true, no doubt, power cost for power made, advantage goes to STS.

Isn't the advantage of a modified roots instant boost?
Isn't that the disadvantage of a turbo?

Isn't one of the two main disadvantages of a truck weight? (the other traction)

wouldn't it be better to get that weight up to speed sooner, vice later?

 

then again, what good is instant boost without traction?

 

Thats what I was gonna say.

How are you guys keeping all this power down on the street? Or is this more a track setup you guys are talking about?

 

Never been in a Radix truck, but several STS. I showed my Formula to a guy with a Vortec.( I know, we are not talking about Vortec). He disliked the SC because everytime it shifts, the boost drops and it falls on its face. An auto with the STS will stay at full boost as long as your right foot is on the floor. So, how about this. Stall it up little to build a little boost and keep the boost on full until you lift. Like I said, I dont know too much about Radix, but can it make the torque the turbo will? Just my .02.

 

The RADIX hits full boost as soon as the throttle opens up no matter if it's from the line or a roll. I'm still going to say stock for stock, the RADIX will have the edge.

There's still something about that rear mount I'm just not fond of. I guess it would keep the temps down and the heat away from the engine, but still .... I just don't think I would feel comfy with a rear mount turbo like that.

 

I'm curious, what is the 'something' you're not fond of? What exactly is it that you're not 'comfy' with? Can you be more specific?

 

someone could just lay on their back and unbolt the turbo

 

A fundamental fact that has been overlooked in this thread is that all "boost" is not created equal. I'll use round #'s for simplicity in this example.

10 lbs of boost doesn't always = 10 lbs. of boost when comparing compressors. All compressors or pumps of any form, have and efficiency range and a point of peak efficiency. For example, a gasoline engine like a V8 hits its' peak efficiency at its' peak torque rating in the rpm band. This is when the cylinder has maximum fill of air/fuel and it has the most energy being exerted on the piston, rod and crankshaft. So, applying that to superchargers and turbos, there is also differences i within them at different operating ranges.

For example: Lets say a 5.3 with a basic tubo system making 10 lbs. of boost using a GT35 turbo makes 400 rwhp. Now, if we up the boost to 15 lbs. using the same GT35, we very well may not make a predicted 500 rwhp, because that little GT35 is way out of its efficiency range. At that point you may just be superheating the air charge. However, at 10 lbs. of boost, there is some great power under the curve, but it may be falling on its face in the high rpm ranges.

Now, if we take the same turbo system on swap out the turbo for something larger, like a T-88, and we keep the boost @ 10 lbs., now the truck is making 500 rwhp. How did that happen? The turbo is more efficient. But deep in mind that now, the poer band is "peakier" than with the smaller GT35. There is more peak power, more bragging rights, but the truck may now be slower down the track due to less area under the curve. However, crank the boost up to 15 lbs. or more, and the big T-88 is just getting warmed up.

Now, that was just comparing 2 turbos, let alone comparing 2 completely different types of compressors.

I think on a roll, like a 35 punch, the turbo would have the advantage in acceleration. From a dead-dig, the blower would probably have the advantage. The turbo can be swapped out for a larger compressor, unlike the Radix which is already a 112" model and can't get any bigger. Also, turbo's can be custom built using different volutes, impellers, exhasut housings and turbines. That's 4 different things that can be altered for a "perfect fit" to someones application.

It's midnight and I may not be making perfect sense. If so, I'll correct it tomorrow. Thanks.

 

good call Tokez

The subject kind of got off when talking about the 'potential' of the kits. I am glad someone fiinally brought up some good info while on this tangent about boost. I could shove a potato in my exhaust pipe and see 18psi, but that is not the idea one is trying to accomplish. CFM, airflow, is what makes power. Also, I am glad someone also brought up parasitic loss with a supercharger -it takes power to make power (about 60hp when spinning a Whipple at 14,000rpm).

Just as a kit, Radix wins in my book. However, a turbo setup will always have the potential to out do a blower.

Does a truck with a 30 "tire and heavy 20" wheels count

 

First off, I'm no way degrading the Radix system. I loved it. Very complete, very dependable (as long as I had it).

The Radix does build boost super quick, but it can't do what F8L has been talking about doing - 7psi launches. Given that, not even sure which would be better off the line. That boost (Radix) does however, peak and drop, peak and drop. A turbo will pretty much remain constant throughout.

Stock for stock - I think you're right. Much else above that, and the Radix may actually be limiting you. Without any different displacement blowers out there, the amount of boost you make, certainly isn't limited by how much you want to make. It's a system thing. The only negative that I personally feel about the Radix.