Nitrous

[William T Wilson]

On Sat, 18 Dec 1999, DIY_EFI Digest wrote:

> Is turbocharging os more effective and is a better option.  A properly 
> sized/designed turbo system WILL give you 400 lb/ft at 2000-2500 RPM  It is 

It's very difficult to get a turbo system to give you 400 lb/ft at 2000
RPM and 400 lb/ft at 6000 RPM also.  Especially on a 4-cylinder engine.

Anyway, why is it that nitrous is only allowable at high RPM?  It would
seem to me that a 50HP shot of nitrous at 2000 RPM wouldn't be any worse
than a 150HP shot at 6000 RPM.

> repeatable, is not subject to dirt getting into a solenoid valve and
> sticking it open, causing the motor to grenade from an unchecked
> supply of N2O with insufficient fuel.  The turbo is always there
> regardless of how many runs you have made.

You don't have to refill a turbo, that's true, but they are also prone to
catastrophic failure.  An impeller blade shooting into the engine isn't
going to do it any good.

Besides, if you want to have catastrophic failure, you might as well do it
with style.  I've never heard of a turbo exploding in the garage :}

> As far as longevity, turbocharging will be easier on the motor, as
> it's not a sudden "jump" in cylinder pressures/temperatures.  It's

I don't believe this is really a problem.  Cylinder pressures and
temperatures jump all the time just as part of the regular combustion
process.  A cylinder running on nitrous or turbo will go from relatively
low pressure (say, 10-15 psi or 0 for nitrous) during the intake phase to
*wooooo-eeee* pressure after ignition.  The difference between a turbo and
nitrous is only the difference in boost pressure from ambient.

Plus, nitrous has a major cooling effect on the intake charge.  This
reduces knock dramatically, which is more important for longevity than
pressure changes.

> tune for than N2O, as a 20 degree variance in ambient temp won't make a 
> 20+% variance in bottle temperature etc.  With an electronic boost 

You just need a good pressure regulator.  It is absolutely essential that
the pressure of the nitrous be controlled, or at least known (so your fuel
system can adjust) at all times.

I think the big problem with nitrous is that people don't take it
seriously.  It is just as dramatic of a change to the induction system as
a turbo, but people try to assemble the most incredible piles of junk into
nitrous systems in ways they would never dream of with turbos.