CarBoy

My thoughts are 1) that GM may not have gotten enough return on investment of the TVS set up (even though it's used in more than just the C6-ZR1)
..and 2) Wouldn't the symbol in this pic have been a different one?



I've not owned or even driven an FI car, so it doesn't necessarily mean anything to me one way or the other.
But Based on the patent application we've all seen, I am however intrigued by the new location concept of a centri and even more so by the possibility of it being driven by an electric motor.
To use "old tech" in new ways screams innovation to me, and am looking forward to what GM does with this.(hopefully they do)
The future of all cars smells of all electric, and the way of the internal combustion engine is coming to a close in the not too distant future.
Perhaps this is more of a "throw caution to the wind, no holds barred" and "let's get wild with it" attitude as a way for a good send off.
Maybe some of these concepts have been on the shelf for years and are just now seeing the light of day.

I guess we'll find out in a few days.

Chicago1

I keep hearing it's gonna be a centri but who knows. Maybe I'm wrong but there didn't seem to be a lot of SC swaps on the ls9 or other SC boosted gm cars. You know when you look at the cobras or gt500 these guys are always swapping to a bigger setup. The GM stuff not so much. Why is that?

Jp23rockstar

Benefits of Centrifugal-type Superchargers[edit]

Power Output[edit]
Centrifugal superchargers add additional boost as the speed of the motor increases. This means the centrifugal supercharger will provide more horsepower at high engine speeds and less boost at lower engine speeds.
Performance[edit]
Centrifugal superchargers enhance engine performance in several areas:
Adiabatic Efficiency[edit]
Because centrifugal superchargers utilize centrifugal forces to compress the air, they offer higher efficiency than positive displacement designs, both in terms of power consumption and heat production. “Perhaps the simplest of all superchargers, the centrifugal can also be the most thermally efficient”.[12] The compressor-side of turbochargers are centrifugal designs as well, and also feature high efficiency.
Minimal Heat Transfer[edit]
Centrifugal superchargers are typically mounted off to the side on the front of the engine. Distancing the supercharger from the engine via a mounting bracket greatly reduces heat transfer from the engine to the supercharger during operation. By comparison, a twin screw or roots blower which is nested in the center (valley) of the engine, will absorb heat (heat soak) during operation due to thermal transfer from the engine block and heads. Elevated temperature levels in the supercharger directly influence discharge air temperatures that next enter the engine. Higher engine inlet air temperatures result in reduced power increases and an increased likelihood of engine damage resulting from detonation within the cylinders.

meadowz06

I would prefer a ZR1 style blower. Better low end torque than a centri.

91Z28350

The original cobra/Gt500 blowers were eaton m112/122 2.1L blowers that were pretty maxed out at about 650 RWHP. Also, because the intercooler and hardware were already in place, it was pretty cost effective to switch to a TVS/Whipple/Kenne Bell depending on your budget and goals. (I run the KB 3.6 Liquid Cooled).
I think one thing that might keep them from wider use in the Corvette is the height of the blower. The vette has a pretty low engine to hood clearance, and some of the twin screw's especially (whipple, kenne bell,lysholm) can be pretty tall (compared to an Edelbrock E-Force 2.3 w/TVS rotor pack). Also, without a forged bottom end, the larger blowers produce too much boost for cast pistons. As an example, the lowest pulley offered for my KB is 15#'s (3.87").

Another factor is cost, a TVS upgrade for a car that originally came with a supercharger is 2-4K depending on the kit. The 3.6 upgrade was 7K.

On the other hand, the shop where I get my Shelby tuned did a Kenne Bell 3.6 LC on a built LSA CTS-V, and that thing is mean!!

All this is of course, IMO.

Chicago1

^ awesome man that's exactly what I was looking for. Thanks for the education much appreciated. Im putting a d1sc on my car at the moment. Would like to get a 13 gt500 one of these days. Happy hunting

ChucksZ06

I hope it is centri...last thing we need is more low end. I would make for a wicked topend on the straights.

91Z28350

Back at ya! And good luck with the procharger. You getting the heavy duty gear drive and belt? Those things sound wicked. here is my setup:

Mdm23

That's the same symbol that's on the ZR1 boost gauge. If it is supercharged it will likely have that same type of blower. Maybe bigger but definitely the same type.

Snorman

No.

91Z28350

Currently, there is not a larger TVS rotor pack available. So if it is a tvs/roots it will be at most a 2.3 ( I hope they wouldn't put a 1.9 on the LT4).

blf0005

The LT4 is pretty clearly a roots type is it not?

91Z28350

That's what I think.

Chicago1

6 rib setup in a a&a bracket. When the motor gets built then I'll do the direct drive and all that. If you have lots of time here is my thread. http://forums.corvetteforum.com/c5-t...pics-soon.html

OnPoint

It's not going to be a centri.

455230

Not likely....TVS is vastly superior than a centri on the street in terms of lower rpm throttle response.....It is a proven design ....and GM did most of the required R&D for the zr1 ....Which would cut down costs...

3 Z06ZR1

I agree!

oicw

Having worked at fuel cell design for an OEM, we had to implement a lot of electric driven centri blowers. But I don't know why we'd want such a setup on a internal combustion engine.

With a fuel cell, you have no choice. How else would you power a blower to have massive flow and pressure?

In 2008, they were costing us $30k a piece, for brushless motors capable of 100,000 rpm. Even at production volume they're be $500 a piece, plus the motor controller, and a GIANT alternator to power one, that's a couple $1000s vs $100 for a bracket and pulley setup.

Problem is you don't gain anything by doing so. The only time you want maximum boost is at full throttle high rpm, where the engine has plenty of reserve to spin a blower mechanically. It would take MORE power to spin up a giant alternator, go through all the losses, a controller, and then a motor.

DoctorV8

Very interesting post!

I think it's clear the LT4 will utilize the TVS design, most likely a carryover from the LS9. I don't know of any centrifugal OEM applications since the early Paxtons on TBird/Studebaker/Shelby in the 50s-60s.