I've got an '05 reg cab step side GMC with the 5.3L motor, auto tranny, and a 3.73 rear end. I'm looking for a power adder that will make the truck feel as if it had an LS6 under the hood, but will sip fuel like my LT1 powered Vette. I've narrowed things down to an STS system or a Radix. I'm concerened that I'll never feel the power that the STS is capable of making unless I have my foot burried in the firewall with RPM"s over 3000. My impression of the Radix system is that it starts making extra power at a lower RPM. I'd like to have the feel of a big block without the fuel economy penalty that goes with it. Am I on the right track or is a "rethink" necessary? Open to suggestion.

 

Anyone?

 

Yeah the Radix sounds like the way to go for you.

 

If you want instant off-the-line torque the Radix is your best bet. Turbos have more potential up high once they are spooled up, but a roots or twin screw s/c will give you almost max boost just off idle.

 

I agree, Radix for low end boost and daily driving. The turbo will be easier to grow with down the road if your HP and/or ideas change. You know the old adages, "There is no such thing as too much horsepower" and "Horsepower is adicting". The STS will make cheaper HP over the two BASE kits.

 

Unless I'm not understanding things right, the STS system isn't any cheaper once you add the intercooler. I know that the air to air cooler on the STS will result in a cooler intake air temp vs the air/coolant Radix cooler. I'm thinking that a stock engine will be OK with air to water intercooling as long as the boost levels are kept moderate. I'm not looking for max Hp in an all out race truck. 6 to 8 psi ought to keep me happy. I can always add a little more cam and a more open exhaust if the HP bug bites too hard. Not looking for a loud drag truck, more of a sleeper that will bring a smile to my passenger and I when the mood arises.

 

Either of them are going to give you what you are looking for, they both make power however the power delivery is what will be different. Either way, your fuel mileage will be the same or better as long as you keep your foot out of it unless the power is needed.

 

I was comparing modded kits more than the base stuff. Both require tuning changes but the turbo systems can me bumped up quickly with an adjustable boost controller vs changing pulleys on the Radix.
I am just speaking from my own experiences and a few others, you get somewhat bored of the base kit output and go looking for more down the road. You will spend less $$$ per HP increase with a turbo if/when you start upgrading IMHO.