As some of you know I am working on a 3800 NA swap into a 88GT. //www.fiero.nl/forum/Forum1/HTML/089035.html The car was a manual car and I am making the car an Auto (daily dirver). Because the car started life as a 5 spd car, it does not have the lines for the trans cooler and I don't plan on installing them if I dont need to. My plan is to run an Aux cooler only, not plumb the trans to the radiator up front.
I went to the junk yard and looked at all the different Aux coolers. The one I bought is about 4"x1"x15" and the plan is to install it just below the front of the cradle in the slip stream under the car. I got one this shape so that I could put it there. Ford trucks have some of the largest Aux coolers out there, and would also work great in the passenger rear "scoop area", i may try that later.
Bottom line - Can the trans be run on just a large size Aux cooler if the air flow is maximized?
Thanks
Rob
[This message has been edited by qwikgta (edited 08-19-2013).]
Bottom line - Can the trans be run on just a large size Aux cooler if the air flow is maximized?
Short answer: Probably not a good idea. The aux cooler (oil-to-air) may or may not provide adequate cooling on a hot day, but it will almost certainly keep the transmission fluid too cool in winter. The transmission heat exchanger in the radiator header both cools and heats the transmission fluid as necessary to maintain a relatively constant fluid temperature. Running for extended periods with too-cold fluid can result in poor shift quality and accelerated transmission wear.
Excess cooling in the winter could be eliminated using a thermostatic valve. I work in a Chrysler/Jeep dealer and just about all the RWD vehicles I see have them (Grand Cherokees, Wranglers, 300s, Challenger/Chargers, etc)
As far as adequately cooling in the summer, the size and airflow would be crucial. Using the above valve it should be impossible to overcool, so I might go for the largest I could fit in the target area.
I think that if your radiator is more than a few years old it's probably better to just replace it. The new ones all have the trans cooler in them and you have to run lines to an aux cooler anyway. You won't be re-inventing the wheel and it will probably cost about the same. Or you could upgrade the rad for your SC engine and kill two birds with one stone.
[This message has been edited by TONY_C (edited 08-19-2013).]
OK, thanks. So what i'm getting from the group is that running just the aux cooler and not using the stock radiator is a bad idea. Again, just to clear this up, I am going to be using the car as a daily driver, and its not a SC motor. I know the SC thing is not relivent to the auto trans but I just wanted to point that out.
I plan to install some scoops to the lower 1/4's in front of the rear tires, not sure which brand to install yet. I've had both "inward" and "outward" scoops, to me is just a looks thing. The plan is to use the driver side to feed the air cleaner, and I was thinking about using the passenger side to feed the trans cooler. If I install one of the larger coolers in the air stream i'd think that cooling would not be the issue. I had not thought about it being too cool in the winter. I just assumed that the engine heat and driving caused extra heat that you wanted out of the way.
I guess what I am not fully understanding is that the radiator mounted cooler just does not seem to offer that much more cooling surface, so why is it so much better. Also, if it does a good job, why do so many folks with 3800 swaps run a cooler in the first place.
I may just give it a try, and see how it goes. I may work in a temp device so I can see the trans temp.
Thanks again for all the advice and if anyone else has any, please share.
I guess what I am not fully understanding is that the radiator mounted cooler just does not seem to offer that much more cooling surface, so why is it so much better.
1) It's an oil-to-water heat exchanger, so heat transfer is much more efficient than an oil-to-air cooler.
2) As posted earlier, the radiator-mounted heat exchanger can heat the transmission fluid as well as cooling it, thus maintaining a more constant fluid temperature.
quote
Also, if [the radiator mounted cooler] does a good job, why do so many folks with 3800 swaps run a cooler in the first place.
The OEM cooler alone may not be large enough to cool properly with a heavy load and/or on a hot day with the larger engine and transmission. A good solution is to use both: an oil-to-air transmission cooler plumbed in series with the radiator-mounted heat exchanger. Route the transmission fluid through the aux cooler first, and then through the radiator heat exchanger. That will provide the best performance and most uniform fluid temperature. (FWIW, my 1998 Dodge Caravan uses exactly this two-stage cooling arrangement, and the original transmission now has 272,000 miles on it. YMMV.)
[This message has been edited by Marvin McInnis (edited 08-22-2013).]
the trans cooling lines take the same basic path as the clutch line. also, if I remember right, all fiero radiators have the trans cooler hookup, its just up to the car whether or not you connect to them. but, no reason you cant use something else - or even use both.
the trans cooling lines take the same basic path as the clutch line. also, if I remember right, all fiero radiators have the trans cooler hookup, its just up to the car whether or not you connect to them. but, no reason you cant use something else - or even use both.
The factory radiators for manual trans cars did not have the heat exchanger but if you still have the factory radiator, you probably need to change it out anyway.
The factory radiators for manual trans cars did not have the heat exchanger but if you still have the factory radiator, you probably need to change it out anyway.
well, it would be good to change out the stock 88 radiator. I quess I was looking for a way out of running the coolant lines all the way up to the front. The manual car does not have them (obviously) and I was hoping a large Aux type cooler could do the job.