[DML] Re: Fwd: Engine Conversions?

[William T Wilson <fluffy@xxxx>]

On Sun, 23 Jan 2000, Carson Clark wrote:

> BAE Turbo charger, I have not had my car on a dyno yet but Don said he
> thought it was putting out around 200hp. I have driven the stock cars

Ahh, turbos - my second favorite topic, after engine swaps <g>

I bet it's closer to 170hp. That seems to be about what other turbo
engines @6psi produce on a dyno. When you think about it, it's really
quite impossible for a turbo at 6 psi to produce more than 183 HP. 6 PSI
is at most a 41% increase in air over naturally aspirated and 130HP * 1.41
is 183 HP. In practice, increased heat will reduce the density of the air
which means a little bit of power loss.

> boost from the turbo. He told me that if he could increase my boost
> (which is a modest 6psi) to around 14 psi he would DOUBLE the
> horsepower output from my engine. Don was talking about possibly

Sort of. Such a setup will require an intercooler. I don't think you
should go over 8 or maybe 9 psi max without an intercooler. At high boost
levels without an intercooler, the heat produced by the turbo combined
with the heat from compression will raise the temperature of the air/fuel
mixture too high resulting in preignition, and that's bad news. Just say
no to preignition. :} As you said, a fuel increase will be required too.

I'd also suggest an ignition amplifier. Bob Brandys found with his dyno
day that at high RPM the fuel just wasn't getting lit. These are fairly
inexpensive devices that can produce the spark to end all sparks. Maybe
some more recent plugs can be adapted too. There have been improvements
in spark plug design (and I'm not talking splitfires and other gimmicks
here) over the past 20 years or so. It's not at all uncommon for spark
plugs from a newer version of the same or similar engine to fit right in
and outperform the old plugs in all respects.

It is likely that a Bosch fuel injection system from a modern turbocharged
car will have injectors that will be compatible with the DMC. Bigger fuel
injectors can allow more fuel to be delivered. I'd start by looking at
injectors from a Volvo 850-T5 or S80. These cars have engines
approximately the same size as a DMC and with approximately the HP output
you're looking for. You'll need a higher performance fuel pump also. At
14PSI of boost, with fuel upgrades and a good intercooler and an ignition
amplifier, you could conceivably get about 240HP (even with an
intercooler, returns drop as boost increases). Finally, your single BAE
turbo might be too small. A turbo that produces 6 PSI with little lag
just by its nature isn't going to be a turbo that can also produce 14 PSI
efficiently. But if you solved these problems and added DMC-Houston's new
headwork to the mix, you could be looking at as much as 300HP. We don't
need no stinkin' engine swaps. :}

> league as Corvettes, or mustangs, but it is 'peppy' with 0-60 times
> probably in the high 7 second range (and i am only guessing).

That's a reasonable guess. Not Corvette territory, but at least you won't
have to worry about that minivan in the next lane. :}