Looking for a cooler running RX-8?
08-26-2006, 09:30 PM
#126
I don't think the logic is whack . It depends on what you want . If (like me) you live in a climate where the A/C is only useful for a couple of months but nice to have the rest of the time you are not going to notice a great dropoff in AC efficiency with underdrive. You may well notice some xtra hp in the low/midrange however which is when you might have the AC on (ie not when racing) . Also - the xtra hp comes from underdriving the AC+water pump+alternator + any gain from weight reduction .Not just the AC.
Same argument applies for the water pump - this car was designed to run any any climate so underdriving the wp in a temperate climate should not create any issues. Especially if you fit this kit - you should get back any cooling you lost.
However if you want really good AC + the extra HP - these two mods may compliment eachother well . Anyway - its just a theory & if anyone has both mods they may be able to tell me if it is BS.
Edit : i guess you have to consider the extra power needed to drive the alternator to keep the fans running & whether the underdriven alternator will be able to keep up - hmmmmm too much thinking
Same argument applies for the water pump - this car was designed to run any any climate so underdriving the wp in a temperate climate should not create any issues. Especially if you fit this kit - you should get back any cooling you lost.
However if you want really good AC + the extra HP - these two mods may compliment eachother well . Anyway - its just a theory & if anyone has both mods they may be able to tell me if it is BS.
Edit : i guess you have to consider the extra power needed to drive the alternator to keep the fans running & whether the underdriven alternator will be able to keep up - hmmmmm too much thinking
Last edited by Brettus; 08-26-2006 at 09:44 PM.
08-27-2006, 12:34 AM
#128
Originally Posted by olddragger
Our water pump impellar is crap.
olddragger
olddragger
It is the same water pump impeller design that was on the '7 (and the 626, Millenia, MX-3, MX-6 and 929).
Someone is going to have to show an actual reduction in water flow at high RPMs to prove that one. So far, all I have seen is increasing temps at higher RPMs shown as evidence and that is BS.
There are no measurable gains from UD pulleys on this application under any circumstance.
Look! Another page-topper.
08-27-2006, 12:41 AM
#129
Originally Posted by MazdaManiac
There are no measurable gains from UD pulleys on this application under any circumstance.
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08-27-2006, 12:46 AM
#130
Originally Posted by MazdaManiac
Based on anecdotal evidence, I presume?
It is the same water pump impeller design that was on the '7 (and the 626, Millenia, MX-3, MX-6 and 929).
Someone is going to have to show an actual reduction in water flow at high RPMs to prove that one. So far, all I have seen is increasing temps at higher RPMs shown as evidence and that is BS.
There are no measurable gains from UD pulleys on this application under any circumstance.
Look! Another page-topper.
It is the same water pump impeller design that was on the '7 (and the 626, Millenia, MX-3, MX-6 and 929).
Someone is going to have to show an actual reduction in water flow at high RPMs to prove that one. So far, all I have seen is increasing temps at higher RPMs shown as evidence and that is BS.
There are no measurable gains from UD pulleys on this application under any circumstance.
Look! Another page-topper.
if getting a photo is needed.... i can pull the one of the motor on the floor..
beers
Last edited by swoope; 08-27-2006 at 12:56 AM.
08-27-2006, 12:53 AM
#131
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Originally Posted by olddragger
do search on 3nd oil cooler, forget who but a member added a low profile one in the nose ahead of the a/c condesor.
In speaking with RX8 racing friends they advise AGAISNT a 3nd cooler as they say it lowers pressure too much and it takes too long for the oil to warm up(street application) they advise to replace the sorry stock coolers with an aftermarket version that fit in the original locations with a thermostant and to make sure any screens does not block air flow.
...
In speaking with RX8 racing friends they advise AGAISNT a 3nd cooler as they say it lowers pressure too much and it takes too long for the oil to warm up(street application) they advise to replace the sorry stock coolers with an aftermarket version that fit in the original locations with a thermostant and to make sure any screens does not block air flow.
...
Also, the way I installed it, its in series with the stock coolers. Therefore, no oil flows until the stock oil cooler thermostat opens. So, there's no way its causing the oil to reach operating temps more slowly.
Thirdly, there really can be no way that a cooler that fits in the same place as the stockers can be that much more efficient. The only real gains to be had are by 1) adding surface area, or 2) increasing the airflow over the surface are you have. If it fits in the same location, its got to have about the same volume as the stockers and hence, about the same surface area. The only gains to be had in the oil cooling department are through fans, or through a third cooler.
08-27-2006, 08:46 AM
#137
no MM not based on ancedotol evidence. i had a long conversation with the tech director of ROAR racing, he explained to me what they have had to do in regard to the water pumps to get their temps down. They have blown several engines due to high temps,And before you say this was just for racing , high rpm needs, he also explained that they did this to their daily use 8's also that also see occasional track days(basically stock cars). Temps are temps whether you see them on the track or in stop and go traffic in high ambeint temp days or in heat soak situations. He was very critical of the impellar(sic) said it was one of the worse he had seen. Starts cavitation at around 6K. Modified it as they have to use the stock water pump.
Mad Dog that was a good mod you did. I remember how you said that the stock coolers were much more inefficant(sic) than the one you bought because how cool they were to the touch vs the 3nd one. There are much better coolers available now that fit in the stock locations. It is all about air flow as you have said and you should see the fins(stainless steel not aluminum!) and the space inbetween them! With the stock ones and the aluminum fins , some get bent and further block the flow. AIr flow is 100% better with their coolers. At the time you did your mod I dont think there was another option. I am surprised that your oil warm up times remain the same with 3 coolers vs 2
UD does help with cavitation and it does free up some power.
study after study has shown that MM.
High rpm really drives the temps(coolant and oil) it is also one of the (high rpm) great things about the rotory. We just need coolant/lube systems that match the need of the engine. And we are getting there.
olddragger
Mad Dog that was a good mod you did. I remember how you said that the stock coolers were much more inefficant(sic) than the one you bought because how cool they were to the touch vs the 3nd one. There are much better coolers available now that fit in the stock locations. It is all about air flow as you have said and you should see the fins(stainless steel not aluminum!) and the space inbetween them! With the stock ones and the aluminum fins , some get bent and further block the flow. AIr flow is 100% better with their coolers. At the time you did your mod I dont think there was another option. I am surprised that your oil warm up times remain the same with 3 coolers vs 2
UD does help with cavitation and it does free up some power.
study after study has shown that MM.
High rpm really drives the temps(coolant and oil) it is also one of the (high rpm) great things about the rotory. We just need coolant/lube systems that match the need of the engine. And we are getting there.
olddragger
08-27-2006, 11:57 AM
#138
Originally Posted by olddragger
no MM not based on ancedotol evidence. i had a long conversation with the tech director of ROAR racing, he explained to me what they have had to do in regard to the water pumps to get their temps down. They have blown several engines due to high temps,And before you say this was just for racing , high rpm needs, he also explained that they did this to their daily use 8's also that also see occasional track days(basically stock cars). Temps are temps whether you see them on the track or in stop and go traffic in high ambeint temp days or in heat soak situations. He was very critical of the impellar(sic) said it was one of the worse he had seen. Starts cavitation at around 6K. Modified it as they have to use the stock water pump.
BTW, why are you intentionally mis-spelling things?
Originally Posted by olddragger
It is all about air flow as you have said and you should see the fins(stainless steel not aluminum!)
Originally Posted by olddragger
UD does help with cavitation and it does free up some power.
study after study has shown that MM.
study after study has shown that MM.
08-27-2006, 12:46 PM
#140
Nope not intentionally misspelling--i just dont speel well.
Go to the viability of the EWP thread and look at the chevy dyno that used UD pulleys, the EWP and OE pullies for one. Independant test. Find some more if you want. I have seen a good bit and I have the agency pulley on my car and I have felt the differance and seen the differance on the temps.
Dont take my word for the cavitation( i dont have spell check--I think I need it
ask others also.
The fins were stainless according to Chris as there were a lot of trouble with the fins getting bent inward cutting off the air flow. I dont thinks the entire cooler was stainless though as you are right about the heat conductivity
Let me add something else to get doubted. Probaly most of us are running oil cooler and a/c protection screens. How much blockage of air flow do you think that is causing?
If interested here is a crude test. Take a screen out, get a good fan. Cut a strip of paper approx 1/2 inch wide and 2 inches long, Iused an old evelope, hold it agaisnt your screen with your thumb --whatever. hold the screen and the paper on the fan (on high)--look at the piece of paper(i looked from the side) and notice how high the fan is blowing it. Now while holding the piece of paper still slowly remove the screen so the the paper remains in the same place but the screen is gone. Does the paper get blown higher or not? You bet it does. I estimate 30-40% higher. Take that for what it is worth.
I took mine off.
olddragger
Go to the viability of the EWP thread and look at the chevy dyno that used UD pulleys, the EWP and OE pullies for one. Independant test. Find some more if you want. I have seen a good bit and I have the agency pulley on my car and I have felt the differance and seen the differance on the temps.
Dont take my word for the cavitation( i dont have spell check--I think I need it
ask others also.The fins were stainless according to Chris as there were a lot of trouble with the fins getting bent inward cutting off the air flow. I dont thinks the entire cooler was stainless though as you are right about the heat conductivity
Let me add something else to get doubted. Probaly most of us are running oil cooler and a/c protection screens. How much blockage of air flow do you think that is causing?
If interested here is a crude test. Take a screen out, get a good fan. Cut a strip of paper approx 1/2 inch wide and 2 inches long, Iused an old evelope, hold it agaisnt your screen with your thumb --whatever. hold the screen and the paper on the fan (on high)--look at the piece of paper(i looked from the side) and notice how high the fan is blowing it. Now while holding the piece of paper still slowly remove the screen so the the paper remains in the same place but the screen is gone. Does the paper get blown higher or not? You bet it does. I estimate 30-40% higher. Take that for what it is worth.
I took mine off.
olddragger
08-27-2006, 01:58 PM
#142
Originally Posted by olddragger
Nope not intentionally misspelling--i just dont speel well.
Originally Posted by olddragger
Go to the viability of the EWP thread and look at the chevy dyno that used UD pulleys, the EWP and OE pullies for one. Independant test. Find some more if you want.
Originally Posted by olddragger
I have seen a good bit and I have the agency pulley on my car and I have felt the differance and seen the differance on the temps.
Dont take my word for the cavitation( i dont have spell check--I think I need it ask others also.
Dont take my word for the cavitation( i dont have spell check--I think I need it ask others also.
Originally Posted by olddragger
The fins were stainless according to Chris as there were a lot of trouble with the fins getting bent inward cutting off the air flow. I dont thinks the entire cooler was stainless though as you are right about the heat conductivity
Originally Posted by olddragger
Let me add something else to get doubted. Probaly most of us are running oil cooler and a/c protection screens. How much blockage of air flow do you think that is causing?
If interested here is a crude test. Take a screen out, get a good fan. Cut a strip of paper approx 1/2 inch wide and 2 inches long, Iused an old evelope, hold it agaisnt your screen with your thumb --whatever. hold the screen and the paper on the fan (on high)--look at the piece of paper(i looked from the side) and notice how high the fan is blowing it. Now while holding the piece of paper still slowly remove the screen so the the paper remains in the same place but the screen is gone. Does the paper get blown higher or not? You bet it does. I estimate 30-40% higher. Take that for what it is worth.
If interested here is a crude test. Take a screen out, get a good fan. Cut a strip of paper approx 1/2 inch wide and 2 inches long, Iused an old evelope, hold it agaisnt your screen with your thumb --whatever. hold the screen and the paper on the fan (on high)--look at the piece of paper(i looked from the side) and notice how high the fan is blowing it. Now while holding the piece of paper still slowly remove the screen so the the paper remains in the same place but the screen is gone. Does the paper get blown higher or not? You bet it does. I estimate 30-40% higher. Take that for what it is worth.
08-27-2006, 03:19 PM
#143
Originally Posted by MazdaManiac
And the point of the above illustration would be? (Those are all nominal levels, except the air intake temp that is a bit high for the ambient at that speed.)
i would not think that 190 was a nominal level as it would have been about 198 before..... as to the intake temp yes it is high as i took the time to heat soak the motor before the run...
intake air temp usually runs about 10 deg over amb temp at a 60 + cruise.
beers
08-27-2006, 04:40 PM
#145
Originally Posted by swoope
i would not think that 190 was a nominal level as it would have been about 198 before..... as to the intake temp yes it is high as i took the time to heat soak the motor before the run...
intake air temp usually runs about 10 deg over amb temp at a 60 + cruise.
beers
intake air temp usually runs about 10 deg over amb temp at a 60 + cruise.
beers
08-27-2006, 05:21 PM
#146
What did I ever do to you? Jesus. You need a hug or something?
Sic is what is used when you dont think you have spelled the word correctly.I did that just for you.
One day you are going to realize that parasidic drain on an engine----- is not engine specific. A mechanical water pump on any engine uses power. It takes more power to spin it faster. It takes less power to spin it slower. Everything else being equal. You really dont understand that?
Kind of hard to use a fin comb in the middle of a race I guess.
Didnt say it was a good test--I said it was a crude test. I thought you would understand that word.
Good night all--you too Maniac
Olddragger
Sic is what is used when you dont think you have spelled the word correctly.I did that just for you.
One day you are going to realize that parasidic drain on an engine----- is not engine specific. A mechanical water pump on any engine uses power. It takes more power to spin it faster. It takes less power to spin it slower. Everything else being equal. You really dont understand that?
Kind of hard to use a fin comb in the middle of a race I guess.
Didnt say it was a good test--I said it was a crude test. I thought you would understand that word.
Good night all--you too Maniac
Olddragger
08-27-2006, 05:26 PM
#147
Originally Posted by Brettus
even with the RB duct in place ?
if i get about 80 mph, the intake temp gets down to 8 deg over outside temp.
this is after a heat soak... if i just drive the car away cold and go cruise it takes a while go get the intake temp. up.
but the norm for my car is 10 deg above outside temp..
stop and go traffic. about at least 30 deg warmer.
beers
08-27-2006, 05:32 PM
#149
A 2 hr drive to Atlanta on a 96-97 degree day at 70-80Mph with or with out the A/C on gives me coolant temps of 185-190 F and oil temps at 190F. Oil temp will go up 10 degrees or so if I do a fair amount of acceleration to pass. Load . of course gives you higher temps.
OD
OD
