Turbo
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Q: I like seeing some of the older carbed turbo motors being used.. but is the yellow module the only one for these motors?
A: Ok, here's my brain dump on the carb'd turbo motors. This is a draw thru turbo design, not blow thru like the later EFI turbos. The turbo has a carbon seal because it flows gas too, not just air. This makes it spool up slower.
I had a 82 Capri, check out my web page for a picture. http://www/davecompton.com
It came with every option, except the 2.3 turbo. It was normally aspirated. Beautiful car, slow as hell. I got it in England, used with 40kMiles. The main cat had been replaced with a test pipe. The precat had not. The guy even had the replacement downpipe without a cat, but had never put it on.
Here's what I did to it and how it worked out.
1) I put the precat replacement pipe on with no cat. WOOHOO! Precat was plugged from leaded fuel use.
2) I replaced the carb with a 38 DGAS weber. This came stock on 3.0 liter v6 Capri GTs. It is a synchronous, not progressive carb. Both barrels open at once. GOOD bottom end and throttle response because of this. I recommend finding one. Car ran real good like this. Probably a sixteen second car at this point.
3) Moved to Texas. Visiting in Maryland, an 80 turbo mustang got creamed by a truck in front of me, in front of a junkyard. The car went straight into the junkyard. I had gotten the Ford manuals with the car, so I knew every part that was different. I asked the guy how much for the turbo stuff. $250. I went to work. Intake manifold, turbo, both wrap-under exhaust pipes, ignition box with boost retard switches, and turbo over boost buzzer assembly, oil lines etc.
4) had turbo rebuilt with a water cooled center section.
5) meanwhile spent LOTS of time working on optimizing the ignition curve. This is most important. Disasemble the distributor, flip the advance plate around 180 degrees to limit the amount of spark available in the distributor. I got a set of various stifness distributor springs from FMS for $3. No longer available, that's a shame. Bump up the static timing, reroute the vacuum line so it has ported vacuum advance instead of manifold vacuum advance. Adjust the vacuum advance can with an allen wrench (in the hose hole) to decrease vac advance sensitivity. Shim up the vacuum can arm in the distributor to limit the advance amount that vacuum advance can contribute. Basically, you're trying to get a quick, small advance curve in the distributor with lots of initial lead.
6) replace the resistor in the harness at the second step of boost retard with a pot and knob hanging from the rear view mirror.
7) 2.5" exhaust from turbo outlet downpipe to rear.
8) Racer Walsh cam gear (never again).
9) Jacobs Energy team ignition. This allowed me to run 50 thou plug gaps all the time. But I wouldn't do it again. Besides it doesn't work well with the EEC-IV, after I moved the system to another car.
There's lots of response and power hidden in the distributor, carb, and exhaust. I never changed the cam, and now I realize I should have. Even for a turbo car, those early cams are too small.
Here's the problems I encountered. It'll knock. Alot, and often. You'll constantly be twiddling the retard knob. You'll try different grades of gas and octane boosters. You'll jet the carb overrich on the main jets to overfuel it under boost. It'll get 13 MPG. It'll run like sh*t on hot days.
however....
One COLD night in Illinois, about 10 degrees... The wastegate had been bad and I was too lazy to replace it. I had just been driving around feathering it for months. I was pissed at the current girlfriend, and floored it away from her house. Hit 20 + psi and held it there, to about 100 mph. No knock. Felt like I'd been hit in the rear by a truck. That night it might've been a high 14 second car.
Conclusion: I could've gone that fast with less trouble by building a normally aspirated 2.3. There were articles in the 80s about normally aspirated 2.3s making 375 hp. Unplugging the exhaust and getting a bigger carb really makes a difference on N/A 2.3s. This, and a late roller cam, and you could probably get 200 hp, or more, easy.
It was cheap, and fun, and a good education. I did it all alone. I read everything Ak Wilks (where *is* that guy now?) and the other turbo guys knew, or were doing. Duttweiler wasn't around, Corky Bell was just starting out. It was a pain in the ass, and not terribly fast. It was adequate, but the grins were kinda few and far between, for all the work.
As for ignition, there is no upgrade box yellow grommet for the carb'd turbo setup. I didn't really have ignition problems though. Gap your plugs at 30 thou and get all new tune up parts. It should supply plenty of enough spark, like Ford's other ignitions.
BTW, the turbo and non turbo engines were very different back then. Mine was normally aspirated from the factory, remember. Sodium filled exhaust valves, forged 9:1 pistons, bigger oil pump etc. I rattled the sh*t out of that thing and NEVER blew a head gasket. 2.3s are STRONG. I never even had the head off. I went about 50K miles on that motor, and then traded the car in on an 87 Mustang GT.
So, basically I wouldn't recommend that turbo. You can never intercool it. It's just a bad design. I'd put EFI and a blow thru (late modle EFI) turbo on it. Then a shot of nitrous and you should be flying. I just proved how easy it is to turbo a late 2.3 without going in the motor. A complete 2.3 from 91 or later with harness and computer should be cheap. Nobody wants em. :))
Exhaust flow, intake flow, and a good cam. These are necessary, the rest is optional.