[DeTomaso] supercharger questions

[jderyke at aol.com]

In a message dated 1/3/10 9:57:57 AM, boyd411 at gmail.com writes:

> Do you think a Whipple twin screw supercharger with an intercooler is a 
> better choice or a Centrifugal supercharger ( like a Paxton or a Vortech ) 
> 
Depends on the engine and what you plan to do with it. First, I would NOT 
supercharge any 351-C that's been overbored unless you have a sonic-test in 
hand that shows over 0.100" cylinder wall thickness everywhere AFTER such 
boring. Thin walls flex with combustion pressures, blown engine combustion 
pressures are significantly higher and cast iron doesn't flex very long. So I'd 
suggest a different engine. Second, actually driving most blowers in a 
Pantera is difficult due to not enough space for a proper width drive belt, 
unless the engine is shifted backward. Shift the engine first before buying any 
blower. Next, most blower kits are made for drag racing and don't work well 
for long-haul use. Depends on your plans for the car. Budget about $7000 for 
such a kit and have an extra block or two around; blower-savvy engine 
bulders say your experience with superchargers is in direct proportion to the 
number of ruined blocks out back...All it takes is one (1.0) backfire to take 
out most systems so a really good ignition and fuel system is much more 
important than higher boost. There's a reason most factory systems only push about 
5-8 psi. Finally, whipplechargers are well known for pushing more air more 
efficiently than other designs, without the lag built into centrifugal 
blowers. A well-designed intercooler (few really are, by the way) is worth a few 
more psi in boost at the cost of extra wt, complication in mounting in a 
Pantera and $$$, plus more damage if the engine pops. You can't practically run 
an air-cooled intercooler with most mid-engined configurations so a 
watercooled assembly makes more sense. Good luck- J DeRyke (who owns two 
factory-blown vehicles- one intercooled. Fun for mountain driving.)