Should I Supercharge?

[RICK LAKE]

Tom Hi Couple of things, Is your drivetrain strong enought for 600 to 700 hp and about the same in tork? Have you driven your car without the blower yet, I would start there and when you are SURE you can drive your car well then add the blower. Fuel system do you have a supply large enough ? Min 1/2" lines, Large pump with a 70 psi limit, bigger injectors, for your motor 50lbs. min. You might want to look at 72lbs and have less open time on the injectors. Re program the ECU with a retard system, MSD. Pulleys and how much boost do you want to make. The pistons should be coated both sides and tops to prevent dentenation. Hope the block is season for after market and strong. Limit the boost to NO MORE than 8 psi. You will need good gas. Look at intercooler or water injection to help. I have been there and done someof the things you are about to try. Rick Lake

[vettestr]

Boost is boost but how it is created carries its own baggage. A roots or mechanical driven compressor is for me the best because of its linear output. A turbo is off then rapidly turns on, a belt driven turbo or the paxton and vortechs are also less linear than roots design but all take about 2 to 4 pounds to overcome their own consumption of being driven under boost to start with and go way up with boost levels. HP is heat and all create heat or HP loss. A rule of thumb is == a 300 cubic inch engine normally aspirated has an output of 1X horsepower the same engine with a boost equal to a second atmosphere will think it is double the cubic inches or now 600 cubes and HP will be 2X.
Cam selection is key to boost efficiency and everything we learned for normally aspirated engines is wrong now. Valve spring selection is very important as well. Intake to exhaust Go Fast lessons we learned are not very important either. Intake is under pressure and will happen, exhaust must just be NON restrictive becuse that extra % we looked for at aspirated RPM no longer matters as much at lower boost and RPM levels.
Carbs are designed to respond to changes in vac signals seen at its baseplate. In a boost world (suck or blow through) there is no changing vac signal so it becomes a on to off metering devise. Electronic Injection gives back all the fine control of changing engine needs under boost via sensor feedback.
Boost levels are in very general terms as follows on the conservative side : start adding to the prior level part list
0-6 pounds OK for bone stock nothing changed ,live long time
6 to 8 LBS start thinking about solid lifter cam and springs
8 to 12 , solid cam, springs, valve girdles, rod bolts, - timing
12 to 14 forged crank, o-ringed block or heads, good HP parts
15+ check book in hand

[SCOBRAC]

You really don't build it differently. In the OEM world certainly there is good better and best for engine hardware. Mostly if your builder is smart there is only one choice. slightly better than best.

Forged pistons, high strength fasteners are all pretty standard here.


I do not suggest supercharging a 2400 pound car without a significant background in high hp to weight ratio machines. I cannot sufficiently explain the hazards involved with coming out of a corner and spooling up (turbo) or hitting the sweet spot in the rpm range and finding yourself in a tree. Yadda yadda. I know. But...

You can do both. Get your builder to go 8 or 8.5 to1 and ad a supercharger later.

[vettestr]

SCOBRAC,
I agree the best parts are best in a blown motor if any real boost is going to be used. The big boys -Ford-GM are selling bone stock cars with 36K mile warr. with boost up tp 9 pounds from their Eaton pumps
I am one of the = if a little is good more must be better type A people too, but if just for looks and the unmistakable whine of a blower is wanted stock parts work. B&M advertises their blowers for stock engines and they live. Yep a bunch do wind up with little parts from big parts after changing drive ratios. Hell my cummins builds 26 pounds boost at full load although 3000 rpm is limit.

[powerpagers]

YES SUPERCHARGE,,GO FOR IT !!!!!!