2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

I've got an idea but I'm not sure how to execute it. Help me?

Thread Tools
 
Search this Thread
 
Old 02-28-13, 07:55 AM
  #1  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts
I've got an idea but I'm not sure how to execute it. Help me?

Alright so here is the preliminary info.

I'm building a track oriented car that will still be street legal.
4 port turbo block with hybrid turbo
I'm buiding a vmount and having difficult finding a nice spot for the oil cooler.


Here is my idea. I'd like to put the oil cooler behind the radiator down near the sway bar with fans on it. NOW the question is, how could I activate the fans? A simple relay system that turns the fans on at a certain temp? Is there a way to utilize the Megasquirt? I figure I could tap the same line powering the coolant fan but then they run at the same time even though it may not need to be running.


The only other place I could think of putting the oil cooler was where the bumper meets the round support bar with the oil cooler laying horizontally.
halp!
Old 02-28-13, 08:19 AM
  #2  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Before you relocate the cooler and depend on fans to make it work, seems like sourcing the fans would be the first step.

I've found the oil temp and coolant temp to mirror each other closely, so having the rad fan and cooler fans activate together would make sense to me.
Old 02-28-13, 02:55 PM
  #3  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts
Fans shouldnt be an issue. I know of fans that pull 250 CFM.
Old 02-28-13, 04:26 PM
  #4  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Tell me they're not PC fans.
Old 02-28-13, 11:53 PM
  #5  
I wish I was driving!

 
Join Date: Dec 2001
Location: BC, Canada
Posts: 5,241
Received 84 Likes on 68 Posts
Originally Posted by driftxsequence
Fans shouldnt be an issue. I know of fans that pull 250 CFM.
That's incredibly low.
Old 03-01-13, 08:09 AM
  #6  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts
Technically they are server fans clokker....

250 may sound low but it puts out a lot of air for its size. Plus, I could fit a total of four of them on top of the oil cooler for a total of ~1000 CFM moving across the oil cooler...

Old 03-01-13, 08:31 AM
  #7  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by clokker
Tell me they're not PC fans.
Originally Posted by driftxsequence
Technically they are server fans clokker....
OK, two things....

PC fans (even "server" fans) are not made to withstand the environment you want to put them in, and...

In order to even approach the CFM flow you hope for, those fans would need to be spaced a few inches off the cooling matrix with a shroud. Otherwise the hub and frame will be blocking most of the airflow through the cooler.
Does your plan account for this added width?

The fan you showed doesn't strike me as anything special, certainly not "server grade".
If you must persist in this folly (and I just don't see it ending well), look into Comair Rotron "Muffin" fans. They feature sealed motors, metal frames and three blade rotors and might give you a chance at what you hope for.
Name:  Muffin1_zpsbe1785f8.jpg
Views: 66
Size:  54.6 KB

Name:  Muffin2_zps51f5796d.jpg
Views: 74
Size:  61.7 KB
Old 03-01-13, 08:50 AM
  #8  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts
Yes I figured I need to find a way to seal the edges to make sure that air is being pulled through the radiator and not just moving air. To go with that I didnt want the fan sitting right on top since usually the blade shaft has a bit of in and out play.

The fan pictured was just a dead 120mm fan, I wanted to see if the size was about right. I figured this would be an easy shot since the fans are small, DC, easily attainable and easy to wire up with the e-fan. Those Comair fans do look hefty. I have a set of metal fans from an old rack mount system that used the fans to vent air out of the top of the unit. I will see if they are any good...

Here is a link to one of the fans I had messed with. Delta TFB1212GHE 120x38mm Extreme High Speed Damn thing was as loud as a vacuum.
Old 03-01-13, 09:08 AM
  #9  
1308ccs of awesome

iTrader: (9)
 
eage8's Avatar
 
Join Date: Sep 2003
Location: Woodbine, MD
Posts: 6,189
Received 17 Likes on 15 Posts
Here is how it's mounted on the new rotary extreme v-mount kit, it uses a scoop to get air into it:



Old 03-01-13, 09:15 AM
  #10  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Ok then, here's what I would do...

(I assume you have an oil temp gauge already installed)

Leave the cooler in the stock location and mount the fans as best as you can (when I was using the Muffins on my watercooled rig the optimal distance of fan to cooling matrix was @4").
See if they actually are capable of dropping the oil temp when activated.

Essentially, the cooler is already positioned to take advantage of the incoming airflow.
As you move the cooler to a less optimal position, you'll be relying on the fans to make up the difference in airflow and you should determine how capable they are before you move the cooler.
Old 03-01-13, 11:03 AM
  #11  
Eats, Sleeps, Dreams Rotary

 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,750
Received 88 Likes on 64 Posts
Use dual oil coolers in brake ducts.
Old 03-02-13, 08:26 PM
  #12  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts

here is a video of a very similar output fan. The Comair rotron 3 blades put out roughly what the other large fan did (110CFM). I think 240 will be enough if I combine 2-3 fans. I'll definitely keep this updated.
Old 03-02-13, 09:35 PM
  #13  
Rotary Enthusiast

iTrader: (1)
 
barkz's Avatar
 
Join Date: Sep 2011
Location: New Hampsha
Posts: 1,261
Likes: 0
Received 1 Like on 1 Post
its not so much an issue of how much air they can move, so much as they will last you a week in the elements
Old 03-02-13, 09:52 PM
  #14  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by barkz
its not so much an issue of how much air they can move...
Well, it kind of is, isn't it?

More to the point (all fluttering sheets of notepaper aside), how much air can it suck through the rather thick, densely finned oil cooler?
Old 03-02-13, 10:07 PM
  #15  
What's the point??

iTrader: (6)
 
papiogxl's Avatar
 
Join Date: Oct 2005
Location: Omaha, NE
Posts: 995
Likes: 0
Received 0 Likes on 0 Posts
You would be surprised what a PC fan can stand up to. I recently was working on an Okuma lathe, and had to remove about a pound of grease from one, and it was still spinning just fine.
Old 03-03-13, 08:48 AM
  #16  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by papiogxl
You would be surprised what a PC fan can stand up to.
Probably not, actually.

I am interested in the outcome of this experiment although I think it will end up badly.
Besides the fact that PC fans are not designed/built to withstand the rigors of this proposed environment, there is a second consideration not yet mentioned.

Computer fans are designed for a static environment, the only airflow present is what they generate themselves. There is no scenario where air is actively pushed at them.
This narrow design focus means that they can be total obstructions to airflow because it's not an issue in a PC...but it sure will be in this application.

It's all in the ratio of hub size to fan blade length and designed fan speed.
To mitigate the effects of the large motor hub, the fan will need to be spaced off the cooling core with a shroud (figure a minimum of 1 1/2", so you add @3" to the depth of the cooler, which needs to be accounted for as well).

Unlike the PC though, your fans will not be running all the time and during those off periods your setup will become an effective restriction of the airflow generated by the car's movement.

I'd guess that this setup could possibly improve idle/static oil temps but get much worse as speed and load increase.

But, it's worth a try and I'm curious about the outcome.
Old 03-03-13, 10:07 AM
  #17  
Rotary Enthusiast

iTrader: (1)
 
barkz's Avatar
 
Join Date: Sep 2011
Location: New Hampsha
Posts: 1,261
Likes: 0
Received 1 Like on 1 Post
Originally Posted by clokker
Well, it kind of is, isn't it?
well, yes lol
Old 03-03-13, 10:15 AM
  #18  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by barkz
well, yes lol
The point I was trying to make there was that if the setup actually works, some people might be willing to swap the fans out regularly...they're relatively cheap, after all.
Race vehicles regularly sacrifice longevity for performance.
Old 03-03-13, 04:54 PM
  #19  
Eats, Sleeps, Dreams Rotary

 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,750
Received 88 Likes on 64 Posts
Money is best spent once. Using PC fans in an engine bay is about the stupidest thing I have ever heard.

It's pretty much up there with Direct Exhaust Injection.
Old 03-03-13, 06:14 PM
  #20  
Eats, Sleeps, Dreams Rotary

 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,750
Received 88 Likes on 64 Posts
SPAL USA

See? If you know where to look there is ALWAYS a properly-engineered solution.

You're still better off using two big fat cores in the brake ducts though...
Old 03-03-13, 07:12 PM
  #21  
Rotorhead

 
Evil Aviator's Avatar
 
Join Date: Feb 2001
Location: Charlottesville, Virginia, USA
Posts: 9,136
Likes: 0
Received 39 Likes on 33 Posts
The CFM rating of fans is based on a given pressure. Those PC fans were not intended to pull air through a thick automotive heat exchanger.

As for controlling fans, keep in mind that a moving fan becomes a restriction once there is a significant amount of ram air flowing through the heat exchanger. Therefore, if you mount the heat exchanger in an area where it will receive ram air when the vehicle is in motion, the fans should be shut off around 30-35mph vehicle speed.

You may want to consider putting a flow divider between the intercooler and the radiator. I am concerned that air will stagnate at the intercooler with your current setup because the intercooler will receive ram air from both the top and bottom at high vehicle speed, and at low vehicle speed the air will stagnate because the radiator fan will pull the air down while convection tries to pull it up.

I'm not sure if you will have room for proper ducting, but here is a link that will tell you how it will work best:
Cooling Systems
Old 03-03-13, 07:56 PM
  #22  
Rotisserie Engine

Thread Starter
iTrader: (8)
 
driftxsequence's Avatar
 
Join Date: Jan 2007
Location: Wilmington, DE
Posts: 1,833
Received 48 Likes on 38 Posts
I see. You guys do make good points. I figured it would work, and it just seemed "right" since the PC fans would fit easily as well.

Valkyrie - I wish I could afford it but for now considering many say the factory oil cooler is more than adequate I can justify spending more (especially since I should be saving for a home.)

Evil - I do plan on making a divider to force air up to the intercooler since it's angle would seem to force most air through the radiator.

Clokker - I appreciate the criticism and saving me from blowing my **** up. If that happens its bye bye rx7
Old 03-03-13, 08:09 PM
  #23  
Anti-Hero
 
thethingthatshouldnotbe's Avatar
 
Join Date: Jul 2011
Location: Brownsburg, Indiana
Posts: 318
Likes: 0
Received 1 Like on 1 Post
Why wouldn't you put the cooler somewhere in cold air?
Old 03-03-13, 08:16 PM
  #24  
Eats, Sleeps, Dreams Rotary

 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,750
Received 88 Likes on 64 Posts
If you can't at afford to build a car right the first time, or at least use the right kind of fans, you have zero ******* business modifying cars.
Old 03-03-13, 09:10 PM
  #25  
Full Member

iTrader: (5)
 
bluemp301's Avatar
 
Join Date: Mar 2012
Location: St. Louis
Posts: 87
Likes: 0
Received 0 Likes on 0 Posts
Just a thought since it hasn't been mentioned, if your on a tight budget, why a vmount as opposed to a less costly and easier fmic setup?


Quick Reply: I've got an idea but I'm not sure how to execute it. Help me?



All times are GMT -5. The time now is 12:25 PM.