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Re: air pump questions

To: mgs@autox.team.net
Subject: Re: air pump questions
From: thorpe@kegs.saic.com (Denise Thorpe)
Date: Thu, 29 Feb 96 11:59:02 PST
For anyone interested in clarification on this subject:
ckr said:

> re laws: I may not have the correct definition of felony ... sorry, I'm a
> ferner (southern spelling of legal alien) 
<snip>

I was wrong too, and I bow to Ernest Gilbert's superior knowledge of the 
law.  But I thought it was spelled "furriner." ;-)

> I'm surprised to hear you say that the air injection system doesn't reduce
> the operating efficiency of the car.  While I'm willing to wager that the
> biggest choke on the 1800cc engine is the bitty motorcycle carburettor they
> stuck on it, and the somewhat over-baffled exhaust system a close second, 

I can't speak about the difference caused by replacing the carburettor 
because I've never driven a late model B that had had just its carburettor 
replaced.  Other people on this list can comment on that.  But I have driven 
a late model B before and after having only its catalyst hollowed out and 
this caused a significant increase in power.

> I'm
> certain that removing an extra drag on the engine, as well as that noisome
> gulp/egr valve combination on the intake side, has improved the overall
> performance by over a quarter bhp. 

If the EGR was removed at the same time the air injection was removed, 
I can understand why removing the air injection system (plus EGR) would 
cause a big increase in power because EGR is a horrible thing to do to an 
engine.

> I'd be willing to bet, theoretically, that
> I could pick up an extra 5 bhp by converting it to electric fans; I'd
> imagine, based on performance before and after, that removing the air pump
> did about the same.  Not that I don't believe your expertise - just that I'd
> be surprised if it's that little.

At the same time I was told that air injection draws 1/4 hp, I was told 
that an early B has 75 hp and a late B 50 hp.  There are different ways of 
measuring horsepower.  And this was when the cars were new; bad bearings 
in a 15 year old pump could increase the amount of drag on an engine from 
the air pump.  However, when the cars were new, I didn't notice an increase 
in power when only the air injection was disconnected.

> The biggest improvement I can see has been a better overall throttle response
> in the car.  With the current set-up, it seems to have a much finer and
> quicker response than it did with the air pump on, and of course more than
> with the air pump off but the Z-S carb on.  ::shrug:: I'd welcome any
> thoughts more experienced hands than mine have.

This describes the difference I experienced when only the catalyst was 
gutted.

> I do applaud your suggestions re: the elimination of smog tests for those of
> us responsible enough to keep our cars in tune.  I'll vote for you.

It would be a mistake to vote someone into office as empress because it 
would be the last time you'd get to vote. ;-)

Denise Thorpe
thorpe@kegs.saic.com

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