Supercharger Vs Turbo!

concept-e · Post by **concept-e** » Tue Mar 30, 2004 10:10 am

My last Vs post seemed to create quite a bit of interest. This is a discussion I have been having with my bro. Im a big fan of the G40 and the Supercharger, and he is a huge RS Turbo fanatic!!!

What are the advantages of each? The supercharger is obviously immediately responsive unlike the turbo which has a lag time. But doesn't the supercharger take drive off the engine unlike the turbo? G40 Vs Fiesta RS Turbo?? Im worried my bro will win!!

I know it will be biased posting on a Polo forum but hey!!

Steve

ereeiz · Post by **ereeiz** » Tue Mar 30, 2004 11:05 am

old slow 8v GTi used to regularly beat my mates Festa RS turdblow.
Now my G40 eats Golfs for breakfast

Chargers are more efficient as they are direcctly driven by the engine so they constantly boost (past a certain point)

Turbos are powered by a turbine thats driven by exhaust gases, thats why they take longer to spool up, there has to be sufficient gases flowing past (i.e you need to boot it or have the engine revved) for the turbine to spin quick enough to force air into the engine.

Thats about all I know really (I think

)

KarlM · Post by **KarlM** » Tue Mar 30, 2004 12:47 pm

A decently set up RS should paste the G. its 300cc up on you so its no suprise.

Turbos are more popular cause they arent as expensive as superchargers (by quite a long way) and they seem to be a bit more reliable (at low boost anyway

)

However most RSTs have been owned by a Barry at some point and so will be f****d - easy race for you then

polo2k · Post by **polo2k** » Tue Mar 30, 2004 2:12 pm

heres an article i wrote on this subject
http://www.everything2.com/index.pl?nod ... _id=349793

When looking to increse the power output of an internal combustion engine there are several methods that can be employed. One method that is employed (usually with large gains) is forced induction. Forced induction comes in one of two flavours, both forcing more air into the cylinders.

The principle on both is the same, in that there is a turbine in a chamber with 2 ports. The turbine draws the air from one port in the chamber wall and then back out of the other port. The first port is connected to the air filter and the second port is connected to the admission side of the engine (i.e. the carburetor/throttle body etc).

The design of this turbine can vary from a simple fan design to the complicated G-ladder (pioneered by VW).

The size of the turbine can affect its performance. If you use a small turbine then the total amount of air that can be moved will be relitavly small compared to a larger turbine. With a larger turbine a much greater amount of air can be moved however it will suffer turbo lag which is when it takes a small amount of time to achive maximum air transfer (boost). VW have recently tried to solve the problems by creating a turbine that acts as a small turbine at low RPM`s but then physically changes the impeller blade angle using the centrifugal forces as the RPM`s rise (this is used on the PD TDI engine range).

Now back to the title of this node. The difference between a turbo and a supercharger is the way that the turbine is driven;

On a turbo the turbine is driven by another turbine known as an impeller, the impeller is sat in a seperate chamber which has again, 2 ports, the exaust manifold is connected to one port and then the other port goes to the rest of the exaust system. The upshot of this is that any waste gasses being expelled from the engine get recycled by driving the impeller, this brings its own problems as it can stall the gasses trying to exit the cylinder.

On a supercharger the turbine is again sat on a shaft however in a supercharger this shaft is driven by a belt so the turbine is directly connected to the crankshaft via a belt (usually toothed). The benefit of a supercharger is that lag is almost completely eliminated. The down side to a supercharger is that there is almost always a whineing.

see also:

Ram air

turbo

supercharger

turbo stall

wastegate

dump valve

any questions
oh and i think itll be close but it will prolly be won by engine condition, mods, driver

david burton · Post by **david burton** » Tue Mar 30, 2004 2:58 pm

Turbos use waste gases, superchargers use engine power - so actually turbos are a more efficient use of fuel.

I think you'll find that superchargers aren't too good at high revs compared to turbos (less of an advantage anyway). So it could also depend on driving style.

Didn't some rally / f1 cars use superchargers AND turbos - to get round lag?

polo2k · Post by **polo2k** » Tue Mar 30, 2004 3:53 pm

yeah thats called compound charging

SpikeyG40 · Post by **SpikeyG40** » Tue Mar 30, 2004 4:20 pm

i've heard that superchargers cost more than superchargers, however, you need to modify the engine alot more to incorporate the turbo, all the seals need to be uprated i think, does that sound right?

so overall, superchargers cost more but r cheaper to fit, n turbo's r cheaper but expensive to fit and upgrade the engine!

i have also heard that tubo's are better top end than superchargers!

not sure how much of this info is right but worth a thought!

dub envy · Post by **dub envy** » Tue Mar 30, 2004 6:19 pm

doug&dan wrote:i've heard that superchargers cost more than superchargers,

you plank.

Why not use both?? Supercharger for the low down boost, then the turbo will kick in higher up the revs to give secondary boost too!!

Superchargers sound the t**s. Turbo's don't sound so good.

Both do have lag, although a s/charger doesn't suffer anywhere near as much as a turbo does.

SpikeyG40 · Post by **SpikeyG40** » Wed Mar 31, 2004 8:37 pm

oops, sorry rob, my mistake, it was ment to say

"superchargers are more expensive than turbochargers"

i must have superchargers on the brain! come on bank balance, show me enough for a g40

ereeiz · Post by **ereeiz** » Wed Mar 31, 2004 9:11 pm

You'd then have to incorporate some form of clutch on the charger though, otherwise it would cause drag on the engine wouldn't it?
Getting technical now

nick euro · Post by **nick euro** » Thu Apr 01, 2004 10:47 am

sorry but charger wins hands down any day, esp over a ford

KarlM · Post by **KarlM** » Thu Apr 01, 2004 12:24 pm

why not have one small spool turbo for low revs and one monster turbo for high revs as in the Supra/300ZX?

hayesey · Post by **hayesey** » Thu Apr 01, 2004 1:23 pm

even a small turbo still has some lag. a supercharger literally has none.

david burton · Post by **david burton** » Thu Apr 01, 2004 2:06 pm

and so say the supercharger owners!

you can easily shift in the turbo range to minimise lag. If the turbo on the RS is like the Escort RS, then it can easilly kick out 200+ bhp with very common and easily accessible mods. Getting that out of a charger will cost a lot of cash?

Superchargers are notoriously expensive too. Especially the G-ladder ones. Spend a grand on a 2nd hand turbo for a 2 litre engine and you'd be laughing all the way down the 1/4 mile strip!

Superchargers rock, don't get me wrong - but I'd rather have a turbo engine for many reasons - running costs, maintenance, speed, modd-ability and less expense. Who says they don't sound good?! Everyone has their own tastes!

KarlM · Post by **KarlM** » Thu Apr 01, 2004 3:58 pm

and thats why i'm building a G40 turbo

vrooom pttssshhhh