David Cairns

I have one on my SS. It is great. I don't have anything to compare it to, but it really gives you the low end power . Wish I could tell you the 1/4 mile time, but I blew my chance this weekend, so I will have to try again.

whitt1

My Tahoe running stock boost and ASM headers turned a 13.28@101mph.I was running a Yank 3000 and the Tahoe absolutely destroyed a stock Lightning on the street about a week ago.

parish8

iTrader: (6)

wow, that chart is nuts, i want to understand it, what is PI? how do you convert M cubed to cfm?

14000rpm? that sucks! i am at 13,600rpm with 9psi on a STOCK 6.0, spining to only 6000rpm. need an intercooled turbo set up.

rgvsierra

iTrader: (7)

David Cairns,

wow a new ss with a radix, one heck of a ride.

Ryan23silverado

iTrader: (1)

PI is the intake pressure. The 1.2 that it starts out with on the bottom left of the chart is really only 0.2bar (metric boost rating) because 1.0 is the starting off point at which there is no engine vacuum and no boost. i.e. the intake is at atmospheric pressure.

There is 14.7psi to one bar. Oh ya, to calculate: 1 m³ EQUALS 35.314666721 ft³

XLR8NSS

iTrader: (4)

Parish - I'm pretty sure PI is the pressure ration on that chart. It is figured with this formula. [(14.7 + your boost)]/14.7

If your running 9psi then your pressure ratio is 1.61.

M^3 is meters cubed. Here is the conversion.

1 cubic meter = 35.3146662 cubic foot

If you see around 55lb/min at 9psi with 13,600rpm input speed that puts you at ~50% addiabatic efficiency on that chart. It kinda looks like the whipple is running outta breath on your motor. That chart is kinda confusing though so I could be wrong.

You need twin 60-1's or a T88 turbo on that motor. Then I bet you'd blow it up.

John

whitt1

I don't know if Blowzilla is needed.I turned the boost up to 91/2lbs and added 1.85SLP rockerarms and blew the rearend and transmission on my first hard launch.The Radix system makes instant boost now all I need to do is find a transmission and rearend that will live with 500+lb/ft of instant torque.As for the boost falling off after 5500rpm mine keeps building if I spin 6000rpm my boost guage shows 11 lbs.I also think the system will flow a lot more than 700CFM why else would all the Lightning tuners be adding larger throttlebodies.I'm adding a ported throttlebody to mine.

parish8

iTrader: (6)

ok, thanks, now can anyone clue me in on the diference between adiabatic eff and volumemetric eff?

another question, that rpm is rated for continuas operation so i wouldn't be too afraid to go over that 13000 or 14000, lets say i keep the boost down to 6psi(1.4) and spin it to 15000rpm can you tell how that may hurt me with that chart? thinking 408 with moderate boost(turbo in the future). i would hate to build a killer 408 and still pump the same amount of air thru it but it looks like that may be how it works

Flem

adiabatic effieciency is the temperature gain during compression. the screw compressors are more efficiant than the roots they compress to the inside of the helix. the roots is a pump and it compresses to the outside of the casing with much more suface are to gain heat.
volumetric eff.is the power produced during the stroke of an engine based off the volume of cylinder fill versus the atmospheric pressure.

XLR8NSS

iTrader: (4)

You might want to post that chart in the forced induction section. There are guys in there that know alot more about those charts than I do. I'm not saying no one in here can help you but, most of the guys that can read that stuff in there sleep are in the FI section.

BTW, a general conversion from the CFM a blower is capable of to the power produced is. .69hp=1cfm. I can't remember if that formula takes into account an intercooler or not. I've got some links that you should read. They are about turbos and efficiencys. They're good reading though for anyone messing with FI. Let me find them.

John