100 bhp per Litre
24 April 2007
involves taking a base model 1993 Plymouth Voyager Minivan
from 100 bhp to 250 bhp. And doing it with reliable, "easy-to-install and
maintain," readily available "off-the-shelf" technology.
The project starts with a 1993 Plymouth Voyager, base-model
("short" wheelbase - 112 in.) minivan. The factory originally fitted
the 100 bhp, 2.5L, 4-cylinder, "Naturally Asphyxiated"
Throttle Body Injection (TBI) with an A-523 5-speed transmission. The original
TBI engine threw a counter-balancer chain, resulting in block and crank damage,
which made the decision to swap engines easy.
To achieve 100 bhp per litre (250 bhp) a Forward Motion-built, 2.5L Stage
III, with Turbo II-spec internals engine is installed, with front-mounted
intercooler, 1990-91 Sequential
Multi-port Injection, and an A-568 (New Process built, with Getrag internals)
To cope with the increased power, the chassis (exhaust system, brakes, suspension,
wheels and tires) is also upgraded. The idea is to create a daily driver with an
improved balance of
performance, handling, practicality, fun, and reliability, wrapped in a stealthy
package. The eco-friendly R-134a A/C is retained, as are the driver's side air
bag. Emissions and daily driveability are actually improved. Towing capacity is
increased from 1500 pounds to 3500+ pounds. The Quaiffe ATB limited-slip
differential provides vastly improved traction and security, especially on wet
or snow-covered roads.
Why would anyone undertake a
Let's face it, the minivan gets no respect. It just ain't cool to be seen in
one. Especially, a 4-cylinder model. The factory offered the Gen-2's from 1991
to 1995, but the 2.5L/5-speed drivetrain was only offered from 1992 -1994, and
only on base model (swb) vans. To the
best of my knowledge no one has ever done this with a 2nd Generation (1991 -
1995) Chrysler Minivan, including the factory. Since the van came from the factory
with the A-523 five-speed manual transmission, it seemed a good candidate for
conversion such a conversion. We liked our van (it's our second, four-cylinder,
T-115). But we knew it's weaknesses and decided it was high time to stop
being the butt of "Click and Clack" jokes.
Project goals: Double the original horsepower
and torque on regular (87
fuel without anti-detonation timing reduction losses using upgraded internal
components. (view the project results: dynojet graph)
Typically this vehicle operates at 5000 feet above sea level with frequent
trips to 9000 feet. The van will also see light (Class II) towing
duty, so good low-to-mid range torque is required.
For comparison the 2002 Honda Odyssey with its 240-horsepower, 3.5-liter,
VTEC™ V-6 engine weighs in at a portly 4350 pounds. Our project van (at 3450
pounds) will have
no problem dispatching this hi-tech competitor, with technology Chrysler engineers
perfected almost twenty years ago! Suddenly, our stealthy minivan instantly
gains 250 hp of "hidden" street-wise respect.
Is a 2.2/2.5 TBI-2-TII project right for you?
Well, if you have the time
(I spent the better part of nine months) and have a lot of patience, I'd say go for it.
Some will condemn such a conversion project as sheer lunacy, others will applaud
your ingenuity. You'll need to learn about the
specifics of your particular vehicle, which the internet and various e-mail
groups make a little bit easier. For a good background site on TBI-2-Turbo
conversion details, I recommend Derek's
Garage. Don't take short cuts, I replaced virtually everything but the gas tank and radiator.
Also, what I'm sharing in this web pertains specifically to my
1993 Gen-2 AS-body, so as they say, "your mileage WILL vary." Click on the menu bars in the left margin to learn more about the subsystem
upgrades employed within each area of Project TBI-to-TII.
yes, as of Summer 2006, my van's IS FOR SALE .. see
Continue to Turbo II (Engine) Overview --
Shown below are
cross-sections comparing the original 2.2L NA and 2.2 Turbo I.