Date: Fri, 12 Oct 2001 07:55:13 -0700
Reply-To: mike miller <mwmiller@CWNET.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mike miller <mwmiller@CWNET.COM>
Subject: Re: Torque Curves for Key Vanagon Swap Candidates
In-Reply-To: <7d.1c45aba5.28f80e3e@aol.com>
Content-type: text/plain; charset="US-ASCII"
yeah, Frank. At last, data! Not seat of pants impressions.
Using this data I can now choose the engine I find best for My van: Ferrari
Testarosa flat 12 [well, OK, I put in a little fudge factor, and some pure
fantasy but it's based on real data]
Mike
the forgoing analysis is similar, if not identical, to the reasoning used by
the California State Legislature when crafting bills from data provided by
yours truly. Eventually they got tired of adding fantasy to data and solved
the problem by removing the data from the equation.
> From: Frank Grunthaner <FrankGRUN@AOL.COM>
> Reply-To: FrankGRUN@AOL.COM
> Date: Fri, 12 Oct 2001 05:13:34 EDT
> To: vanagon@GERRY.VANAGON.COM
> Subject: Torque Curves for Key Vanagon Swap Candidates
>
> Gentlemen and Ladies,
>
> For some time there has been an ongoing philosophical discussion as to the
> best engine swap possibility as well as intangible discussions of the
> propulsive merits of the stock versions. I have maintained, in a similar
> polemic vein, that everything is straightforward and understandable if one
> compares the torque curves for the various possibilities, scale those curves
> by the leverage generated through the transmission and wheel combination and
> compare these values to the force needed to propel the typical Westfalia
> through the ether.
>
> As I have said, torque is everything (next to the engine fuel efficiency map)
> to understanding the performance of these vehicles. Well, anyway, for some
> time, I have collected the engine performance curves from VAG technical
> publications. I'll publish the references if anyone wants to know.
>
> Back to the point. I have collected the horsepower, torque and fuel
> consumption maps for the 8V 1.8L Digifant, the 2.1L Waterboxer, the 1.9L
> Waterboxer, the 2.0L Air-cooled boxer, the Vanagon 1.6L Diesel, the Vanagon
> 1.6L TurboDiesel, the 2.0L Audi 3A, and the Turbocharged Audi 3A nee SAAB
> 2.0L Turbo. I have digitized the curves (all representing flywheel torque)
> and plotted them together in a series of plots for direct comparison. The
> plots are available to any hardy soul who sends an email request.
>
> The data is quite interesting. Obviously the diesel is at the bottom of the
> pack in torque, but the curves for the 1.6L turbo diesel and the 2.0L
> gasoline air-cooled version are essentially identical. When coupled with the
> transmission gearing, the 1.6L TD clearly out performs the air-cooled
> version. The 1.9L waterboxer outperforms the A/C engine, but is significantly
> inferior to the I-4 1.8L 8V engine. However, the 2.1L waterboxer is a
> credible performer clearly outdoing the 1.8L I-4. The curve for the Audi 3A
> 2.0L which should be representative of the ABA block and the SA/TIICO
> offering is stronger than the 2.1L WB, but not by much. Of course the Turbo
> Audi 3A blows them all out of the petroleum.
>
> BUT the curves show that the so-called lack of low end torque on the part of
> the I-4 engines is a function of displacement only. The 1.8L I-4 engine has
> identical low speed torque as compared to the 1.9L WB, and puts out more umph
> at higher RPM. Likewise, thank you, for the 2.1L WB as compared to the 2.0L
> I-4 blocks. Of course the Waterboxers may have been already sucking water on
> the dyno for these tests (extra power through OH assist!).
>
> Furthermore, when you take into account the drive train leverage, the 1.8L
> I-4 engine mounted with the Diesel trans has significantly more torque on the
> road as compared to the stock 2.1L WB. Putting the 1.8L I-4 in a vehicle with
> a WB or AC transmission reduces the available thrust to that of the 1.9L WB
> versions. The impact of switching from 185-14 tires to 215/75-15's represents
> a drop in torque of 8.7% depending on brand (I'm comparing Michelin to
> Yokohama Geolanders).
>
> So how much performance will you lose switching to the larger tires in your
> misguided attempt to reduce wear and increase fuel economy? The Sanden Air
> Conditioning compressor requires more than 8 HP at 4000 rpm. So, if you want
> a pretest of the performance hit, run out with your friendly
> van-o-box-on-wheels, take 'er up to 55 mph and turn the AC on! The kick in
> the slats will show you the importance of those ponies. Remember, 37 kW to
> move the Vanagon through the air at 60 mph.
>
> I also have curves for thrust at the wheel, as well as HP and real fuel
> consumption. No data for the Subaru crowd, the Chevy or Buick group, the Audi
> V6, the VR6 gang or the Mazda Rotary crew
>
> Hope someone finds this as entertaining as I did.
>
> Frank Grunthaner
>
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