Date: Mon, 01 Mar 1999 08:47:37 +0200 From: "Roy Björkstrand" <nospamroilonopsamut.fi> Subject: Re: torque vs. horsepower
> Getting back to Saabs, it has been said that the 8v B201 engine is more > 'torquey' and 'responsive' than the 16v B202 (I'm thinking about classic 900 > turbos here) at the expense of a lower top end. Considering the engines are > pretty much the same apart from the > head, why do 16v engines differ in this way from 8 valvers? Is it simply a > bigger overall valve area? Or is it the different drivetrain gearing on the > 16/8v cars? > > P.J.J.J. Has 8V more torque? When I bought my 16V it felt to have much more torque than my 8V. Of course there was a big difference with the mileage. Basicly good torque on low rpm corresponds among many other things to valve area. Bigger valve area, bigger "filling" of the cylinder, more torgue. Also with 16V you are able to put the spark plug in the middle of the cylinder in oder to achieve an even "explosion". So 16V seems to have better "start" on the paper. Possible reasons why 8V "feels" to have more torgue. (no experience on turbos). - 8V´s might not have catalytic converter - the engine is able to use more fuel (rich mixture) on low rpm (at idle). Engine feels responsive because you can take off at idle. - reputation - corresponding to the other engines that age it had a great torque. So, people still talk "it had the best torque ever". - 16V´s are newer - lower emissions demand all sorts of adjustment to keep idle (and low rpm) emissions in control (see point 1). These adjustments restricts low rpm behavior. - "Breathing" of the engine may vary between 8V & 16V engine. Breathing has a very important role in low rpm torque. The engine was designed to be 8V, 16V is a "tune up" and for the best performance there might be need for bigger changes. -Talking about the turbos - there might be some changes in turbos, though those should be in favor of the 16V engine. There are many things which are involved in designing the engines. Behavior of the engine is more or less unpredictable. I personally liked more of the 8V engine, maybe just because it´s behavior was like a diesel engine (I used to drive trucks - love it). You could take the cluth up, car starts to move softly and then push the gas pedal. With 16V (and other new(er) cars I have driven) you have to give some gas first, then take the cluth up. BTW my first impression of the 16V engines was that "hey, someone has taken a half of the flywheel off" - it seemed to have much less "inertia". Roy 99 -82 900 -85 900 -91
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