Diff Cooler Questions

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
Hey folks.
I'm building a diff cooler rig and had a few questions:

1. Does the temp sensor need to be 'touching' the fluid, or can it be further up the line (before the pump, of course)?
I understand that the reading might be off by a few degrees, and that would prevent the pump from kicking in/turning off at the absolute 180ºF mark. But, in theory, the air temp inside the hose should be very close to the fluid temp. considering the short section of hose being used.
I ask because there are several inline temp sensors that I'm considering that would not only aid in installation (no extra hole drilled into diff cover), but also get the temp sensor out of harms way.
The other reason for moving the temp sensor is to get it away from the heat the diff. itself is putting out. While the fluid might be 175º, the housing and cover could still be at 190º, setting off the temp sensor and kicking the system on (or off when it's cold out).

2. What size radiator to use?
I've found several that would fit this application- 19"x7"x4" being the largest; 8.5"x3"x2" being the smallest.
Is there a minimum size required? Maybe in relation to how much fluid is in the system? (I'm running a little over 3 quarts)

3. In respect to question #2, I am thinking that more than the OEM amount of diff. fluid will be required when running a diff. cooler.
Is there a specific amount that needs to be added, or just follow the Comp. Coupe filling guide?

4. While the Comp. Coupe runs a Tilton pump (and those rock the hizzouse) are there any other comparable options out there?

5. -06AN and -08AN seem to be the two hose sizes of choice.
Any advantages/disadvantages of one over the other (aside from fluid movement and price of hose/fittings)?

Thanks for any help or insight you can give.
I appreciate it.
 

Shadowman

Enthusiast
Joined
Jan 29, 2009
Posts
55
Reaction score
0
Hey folks.
I'm building a diff cooler rig and had a few questions:

1. Does the temp sensor need to be 'touching' the fluid, or can it be further up the line (before the pump, of course)?
I understand that the reading might be off by a few degrees, and that would prevent the pump from kicking in/turning off at the absolute 180ºF mark. But, in theory, the air temp inside the hose should be very close to the fluid temp. considering the short section of hose being used.
I ask because there are several inline temp sensors that I'm considering that would not only aid in installation (no extra hole drilled into diff cover), but also get the temp sensor out of harms way.
The other reason for moving the temp sensor is to get it away from the heat the diff. itself is putting out. While the fluid might be 175º, the housing and cover could still be at 190º, setting off the temp sensor and kicking the system on (or off when it's cold out).

2. What size radiator to use?
I've found several that would fit this application- 19"x7"x4" being the largest; 8.5"x3"x2" being the smallest.
Is there a minimum size required? Maybe in relation to how much fluid is in the system? (I'm running a little over 3 quarts)

3. In respect to question #2, I am thinking that more than the OEM amount of diff. fluid will be required when running a diff. cooler.
Is there a specific amount that needs to be added, or just follow the Comp. Coupe filling guide?

4. While the Comp. Coupe runs a Tilton pump (and those rock the hizzouse) are there any other comparable options out there?

5. -06AN and -08AN seem to be the two hose sizes of choice.
Any advantages/disadvantages of one over the other (aside from fluid movement and price of hose/fittings)?

Thanks for any help or insight you can give.
I appreciate it.

With regards to most of your questions I will respectfully defer to another with Viper specific experience however to the initial question I will reply;

The answer is "yes"; if the probe is not in the fluid it will be worthless; these are not air temperature sensors.

All the best with your project

Shadowman
 
OP
OP
K

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
Thanks, Shadowman!
I'll try to find one that's unobtrusive but still durable enough to hang out on a diff. cover.
 
OP
OP
K

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
Well, in case anyone is reading this and wondering *** is happening....

A couple of questions have been answered.
1. A temp sensor has been located:
Optimum Motorsports - AiM Sensors and Expansion
I like that it's stainless steel instead of brass, as the rest seem to be. About 3x the cost of a brass sensor, but.....

An extra (3rd) hole will be drilled in the diff. cover this week. It will be 1/8" NPT to accommodate the temp sensor.
There's a perfect flat spot on the cover located approx. 2/3 'deep' into the diff. fluid level. Before and after pics coming soon.

5. The Comp. Coupes run -08AN lines. I will do the same. I don't think -06AN provides enough of a flow rate whether racing or not.
 
OP
OP
K

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
Time to bring up my old thread as this project is back on the front burner again.

If a Comp. Coupe owner could post the dimensions (L x W x H) of their diff cooler radiator, I would greatly appreciate it.

Also. does anyone know the difference (aside from the $40 in price) between the Tilton 40-524 and 40-525 pumps?
Specs look identical.
Both Summit and Jegs show a "40-524-1" model number under the 40-525 part number. Not sure WTH is up with that.

If anyone has any suggestions on thermostat/temp control switch setups, I'm all ears.
Anything from basic on/off to uber-tech. Bring 'em on!

Ordering more AN fittings and hose now! :)
 
OP
OP
K

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
MASSIVE props to John @ Archer Racing for answering my inane questions this afternoon.
THANKS JOHN!


If anyone is considering doing this, be forewarned: It's going to be about a $700 project, w/o mounting and uninstalled.
If that doesn't deter ya, let me know and I'll get you a complete parts list.

I may do a DIY for this one....not sure yet.
 
OP
OP
K

Kevan

Enthusiast
Joined
Dec 11, 2006
Posts
2,556
Reaction score
1
Location
New Albany, OH
Found out the difference between the two Tilton pumps:
40-524 = Buna-N (nitrile) seals
40-525 = Viton seals.
Yeah...$40 for different seals.
Anyway, the CC uses the 40-524.

The switching system for the pump is on it's own circuit. If the temp is high, the pump runs, even if the car is turned off. The pump will run until the fluid is sufficiently cooled.

While that's nice, I wanted to upgrade it a bit.
The switching system I found will do the automatic temp-controlled pumping like the CC, but there will also be an in-cab ON/OFF switch.
This will let the driver turn off the pump if there's a problem or if temps are too cool.
It will also help facilitate diff. fluid changes! No more hand-pumping! You can use the pump on the diff cooler now! :)
(They say you can use a jumper wire on the CC's, but.....I think a switch is better. LOL)
I really wanted a digital temp display with adjustability in the cab, but I think since we're not going into space, this setup will work great.
The other nice thing is that you'll be able to pick the temp you want to start cooling at, in 10F degree increments (up to 300F!).
This should work nicely.

The radiators in the CC's are sized to handle the smaller diff found in the cars.
The diff in the truck is considerably larger (and thus holds more fluid), so a larger radiator (about 30% bigger) will be used.

Okay...back to the shop...
:D
 
Top