<MISC> Dynos and Borlas

[ingraham@xxxxxxxxxxxxxxxx (Curtis A. Ingraham)]

Regarding the suggestion that a Borla exhaust might give less 
performance than a stock exhaust on an E36 M3, it was in BMW
Digest v09.n111 writ:

> That was a MYTH spread out over the digest by some individuals I wont
> mention.  But my dyno results for a STOCK '95 M3 with Borla Cat-back are:
> 213hp and 208 lb/ft.  I bet the curve is as smooth as any out there.  This
> is supposedly too high for a stock car.  If it is too high, and the Borla
> lost power, then what could it have been before I changed exhausts?  WAY,
> way too high!  So, use your own judgement.  I've heard them all, and I have
> to agree that the Borla sounds the best.  If you want the DTM tips, just
> order the ACS V-2A tips, they will fit right onto the Borla I've *heard*.

Two numbers do not constitute "dyno results", nor do they represent 
the performance of an engine or exhaust.  Any dyno run worth doing 
would result in a graph or table showing power and torque over the 
rev range of the engine.  A broad, high torque curve is usually 
considered more useful than a narrow peaked curve, so the peak 
reading alone is not all that informative.

One dyno run on one car with one Borla exhaust is completely meaningless 
by itself.  A valid comparison could be had with a similar run on the 
same car with a stock exhaust.  Better yet, for the purpose of predicting 
the performance with Borla versus stock, would be a series of tests on 
several stock and several Borla exhausts on the same car.

The dimensions of torque are force times distance.  In the units 
customarily used in the U.S., torque is expressed as pound-feet (lb-ft) 
not pounds per foot (lb/ft).

Curt Ingraham
'72 2002tii
Oakland, California

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