Bill's Garage

Mustang Turbo Engine Swap

This page will show how we swapped in a 2.3 Litre Ford Thunderbird Turbo Coupe engine into our 1988 Mustang. The Mustang had originally came with a 2.3 Litre 4 cylinder which produced 88 horse power. The Turbo Coupe engine produced more than twice that amount. Plus we swapped out the original automatic for a 5 speed transmission. This engine/trans swap transformed the car from a super slow ganny mobile to a tire smoking performance car.

NOTE: We did the engine swap before we did the body work and paint. We wanted to get the car to move under its own power first.

Donor Car

'88 Turbo Coupe
(Click to enlarge)
We were coming home from Hersey Park shortly after buying the Mustang and we see a Thunderbird Turbo Coupe on the side of the road for sale. We pull over and look inside and its a 5 speed. The car had a replacement engine in it and it ran well. The car was in horrible shape otherwise. A total pile of junk. Everything was broken, nothing worked, wires everywhere, none of the panels lined up, but it had a good engine and transmission. This was just the car for us! So a deal was struck and we brought the car home. We ended up getting the car for less money then it would have cost to fix the automatic transmission in the Mustang. Plus the Turbo Coupe engine and transmission was a direct bolt into our car.

So we pull the engine and trans out of the Thunderbird and proceed to strip the car completely down to the shell. A local junk yard hauled the body away for free. We knew we could get good money by selling the parts we did not want. We kept the engine, trans, engine control unit, sensors, front brakes, and radiator. All other parts were sold.

Engine Detailing

Turbo Engine Detailing
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The Turbo Coupe engine didn't look too bad but while it was out it was a good time to pretty it up. So we removed the manifolds and wiring harnesses, degreased the engine, and stripped the old paint off. We also ported the intake and exhaust manifolds and then painted them. Everything was cleaned up and the engine was then put back together.

Removing the Mustangs Engine

Removing Mustang Engine
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We then remmoved the Mustangs 88 horsepower engine and automatic transmission. After 150,000 miles it was greasy and very dirty. But since the car was from the south all the bolts came loose fairly easy. Before we pulled the engine I put a new timing belt on it and got it running pretty good. So we hung onto that engine because the block and crank are the same as a Turbo engine so its a good spare.

As for the automatic transmission, hmmm, we dropped that off at the junk yard...

Swapping in the 5 Speed

5 Speed Swap
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The Thunderbird 5 speed is a direct bolt in to a Mustang. We also bought a complete 5 speed set up from a local junk yard prior to buying the Thunderbird. So we had plenty of 5 speed parts to do the conversion. We decided to go with the cable actuated clutch set up instead of the hydraulic set up from the Thunderbird. Either one would work but we liked the simpler cable instead of the more complicated hydraulic set up.

The hardest part of the conversion was removing the single brake pedal assembly that this automatic car currently had and replacing it with a clutch/brake pedal assembly. This pedal swap required removing the dash cluster and complete steering column from the car. Even with those things out of the way it was very difficult working in the tight area under the dash. This process took quite a few hours and was very tedius. We removed the seats to make more room; and also give the carpet a good cleaning.

Once the clutch pedal was in we had to trim the hole in the floor a little bit for the 5 speed shifter to fit through. We also used a Mustang 5 speed drive shaft we got from the junk yard because the Thunderbird shaft was too long. We did use the Thunderbird Turbo Coupe clutch because it is bigger than a regular 4 cylinder Mustang 5 speed clutch. Other than that everything just bolted right in.

The interior of this car was in good shape when we got it. All we did was clean it up and it looked plenty presentable.

Turbo Engine Install

Turbo Engine Install
(Click to enlarge)
We decided to paint the engine compartment and the under side of the hood prior to dropping the engine and transmission into the car. So we degreased the engine compartment, sanded it down by hand with 400 grit, primered it, and with a spray gun shot a single stage coat of Medium Shadow Blue Metalic paint; the car's original color. We were able to get the paint laid down nice and even with a great shine.

After that we bolted the transmission and engine together and dropped them in the car as one unit. Then we had to make some wire changes because the turbo engine has slightly different wiring then our Mustang had. Then we had to hook up drive shaft, clutch cable, hoses, wires, fill with fluids, etc etc.

So for the first time since we owned the car it could now move under its own power. Prior to starting it we did drop the gas tank, drain all the old fuel out, and put a high flow fuel pump in the tank. The 5 speed shifted great right from the start and the car could easily spin the tires without effort. However we did have a few issues to work out. Some of them took quite some time to finally get solved:

The above problems proved to be very challenging to solve. What added to the mystery is the engine ran perfect when it was in the Thunderbird. Countless hours of diagnostics, trouble shooting, a lot of reading, testing, measuring, and head scratching allowed us to finally figure it out.

So that is how we swapped the turbo engine and 5 speed into our car. I hope you enjoyed reading and viewing the pictures.