el es tu

After finding out I needed to do a trans filter and fluid changeout, I decided to add a transmission cooler to my car - a Hayden 678 trans cooler which has a core size of 11" x 7.5" x .75" (the barbs for the lines are 3/8") and looks like the factory z06 and z51 engine oil coolers. I also bought a second one to use as an engine oil cooler just because of this (the $35 dollar price is also very reasonable compared to the ridiculous amount the factory wants to charge). I know I could go with a larger cooler as some folks who road race get temp issues after longer runs, but would like to stay in this range because it has to survive on the street in the cold and any hard driving will be for shorter sessions.

Rather than route the lines for the transmission from the radiator return to the cooler and back to the return in order to allow the transmission to warm up, I plan to sandwich the transmission cooler between the radiator and the new engine oil cooler which will sit in front. This should allow the transmission some heat to get to operating temp in the winter, but still keep it cooler (than using the radiator based trans cooler) in the summer on harder drives.

My one concern - on one of haydens catalogs they use a blanket statement for almost all their products (many of which look nothing like the parts similar to the factory style units I bought) saying not to use transmission coolers for engine oil because of the possibility of flow restrictions.

aside from the length and width (these coolers are in between the size of a Z51 and the Z06), everything about the cores of the coolers I purchased looks exactly like what GM used for engine oil on the ls3 and ls7.

I have attached photographs of the cooler design - Im hoping to get some input as far as whether its the worst idea in mankind or worth trying. Im not afraid of R&D and would obviously test/compare engine oil pressure while idling prior to driving and then keep monitoring it while taking it easy driving after first installing to make sure everything is ok...

thanks!















EDIT:

Here are pictures of the factory ones (Z51 and Z06) for comparison to the hayden:

ErnieN85

the trans cooler is ok however it could be bigger. get as bigga one as you can find & fit
the use of that for engine oil isn't good the lines are too small

CHJ In Virginia

Two comments / thoughts. First do not stack the coolers. You are looking for cool air flow to bring the fluid temps down. You do not want to "preheat" the air flowing into the second cooler. If you are worried about warm up in winter months, make a removable cover for the tranny cooler. That's what I did on my Z06 engine oil cooler. Second - DO NOT use a cooler designed for transmissions on an engine oil system. BELIEVE the manufacturer's statement. The cooling tubes are designed for less flow and often have "swirl generators" inside them to slow down oil flow to get max heat transfer and greater cooling.

el es tu

I started to think that and checked - most are 1/2"

I guess Ill have to wait to do my engine oil cooling... (will likely go with the drm setrab setup)


New plan is to use both of the haydens stacked together for the trans fluid cooling, but tap off the return line so I can get some heat to the transmission on cold days.

Thanks for the quick reply!




Didnt see this comment while i was replying to the prior response

I could put these side by side, but not sure if its as big of a deal is theyre both going to be used for the transmission now... My concern is blocking off the radiator too much - especially if Im going to add an engine oil cooler down the road (meaning when I can afford it )

Thanks!

el es tu

idea for dual trans cooler setup

metal line would be used for the bend between the two due to the fact that rubber hose has to be a minimum of a 3" bend and this would be much tighter than that...









total core dimensions would be 1.5" x 7.5" x 11.0" I hope this would be enough to keep it cool while still using the radiator "cooler" [heater]


btw only reason for tieing in to the radiator setup is for warming in the winter because some folks say running hard in cold temps is bad for autos, however the A6 has different pressure commands for different temp ranges, so Im not so sure if I even need to warm it up for longevity (as opposed to most older automatics that dont have the benefit of picking pressure based on temp) - any thoughts on this?

ErnieN85

save your money for a Dewitts radiatorwith EOC and Trans cooler
use the haydens also

Bill Dearborn

DeWitts or Ron Davis will work well and cool things down. You will get cooler coolant, cooler oil and cooler transmission temps, especially if you tie the Hayden unit into the trans cooler circuit after the fluid goes through the radiator trans cooler.

Bill

mikeCsix

Ernie,
Mine doesn't have enough capacity.

I'm thinking of installing a Z06 engine oil cooler.

For the transmission and pertinent to this thread, the differential on the A-6s is certainly part of the culprit for all of the heat generation. I'm currently thinking if I abandon the DeWitts EOC in the radiator, perhaps I could use it to cool the differential oil if the diff oil pump generates enough 'head' pressure.

Thoughts?

HOXXOH

If you mount the cooler horizontally at the bottom of the radiator, instead of vertically in front of the radiator, you won't block direct airflow to the radiator.

Then run an inline t-stat to control the downside temps.

timd38

I did a Z06 engine oil cooler. Bolts up and works great.When guys put blowers on Z06s, they sell the coolers, so you can normally find them with the line for about $300 in the parts section.