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

[brufleth]

Originally Posted by 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.

I'm glad to actually see someone explaining this so well. I see so many people talking about lag on a dyno where the car is running pretty much steady state. As someone who works with jet engines I'm super sensitive to power lag. People really need to consider the responsiveness of a given setup and not just the steady state high end power output.

[SillySaxon]

I think these cars suffer most in the low RPM range.
I myself hate that first gear is so weak.
So this being the case, a turbo would most likely be the best option to get lower end power?
This car is great on the twisties but my goal is to make Mustangs feel the shame at stop lights.
That being said, i've found most turbo kits are cheaper, but I think that's the price without all the other mods that go into it.
For the SC like Vortech it's petty much plug n play. For the turbos, are we needing new fuel delivery systems, headers (obviously) and other systems?

[sw20kosh]

Originally Posted by SillySaxon

I think these cars suffer most in the low RPM range.
This car is great on the twisties but my goal is to make Mustangs feel the shame at stop lights.

If all you are concerned about is bumping up low end power, then get a tiny turbo or twin screw sc.

[AVOturboworld]

Originally Posted by SillySaxon

For the SC like Vortech it's petty much plug n play. For the turbos, are we needing new fuel delivery systems, headers (obviously) and other systems?

The need for fuel upgrades is in direct relation to the amount of power made. The FI system that creates that power doesn't affect that need. The only variance is that FI systems with more parasitic loss at the engine will need more fuel to reach certain at-the-wheel power goals.

Almost all turbocharger systems come with a header as part of the kit. It's the s/c systems that don't, and are thus the ones that most commonly upgrade their headers. All FI systems benefit from a freer flowing exhaust system.

If a turbocharger kit *needs* other upgrades besides the kit itself, it's because it's exceeded the limits of particular OEM equipment - such as the fueling or clutch. If that's an issue, simply make sure to buy a FI system that doesn't exceed those limits, at least in base configuration.

[SillySaxon]

Originally Posted by sw20kosh

If all you are concerned about is bumping up low end power, then get a tiny turbo or twin screw sc.

Not just low end, but i want a system which will give me the greatest low end boost. Since I live in an area where I'm racing from stoplight to stoplight instead of up a mountain trail my concern right now is quick, immediate, straightline power so that big muscle car junkies can gawk at my little "cracker jack box" import beating them.

Originally Posted by AVOturboworld

The need for fuel upgrades is in direct relation to the amount of power made. The FI system that creates that power doesn't affect that need. The only variance is that FI systems with more parasitic loss at the engine will need more fuel to reach certain at-the-wheel power goals.

Almost all turbocharger systems come with a header as part of the kit. It's the s/c systems that don't, and are thus the ones that most commonly upgrade their headers. All FI systems benefit from a freer flowing exhaust system.

If a turbocharger kit *needs* other upgrades besides the kit itself, it's because it's exceeded the limits of particular OEM equipment - such as the fueling or clutch. If that's an issue, simply make sure to buy a FI system that doesn't exceed those limits, at least in base configuration.

Good info. That said, what all would we need to purchase extra for your AVO Stage 1 bolt on kit if we are completely stock beforehand?

[AVOturboworld]

Originally Posted by SillySaxon

Good info. That said, what all would we need to purchase extra for your AVO Stage 1 bolt on kit if we are completely stock beforehand?

Whatever BOV of choice you want to run with, and I'd suggest a high flow panel filter.

[Sonolin]

Originally Posted by SillySaxon

Not just low end, but i want a system which will give me the greatest low end boost. Since I live in an area where I'm racing from stoplight to stoplight instead of up a mountain trail my concern right now is quick, immediate, straightline power so that big muscle car junkies can gawk at my little "cracker jack box" import beating them.

If you want a chance of beating any of the modern muscle cars, you'll probably want to run a turbo with fairly high boost (or big turbo with low-medium boost) and target ~350-400 whp+

Its not going to be easy getting these cars to beat a new v8 mustang in a straight line, and you'll need better tires and suspension to give it a hope to stick. If you notice most cars with F/I are actually in the 13-14s 1/4 mile times which isn't very fast for 1/4.

These cars just seem really hard to launch even with sticky tires.

Or just give up on the silly notion. This car was made for curves why do you need to prove yourself to a v8 mustang which was built for going as fast as possible for the money?

[Brian@Vortech]

Originally Posted by jamesm

Centrifugal supercharger are a bastardization of the two, and IMHO, not worth consideration. They are mechanically driven turbos for all intents and purposes. So, you get boost that ramps up as RPM's rise. It's basically the worst of both worlds: limited efficiency, parasitic loss, etc. without the benefits down low of a PD blower. The upside is that they're generally easy to install and package.

In the end it comes down to what you prefer. It's very subjective.

While you did state it was your opinion, there are other very noteworthy parts to consider.

Centrifugals may seem to you like it is not the best option, however a great deal of the equation is being skipped over entirely.

Centrifugal superchargers have many of the benefits of a turbo, without the enormous heat concerns of a turbo. If you don't generate the heat in the first place, you don't have to go to great lengths to get rid of it. Plus, without the charge cooler being a safety precaution, it becomes an additional add-on for increased power gains, with IATs coming in relatively close to ambient on a consistent, stable basis in most applications (and we are not just talking about iced down setups on a perfectly controlled dyno situation). In addition, while a centrifugal compressor may have some parasitic loss due to being belt driven, the losses are drastically less than any positive displacement unit. The amount of horsepower it takes to spin a Vortech is nominal compared to any roots or twin-screw. This is one of the main reasons we have display units with drive pulleys on them at all the shows and events we attend. People comment all the time once they see (and feel) first hand that the effort to turn the compressor is quite low, practically free spinning...especially compared to any other supercharger.

Adiabatic efficiency also comes strongly into play when comparing types of superchargers. No positive displacement compressor can ever come close to the efficiency of a centrifugal, especially the 78% (or higher) efficiency of the current line of Vortech units. Most pd blowers come in at an abysmal 50-60% efficiency, which comes right back to heat and parasitic loss. With a 50% adiabatic efficiency, literally HALF of the work going into turning the compressor is being converted directly into heat, and (as everyone knows) cooler air makes more power.

Other things to consider are possibility CARB approval, (in some cases) underhood packaging, and (as stated) ease of installation.

The options cannot be so quickly dismissed. They all have their merits and detractors.

[Hanni_0176]

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

Why is a twin turbo worthless on our platform? From what I've read about boxer engines, wouldn't a twin scroll design provide the greatest efficiency with minimal lag while retaining good top end power?

I'm not the most knowledgeable person when it comes to auto mechanics, so I'm not saying you're wrong. I guess what I'm asking is, can you explain why twin turbos are worthless on our platform?

[xjohnx]

Originally Posted by Hanni_0176

Why is a twin turbo worthless on our platform? From what I've read about boxer engines, wouldn't a twin scroll design provide the greatest efficiency with minimal lag while retaining good top end power?

twin turbo!=twin scoll

[Hanni_0176]

Originally Posted by xjohnx

twin turbo!=twin scoll

Well, a twin scroll is a twin turbo, but not all twin turbo designs are twin scrolls.

[xjohnx]

Originally Posted by Hanni_0176

Well, a twin scroll is a twin turbo, but not all twin turbo designs are twin scrolls.

Not exactly. Twin turbo means 2 of the exact same sized turbos, no?

I think you're thinking more of a bi-turbo or sequential type setup (a smaller turbo for low lag, and a bigger one for high flow, which in my understanding is the same concept in which twin scrolls operate.)

[Frs300]

Originally Posted by xjohnx

twin turbo!=twin scoll

Originally Posted by Hanni_0176

Well, a twin scroll is a twin turbo, but not all twin turbo designs are twin scrolls.

Twin scroll isn't twin turbo..twin scroll has two holes that blow air over the exhaust wheel. One is open at low rpms to increase air velocity, at higher rpms second one opens up to help out the top end. Twin scrolls usually spool at low rpms and are tq monsters.

[InvalidJohnny5]

I remember seeing two tiny turbos on a 3000gt, they made my turbo look beefy hahaha