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I thought you guys were installing an ATF t-stat, not a fan t-stat.
Yes, I have occasional problems cooling during the summer in heavy traffic, but I have bigger problems trying to get up to temps in the winter while sitting in the staging lanes. Maybe you park it in the winter.
Now there's an idea!
That's actually exactly what we need in these cars, in my view: An ATF cooling system that works (sort of) like the engine cooling system, where the ATF is controlled by a thermostat that only opens to allow the ATF to be circulated through the cooler when the ATF reaches a certain temperature. Until that temperature is reached, the ATF cooler is bypassed and the fluid is simply circulated through the transmission. This would also help the trans to reach operating temperature quicker and would work much better during winter conditions as well.
And it isn't that hard to do. My boat has a thermostatically controlled EOC that I installed myself, which has a high flow thermostat that does the exact same thing with engine oil. I had to instal the thermostat system after installing the engine oil cooler because without it, the Engine oil cooler, which is actually a fluid to fluid heat exchanger (water cooling engine oil) worked too well and I couldn't get the engine oil to warm up enough. So, if I can do that in my backyard, it should be a breeze for a car manufacturer to make a properly functioning system for automatic transmissions that they install in high performance cars.
Now there's an idea!
That's actually exactly what we need in these cars, in my view: An ATF cooling system that works (sort of) like the engine cooling system, where the ATF is controlled by a thermostat that only opens to allow the ATF to be circulated through the cooler when the ATF reaches a certain temperature. Until that temperature is reached, the ATF cooler is bypassed and the fluid is simply circulated through the transmission. This would also help the trans to reach operating temperature quicker and would work much better during winter conditions as well.
And it isn't that hard to do. My boat has a thermostatically controlled EOC that I installed myself, which has a high flow thermostat that does the exact same thing with engine oil. I had to instal the thermostat system after installing the engine oil cooler because without it, the Engine oil cooler, which is actually a fluid to fluid heat exchanger (water cooling engine oil) worked too well and I couldn't get the engine oil to warm up enough. So, if I can do that in my backyard, it should be a breeze for a car manufacturer to make a properly functioning system for automatic transmissions that they install in high performance cars.
There are several manufacturers of relatively simple and effective oil t-stats for well under $100. If my current plumbing method doesn't stand the test of our 110+ degree summer heat, I'll be switching to a larger cooler and an inline t-stat to handle the winter problem.
Nice that it worked out. When I tried it with the thermo switch I found it got to hot. I think by the time that switch read 181 I was already reading 200 in the tranny. Maybe my switch was defective, don't know. If you have the chance, let me know what temp you get to in heavy traffic on a hot day. If it's still good I might try the switch again.
My fan was coming on when temp read 181 on the DIC.
The lines run to the radiator to get some warming effect, then exit to the coolers. I installed this setup a few months ago and have not had the temperatures go past the 160s.
The lines run to the radiator to get some warming effect, then exit to the coolers. I installed this setup a few months ago and have not had the temperatures go past the 160s.
I had installed one of these on my H/C/I LS3 base this past summer and it kept the trans at around 140-156° cruising on the highway or on the street but still got up to 190° in stop and go. If air is moving over it the cooler works perfectly but it honestly shows its limitations in traffic. I will be going with an electric fan unit on my new GS.
I didn't bypass the radiator I ran the cooler in sequence so that it could get up to operating temp faster. I will however completely bypass the system on the new car and use a thermostat to keep the temp in optimal range.
I had installed one of these on my H/C/I LS3 base this past summer and it kept the trans at around 140-156° cruising on the highway or on the street but still got up to 190° in stop and go. If air is moving over it the cooler works perfectly but it honestly shows its limitations in traffic. I will be going with an electric fan unit on my new GS.
I didn't bypass the radiator I ran the cooler in sequence so that it could get up to operating temp faster. I will however completely bypass the system on the new car and use a thermostat to keep the temp in optimal range.
Reading all the reports of one cooler not cutting it, I decided to I put two of the 678s in from the get go.
No t-stat, no bypassing the radiator, no fan, just two coolers stacked in the front of the car.
Reading all the reports of one cooler not cutting it, I decided to I put two of the 678s in from the get go.
No t-stat, no bypassing the radiator, no fan, just two coolers stacked in the front of the car.
Report back this summer.. I'm interested in how this will work. I honestly don't think it's a good use of space vs. one cooler with a fan, but if someone isn't going FI it shouldn't be a problem..
I had installed one of these on my H/C/I LS3 base this past summer and it kept the trans at around 140-156° cruising on the highway or on the street but still got up to 190° in stop and go. If air is moving over it the cooler works perfectly but it honestly shows its limitations in traffic. I will be going with an electric fan unit on my new GS.
I didn't bypass the radiator I ran the cooler in sequence so that it could get up to operating temp faster. I will however completely bypass the system on the new car and use a thermostat to keep the temp in optimal range.
I wouldn't go with this setup, personally. My car was setup like this without a thermostat, and it took forever to get up to operating temp during the summer (100+ ambient temps). During the winter you can forget about driving it hard because you won't get it above 130 (and I use winter lightly. maybe 40 or 50 degrees). I don't think the transmission alone will heat the fluid rapidly enough to get to operating temp in a satisfactory time.
As it is, I had the system re-routed back through the factory radiator, then into the aftermarket cooler. Still took too long to heat this time of year, so I have the fan switched off entirely (the installed didn't use the thermal switch, and I haven't had time to get under the car and figure it out yet.
I have plans to install a thermostat if the system continues to be too slow to heat up. Essentially it will run through the radiator only until it's up to temp, then through the aftermarket cooler and radiator (flow starting at around 160), with the fan on the cooler turning on around 180.
I haven't had the system plumbed like this while it's been hot out, but I doubt that it will be sufficient for me during the summer months. I suppose we shall see...
I wouldn't go with this setup, personally. My car was setup like this without a thermostat, and it took forever to get up to operating temp during the summer (100+ ambient temps). During the winter you can forget about driving it hard because you won't get it above 130 (and I use winter lightly. maybe 40 or 50 degrees). I don't think the transmission alone will heat the fluid rapidly enough to get to operating temp in a satisfactory time.
As it is, I had the system re-routed back through the factory radiator, then into the aftermarket cooler. Still took too long to heat this time of year, so I have the fan switched off entirely (the installed didn't use the thermal switch, and I haven't had time to get under the car and figure it out yet.
I have plans to install a thermostat if the system continues to be too slow to heat up. Essentially it will run through the radiator only until it's up to temp, then through the aftermarket cooler and radiator (flow starting at around 160), with the fan on the cooler turning on around 180.
I haven't had the system plumbed like this while it's been hot out, but I doubt that it will be sufficient for me during the summer months. I suppose we shall see...
Where abouts in the country do you live? It's 78° here today.. Winter doesn't really come to Texas outside of a handful of 40° days and one major ice storm a year; I do however have at least 4 months of 90°-100° days to look forward to.
My GS is bone stock, and I daily it (20 miles or so round trip) and I'm seeing 150°-190° temps by the time I pull into my office parking lot depending on traffic and how I put my foot down. That's in D mode, I'm not even using the paddles. These cars just run hot.
Where abouts in the country do you live? It's 78° here today.. Winter doesn't really come to Texas outside of a handful of 40° days and one major ice storm a year; I do however have at least 4 months of 90°-100° days to look forward to.
My GS is bone stock, and I daily it (20 miles or so round trip) and I'm seeing 150°-190° temps by the time I pull into my office parking lot depending on traffic and how I put my foot down. That's in D mode, I'm not even using the paddles. These cars just run hot.
If you haven't done so already, try putting a 160* thermostat in it and Water Wetter. I did this on mine and the trans temps usually stay around 170-180 and pretty closely track the ECTs during normal driving and in traffic. If I drive it aggressively the ATF temps will go up to ~190 but it doesn't go over 200 likes it used to with the stock thermostat. With just the stock in-radiator cooler, the ATF temps are going to track the ECT unless you drive it aggressively, then the ATF temps start to climb above ECTs and once you start cruising again, it comes back down until it equalizes with the engine coolant temp.
The stock in-radiator cooler just doesn't have the capacity to cool these transmissions for anything other than cruising around and my suspicion is that this is the reason for most failures of the A6 trans in Vettes.
I have a Hayden plate type cooler (#679 - 11"x 11 5/8") in my garage (like the one that Yank advertises on their site). I'm definitely going to have to tackle this now, as I have a 3600 stall on the way.
Just by way of an update: I finally got around to installing the Hayden ATF cooler the other day. I plumbed it in series with the stock in-radiator cooler, with the ATF going through the stock one first and then into the new cooler. I simply mounted it in front of the A/C core.
After driving now on a number of occasions in ~79- 85 degree weather, it looks like the cooler has taken about 15-20 degrees off the temps I used to see before installing it.
The ATF still seems to warm to operating temperature up fairly quickly, to about 145-150 if Im just cruising around, and it now stays roughly about 20 degrees less than the ECT, whereas before it would tend to equalize with the coolant temp. After about an hour of driving around, I found a convenient piece of road did a bunch of hard launches and burnouts, brake-stalling the converter hard to put some heat in the ATF. The highest I could get it to was 174 degrees. This is at least 20 degrees lower than what I was seeing before, under similar driving conditions. I also drove it around for a few hours in stop and go traffic a couple of days ago and it still hasn't gone over 175 degrees, although that day the outside temp like 79 degrees.
I guess I will see soon if it's enough to keep the ATF temps cool with the 3600 stall and 3.42s that I'm about to install.
Thanks for the update CI, I'm curious how you mounted the external cooler ahead of the radiator and is there room for two coolers mounted side by side? I would use one for engine oil, the other for transmission.
Thanks for the update CI, I'm curious how you mounted the external cooler ahead of the radiator and is there room for two coolers mounted side by side? I would use one for engine oil, the other for transmission.
Thanks for the update CI, I'm curious how you mounted the external cooler ahead of the radiator and is there room for two coolers mounted side by side? I would use one for engine oil, the other for transmission.
I just followed the instructions included with the cooler and used the ratcheting spike straps that came with the kit and shoved those through the flanges on the cooler. They easily went right through the fins on the A/C core and radiator, and all I had to do was unbolt the fan assembly so I could instal the "nuts" or "lugs" over the sharp end of the spike straps and cinch those down so that the cooler pulled tight against the foam pads (included with the cooler) that are sandwiched between the cooler and the A/C core, then I cut off the excess straps flush with the backside of the lugs and reinstalled the fan. I was happy to see that the fan cleared the lugs when it was spinning. I then punched a couple of holes in the side of the radiator shroud to route the hoses through and connected one to the bottom bung of the TOC in the radiator, using a Hayden quick disconnect fitting, and the other hose over the end of the lower TOC line (that one was a b!tch of a tight fit). All in all, a straightforward install.
I will try to take some pics tomorrow and post them up on here.
I don't think that you can mount two of these coolers side by side on the C6 radiator, but this is the largest cooler Hayden makes in this line, so maybe that could work with two smaller coolers.
I actually wish they made a bigger cooler. Im thinking that when I go with the ECS kit, which will require me to move this cooler, I will try to fit a cooler between the A/C core and the radiator, because there looks to be just about 3/4-7/8" of space between those.
I just followed the instructions included with the cooler and used the ratcheting spike straps that came with the kit and shoved those through the flanges on the cooler. They easily went right through the fins on the A/C core and radiator, and all I had to do was unbolt the fan assembly so I could instal the "nuts" or "lugs" over the sharp end of the spike straps and cinch those down so that the cooler pulled tight against the foam pads (included with the cooler) that are sandwiched between the cooler and the A/C core, then I cut off the excess straps flush with the backside of the lugs and reinstalled the fan. I was happy to see that the fan cleared the lugs when it was spinning. I then punched a couple of holes in the side of the radiator shroud to route the hoses through and connected one to the bottom bung of the TOC in the radiator, using a Hayden quick disconnect fitting, and the other hose over the end of the lower TOC line (that one was a b!tch of a tight fit). All in all, a straightforward install.
I will try to take some pics tomorrow and post them up on here.
I don't think that you can mount two of these coolers side by side on the C6 radiator, but this is the largest cooler Hayden makes in this line, so maybe that could work with two smaller coolers.
I actually wish they made a bigger cooler. Im thinking that when I go with the ECS kit, which will require me to move this cooler, I will try to fit a cooler between the A/C core and the radiator, because there looks to be just about 3/4-7/8" of space between those.
Good idea.
Someone sandwiched a TOC between the condenser and the radiator on a C5, made a nice installation. I would worry about slowing the airflow through the radiator too much if the TOC was really large (wide/tall), but I don't recall hearing of any problems.
My brother used the spike strap idea on a different car, but used very long/thin bolts instead. After a year or so, one of the bolts wore through the radiator tubing and caused a coolant leak. The spike straps are plastic (I hope) and less of a problem, but I'd keep an eye on it over time.
Awesome CI, thank you for the followup... and Merry Christmas!
Merry Christmas to you as well!
I didn't get a chance to take any photos today (Xmas eve is always crazy).
I'm going to be trying out my newly installed lift over the holidays though, so I'll take a few photos and post them up then.
Gearhead Jim: Yes, the spike straps are plastic and seem to work good, once you use the foam pads, which keeps sufficient tension on the cooler to hold it in place, whilst providing a sort of "shock absorber" when the cooler gets jolted by the car driving over bumps, etc. As such, they shouldn't chew away at the radiator core like a metal bolt would, but Ill keep an eye on it.
We've had a lot of discussions about where to put auxiliary TOCs on the Vette, and that becomes a real problem with FI when you need to put an intercooler or heat exchanger up front, so I think we need to think about putting it between the rad and the A/C core, if it can fit there. I'll look at it again when I have it on the lift and take some photos.
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These cars just run hot.
