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Old 02-25-2009, 02:15 AM   #141
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Originally Posted by patsmx5 View Post
I'd be willing to bet that if you did nothing more than put a big ******* fan on that radiator the engine would never overheat. You don't believe this though. But it's the ******* truth. A big 25 or 30A fan will pull so much ******* air through that radiator the car will lurch forward at a red light when it comes on....

Or if you did the shrouding like I showed it wouldn't overheat with stock fans. IMO, adding scoopers and ducts to get more air to the front is a joke. There's plenty of area up there for all the air you need. You don't race at 3 mph. Most of the air that hits the front of the car doesn't go through the mouth. It goes around it. Putting a bigger opening won't do ****. Putting a scooper won't do ****. You have to do things to make air flow. Pressure building up in the engine bay doesn't help flow through the heat exchanger. So adding 4 times more frontal area to the mouth just causes more air to built up under the hood.
too bad it costs me about $300 each time I want to test it out and see what works.
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Old 02-25-2009, 02:21 AM   #142
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Originally Posted by patsmx5 View Post
I'd be willing to bet that if you did nothing more than put a big ******* fan on that radiator the engine would never overheat. You don't believe this though. But it's the ******* truth. A big 25 or 30A fan will pull so much ******* air through that radiator the car will lurch forward at a red light when it comes on....

Or if you did the shrouding like I showed it wouldn't overheat with stock fans. IMO, adding scoopers and ducts to get more air to the front is a joke. There's plenty of area up there for all the air you need. You don't race at 3 mph. Most of the air that hits the front of the car doesn't go through the mouth. It goes around it. Putting a bigger opening won't do ****. Putting a scooper won't do ****. You have to do things to make air flow. Pressure building up in the engine bay doesn't help flow through the heat exchanger. So adding 4 times more frontal area to the mouth just causes more air to built up under the hood.
So what you're actually saying is that Begi is wrong with air scoopers and all aerophysics is disproven and all the aftermarket bumpers from amemiya, aizawa, garage vary, any shop or racecar that used or made functional parts with larger ducting area are wasting time?
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Old 02-25-2009, 02:25 AM   #143
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too bad it costs me about $300 each time I want to test it out and see what works.
You can get an idea of how well your system works on the streets. It's not the same, but it will give you an idea. Like right now if I'm idling and the fans come on, they run 30-40 seconds before they go off. Before I sealed an IC and condenser to the front of the radiator they only ran 25-30 seconds before they kicked off, that's with a 5* hysteresis. I obviously hurt flow some at idle. BUT, the fans run less when at cruise.... Now, say I put a huge 25 or 30A fan. Now when when the fans come on they'd probably run 10 or 15 seconds and kick off. This would give you a VERY good idea of how much better your setup is as this shows the rate of heat transfer out of the radiator has improved substantially. And cost you nothing to test other than the cost of the parts, which is a given.

Last edited by patsmx5; 02-25-2009 at 03:18 AM.
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Old 02-25-2009, 02:37 AM   #144
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Originally Posted by Sam Amporful View Post
So what you're actually saying is that Begi is wrong with air scoopers and all aerophysics is disproven and all the aftermarket bumpers from amemiya, aizawa, garage vary, any shop or racecar that used or made functional parts with larger ducting area are wasting time?
No, I'm talking about miatas. But yes, there are A LOT of parts made that appear to function but are poorly designed. I'd say that for hustler's setup a begi scooper isn't needed. He has a plenty of frontal area given the size of his heat exchangers, amount of frontal area, and total heat he needs to reject. Air will not compress when you're driving (more or less, for cars going sub 200mph) If you have X amount of surface area for a heat exchanger, adding 2X or 3X or 10X of surface area to feed it is of no benefit. That much air will not be forced through the heat exchanger. It will just build up and go around. That's why you have a splitter that goes at the bottom of the bumper, to keep some of that air that builds up from going under the car.

A fan will spin and create a pressure differential across the heat exchanger, causing air to flow.

Id say keeping air from getting under the hood will help air flow through the heat exchangers much more than adding frontal area. As hustler mentioned before, he's seen where the hood will bulge at speed from air building up under the hood.
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Old 02-25-2009, 02:48 AM   #145
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I don't want to hack my ****...i want to make it look like this:

without the nacas.
hacking your **** would be like the time when you tried to circumcise yourself with that rusted, dull butter knife.

If you ever put naca ducts, that hideous, on your car, I hope to God that you run into a tire wall head on without a helmet or a harness.
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Old 02-25-2009, 03:44 AM   #146
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Well now I think that that miata looks fantastic.. only gripe I would have is that the design of the NACA duct is wasted there as the airflow hits it directly instead of passing over it, but the fact that it is a NACA duct doesn't mean it works any less well than any other shape hole there..

To pat - I agree that there are many parts out there which would appear to work a certain way but don't do as good of a job as one might hope in the real world, but when it comes to the frontal area of the car, a bigger opening to allow more air in will help given that as much work has been put into giving the air clean ways to get out as well.

Hustler - I would really focus on getting the air out of the engine bay and shrouding the entry so that the air entering does not get wasted. Also, the BEGI scooper is a good piece and should be installed - it will help. I agree with many here that I doubt it will be necessary for you to cut up the bumper for more air to get in. An extraction hood and a front splitter as well as shrouds from the bumper inlet to the IC/rad should really be everything you need and then some. I don't know if it is already in your plans but personally, for a track only car, I think it would be a huge mistake to not use some form of extraction hood.

-Ryan
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Old 02-25-2009, 03:52 AM   #147
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Originally Posted by patsmx5 View Post
You can get an idea of how well your system works on the streets. It's not the same, but it will give you an idea. Like right now if I'm idling and the fans come on, they run 30-40 seconds before they go off. Before I sealed an IC and condenser to the front of the radiator they only ran 25-30 seconds before they kicked off, that's with a 5* hysteresis. I obviously hurt flow some at idle. BUT, the fans run less when at cruise.... Now, say I put a huge 25 or 30A fan. Now when when the fans come on they'd probably run 10 or 15 seconds and kick off. This would give you a VERY good idea of how much better your setup is as this shows the rate of heat transfer out of the radiator has improved substantially. And cost you nothing to test other than the cost of the parts, which is a given.
Not at all.
Driving on the street is NOWHERE near as abusive as track driving. My track toy runs perfect on the street, never turning on the fans. Track driving is a different story, 290* oil temps and 260* coolant temps. It sucks. And there is ducting in place and no thermostat....
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Old 02-25-2009, 04:24 AM   #148
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Not at all.
Driving on the street is NOWHERE near as abusive as track driving. My track toy runs perfect on the street, never turning on the fans. Track driving is a different story, 290* oil temps and 260* coolant temps. It sucks. And there is ducting in place and no thermostat....
Now now, we don't need Hustler any more paranoid than he already is.

P.S. Could you elaborate on what ducting is done, what vents/extractors are used, what radiator, if there is an IC, oil cooler, etc.? Thanks
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Old 02-25-2009, 12:14 PM   #149
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Well now I think that that miata looks fantastic.. only gripe I would have is that the design of the NACA duct is wasted there as the airflow hits it directly instead of passing over it, but the fact that it is a NACA duct doesn't mean it works any less well than any other shape hole there..
That miata does look bad ***. The naca ducts are way too big for the bumper and don't follow the body lines.
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Old 02-25-2009, 01:14 PM   #150
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Originally Posted by crashnscar View Post
Not at all.
Driving on the street is NOWHERE near as abusive as track driving. My track toy runs perfect on the street, never turning on the fans. Track driving is a different story, 290* oil temps and 260* coolant temps. It sucks. And there is ducting in place and no thermostat....
Cuz you much not running a thermostat helps....Hahahaha

Try running one and watch what happens.
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Old 02-25-2009, 02:33 PM   #151
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Originally Posted by crashnscar View Post
Not at all.
Driving on the street is NOWHERE near as abusive as track driving. My track toy runs perfect on the street, never turning on the fans. Track driving is a different story, 290* oil temps and 260* coolant temps. It sucks. And there is ducting in place and no thermostat....
I didn't say that driving on the street introduced as much heat into the cooling system as tracking the car, did I? Did you read my post? What I wrote was just a casual way to observe the rate of heat rejection out of the radiator when the fans come on. It's not necessarily a great test, but it's something.

No thermostat = Fail. Sorry, but that's a very poor decision to make. The thermostat is there for a reason. Without one you will get uneven cooling throughout the block.
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Old 02-25-2009, 02:42 PM   #152
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Pat, is that true on all motors? I can see how it's true with a stock-flow BP, but I think it might be different on the LS3 in his track toy.
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Old 02-25-2009, 02:50 PM   #153
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Cuz you much not running a thermostat helps....Hahahaha

Try running one and watch what happens.
Yeah, it does help actually. I get about 15 minute out of a session instead of the 10 minutes I got before. If you actually know something, post a useful post.

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Originally Posted by patsmx5 View Post
I didn't say that driving on the street introduced as much heat into the cooling system as tracking the car, did I? Did you read my post? What I wrote was just a casual way to observe the rate of heat rejection out of the radiator when the fans come on. It's not necessarily a great test, but it's something.

No thermostat = Fail. Sorry, but that's a very poor decision to make. The thermostat is there for a reason. Without one you will get uneven cooling throughout the block.
I'm just saying that your street observations really have nothing to do with what happens on track, unless of course you are overheating on the street then your fucked.

Why is no thermostat failing? The thermostat is there to keep the car operating at a certain temperature on the street, where without one it would run too cold, especially on a cold winter night. BTW, this isn't on a Miata motor, but I'd still like an explanation of why no thermostat is so bad. I actually have one reason that I know of that it could be bad, but am not completely convinced it is true.
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Old 02-25-2009, 02:51 PM   #154
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Pat, is that true on all motors? I can see how it's true with a stock-flow BP, but I think it might be different on the LS3 in his track toy.
It's true on a miata. It's not necessarily the case on every engine though. I was certainly talking about BP engines. I don't know anything about LS3's so I can't say if it hurts or not. I still don't seen why to not run a thermostat though. They open when the water gets hot.

I still don't buy that putting more frontal area up front is gonna magically force more air through a heat exchanger.
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Old 02-25-2009, 02:57 PM   #155
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Increase the frontal area and you increase the pressure against the radiator. Ducting does the same thing, just more effectively (and with more effort). Pressure deltas are the name of the game.
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Old 02-25-2009, 03:09 PM   #156
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Increase the frontal area and you increase the pressure against the radiator. Ducting does the same thing, just more effectively (and with more effort). Pressure deltas are the name of the game.
what happened to your vented hood? What kind of bullshit do you have under the car? Do you have ducting on the front of the rad?
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Old 02-25-2009, 03:22 PM   #157
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what happened to your vented hood?
Hookers and blow.


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What kind of bullshit do you have under the car?
Hookers and blow.

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Do you have ducting on the front of the rad?

...hookers and blow?
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Old 02-25-2009, 03:31 PM   #158
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Do not ever PM nudes to me again. Its over between us. Seriously.

OK, I'm ready to go back home now and put my FM hood on, and track my car.
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Old 02-25-2009, 03:36 PM   #159
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Increase the frontal area and you increase the pressure against the radiator. Ducting does the same thing, just more effectively (and with more effort). Pressure deltas are the name of the game.
Oh really? How so? Does it funnel air and cause it to compress? So a bigger funnel makes it compress more, right? Perhaps if you had a 20'x30' funnel that stuck out of the front it would catch so much air and compress it so much you wouldn't overheat? Hell, maybe you could just hook that to the engine and have free boost.

Why not. Pick one and why.
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Old 02-25-2009, 03:38 PM   #160
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Here's a chart I found that relates pressure to speed. Funny it doesn't mention frontal area... You know, since more area = more pressure....

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