Quote:
Originally Posted by JohnJL
Thanks guys. I'll try to get all this in...
Adam, thanks for the message, I've replied. I agree, I also have Ray's dyno charts here and he was different results. My supercharger is 1 size larger and of the same design and manufacturer as Ray's. His is an autorotor 3150, mine is a 417. His puts out 1.5l per revolution, mine (is supposed to) put out 1.7l per revolution. His is running an 80mm supercharger pulley, mine is 60mm. Both our crank pulleys are 120mm. We use the same belt.
The supercharger is geared so it hits its maximum continuous-rated speed at 6500 rpm. So at 6000 rpm (3000 engine rpm, where things seem to go awry) it still has a lot of headroom.
|
Definitely doesn't sound like a supercharger sizing issue to me then.
Also people should bear in mind that these superchargers are a positive displacement twin screw supercharger, so the speeds they spin at relative to crank speed are very different to some other supercharger designs that are more like a mechanically driven turbo compressor wheel.
Quote:
|
Eric, that's an interesting comment on plugs. Hans also said that same result occurred with an Audi tuner in the US. I have iridium plugs gapped .85mm. Tops are one range cooler than the bottoms.
|
What kind of ignition system are you running ? Some manufacturers of aftermarket ignitions advocate an increase in plug gap with some aftermarket ignitions.
As an example, MSD's FAQ page at
http://www.msdpowersports.com/faq.html reads ...
Quote:
Spark Plug Gap
With a MSD Ignition you can run a wider spark plug gap than you would be able to with a stock ignition. The MSD Ignition has a higher voltage output and can jump the spark plug gap easier. As an example, if you normally would run a .028 inch gap on your spark plug with a stock ignition, you could run a .032-.034 inch gap with a MSD Ignition. There are variables that will affect the gap size: the higher the compression - the smaller the gap; the hotter the output of the ignition - the larger the gap, etc.
|
- Adam