why does coolant make a double pass
01-11-2011, 11:49 PM
#126
SARX Legend
iTrader: (46)
the header wont make the egt drop unless its acting like a heat sync. in which case u would need it to be finned. surface area is what cools things down. so you would need to create more surface area to radiate the heat. in turn this would make a hotter exhaust up front so u would also need a heat shield and to make certain its being vented.
your better off cooling the motor, and running a vented hood. my hood has 3 small cowlings over the right rear and u can put your hand over them on any given day to feel the heat being vented. this leads me to believe that while driving, since heats a fluid that takes the path of least resistance and up, that while driving cooling is improved even more. this actually has worked since i have seen an 8-10 degree drop during normal driving conditions. once in a while i get really lucky and it peaks to 15 deg cooler.
remember our hoods are insulated and trap heat. the hood i saw on Mazda's rx8 was vented on the edge of the rotary shape. i think they just didn't want us to have to deal with cleaning the vents. plus they covered all the engine parts. why would u cover the battery and protect the alternator then go add insulation to a sealed hood?
your better off cooling the motor, and running a vented hood. my hood has 3 small cowlings over the right rear and u can put your hand over them on any given day to feel the heat being vented. this leads me to believe that while driving, since heats a fluid that takes the path of least resistance and up, that while driving cooling is improved even more. this actually has worked since i have seen an 8-10 degree drop during normal driving conditions. once in a while i get really lucky and it peaks to 15 deg cooler.
remember our hoods are insulated and trap heat. the hood i saw on Mazda's rx8 was vented on the edge of the rotary shape. i think they just didn't want us to have to deal with cleaning the vents. plus they covered all the engine parts. why would u cover the battery and protect the alternator then go add insulation to a sealed hood?
This hood venting issue has been settled long ago I think. At a stop you might get some benefit but some of the pros have already determined that most aftermarket vented hoods do nothing but upset the airflow at speed. I'm too lazy to search but I even remember reading that the stock side vents are functional for that reason and a vented hood negates that. I looked into this and pretty much learned that on street non FI rx8, it's pointless venting or running a vented hood unless you are just doing it for looks, which if done right can be cool but the CF look hoods are played out IMO.
None of the speedsource or other grand am RX8 race cars are running vented hoods. But what do they know anyway.
01-12-2011, 07:55 AM
#128
Hood Vents, etc.
There are about four categories of reasons to modify a car:
1) Appearance/Vibe/Ego
2) You like to fiddle with stuff
3) You want to learn the technology
4) To solve a specific problem
All of these could fall into the higher level categories of "fun" or "work", depending on things like whether you have another car to get to 7-11 in, how much spare money is lying around, or whether your income depends on winning races. I think most of the regulars on the list work from the POV of the first three most of the time. Eric works from (4) and I for one, am very happy to have him here for that. He has solved, with resources and persistance far beyond what most other listers have, the cooling problem of RX-8s at racing speeds. Are there other solutions or flavors of solutions? Quite likely. However if one's goal is (4), the simplist, most pragmatic, and likely most effective solution is to copy what he's done and *poof*, problem solved.
Hood vents: Holding one's hand over a hood vent and feeling air coming out does not mean that they work at 100 mph or 20 mph for that matter. It's very easy to get air flowing the wrong way from effects air flowing around the car at speed. Short of wind-tunnel time, one could buy 25 different hoods and test them on an instrumented cooling system, or take tin snips to a stock hood and punch holes in various places. If one's goal is to cool an 8 at racing speed, an answer has been given. If one's goal is to cool an air-conditioned 8 in a 45 minute summertime Phoenix traffic jam, perhaps not. A vented hood may help there, but also may hurt at speed on a road course. YMMV
1) Appearance/Vibe/Ego
2) You like to fiddle with stuff
3) You want to learn the technology
4) To solve a specific problem
All of these could fall into the higher level categories of "fun" or "work", depending on things like whether you have another car to get to 7-11 in, how much spare money is lying around, or whether your income depends on winning races. I think most of the regulars on the list work from the POV of the first three most of the time. Eric works from (4) and I for one, am very happy to have him here for that. He has solved, with resources and persistance far beyond what most other listers have, the cooling problem of RX-8s at racing speeds. Are there other solutions or flavors of solutions? Quite likely. However if one's goal is (4), the simplist, most pragmatic, and likely most effective solution is to copy what he's done and *poof*, problem solved.
Hood vents: Holding one's hand over a hood vent and feeling air coming out does not mean that they work at 100 mph or 20 mph for that matter. It's very easy to get air flowing the wrong way from effects air flowing around the car at speed. Short of wind-tunnel time, one could buy 25 different hoods and test them on an instrumented cooling system, or take tin snips to a stock hood and punch holes in various places. If one's goal is to cool an 8 at racing speed, an answer has been given. If one's goal is to cool an air-conditioned 8 in a 45 minute summertime Phoenix traffic jam, perhaps not. A vented hood may help there, but also may hurt at speed on a road course. YMMV
01-12-2011, 11:11 AM
#130
SARX Legend
iTrader: (46)
Doc, are yous seriously trying to compare a four rotor car and other extreme blown cars to yours? 
I said, non FI and you post of pics of a four rotor, and some 3 rotor turboed cars.
Not to mention I don't really consider drift cars on the same level as a race car that is designed to got full tilt for hours.
I said, non FI and you post of pics of a four rotor, and some 3 rotor turboed cars. Not to mention I don't really consider drift cars on the same level as a race car that is designed to got full tilt for hours.
01-12-2011, 11:14 AM
#131
Doc, are yous seriously trying to compare a four rotor car and other extreme blown cars to yours? I said, non FI and you post of pics of a four rotor, and some 3 rotor turboed cars.
Not to mention I don't really consider drift cars on the same level as a race car that is designed to got full tilt for hours.
I said, non FI and you post of pics of a four rotor, and some 3 rotor turboed cars. Not to mention I don't really consider drift cars on the same level as a race car that is designed to got full tilt for hours.
Even the one they took to Macau Grand Prix use 13B-REW 2 rotor engine. Next one (this year) they will bring FD back, cuz its much cheaper to build on FD
01-12-2011, 11:14 AM
#132
SARX Legend
iTrader: (46)
I agree, properly placed vent can be very beneficial on some cars, in some situations, especially turbocharged cars with huge top mounted turbos. On ours the vent would need to be at the rear of the hood, not right in the middle. Again, this has been discussed at length.
01-12-2011, 11:17 AM
#133
SARX Legend
iTrader: (46)
BTW, is this what I think it is?
and
Last edited by 9krpmrx8; 01-12-2011 at 11:22 AM.
01-12-2011, 11:29 AM
#135
SARX Legend
iTrader: (46)
01-12-2011, 11:32 AM
#136
BTW, is this what I think it is?
and
Last edited by nycgps; 01-12-2011 at 11:40 AM.
01-12-2011, 11:35 AM
#137
01-12-2011, 11:44 AM
#138
13B-REW swap, at Qualify they tune it to 510 ps, but at the race, they "de-tune" it to 400 ps. because the driver feel its more than enough + much more reliable that way.
sadly, when the race start the ******* retarded GT-R behind with their 4wd system accelerate faster(always) but then he lose control and crash Knight Sports 8 + 4 other cars. tons of people in the racing community bitch at him, the driver of that GT-R is a race shop in Hong Kong, Philip Yau, he said he didn't do it on "purpose", yeah right. whatever. FIA gave him a 1K USD penalty for being so ******* stupid. suck it bitch.
but ...
sad ... I was there and the whole team looks very down.
Last edited by nycgps; 01-12-2011 at 11:46 AM.
01-12-2011, 11:51 AM
#139
just wanna say that as much as we laugh about the Civic guys being so "OMG ITS JDM y0!"
some of the Japanese stuff are really ... interesting.
Check Autoexe, RE-Amemiya, Fujita and Knight Sports out. those guys are pretty serious about their mods.
I have Knight Sports Radiator, its made by Koyo but its not the same as Koyo's "Stock replacement" rad. Its more like a N-Flow(some ppl call it Z-Flow or U flow, whatever) design with ultra thick core (53mm, stock is 38mm, which is a bitch to install), pretty good. (not good for wallet tho)
some of the Japanese stuff are really ... interesting.
Check Autoexe, RE-Amemiya, Fujita and Knight Sports out. those guys are pretty serious about their mods.
I have Knight Sports Radiator, its made by Koyo but its not the same as Koyo's "Stock replacement" rad. Its more like a N-Flow(some ppl call it Z-Flow or U flow, whatever) design with ultra thick core (53mm, stock is 38mm, which is a bitch to install), pretty good. (not good for wallet tho)
Last edited by nycgps; 01-12-2011 at 11:54 AM.
01-12-2011, 01:17 PM
#143
SARX Legend
iTrader: (46)
Yeah I was actually looking at an extra one of those bolts I have laying around and I see what you did. I am going to do it for **** and giggles but I wonder if some styles of the Oil temp probe/sending units would protrude too far in and effect flow.
01-12-2011, 03:25 PM
#145
You have to be careful when you machine the threads....most sensors are pipe threads .....and depending on threaded depth..the hole will allow more or less penetration into the center of the bolt
One I used a threaded bushing to get it in the correct place.....I cut a 1/4NPT hole...and used a 1/8-1/4NPT bushing...and that placed the sensor in the same place as the bolt head used to be.
The easiest is a pressure transducer..they don't have a protrusion like a temp sensor usually does
One I used a threaded bushing to get it in the correct place.....I cut a 1/4NPT hole...and used a 1/8-1/4NPT bushing...and that placed the sensor in the same place as the bolt head used to be.
The easiest is a pressure transducer..they don't have a protrusion like a temp sensor usually does
01-14-2011, 11:52 AM
#147
Measured where ? Your choices would be pre-oil cooler..post oil pump....seen up to 255 there
Post coolers..pre-engine...seen up to 240 there, but after mods to the oil coolers
Oil Pan...seen up to 255 there as well.....I think that is the best place to measure oil temp..
Where would you measure more post engine oil temps?......everthing dumps into the oil pan from the bearings and rotors
Post coolers..pre-engine...seen up to 240 there, but after mods to the oil coolers
Oil Pan...seen up to 255 there as well.....I think that is the best place to measure oil temp..
Where would you measure more post engine oil temps?......everthing dumps into the oil pan from the bearings and rotors
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