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Supercharging 308 blow through setup

Started by PSI-EFI · 25 Aug 2013 · 1 replies

Preserved from CalaisTurbo. Original authors and dates are shown; archived members are not current Holdcom accounts. View original archive ↗

PSI-EFIArchived member
Hey guys I'm really keen on putting a side mounted blower on my 308 for a bit of extra grunt. My aim is around the 500-520 hp mark (not at the wheels). I have a few questions that I'm unsure about Motor as is inj 5 litre block, balanced 308 crank, shot peened rods, flat tops, think 8.9 comp, yella terra heads, edelbrock performer dual plane, crane 286 cam and Holley 650 mech secondaries. Fuel pump is mechanical and dizzy is electronic vh one First q is, would a 650 setup as a blow through be enough to push this power? Would this cam and comp work with a blower ? Would a mechanical fuel pump work with a blower or do I need electrical? And what sort of ignition system would be adequate for this? I don't know much about these setups as im into n/a v8's so help would be appreciated And main reason for this is I want to keep the manual in it and want the extra hp. As is with this cam it's laggy. So I'm hoping I can strap a blower on with minor changes and have a pretty reliable quick motor. Cheers
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bachig24uArchived member
back in the day I used a 750 double pumper with mechanical secondaries, annular discharge and boost enrichment power valves to feed a similar setup. around 13psi. had a lot of trouble with leaded fuel back then and it always needed 104+ octane booster. the only changes I made to the ignition was MSD 6AL, MSD blaster coil and a crane/Alison electronic dizzy pickup to fire the coil. bottom end had forgies but you will get more from a Blower Cam (small over lap but large exhaust duration) and pocket ported exhaust ports if need be. must have 1"3/4 primaries and 4-1's best but tri-y will just suffice. when you go blow through instead of a valley mount draw through setup you need to enclose the carb to stop fuel spraying out of every hole when it comes on boost. to be honest it will be horrible to tune. either go draw through setup or fuel injection. basically a 308 set to make ponies as a nat asp is going to need some major changes to make the power you want on boost. mainly cam and induction manifold, regraph distributor, carburation, boost box for the carb, plumbing. might be worth asking redline if they finished the blower manifolds for the 308 yet. I had a hays street/strip heavy as hydraulic clutch in my old HJ Staty and I can tell you it didn't hold too well with a car load but geeze it was fun with the super T-10. eventually smashed the manual's 3rd gear to bits and went back to the T400, transbrake, mech diode, stally etc that I bought off Adrian Moore's 454 HQ kingo. by the way, side mounted blower on a V-engine usually means right over the exhaust somewhere so you are starting off with a heat problem and spending another small fortune to fix with intercooling or water/meth injection just to keep the engine from detonating to pieces.
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