Dinan/RMS Vortech Stage 2 Boost level/Pulley size = HP levels?

[DocWyte]

Trying to get an idea of how much boost I need to run to make certain horsepower levels. I'm looking at my NASA Time Trial rules and have to fit into certain power to weight targets depending on which class I want to run in.

NASA uses an average horsepower at the wheels measurement, taken from a Dynojet. For my car it's the peak HP, and then the next 5 highest values at 250rpm increments. For TT4, I can have an average of more than 290rwhp. Next class up is no more than an average of 355rwhp. My car has all the bolt ons, including Schrick 264/256 cams.

Can anyone give me an idea of how much boost I should run to hit those horsepower targets, as well as what pulley sizes I need? I have the RMS 6" crank pulley, so really I just need to know what blower pulley sizes I should be running.

Posting up some dynos showing how much power you've made with what mods/boost levels would be very helpful for me to ballpark where my average will end up as well.

TIA!

[pbonsalb]

And this is for 5000 feet altitude.

[DocWyte]

Well, sorta. NASA will use the adjusted numbers that the Dynojet kicks out. The correction factor Dynojet uses for altitude is fairly accurate, it's still a little low compared to if I dynoed at sea level, but its certainly within the ballpark.

So just assume average whp/boost levels at sea level and I'll follow those. I know I'll make ~2psi less up here, but the dyno won't care and will correct for it...

[pbonsalb]

A centrifugal supercharger pulleyed for 13 psi at sea jewel might make 11 psi at 5000 feet. A turbo wastegate to 13 psi will make 13 psi at 5000 feet. How does the Dynojet compensate in each case to give the same power as each car would have at sea level?

[DocWyte]

No idea. They've worked it out tho.

So, can anyone post their vortech supercharged dynos as well as tell me how much boost I need to make for certain power levels?