jono wrote:OK, I've been thinking about doing a supercharger install for a bit now.
Perhaps Brayden can answer my questions...
With the fuel system, I'm guessing I will need a FPR as well as a lift pump? I currently have my VL pump sucking fuel from the tank. Aslo, will a surge tank be a must? I saw one on ebay which was from a VL but think it might be too big.
I'm not looking for radical performance, only a few psi of boost to get me moving a bit faster
Having played around with both draw through and blow through carby supercharger setups, I'd have to say the draw through setup is waaaay easier to deal with. The only real disadvantage is not having the option to intercool - but at 5-8psi that shouldn't be an issue anyway.
Draw through makes carby tuning much easier and a simple water injection system can be used to overcome the lack of itercooling if required.
As sort of a summary:
Blow through requires a carb that is sealed to take positive pressure, a high(er) pressure fuel pump (essentially one capable of delivering about 5psi + boost pressure), a rising rate fuel pressure regulator, a blow-off valve, brackets etc to mount the supercharger and pulleys/belts to drive it. An air to air or air to water intercooler is an option. For a carby setup, no fancy lift pumps or surge tanks are required - your carb already has a built-in surge tank. . .
A draw through system requires a custom manifold to bolt the supercharger to the motor (as well as pulleys, belts etc), a normal carb, a normal fuel pump and you don't need (in fact, you cant use) a blow off valve or an intercooler.
In either case, a regraphed dissy would be nice but not necessary (just retard the static advance so that it doesn't ping at high load.
If I was to supercharge a MB/Hatch/Alto, I'd probably go for an AMR300 or 500 and use a HS4 (or HIF38) SU carb. Supercharger to head manifolding would be a bit fiddly due to the water jackets inside the standard inlet manifold but, other than that, it should be reasonably straight forward. . .
As for dyno tuning it. . .once again, nice but not necessary. Set it up and get out and drive it. Check plug colour and how it 'feels' to drive. . .keeping an eye on temperatures etc while you're doing it. If you were really keen, Innovate Motorsports (I think that's their name) does a wide band oxygen sensor for under $500 these days. If you used an SU carb (easy to tune) together with a wide band analyser, tuning would be quite quick and simple (and then you can hire out your analyser to other people to recoup some of the costs
).
