Date: Wed, 16 Oct 2002 12:49:10 -0400
Reply-To: Kim Brennan <kimbrennan@MAC.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Kim Brennan <kimbrennan@MAC.COM>
Subject: Re: Roadhaus - 2.2L Engine Install , Prelimanary Report
In-Reply-To: <023b01c27527$ee658480$7a810fce@vern>
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On Wednesday, October 16, 2002, at 11:22 AM, Robert Donalds wrote:
> The horse power claims for this engine are way of base for the
> changes made. and I am harping on the compression ratio change as it
> is the biggest change in the engine. I also recall in previous post
> that the claims of power from these folks where reported to come from
> the higher compression ratio. we don't have a fuel that supports this
> kind of compression ratio without using a knock sensor. The
> displacement change is minor and could not account for the huge
> advertised increase. The camshaft is I am sure very close to stock as
> the fuel injection can not tolerate more duration without loosing all
> low end drivability because the poor vacuum signal at idle. and as I
> said the European 115 hp engine does not use the digifant injection. I
> think if somebody looks at the European Edka they might see that the
> exhaust is not the same.
A more reasoned criticism (for which I thank you.) On the other paw,
I'd probably have stated "for the changes PUBLICIZED".
As you are no doubt aware similar engines...even engines with similar
designs >CAN< have different HP/Torque figures. The horizontally
opposed engine used in rear engined Porsches and Subarus are derived
from the same background as the wasserboxer. But they also have higher
HP/Torque figures than the wasserboxer. So it is 'possible' to get more
power from the design.
As for seat of the pants feel. Most lay folk I have dealt with think
that the car has more HorsePower, when in fact where they are
experieninge the change is in increased Torque...at a given RPM. That
doesn't mean that there is higher max torque, just that there is more
at a point where the folks notice it.
The difference between a wasserboxer and a Tiico is more than just max
HP and max torque...it is also WHERE those values peak. When I put a
Tiico engine in my GoldBrick I barely noticed any difference between it
and the wasserboxer (less than 2 years old new engine) it replaced. It
wasn't until I started taking the Tiico to higher rpms that I realized
the real difference between the engines. The Tiico's max hp/torque
figues occur at higher rpms than the wasserboxer...and as I normally
drive, I wasn't getting anywhere near that high an rpm on the Tiico. It
should be noted with an aside that the Tiico is a "smaller" engine than
the wasserboxer, but has higher max hp/torque figures, so the "added
displacement" isn't the only thing to consider when reasoning out
hp/torque values of a given engine.
The only thing (outside of your point of view) that I questioned with
the Eurocars engine was the 2.2l European engine that they (and only
they) seem to know about. As far as I know (though I'm hardly the
repository of world knowledge) the Europeans only had access to the
same 2.1 and 1.9 liter engines we did (though exhaust and engine
management systems may have differed.)
As to dyno tests, from what I have read, dyno results can be reported
in differing ways. So let's say for example that (I don't know that is
the the case) VW reported HP for the 2.1 digifant engine based on
HP...at the wheels. There is always some loss of HP in the translation
from the flywheel down to the wheels. So if someone else reported HP
for the 2.1 based on HP at the flywheel, they'd mysteriously appeared
to have gained, say, 20HP. When in fact there was no difference, just
a reporting difference.
The "snakeoil" that Eurocars might be selling, could be that they take
the VW published values and line them up directly across from their own
engines values. We really don't know if they were measured the same
(assuming Eurocars >DID< measure the values.)
You are in the best position to confirm whether VW's published values
are based on at the wheel HP or at the flywheel, sinced you have done
some dyno'ing of the engines you build.
And it isn't inconceivable if VW's values are at the wheels that
Eurocars has made an unwitting mistake by measuring at the flywheel.
Something to consider.
Or you could be entirely correct.