Join Date: Aug 2002
Location: At the apex, blocking your pass.
With all due respect to Jim at PPI (whom I've known longer than most of you have owned Mustangs,) I'd pass on the Cobra R cooler for the larger Derale cooler. Both get the job done, but the larger Derale is going to work better for extreme applications, IF you really need it.
Do you need it? Depends. How hard are you working the power steering system? Oddly enough, Autocross tends to work the steering MUCH harder than road racing, and you are more likely to boil the power steering fluid on a hot day at the autox than you are at an OT event or race. I don't see a lot of my AI or AIX competitors having steering issues due to boiled fluid and keeping it cool isn't much of an issue. Many of us (myself included, these days,) find the factory cooler works just fine.
(Full disclosure -- I used to have boiling issues at TWS years ago. I tried a Cobra R cooler from PPI, which worked much better than the factory cooler, but I still would boil the fluid on very hot days. I switched to the Derale cooler which did the job well. When I retired my car from the street, I removed the Derale cooler to make room for an external oil cooler that never got installed. I figured I'd get around to reinstalling the Derale, but it never happened. At the same time I switched to synthetic ATF fluid in the power steering system and I've never boiled it -- ever.)
If you're not having PS fluid cooling issues and want a little insurance, or are having mild issues, the Cobra R cooler may be for you. It's small, well-made, and easy to mount. If you're building a Cobra R clone, it's a must-have.
If you're having persistant cooling issues, or are a hard-core autocrosser in a hot climate, the Derale cooler would be a better choice. However, it is bigger, meaning it'll be harder to find a suitable mounting location. Whatever you do, do NOT follow Derale's advice and attach it to the radiator core or A/C condenser! Those things are not designed as mounts for other equipment and are rather fragile (the same goes for mounting aftermarket fans.) Do what I did and fabricate a bracket from aluminum angle stock from Home Depot. It takes about 20 minutes.
-- Robert King
NASA AI #42, Texas
Instructor, NASA Texas Region
Instructor, TWS Perf. Driving School
Last edited by gt40mkII; 03-11-2009 at 10:34 AM.