Three stages to 2.3T bliss 

Here are three progressive stages to the 300 HP range for your 2.3T. Most of the items listed will be readily available and should not break the bank too badly. Our intention here is to provide a general guide to 300 horse power. By no means is this list the only way to go, nor is it a set path to follow. Most enthusiasts mod when money permits thus the inexpensive mods are usually done first. You can build your car any way you want and add these mods it in any order that fits your means.

I have denoted a path for highest horse power gains and least expense with the "*" I can't give a firm number on these mods, but my best guess would be 50 total horse power; slightly more if you are working with a stock 84-85.

Stage 1
 

• K&N Filter on VAM *
  
• Aftermarket boost Valve set @ 17PSI *
  
• Bypass kit (A good idea when switching out the stock airbox with a K&N and running higher than stock boost) *
  
• Adjustable cam sprocket
• Turbo Coupe intercooler *
  
• Unplug the knock sensor *

Stage one should net you from 20 to 25 BHP depending on the cars condition. If you are only putting down 150RWHP in an 86, you’ve got problems, but you will also see a 40+ increase in horse power from these mods after you fix the car.
 
Estimated RWHP based on the stock 86. - 200RWHP

1984 and early 85 cars will need the following additions to match the HP. Results may be a bit better due to the superior fuel system in 84/85 cars.
 

• 35# injectors
• LA3 or PE computer swap.

Stage 2

In addition to above items 

• Ported E6 (Skip if you are building right to stage 3) *
  
• 3 Inch down pipe *
  
• 3 Inch exhaust with or without a high flow cat, high flow mufflers (check local emission laws)
• Ported upper & lower intakes *
• 255 LPH in-tank fuel pump
• Fuel pressure regulator: Adjust during Dyno-tune for good curve (Accufab recommended)
• Injectors Balanced and pressure tested at 60 PSI
• Increase fuel pressure as needed while dyno tuning, but don't go beyond 45 PSI (vac line unplugged). You will get 1 psi of fuel pressure per 1 psi of boost, so if you are running 20 PSI of boost 45 psi fuel pressure will grow to 65 psi @ max boost and may spring a leak.
• Throttle Body Adapter Kit and 65mm Throttle Body (Available through Forced4 Motorsports)

Stage 3 

It gets just as involved here monetarily as it does mechanically. If you’re on a budget, just skip some of the more pricey mods and you should still come out ahead in power. 

The stock 84 SVO turbo 63 A/R turbine does not really have much lag as it is, and it’s a much better wheel when you have eked out more power from the engine through intake, exhaust and porting. A 90 HP motor will net you 180HP @ one bar, but after stage one and two, and especially stage three, that motor is no longer 90 HP N/A.

On the conservative side, with the exhaust, intake, K&N, other bolt ons and the added big valve head in the list below you could be looking at 110 to 120 HP now, so 1 bar – 14.7 PSI is going to put you in the 220 to 240 range. With good cooling and the 255 LPH fuel pump, up the boost to18 PSI and you hit between 244 and 266RWHP. The only way to get exact numbers is to run the car on the Dyno NA and then run it through the various stages from stock to stage three – I’d rather make my best guess and use all that Dyno money for mods already proven to produce gains and one good Dyno tuning session. Numbers may vary a bit, but not by much; and as I have said I'm being conservative with the numbers.

Now on to Stage Three.
 

• Under drive crank pulley (It would be wise to upgrade the alternator to a 160 amp at this point. The stock SVO/XR/TC alt is only 65 amps and with the UD pulley on the car you may run into charging problems.)
• Front Mount intercooler
• T3/TO4E Hybrid Turbo: 57 Trim compressor with 63 A/R turbine. (good for 400HP)
• Big valve iron head 189 intake 159 exhaust, increase valve springs pressure (Racer Walsh for about $900)
• A234 or A237 Cam. Both are very close. Use the roller cam for stock RPM range and long life and tappet cam for high RPM range applications. Increase valve spring pressure to eliminate valve float.  If you are going to run higher than stock spring pressure, be sure to break in the tappet cam or you will eat the lobes.
• Bob Lee’s Big Log Header or a stainless tubular header
  

That’s it. It too is a short list, but lots of bucks in comparison to the first two stages. This should put you in the 300HP range with the only restriction being the front side of the fuel system. Unless you run WOT all the time, it’s not necessary to get larger injectors or the equipment to run them, but it would open you up to quite a bit more horsepower with all three stages in place. Your electrical needs to be in really good shape, so before moving on to stage three, be sure to read all the service bulletins Ford had on these cars to fix any weak links before upgrading the Alt and to ensure good spark at high RPM.

Tune the car on a Dyno with a wide band o2. This is a must. The injectors will be running at 90% duty cycle if not more at WOT and it’s just best to tune in an environment where you can make sure things are working well. You don’t want to pop a gasket; or even worse a piston before you even hit the track. For normal daily driving, expect not to see much of a difference in over all drivability other than a quicker throttle response. City millage will drop a bit, however highway gas mileage should remain almost the same if you are not heavy on the throttle all the time. You can always turn down the boost.