seriously though, can you explain that a little further for me?

 

I still think the off idle boost thing is a weak brag for a Twin-screw. I mean in almost all racing situations you are into the throttle at least a little before the start of a race so it is kind of a waste. The other problem is most types of force induction don't work as efficiently over the entire rpm band. Usually you give up something some where and for me I would rather give up power down low and gain power up high for racing situtations since you generally don't drop below 3-4k rpm at WOT.

Maybe things have changed a lot since I was looking at Twin-Screws back when Whipple was almost your only choice (92') but ETs never lied in the fact that Twin-Screw setups rarely won races compared to similar sized centrifugals and turbos.

 

damn! 500degrees cooler? that is alot. How hot do those things usually run?
I've got nothing against oem quality, works for me. Although, I won't turn away better quality either

 

I was talking street.

On a drag strip, well, I can see your point. That's a whole new ballgame, less restrictions, no CARB, etc.

What do you think about my above case with regard to off idle boost?

 

I am soo lost trying to read all the stuff you guys posted abd being at work all day didn't help. Lemme go over the stuff and I'll get back to ya. Plnety of great info though

A quicky though. IMO we are indeed splitting hairs when talking off idle boost quickness. Once you floor it things happen VERY quickly on most superchargers so the miniscule amount of time it takes the Radix to make boost vs the Whipple to blow something other than hot air is minor. This is in ideal conditions obviously. If you have been sitting in traffic for an hour then none of this maters as you shouldn't be flooring it anyway in a FI car/truck :p

 

This has indeed been a fascinating thread, one of the best I've seen on this forum!

Two questions, though:

1: As a Roots blower transitions from off-boost to boost, wouldn't there be some time delay as the bypass valve closes? Not much I know, but some, as it is vacuum operated?

2: I remember that back in the 1980's when turbo's first became popular, they were considered "consumable items", as they would invariably burn up after 35k to 40k miles. Is this still true?

Again, thanks to everyone for the excellent information.

GMC_DUDE

 

Another "secret of the Radix" its bypass valve. This small valve, between the the throttle body and the intake manifold, increases fuel economy and reduces parasitic power loss. The bypass is operated by a vacuum actuator and is normally closed. When manifold pressure is low (high vacuum typical of light throttle operation) the actuator opens the valve, allowing charge air to flow from the throttle body directly into the intake manifold, bypassing the blower and equalizing pressure in the system. The bypass valve open at low manifold pressure eliminates parasitic loss in a practical sense. Magnuson superchargers running with an open bypass consume only about one horsepower. When the supercharger begins to make boost, the bypass valve snaps closed, allowing pressure to build in the intake ports.

My thoughts: I suppose there's room for delay.
How do you interpret "snaps closed"?

This would apply to a twin screw as well though.

 

I'm glad to be apart of this thread as it seems many have enjoyed it

Where the heck has the Champion for the Radix been?

 

A turbo under boost can get hot enough to glow. This will not happen with the STS. Now, we do loose heat energy from being further away from the engine, but it works very well.
This has been the most civil exchange of info and opinions on the STS ever.
Cool!!

 

I think we just split the atom