A
Few Words On Turbocharging
I
receive a lot of e-mail from people who want to buy a turbo
engine from the bamboo or scrap yards, and have no idea what
is involved to set it up properly.
Well,
I'm no expert on turbocharging,
but in November 1998 I did purchase my own Sunny turbo engine
and boy did I learn a lot. I have read a good bit on the topic
in both on the net and in the popular import car publications.
I have a reasonable knowledge of the theories and the equipment
involved in turbocharging a small 4 cylinder engine.
I
would like to say first and foremost, turbocharging a vehicle
is not as simple buying a kit or engine and bolting it up
and driving. There is a lot more involved in this if you plan
on having dependible transportation that will last longer
than a few weeks.
Bolt
on Mods:
First, the engine you want to turbocharge cannot have a high
compression ratio. The traditional compression ratio for a
four cylinder engine is 8.5 to 1. You can go a little higher
with multi-point injection. Most non-turbo cars have 9 to
1 or higher compression ratios. You can get away with about
9 to 1 turboed but beyond that, and the boost you add with
the turbocharger will cause pre-detonation and blow your engine.
Also, the higher the compression ratio, the less boost you
can pump into the engine.
So
you'll be rebuilding the engine with custom low compression
pistons to lower the compression ratio, and at the same time,
you'll be strengthining the block to take the additional stress
of the turbocharger.
Obviously
the entire computer system in you car has to be changed over
to the the system for the used engine. You will need to get
the the ECU, the engine wiring harness, all of the engine
sensors, all of the solenoids and actuators and additional
electronics which control the turbo system. So ensure that
a trained mechanic is with you when making the purchase.
Next
up , the fuel system delivery will have to be upgraded. You'll
need higher flow rate injectors, a higher pressure fuel pump
and sub-pump, and a rising rate fuel pressure regulator. Without
the additional fuel, the engine will run too lean under the
boost of the turbo, and will detonate, and blow.
You
have to convert the entire induction system, which includes
intake manifold, exhaust manifold, air plenum, waste gate,
intake piping, and intercooler.
Now
we're done with the engine up grade or replacement, it's time
to look at all of the other changes you have to make.
The
clutch is the most obvious, the turbo needs a stronger clutch.
You'll burn your stock one out in no time with the extra power
. If it's a transmission, the stock tranny is not like the
heavy duty tranny used on turbo models. You may be replacing
cluster gears on an annual basis if you don't upgrade or change
yours for a turbo model tranny.
The
crown wheel and pinion gears and differential in your stock
application are most likely not as durable as those in the
turbo models. You'll pop a few diffs until you upgrade to
the turbo parts.
The
heat form the turbo can affect the engine's cooling, thus
requiring you to upgrade radiator or fans.
Also affected by the heat is the paint on you bonnet, please
insulate the engine room.
Do
not forget the cash outlay for gauges, turbo timer, etc.
So
it becomes quite obvious that it is no small task to put a
turbo onto a non-turbo car. I cannot imagine that installing
the turbo and accompanying parts your car would cost less
than $10,000TT. Even though if you shop around in the Bamboo
you could manage to get the parts to get you going for around
$7500TT including installation (right Prentice?).
There
is another option though. There are several US companies who
make custom turbocharging kits that work on non-turbo import
cars even those whose compression ratio is a little too high
for the stock system changeover. This will involve lots of
custom piping and some electronics that will be piggybacked
onto your ECU and sensors to trick the computer into thinking
that your car is operating within normal parameters. This
still doesn't solve the drive train durability issues, but
the end product will likely out perform the stock turbo counterpart
and additional tuning for more power will be easier, because
you are starting out with more flexible equipment which won't
need to be upgraded from OEM to work with.
Jus
cool.
See
also article on Turbocharging vs. Supercharging
in D Shop.
Also
check out our Glossary of Terms
or refer to De Forum for interactive
help from people in the know.
Questions
or comments? let us know - email us at info@trinituner.com
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