Lowering Trans Temps
Pro
Joined: Jul 2013
Posts: 509
Likes: 62
I'm inclined to agree. Just from memory of what the area looks like, there's really no way you'll see decent airflow through the cooler there. In the end all coolers are heat exchangers; you're making the trans fluid cooler by making the air around it hotter. If you're dealing with a small, static amount of air, you will quickly reach the upper limit on your cooling capacity.
My setup is very similar to realcanuk's, except mine is in the driver's fender. As said before, I've had good luck with it, even on road courses (temps stay around 230 there). Repeated (20+) passes on the strip and I never got over 185 this summer. I expect that adding a cam and converter may have me looking into adding another cooler and a thermostat if I plan to go to the road course more often, but for street/strip duty a single B&M with proper airflow will get most people through it. Even in south LA we don't get the kind of days that HOXXOH gets in AZ, though.
My setup is very similar to realcanuk's, except mine is in the driver's fender. As said before, I've had good luck with it, even on road courses (temps stay around 230 there). Repeated (20+) passes on the strip and I never got over 185 this summer. I expect that adding a cam and converter may have me looking into adding another cooler and a thermostat if I plan to go to the road course more often, but for street/strip duty a single B&M with proper airflow will get most people through it. Even in south LA we don't get the kind of days that HOXXOH gets in AZ, though.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
I don't have a super charger or inter cooler, but have the vararam and my 12"x12" hayden stacked cooler is wedged dead center and behind the vararam and pressed against the condenser radiator, i have to force the vararam down when replacing it as one unit, yet my trans temps stay under 160 most of the year with aggressive driving, even an all day track rental with multiple series of 5 hotlaps its never reached190
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
It's not rocket science. Myself and a few others have said what's working perfectly. Why not just do the same, rather than reinvent the wheel.
If my built trans, with triple disc converter, behind 1000 rwhp, stay cool, I am pretty sure a similar cooler setup would work for almost anyone.
The exception might be road racing, which I dont do. That is probably hardest on the trans and I would think maybe dual coolers could be a consideration for that.
If my built trans, with triple disc converter, behind 1000 rwhp, stay cool, I am pretty sure a similar cooler setup would work for almost anyone.
The exception might be road racing, which I dont do. That is probably hardest on the trans and I would think maybe dual coolers could be a consideration for that.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
There's a whole lot more to coolers than just the brand. I have a B&M 70273 that's 11 x 5.75 x 1.5 stacked plate and rated at 15,000 BTU/HR. Because of how it's mounted, I can only get airflow through 11 x 3, which means I'm getting about 8,500 BTU/HR effective usage. Rather than cut up part of the car and then create a new mount, I just bought a Derale 51006 that's 12.5 x 2.875 x 2 stacked plate and rated at 20,000 BTU/HR. Now I'll be able to get full airflow through my 3" opening and the 2" thickness of the plates is why there's an extra 35% more capacity.
I still need to check on exactly how the Derale t-stat functions before I order, since their description is a little vague, but I do plan on using one.
If this doesn't do the job, I'll buy a second one and mount them in series.
I still need to check on exactly how the Derale t-stat functions before I order, since their description is a little vague, but I do plan on using one.
If this doesn't do the job, I'll buy a second one and mount them in series.
Their 13011 t-stat allows 10% flow through the cooler at all times the fluid is below 165 degrees, while returning 90% to the transmission uncooled. When the fluid temperature reaches 165 the percentage of flow to the cooler starts to increase until at 180 the flow is at 100%. Since most mechanical thermostats are bi-metal springs, the rate of change is constant in that 15 degree range. So I assume the sizing of the internal passages allow the same rate of change for the flow to keep the pressure constant.
Now if my worst case heating never exceeds the 20,000 BTU cooling capacity, my transmission temps will quickly get into and stay in the 165-180 range. The cooler wants to be independent of the OEM radiator cooler to avoid being a supplement to the engine coolant.
Pro
Joined: Jul 2013
Posts: 509
Likes: 62
Just got off the phone with tech support at Derale and here's the skinny.
Their 13011 t-stat allows 10% flow through the cooler at all times the fluid is below 165 degrees, while returning 90% to the transmission uncooled. When the fluid temperature reaches 165 the percentage of flow to the cooler starts to increase until at 180 the flow is at 100%. Since most mechanical thermostats are bi-metal springs, the rate of change is constant in that 15 degree range. So I assume the sizing of the internal passages allow the same rate of change for the flow to keep the pressure constant.
Now if my worst case heating never exceeds the 20,000 BTU cooling capacity, my transmission temps will quickly get into and stay in the 165-180 range. The cooler wants to be independent of the OEM radiator cooler to avoid being a supplement to the engine coolant.
Their 13011 t-stat allows 10% flow through the cooler at all times the fluid is below 165 degrees, while returning 90% to the transmission uncooled. When the fluid temperature reaches 165 the percentage of flow to the cooler starts to increase until at 180 the flow is at 100%. Since most mechanical thermostats are bi-metal springs, the rate of change is constant in that 15 degree range. So I assume the sizing of the internal passages allow the same rate of change for the flow to keep the pressure constant.
Now if my worst case heating never exceeds the 20,000 BTU cooling capacity, my transmission temps will quickly get into and stay in the 165-180 range. The cooler wants to be independent of the OEM radiator cooler to avoid being a supplement to the engine coolant.
http://www.improvedracing.com/oil-th...65f-p-423.html
Looks over-engineered: just the way I like it! LOL
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
There are some less expensive ones out there I think, but eventually I'll probably add one of these if I get a second cooler:
http://www.improvedracing.com/oil-th...65f-p-423.html
Looks over-engineered: just the way I like it! LOL
http://www.improvedracing.com/oil-th...65f-p-423.html
Looks over-engineered: just the way I like it! LOL
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
I haven't tried any other thermostats but my experience with the one in the B&M cooler is as follows.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
Team Owner
Joined: Sep 2000
Posts: 25,001
Likes: 2,701
From: Far NW 'burbs of Chicago
St. Jude Donor '13
I haven't tried any other thermostats but my experience with the one in the B&M cooler is as follows.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
Also, were you running in series with the stock radiator cooler, and if so, was the extra cooler before or after the radiator?
Thanks!
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Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
Can you recall what trans temps the 176' thermostat actually produced for you, in conditions where the thermostat was running in its working range?
Also, were you running in series with the stock radiator cooler, and if so, was the extra cooler before or after the radiator?
Thanks!
Also, were you running in series with the stock radiator cooler, and if so, was the extra cooler before or after the radiator?
Thanks!
When I first installed with the thermostat connected, I getting to 200 fairly easily. With the fan running all the time, I rarely see over 180.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
I haven't tried any other thermostats but my experience with the one in the B&M cooler is as follows.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
The thermostat opens at 176 degrees which sounds great on paper. What I found was that by the time it opened, the temperature in the trans itself was already higher than that, and higher than I wanted.
During the warm weather, I run the fan all the time. When it gets cooler, I just turn the fan off completely, and the cooler itself keeps the temps good. I can always turn the fan back on if I am really pushing it , or at the track.
The type of t-stat I've been discussing, relates only to trans fluid and is independent of the cooler and/or cooler fans.
I'd also like to ask what is the stall speed of your converter, since that's the primary source of heat? Of course, the triple disk unit doesn't slip as much to create heat, but the higher the stall, the higher the slippage.
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
I think there's a basic difference and to clear it up, I'd like to ask if the cooler you have is the B&M 70298? If that's the one, it has a t-stat to switch the fan on (176*) and off (140*).
The type of t-stat I've been discussing, relates only to trans fluid and is independent of the cooler and/or cooler fans.
I'd also like to ask what is the stall speed of your converter, since that's the primary source of heat? Of course, the triple disk unit doesn't slip as much to create heat, but the higher the stall, the higher the slippage.
The type of t-stat I've been discussing, relates only to trans fluid and is independent of the cooler and/or cooler fans.
I'd also like to ask what is the stall speed of your converter, since that's the primary source of heat? Of course, the triple disk unit doesn't slip as much to create heat, but the higher the stall, the higher the slippage.
My converter is only 2800 stall. I don't see why a triple disc would run cooler, unless you are locking it a lot. Mine doesn't lock when in around town traffic, which is where I find temps the highest.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Yes.. you are right. The thermostat on the cooler I use controls the fan, not the actual flow of fluids. I found the fan made all the difference, and one could probably find a thermostat that turns it on earlier, if they didn't want it running all the time. 176 is just too late......by the time its that temp at the cooler, its hotter at the trans.
My converter is only 2800 stall. I don't see why a triple disc would run cooler, unless you are locking it a lot. Mine doesn't lock when in around town traffic, which is where I find temps the highest.
My converter is only 2800 stall. I don't see why a triple disc would run cooler, unless you are locking it a lot. Mine doesn't lock when in around town traffic, which is where I find temps the highest.
We have weather conditions that are at opposite ends of the spectrum.
You with generally cool ambient temps, a much higher HP that requires a triple disc converter to hold it, and a 2800 stall.
Me with generally hot temps, a lot less HP and a single disc, but a 4000 stall.
We both drag race and use the car as a DD in heavy low speed traffic.
While we both need more cooling capacity than the OEM radiator can supply, your needs can be handled with a lower BTU cooler and a fan. Mine require a high BTU cooler and I still don't have results to know if what I bought will be enough. I additionally desired the ability to quickly reach working temps and maintain them as a minimum, because I drive all Winter and occasionally it gets in the 30's. Winters in Phoenix are like Summers in Montreal, but without the rain.
Update: The Derale cooler arrived and the t-stat has shipped. Maybe a weekend install. Today in afternoon rush hour traffic the coolant hit 226*, the trans 223*, and the ambient was only 98*. Ten miles of driving between 5 and 35 makes for tough conditions.
Last edited by HOXXOH; Oct 16, 2015 at 02:00 AM. Reason: update