Intro: The Turbo Charged Fuel Injection Mod
If you're like me, you want something simple, effective and relatively
inexpensive. With these three factors in mind I set out to find the ultimate
performance mod that would solve my carburetor problems and supply a big
HP increase in my little 1641cc Bug motor.
I didn't want to tear the motor down for a major upgrade so I needed
something that I could bolt onto the motor.
One alternative was to go with dual Webers at a cost of $500 or more. Of
course, then I would still have linkage problems, jets, and of course dirt or
sand getting in there and changing everything. On top of that, how much HP could
I reasonably expect from a $500 set of carbs? Not enough for me to justify the
expense. In addition, a fancy set of carbs will only really start adding
significant horsepower if you build the rest of the motor to flow the air they
The obvious choice was a turbo. Turbo chargers are arguably the most
efficient way to add a lot of HP to a motor. They are basically an exhaust
driven air pump that pumps pressurized air into the motor rather than the motor
simply sucking air. But how to feed this motor with the required fuel? All the
new cars use fuel injection and that seemed like the way to go. The aftermarket
kits easily cost upwards of $1500 so that pretty much killed my third parameter
of the mod being relatively inexpensive. So back to the drawing board. I
have a little (very little) electronic experience so I wondered if it would be
possible to build a simple Fuel Injection setup. I searched the internet and
came up with one group of smart guys who are building FI
computers. Take a look at DIY-EFI.
This digital controller has tremendous future potential for the DIY guys but
it's not quite ready for my purposes and I'm a little worried about how it
would handle the rigors of off roading.
|Simple? Ok simple may be a
stretch. I was mainly referring to the computer being simple in design. This is
not an afternoon bolt-on job and can be complicated depending on how far you
want to go with it. This mod will require some basic fabrication. You will need
to add injectors to a manifold, or buy a Fuel Injection Manifold, or build your
own manifold. You will also need to modify your exhaust to bolt to the
turbo, do some basic wiring, and install a couple fuel lines on your gas tank.
If you have the capability to fabricate metal, follow directions, and use your
mechanical skills, you should be able complete this project.
So I'm back to square 1 and back to researching what type of carburetors
people are using on their turbos. Then I get an email from Tim Van Setten.
Tim has been building electronic fuel injection controllers for buggies for 10
years. The price was inline with what I wanted to spend and with the addition of
an inexpensive junkyard turbo I could meet all three parameters: Simple,
Effective, and Relatively Inexpensive.
I plan to present this document in 2 sections. The first section will be
about the technical aspects of turbos and FI and will include information from
Tim Van Setten of Tim Systems. It should be noted that volumes could be written
on the science of Turbos and Fuel Injection and nobody knows it all. This is a
complicated subject and advancements are being made every day. I have attempted
to supply the necessary information to complete the mod while simultaneously
keeping the information as simple as possible. If you require more information,
by all means read the books, web sites, ask questions, and do your own research.
Dyno is a slick little software product that calculates Torque and Horse
Power. It does this by processing the recorded output of one of the ignition
wires. By timing how fast the engine is accelerating, it can calculate how much
work the engine is doing and then convert this to a power curve.
The nice thing is that it measures the actual torque and horsepower is being
transferred to the ground on your particular setup. (That's what really counts
right?) The drawback is that traction and other outside forces becomes a factor.
These external forces can be minimized with the proper testing procedure. As a
side note it may also be useful to measure rear tire traction between various
tread patterns but I'll leave that to your own experimentation.
The second section will detail the actual construction process of the
Turbo-FI modification as I install it on my own motor. I will use the Home
Dyno software before and after the mod to compare the Torque/HP curves and
verify the results.
With that said, grab a cup of Coffee and let's get started!