Hi guys....
As koyo doesnot make radiators for automatics .....
Which companies do????

Thanks

 

Try searching next time.

https://www.rx7club.com/showthread.p...ator+automatic

 

^
thanks for the link im in the same boat as him and that helps

 

or run a transmission cooler...

 

I wouldn't bother..Fluidyne makes a very good radiator for automatics and is relatively inexpensive.

 

The Auto FD already has a transmission cooler. The radiator feeds in from the cooler and back out.

 

The reason the post you commented on mentioned a separate cooler is that the original poster (OP) needs a new radiator, and there are very few suppliers where he lives. And the Koyo rad he wanted to get doesn't have an auto-trans model with a cooler built in.

Dave

 

I think what he meant is that the FD already runs the fluid through a separate cooler and the radiator. My first FD was an auto and that was the way it was setup. Pretty much a second oil cooler setup (like the R1) used as a trans fluid cooler and it also routed through the auto radiator.

 

Hmmmm...

Then I apologize for my comment...

Dave

 

A lot of people have bypassed going to the radiator when using an aftermarket radiator on the auto FD. They have just run to and from the tranny cooler.

 

I've always wondered why cars pass auto trans fluid through the radiator in the first place. Is it to keep the trans fluid at a nominal operating temperature (regulated by coolant temperature)? ...Or does the transmission fluid in an auto really get so hot that it needs to be cooled?

 

Actually, it's both. Too cold, and the trans may not shift properly, and the too-thick fluid can cause clutch slippage. On the other end of the scale, auto-trans fluid can, and often does, get so hot that it oxidizes. This results in glazing the clutches, and/or loss of lubricating properties, either of which is obviously not good. Typically, oxidized fluid will begin to turn brown and murky-looking. It will often also smell burnt.

Dave

 

Perfect explanation, Dave W.

 

Thanks for the explanation. Why don't manual gear boxes need cooling? Would they benefit from regulated temperature?

 

www.rondavisradiators.com

High quality aluminum race radiators.

 

Manual gearboxes are generally very efficient (don't turn much energy into heat) and don't have the heat-generating clutches and torque-converters, so unless it is a VERY highly stressed unit, no additional cooling is needed in addition to the heat conducted to and dissipated through the case.

Also, gear oils used in manuals are not (in most cases) as sensitive to heat as most automatic trans fluids, which need to have very closely controlled friction properties so that the clutches will work.

Dave

 

Additional comment - shifting when cold could be improved by better temperature regulation (heating the fluid in cold weather, similar to what the radiator cooler does for automatics). However, in most cases, it is not enough of a problem to warrant the addition of a pump to circulate the fluid. In an automatic tranny, there is already a pump(s) present, so circulation is not an issue.

Dave

 

just bypass it and run synthetic ATF you will be just fine.

Jeff

 

Guys, just talked with Fluidyne and koyo, neither make a radiator for the FD.
Here is one:
http://www.awrracing.com/store/produ...&products_id=6
From my point of view it is the most cost effective way to go.



The cost of additional cooler, associated parts, fabrication and added weight doesn't warrant it for me. Besides if motorsport uses it then that is just another mark in its favor. I believe the "you can pay me now or pay me later" applies here also.

My thoughts on using the manual radiator and not adding an external. Driveability could suffer due to slow warm up of trans oil, long term it will hurt the transmission. Changed the fluid more frequently would help buy time though.



Dave w's post explains it well:


Quote:
Originally Posted by alexdimen
I've always wondered why cars pass auto trans fluid through the radiator in the first place. Is it to keep the trans fluid at a nominal operating temperature (regulated by coolant temperature)? ...Or does the transmission fluid in an auto really get so hot that it needs to be cooled?



Actually, it's both. Too cold, and the trans may not shift properly, and the too-thick fluid can cause clutch slippage. On the other end of the scale, auto-trans fluid can, and often does, get so hot that it oxidizes. This results in glazing the clutches, and/or loss of lubricating properties, either of which is obviously not good. Typically, oxidized fluid will begin to turn brown and murky-looking. It will often also smell burnt.

Dave
___________

Here in the desert we are always looking for better ways to cool rotaries and really are hard pressed to give up any means of cooling.

I think this thread is turning out to be a better resource for information on radiators for the auto fd than - radiator+automatic

thanks
J

 

I would purchase the KOYO (as I did), bypass the radiator's coolant coil lines directly to the dedicated transmission cooler. My FD was automatic, and I did just this. In all honesty, the temps will more than likely drop due to not being heated by the already hot engine coolant. The effects of the transmission coil are only purposeful in extremely cold climates to assure the transmission coolant isn't below a safe operating range.