Turbo Performance Upgrades
Turbocharging is an old favorite for hotrodders who want more performance out of their vehicle. The creative (and mechanically inclined) car owner can add a turbo to just about anything on wheels, but it sure is nice to start with a vehicle which was turbocharged by the factory... and multi-point fuel injection is a plus, too.
Chrysler corporation has sold more turbo-equipped vehicles than any other automaker. These turbocharged engines are a great platform for economical performance and reliability. Many people wonder what they can do to increase the power of their turbocharged car; thus the creation of this web page. Having owned and modified a few Shelby Dodge turbo cars over the years, I have gained a bit of experience in this area. I also stay in close contact with many other Shelby Dodge turbo enthusiasts and the successes they have. What changes would I recommend, based on all of these experiences? Read on.
Most performance enhancements for these cars can be grouped into two general categories. The deciding factor is whether or not you let the computer remain in total control. I have broken these modifications down into two subpages--one for each general style of enhancement. Decide which course you'd like to take, and read the appropriate information.
IMPORTANT NOTES: before reading any of these pages, be sure to check out my new general instructions page. This page will define all the hardware we will be using, which barb is which, and so on. This is required reading; all other pages are written with the assumption that you thoroughly understand the information found here. Also, these pages were written specifically for 2.2L/2.5L 8-valve Dodge, Chrysler and Plymouth vehicles which were turbocharged by the factory. If you came to this page for information on modifying another kind of car, you will need to do some extra research in order to determine if what I say applies to you.
For the faint of heart or those who wish to let the car's computer call the shots, Recipe A is a good foundation for increasing your car's performance. The modifications are few, simple to perform, and are complete no-brainers once installed--just add these pieces and drive off in high performance bliss. It doesn't get much simpler.
Now we're getting serious. Recipe B opens the door to maximum performance for minimal cash outlay. You'll assume manual control of certain engine functions which the computer wants to oversee, so this recipe is reserved for serious enthusiasts only.
A lot of you out there are fairly content driving cars that are 100% stock; you've perhaps just thought to yourself "I'd like to run just a couple pounds more boost." If only increasing from 7 to 9 psi (or 9 to 11 psi) is your ultimate goal then a simple bleed is the easiest way to get there. This page shows you how to do it.
For people who want a simple bleed but would like to go closer to cutout and not experience overboost shutdown (in other words, 12 or 13 psi) here's the solution. You don't need the special quick shutoff, or "high quality" switch for this, since it's the bleed that holds the boost. The solenoid doesn't cycle; it comes on just once to prevent overboost shutdown.
Tired of trying to dial in your boost peak right to the cutout limit, only to have it cross the line and hit overboost during the heat of battle? You don't have to put up with this any more. Here are instructions on building a setup that will keep your boost level right at the line without crossing it. Plus it also gives you the effect of having a Turbo Response Kit at the same time, and it'll only set you back about $20. Check it out! NOTICE: this particular setup works well with blow-through turbo setups (88+ TurboI and all TurboII, TurboIII and TurboIV) but performs less precisely on a draw-through setup (all '87 and older TurboI engines). We aren't certain exactly why this is, but it seems to be related to the dynamics of draw-through verses blow-through. If you have a draw-through TurboI then we suggest you use either A Simple Bleed Without Overboosting or Two-Stage Boost Control with Overboost Eliminator instead.
Having trouble finding a quick-release pressure switch? Or maybe you don't want any wiring hassles at all? No problem. This method uses a mechanical pressure relief valve (also called a Grainger valve) to perform the same function as the electronic pressure switch in the above modification. And it still costs less than $10! Take a peek at my new page that tells all.
This slick setup is the best of both worlds. You can use the two-stage feature to ensure traction off the line plus you won't experience overboost shutdown. Sound desirable? Then go see how easy it is.
If you're serious about performance, you've surely defeated the overboost cutout by now. But your newfound power is overwhelming your tires. What to do? Build a two-stage setup using two grainger valves! It's easy, it's cheap, and it works.
So you're finally ready to trick the MAP sensor and run more than 14 psi of boost. You're going to need more fuel. A simple and inexpensive way to do this is add a cold start injector to your car. Look over my detailed page and all the photos to get a feel for the job.
Modified 6/1/05.