (280 bhp) engine had its fin-pitch changed from 1.1 mm (0.04 in.) to 1.3 mm (0.05 in.). Twin cooling fans' blades have also been increased, one from five to seven blades and the other four to five blades, while the high-speed electric motors' consumption has been changed from 160W to 120W."
http://robrobinette.com/sae_article.htm
03-15-03, 10:40 PM
#29
I'm a CF and poop smith
Originally posted by Cihuuy
if you want to do a rice mod...
u can put a couple of washer to the bolt of the hood... this will lift up the end of the hood near the wipers... and leav a small gap to let hot air out... 
dont know how much temperature drop you will get but its so rice that it is cool... hehehe
if you want to do a rice mod...
u can put a couple of washer to the bolt of the hood... this will lift up the end of the hood near the wipers... and leav a small gap to let hot air out... dont know how much temperature drop you will get but its so rice that it is cool... hehehe
03-16-03, 12:16 AM
#30
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I have been running at least one year without the rear hood seal and I havent seen any temp changes with or without the seal in place.I know for sure that in traffic I do see heat waves coming out from under the hood gap so I think it cant hurt. I would think you would need to be going really fast to restrict flow into the radiator.
03-16-03, 12:19 AM
#31
The 7 can't lose!
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Originally posted by 1FooknTiteFD
GotoRX7, what type of hood do you have?
GotoRX7, what type of hood do you have?
There are pics on my website (in my sig).
03-16-03, 09:08 AM
#32
canadian monster
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i have seen no difference when running but the temperature drops at idle at a light, which i had never seen with the stock hood.
i have a mazdaspeed replica
i have a mazdaspeed replica
03-16-03, 05:25 PM
#33
Senior Member
Originally posted by RonKMiller
Pete-
Since I've got a 99 spec bumber on the way, would you happen to know where I can get a copy of the SAE report? Not only would I like to read it, but it might make the $2,000 expense a little easier to swallow, knowing that I am "doing the right thing".
Thanks!
Ron
Pete-
Since I've got a 99 spec bumber on the way, would you happen to know where I can get a copy of the SAE report? Not only would I like to read it, but it might make the $2,000 expense a little easier to swallow, knowing that I am "doing the right thing".
Thanks!
Ron
In addition, the enlarged air intakes in the car's front
end also contributed to the enhanced performance of
the 13B-REW. The RX-7's new front fascia design
allowed an increase in cooling air intake area, by 110%
for the radiator, by 80% for the intercooler, and by 80%
for the oil cooler, respectively. Improved efficiency of
the intercooler had a direct effect on the engine's
performance, while the enhanced cooling capacity of
the radiator, complemented by increased core
thickness, helps improve the engine's reliability.
end also contributed to the enhanced performance of
the 13B-REW. The RX-7's new front fascia design
allowed an increase in cooling air intake area, by 110%
for the radiator, by 80% for the intercooler, and by 80%
for the oil cooler, respectively. Improved efficiency of
the intercooler had a direct effect on the engine's
performance, while the enhanced cooling capacity of
the radiator, complemented by increased core
thickness, helps improve the engine's reliability.
-pete
03-16-03, 06:22 PM
#34
omgwtfposlol
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-stupid question;
What about rain water getting into the engine area when stopped in traffic, or in a parking lot on a rainy day. Does water not hurt the engine assuming that all the wiring is sealed correctly?
What about rain water getting into the engine area when stopped in traffic, or in a parking lot on a rainy day. Does water not hurt the engine assuming that all the wiring is sealed correctly?
03-17-03, 05:23 AM
#35
The 7 can't lose!
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Originally posted by particleeffect
-stupid question;
What about rain water getting into the engine area when stopped in traffic, or in a parking lot on a rainy day. Does water not hurt the engine assuming that all the wiring is sealed correctly?
-stupid question;
What about rain water getting into the engine area when stopped in traffic, or in a parking lot on a rainy day. Does water not hurt the engine assuming that all the wiring is sealed correctly?
03-17-03, 06:50 AM
#36
crazy canuck
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I can't beleive there are somany opinions on this?
the engine is designed to be running at the same temp. ie termastat.
opening the hood is like opening your house door on a cold day....hello people, do you feel colder by the door when it is open, or closed?
of course it will help cooling!!!!
man oh man, people with 1000's of posts, do you like seeing your writings on the net??? or are u disability or something?
the engine is designed to be running at the same temp. ie termastat.
opening the hood is like opening your house door on a cold day....hello people, do you feel colder by the door when it is open, or closed?
of course it will help cooling!!!!
man oh man, people with 1000's of posts, do you like seeing your writings on the net??? or are u disability or something?
03-17-03, 11:41 AM
#37
My Knighsports hood and the decision
process I went though and notes on my installation
http://www.negative-camber.org/crispyrx7/hood.htm
Regards,
Crispy
process I went though and notes on my installation
http://www.negative-camber.org/crispyrx7/hood.htm
Regards,
Crispy
03-31-03, 01:37 AM
#39
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Great write-up and awesome work done on the hood Crispy! The only thing that I don't understand is that with the rain guards in place, it doesn't look like the hood vents very well. Am I missing something here? Is there a certain amount of space between the hood and the guard that lets air though? Or do you just remove the guards when you go to the track?
03-31-03, 01:50 AM
#40
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Originally posted by RX7Elmo
it really depends on the hood. I've heard from people wiht the scoot hood that it makes a noticeable difference. Some even have probems where they can't get their cars to get out of warm-up mode etc.
it really depends on the hood. I've heard from people wiht the scoot hood that it makes a noticeable difference. Some even have probems where they can't get their cars to get out of warm-up mode etc.
That's the biggest crock of shiet i've ever heard of.
04-01-03, 10:37 AM
#42
itRx7,
Rainguards are for "winter" use only. They are removed for track use and during the summer.
I Also run a Mazdacomp radiator, full ducting, water wetter and in the summer a drilled T-stat.
In the winter with the hood and drilled T'stat
during highway driving I couldn't even get enough heat into the motor to get the car out of warmup mode, i.e., less than 75degC indicated by the PFC. So in the winter I pop the vent covers back in and switch back to an undrilled T'stat.
FWIW
Crispy
Rainguards are for "winter" use only. They are removed for track use and during the summer.
I Also run a Mazdacomp radiator, full ducting, water wetter and in the summer a drilled T-stat.
In the winter with the hood and drilled T'stat
during highway driving I couldn't even get enough heat into the motor to get the car out of warmup mode, i.e., less than 75degC indicated by the PFC. So in the winter I pop the vent covers back in and switch back to an undrilled T'stat.
FWIW
Crispy
04-18-03, 12:40 AM
#44
Eats, Sleeps, Dreams Rotary
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Anybody have more pictures/purchase info on the Odula or Stout hoods?
Seen a couple of pictures, and those look to be one of the least overboard hoods I've seen.
Tried google, but can't find either of their home pages.
Seen a couple of pictures, and those look to be one of the least overboard hoods I've seen.
Tried google, but can't find either of their home pages.
04-18-03, 06:43 AM
#46
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Originally posted by cavellm
Anybody have more pictures/purchase info on the Odula or Stout hoods?
Seen a couple of pictures, and those look to be one of the least overboard hoods I've seen.
Tried google, but can't find either of their home pages.
Anybody have more pictures/purchase info on the Odula or Stout hoods?
Seen a couple of pictures, and those look to be one of the least overboard hoods I've seen.
Tried google, but can't find either of their home pages.
04-18-03, 08:24 AM
#47
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I have the hood by Atihun, a Mazdaspeed look-alike I believe, and although I have no way to measure exact degrees my '93 definitely ran cooler. The one thing that surprised me and was a great bonus was the temp in the passenger cabin was noticeably cooler. In the summer it doesn't get so heat soaked and is definitely cooler. By the way, whenever I park my car in a protected place (my garage, secure at work) I raise the hood to let out the hot air, unless it's raining. At home I even have a fan that is plugged into a Radio Shack switched outlet with a RF remote control. When I pull in my driveway I click the garage opener, then I click the radio shack remote and the fan comes on. I pop the hood and pull in my spot and turn all off. The turbo timer runs for a minute. Meanwhile I'm raising the hood. In the winter I don't want to leave the door open so I don't run the fan, just raise the hood.
The Atihun / Mazdaspeed design is great.
The Atihun / Mazdaspeed design is great.
04-18-03, 05:40 PM
#48
Rotary Enthusiast
Thanks for the good word! We still sell the Mazdaspeed Replica hoods.
I live in Southern California, so it gets warm here. When I drive with our vented hood, my intake temperatures are lower as well as my engine temperatures. The differences are noted by the numbers on my PowerFC.
Also what is nice, is that if I sit in traffic, the temps don't go as high, and they decrease much faster once moving again.
When I get a datalogit, I will setup a test and record all results for those that do not believe.
You can find more information on the hoods here:
www.atihun.com
Thanks,
I live in Southern California, so it gets warm here. When I drive with our vented hood, my intake temperatures are lower as well as my engine temperatures. The differences are noted by the numbers on my PowerFC.
Also what is nice, is that if I sit in traffic, the temps don't go as high, and they decrease much faster once moving again.
When I get a datalogit, I will setup a test and record all results for those that do not believe.
You can find more information on the hoods here:
www.atihun.com
Thanks,
04-18-03, 08:01 PM
#49
I'm a CF and poop smith
did mazdaspeed hoods ever come in CF or were the Cf ones only replicas (note: I dont care if it was or not and it should not matter if it was made well, just wanted to know for my own info)
thanks
thanks
