The Twin screw supercharger is the best balance. They still draw parasitic losses, but they are still very efficient.
Plus they generate less heat than a roots.

You're looking at it wrong.
It isn't the flowof the exhuast gases that spins the turbo. When an engine expels the spend gases, the combustion event can be only milliseconds ago. The (very hot) gasses which are exiting the engine and passing through the turbo are still expanding. So it is more the residual thermal expansion energy of the gasses which the turbo is recycling, rather than the exhaust gas flow. I refer to this energy as residualas the initial thermal expansion at the point of combustion is what pushes the piston down the bore to make the engine run in the first place.

The turbo is more efficient because it harnesses the otherwise wasted energy. (VS the belt driver blower's parasitic losses to drive)
The difference is that with their being no lag, the supercharger has the scope to generate substantial bottom end torque.

Horsepower sells cars,
TORQUE wins races.

Most folk here know all too well which camp I'm in.

Rogue ran one of these on an A series IIRC.
I have a mate who runs the AMR300 on an eight horsepower honda sidevalve engine in a homebuilt drome racer. It makes 20psi of boost, all day everyday.
If this was in NZ,(And in NZD) and I wasn't suffering post Xmas poverty I'd be all over this.
It would scream on a motorbike. (turn a 250, into a 1000)

Holy sh!tballs batman!
I just came one here to start a thread about this, and this old thread has been bumped already.

So, today I was cutting my jungle length lawns. (Damn I hate mowing grass) And as per usual I had to shift piles of wheels/tyres/BBQ's/scooters/gokart etc etc to mow the whole back lawn. As I was moving a pair of R33 wheels, I thought gee, I should refit the tridens to the rear of my 1200, and hock off this R33 set. Two are on the rear of my 110.
But then I remembered that the typical offset rear axle problem that 1200's suffer from means that the right rear tyre eats the guard with the 185/60/13's on the 13X6 mags.
Since the tyres are just about totally screwed anyway, I had entertained the idea of machining a bit off the back of the rears to tuck them in further. But that would only be 5-7mm, maybe 10 at a pinch if I was lucky.

Then a brain wave (or is that brain fart?) hit me.
The fix for this problem, (Which seems to plague many 1200's) might be this,

open up the king pin locator hole in the spring pad as large as a one dared. (Maybe 20-25mm?) And then make a new locator bush which is a really tight fit in the spring pad, and an equally snug fit over the kingpin. Except with the holes offset by the same amount that the axle is offset. Thus re-centralising the axle. Sounds quite workable to me.
What do you fullas reckon?

Do you need parts, or tune up info?
The Haynes manual for the gn620 truck has the tune up intto for the J15. I imagine it's much the same as the J13.

That's odd?
If I ever get five mins to myself in the shed, I'll reweigh them, and compare the numbers off the beams.

Regarding the rods,
I'm pretty sure that CA16de rods are very like ca18det rods, (look the same) only they're a bit lighter. I don't remember how much lighter, but when I did a comparo weighing a ca18det rod (less cap) and a Ca16 de rod less cap there was a difference.

ARP rod bolts have more clamping force. Therefore the big end will change shape when torqued down, and must be resized to ensure optimum size and shape.

Dont turbo, supercharge it!
Like this http://www.youtube.com/watch?v=WmA7cY ... ature=player_embedded#t=1

Whole thread for the bike is here http://oldschool.co.nz/2011/forum/ind ... 01-10-5s-velobike/page-15

Cheers Crumb!