What car and what year:
The donor car for the Catfish is a Mazda Miata MX-5 from 1990-2005. The sweat spot for donors seems to be from 94-98. These years came with the 1.8L engines and still maintain the older styling. The larger engine is good for a few extra ponies and a bit more torque. And the first generation bodies do not command as much premium as the newer bodies. I was hoping for a 94-95 as the engines have slightly less compression than the 96-98 engines; preferable for the forced induction that will inevitably added later. Another consideration is the 94-95 cars use OBD-I. For those who live in states that have inspections it is easier to hide ecu tuning on pre OBD-II cars. OBD-II cars have the benefit of access to several aftermarket data acquisition systems the plug into these later engine diagnostic systems.
A lot of folks will tell you to get the best donor your pocket book can afford. I am not sure that they are right. A low mileage strong engine is certainly worth a couple bucks more than a high mileage street raced one. A good interior and good body panels are worthless. Trust me you will agree when you have to strip the seats out of the car, they must weigh 50 lbs. a piece.
Additional selection criteria:
I found mine on Copart.com, an auto insurance liquidation auction site. It looked decent enough and meet my criteria; which admittedly was pretty low. I was looking for a 1.8L motor car. I was looking to spend less then $1K. It had to be nearby; transport costs will easily be over the total budget of the donor. And finally it could not have major collision damage. The thing with Copart and other insurance auctions is that you really can’t inspect the cars before bidding on them. I should have added shows no signs of rust.
Being from South Florida I don’t typically run into cars that have had to deal with salt on the roads in winter. This one clearly is one of those cars. C’est la vie. There is maybe one or two frame parts I might have to buy off of Ebay as a result but with a working power train and all the goodies that come along with it I did alright for $900.
{Update 05/15/2013: After having stripped the body and power train from my donor I can now say with 100% confidence make sure you do not buy a rusted out bomb. At this point I will be spending close to 500$ for the parts I need to replace because of rust. Could I make them work? Yes. Do I want to? No. I could sell the motor and make my money back but I am not interested in stripping another car so soon. The cheapest car you can, that’s not rust to hell.}
Preventative Maintenance:
Plan on doing a complete bushing refresh. Its a given that in the last 10 years no owner has spend the money on replacing the bushings. A complete poly bushing kit runs about 300$ and a press from Harbor Freight is another 100$. Now is the time, just do it.
Fuel system is next up in your PM list. Fuel tanks are rarely serviced while the car is on the road and a little bit of sediment or debris will play havoc on your fuel injection system. Dead fuel pumps are certainly the cause of many failure to start frustrations. No sense in installing one that’s ready to fail. The rigid fuel line…don’t know. After pulling it from the donor inspect it, clean it, and make your own call. If it has any signs of oxidation inside or out just change it.
Brake lines, when you drain the fluid, before pulling the lines, watch for rust or sediment. Moisture will find its way into the brake systems and rust the lines from the inside. Its pretty standard fair when restoring any classic car. I personally am not a fan of flairing new brake lines so I just pay a professional to terminate them once I have routed them. Cord has told me they will be reused in the build so take care when removing them.
There you are a few points to think of when attacking the donor car. There is plenty more to think about this is just a starting point.
Catfish? 