Any boost will eventually hurt an LT1... centrifugal, roots, screw or turbo.

 

What about...an....LS3?.......

 

I personaly think centrifugal is junk compared to screw or turbo.

Your max boost is basicly achieved at your higher RPMS. At least with my turbo I hit full boost at a lower RPM and it holds it to the end. Same with the screw.

But not saying a centrifugal charger IS junk. It jsut has nothing on it's brethren. Plenty of people have cars that run outragous times and numbers with them. Just not my first choice.

 

Agree.

Rich

 

Is an LT1 really that weak?
Wow...

 

Yes... 10.5:1 CR from the factory... cheap pistons... it may last 20k miles or 20 miles.

 

Wow. A pretty strong statement. Do you even have your turbo running yet?

My friend has a twin screw on his Ford Lightning and his IAT's are incredibly high (160 just driving around town). It runs strong down low but up top it peters out. Maybe with a different cam it might be better.

With a centrifugal its a cleaner install, easier to tune, and easier to control wheelspin.

 

Just wondering what size screw charger he has and what brand. Does it "peter out" up top on the dyno or during some highway pulls? Dyno tells the story and just about all cobra guys are making peak hp @ 63-6500rpm with the KB screws.

 

Its a whipple. Not sure of the size. It runs about 10 psi on the guage. I've done highway runs and helped him street tune it. Like I said if he had a different cam it would probably be stronger up top.

 

Okay, fair...but what of these claims that "High revs, and their consequencial inertia loads are what damage the engine. And that roots and twin screws manage to create power down low, so you don't need to rev high to make power - which aleveates this problem."
Taken more or less form the KB website...

 

Each type of blower (posirive displacement, centrifugal, and turbo) has there own advantages and disadvantages. Corky Bell's book Supercharged! Design, Testing and Installation of Supercharger Systems has a good basic explanation of the differences between them. It's a good read. I have experience will all three and would try to focus the discussion a little better. To decide which type of blower you need, you must have a firm set of goals in mind as well as a budget. Without that, the discussion can go round and round like it has in this thread.

My own conclusions, based on experience and knowledge of theory suggest the following general guidelines. A PD type is good for low end torque but not high boost. It is the most expensive of the three types of blower. If there is no kit available, it is the hardest to fab up an install. Unless very low boost is used, it MUST have an efficient intercooler.

A TC has the most power potential and can deliver boost at both low and high rpm. It is intermediate in price for a basic installation. Lag can be a problem as well as too much low rpm boost. Both can be minimized woth proper design and component choice, but this adds to the cost and complexity. Relatively low boost setups can get away with water/meth injection.

A CSC is the default type as it is the least expensive and easy to install. Very high boost can be achieved, as with a turbo but not as much hp will be made due to parasitic losses driving the compressor. Boost is progressive, which can be of benefit in a high torque car like an F-body. Low to moderate boost can get away w/o an intercooler if water/meth injection is used.

Rich

 

I like that. ^ Thanks again.

you say you've had experience? Has it all been on an F-body? I'm not challenging you, at all - i'm just curious.

and based on what you've said above, The CSC /o TC (STS) seems better for my intended application.

So...my next question is: If we put 3 identical cars, with three identical engines (LS2) next to each other, with three identical drivers, and 1 has P/D, one has CSC, and one has a Turbo. All producing equal boost. Which will win in a quarter mile race? or even a mile race?

Then, and this will most likely be my final question...On, say an LS2 again, for argument's sake...Will all types of boost damage the engine? This I've heard too many times, and it doesn't make sense to me, too many people are boosting their stock rides to say that any type of FI will kill an engine...


You have no idea how much I appreciate you're helping me out. Thank you sooo much.

 

The turbo will will at equal boost. Ot is driven largely by waste heat energy in the exhaust so makes more hp/lb of boost compared to the mechanically driven types. They take considerable hp to turn.

As far as engine damage goes, generally speaking, boost is boost.

I have some experience with a number of different vehicles, both street and strip.

Rich

 

I'm sorry, I know this is a pain...but,

meaning?

 

Sure does ... this just the only forum i haven't updated yet