what's the difference between twin screw, centrifugal, single turbo and twin turbo?

[Splat]

Originally Posted by NomoreNA

Twin screw = low end torque, centri = linear power/torque, single turbo = big power on the top end "high rpms", twin turbo = worthless on our platform. That covers the basics

Thanks, that is why I want twin screw...I am happy with the high end revs and power.

[Floggin Tires]

Also to note Turbos:

Lag= Delay of boost.
When throttle position changes to the time of actual noticeable boost
when the engine is at an RPM that boost can be made.

Example:
Boost set at 10psi.
Cruising, at 4500 RPMs where 10psi can be made.
For now, no vacuum, no boost. Were just cruising.
Floor it.
Lag is the time it takes from here to build boost.

Boost threshold= The lowest RPM an engine can begin making boost.

Example:
Rolling 5mph 800 RPMs
Floor it.
Boost threshold is from here to the lowest RPM at which boost starts.

Boost threshold is often confused with lag.

[wparsons]

^^ Further to that, you won't have lag with a supercharger. You'll get some delay because of boost threshold with a centrifugal blower, but no lag.

Superchargers are also more predictable in how they react since the amount of boost produced isn't dependent on engine load like a turbo is. In a straight line or drag racing this doesn't matter, but mid corner on a road course you'll sure care.

[nonicname]

twin screws for our cars are made by sketchy companies that lie a lot and have terrible customer service

[AVOturboworld]

Originally Posted by wparsons

Superchargers are also more predictable in how they react since the amount of boost produced isn't dependent on engine load like a turbo is. In a straight line or drag racing this doesn't matter, but mid corner on a road course you'll sure care.

When you use a turbocharger from a drag setup, yes. But I'd think the sheer amount of turbochargers used in racing would indicate by now that they can be predictable in a corner. Especially when you use a turbocharger sized for road racing.

Turbocharging is not just for big hp, big lag setups. Look at the sheer amount of car manufacturers that turbocharge. They do that because you can size a turbo for low-end and mid-range torque, and still retain all the benefits of off-boost MPG efficiency.

[sw20kosh]

Originally Posted by AVOturboworld

When you use a turbocharger from a drag setup, yes. But I'd think the sheer amount of turbochargers used in racing would indicate by now that they can be predictable in a corner. Especially when you use a turbocharger sized for road racing.

Turbocharging is not just for big hp, big lag setups. Look at the sheer amount of car manufacturers that turbocharge. They do that because you can size a turbo for low-end and mid-range torque, and still retain all the benefits of off-boost MPG efficiency.

This.

[wparsons]

Originally Posted by AVOturboworld

When you use a turbocharger from a drag setup, yes. But I'd think the sheer amount of turbochargers used in racing would indicate by now that they can be predictable in a corner. Especially when you use a turbocharger sized for road racing.

Turbocharging is not just for big hp, big lag setups. Look at the sheer amount of car manufacturers that turbocharge. They do that because you can size a turbo for low-end and mid-range torque, and still retain all the benefits of off-boost MPG efficiency.

I realize it's not just for big hp setups, but they still aren't as predictable as a supercharger mid corner. Sure they're good, and more modern higher efficiency turbos are getting better and better at part throttle response, but they still depend on engine load which is an extra variable over rpm and throttle input.

[AVOturboworld]

Mid-corner throttle response implies you are frequently stabbing the throttle mid-corner, at least that's the way everybody makes it sound. I know from personal experience that you are usually feathering the throttle to hold it at the limits of adhesion, and in those situations engine load isn't changing. There's no sudden surge of power just waiting to throw you into the run-off - unless you are running a large turbo that has it's spool-up point right at that rpm range you are cornering in.

[ptuning]

I'm going to totally agree with Paul here. There are a lot of misconceptions about the power delivery of a SC vs. a turbocharger. If turbos were no good for road courses then the also RWD McLaren MP4-12C, Porsche GT2, and Pagani Huayra (amongst a sea of turbocharged supercars) would be the slowest cars on track and as we know that is not the case.

Keep in mind too that these cars run close to or higher than 20 psi of boost so the power sweep from off throttle vacuum to full boost is very wide, but this alone does not affect how the power comes in, that is dictated by your right foot. Formula 1, the absolute pinnacle of motorsports, is switching to 1.6L turbo V6 engines in 2014 and it's not because they want uncontrollable power delivery.

The mid corner and corner exit control is more difficult with a high powered turbo car because..... it makes more power. A lot of people are under the impression that this makes for a slower car around the track. This is simply not the case. Between two cars that are identically set up, suspension and aero-wise, the one with more power is going to be faster around the track with a good driver.

Most SC's allow you to smash the throttle on corner exit, because there will likely not be enough torque on tap to break traction, it's as simple as that. Mid corner control is no different. If you look at your boost gauge while you're going through the corner, you will most likely freak out and mess up your line, but if you feel out the corner with the feedback from the car, you'll be able to modulate the throttle correctly regardless of whether your car is NA, SC'ed or turbocharged.

For the novice just getting into HPDE's, the lower powered car will be the faster one around the track, initially. Turbo's and SC's both have their pluses and minuses, but to distinguish one as being road course worthy because of better power delivery would be incorrect. :happy0180:

[Draco-REX]

I was wondering what direction this thread would take.

There are benefits to each type of FI, and ways to get around most of each's shortcomings. The right choice depends not only on application, but intended use AND driving style.

[Floggin Tires]

AVO, PT, and Draco
I concur, good points.


Now to go off topic.

I was aware,
but read this again,
makes me

Originally Posted by ptuning

Formula 1, the absolute pinnacle of motorsports, is switching to 1.6L turbo V6 engines in 2014:happy0180:

and raise you a :happy0180:

[wallace03]

So does a turbo lag take away from the the NA throttle response that's already in the car? or is does it just "lag" compared to sc?

[Sportsguy83]

Originally Posted by wallace03

So does a turbo lag take away from the the NA throttle response that's already in the car? or is does it just "lag" compared to sc?

That will depend on a lot of factors, more importantly how big or properly sized is the turbo. On a properly sized turbo, its really hard to notice the lag. On a BIG turbo, lag will be bad.

[s2d4]

I don't think the way lag is used in this thread is correct.

That is unless you are dropping compression then add an oversized turbo.