Turboing vs. Supercharging - Pros and Cons

[b2tf]

sorry if this has already been covered somewhere else, i had a look and didnt find it

As the title suggests, what are the pros and cons of a Turbo or Supercharger Application?

As I understand it a Supercharger is easier but does not get as higher figures as a Turbo? (Or am I way off).

I know virtually nothing about Turbos or Superchargers so as much info as you have would be great.

[MITCHAY]

Ive heard somewhere that with superchargers your limit to pulley ratios compared to turbos where tuning is virtually unlimited. With turbos you just tap into the exhaust.

Superchargers have smoother delivery of power while, while turbos kick in. Superchargers draw some of the power from the crankshaft but make up for it
turbos increase backpressure.

This is all the shit ive found on the net

[Steffo]

Superchargers, Centrifugal, Twin-Screw and Roots are less efficient, end of story. They all incur higher parastic loss then a turbocharger does and will all produce less power in any given application. They'll all also be worse on the fuel efficiency side of things.

[dynosteve]

pro-charger, get the best of both worlds

[Steffo]

Not really. Centri's give you the parasitic loss of a s/c combined with the lag of a turbo. They're the most space efficient type of forced induction though... and yes, Pro-Charger's rock

[b2tf]

Ok to further things a little I will be honest and say I am doing my homework on a suitable boost application for the Focus. It's only a 'what if' at this stage but I would like to know as much as I can about it.

I am not really keen on turboing as from what I know (very little) it needs a lot of added piping, oil lines etc. I dont want anything that is difficult to add or remove to the engine as it is now, which is why I was thinking a Belt driver supercharger might be a suitable option. kW increase in number is not important to me - I'll take whatever i get as long as someone in the know can tune it for me and they are happy with the figure, then so am I.

What's a "pro charger"?

[MITCHAY]

Id say a turbo for the focus. I really think there isnt any point in having them on anything smaller than a V8. Doesnt supercharging require a lot of engine work?

[geckoGT]

yeah, what is pro charger?

[Biggoggs]

I'd personally go for a turbo. By definition, a centrifugal 'charger is driven off power- think `air con for your engine'. It might make up for it in additional kw, but taking energy from the engine to force in more air can't be good for mileage.
Turbos however run off the otherwise `wasted' (on an N/A car) energy from the exhaust (air pressure, sound, heat), but it does make things more complicated. Expect more power from a turbo than a mechanical supercharger, but either way, both methods aren't going to be a) cheap b) easy.

[mcflux]

With your car being an auto, I suspect that it'll change gears before a turbo has a chance to really spool up (depending on how highly strung a setup you have)

Supercharging small fours isn't that common, and turbocharging is usually more popular due to a four's ability to rev. The higher the revs, the higher the flow, the highter the exhaust gases --> turbo spools up, then forces more air into the engine through adjoining impellor. Forced air (+ fuel added) makes its way thru engine, goes thru turbo, turbo forces more air into the engine, and so-on.

A centrifugal supercharger is basically a turbo, but instead of using the exhaust gases to drive it, it uses the crank (thus sapping engine power).

A rootes/twin screw supercharger uses the crank to rotate a set of rotors or helical screws which stuff more air into the intake manifold, giving a pretty-much flat (and fat) torque curve throughout the rev range, so you technically get max boost the whole time. Downside is, the blower can only be driven by the crank to a certain speed before limits come into play such as frictional/inertial sapping of power from the crank, or metallurgical limitations of rotating parts, or the strength of the belt, etc etc. (this is coming off the top of my head, if any of this sounds like crap, please correct me!)

I remember reading an ad a while ago for supercharging setups for Hyundai Excels... But usually people go for turbos, because the 4's strong point is its revs, and that's what the turbo works off ;) ;)

Ugh, it's 4.30am, and I'm halfway thru an assignment due in 4.5 hours... neeeeeed coffee

-Dave-

[Mike Gayner]

Originally Posted by Steffo

They all incur higher parastic loss then a turbocharger does and will all produce less power in any given application.

Oh yeah that's why you see so many turbo charged top fuelers, right? :rolleyes:

Why would you want to bother boosting a Focus? I mean, they're an okay car for a shopping trolley but why would you even bother trying to make it go fast?

[Racecraft]

Originally Posted by Mike Gayner

Why would you want to bother boosting a Focus? I mean, they're an okay car for a shopping trolley but why would you even bother trying to make it go fast?

Power to weight you goose... The size of the car is totally irrelevant to 'making it go fast'

What a silly comment or are you just trolling for a bite. :yeees:

[The MaDDeSTMaN]

I think a turbo would make more sense - it's what I would go for personally. Reason being that you can drive around at low revs and not have the turbo spool up, so then it'll be as if there is no turbo there, so no fuel econ hit as well as it still being nice and easy to drive. Also that way, if you want that power from the turbo, all you have to do is let the revs climb and bang, there's the turbo spooling up and off you go. If you go for a suitable turbocharger (seeing as you're not going for any world records in power), it will have very little "turbo lag" because as a general rule, the bigger the turbo, the more power it can make but also the longer it takes to spool up and hence you get more "turbo lag".

Now, for comparison a supercharger is always on, and as has been said above, saps engine power to make it work. So at low revs, while it will be boosting your engine, it will also be using some of the engines power to do that. End result being, if you're cruising along at 1500rpm (for example), the supercharger will be working, you'll be making a little more power then you normally would at those revs, but you'll also be using more fuel then you'd expect, because while your engine will be making slightly more power then it would without the supercharger, if you take out of the equation the extra power the supercharger is making, the engines power will actually be down, while still using the same amount of fuel, as a result of the engine also having to drive the supercharger. So to use some (admittedly rubbery) figures, lets say the supercharger saps 20% of your engine power to run, but you end up with a 10% increase in engine power through the rev range. That would mean that, for that 10% increase, the supercharger is actually contributing 30% of the power, so instead of a 10% increase in fuel usage, you would be looking at more like 15% or perhaps higher, with the important part being that it would be all the time, even when you're driving like a granny, unlike with a turbo.

Personally, I think a supercharger is more suited to a 6 or 8 then a 4, and I'd personally prefer to be able to drive off boost if I want to as you can with a turbo. But I hope I've been helpful in telling you what I'd consider the advantages and disadvantages of each are.

PS Racecraft, I wouldn't worry, from my experience, some people just don't seem to like 4 cylinders, I know my Escort is no shopping trolley, LOL!

[TheSneakiness]

Originally Posted by Mike Gayner

Oh yeah that's why you see so many turbo charged top fuelers, right? :rolleyes:

Why would you want to bother boosting a Focus? I mean, they're an okay car for a shopping trolley but why would you even bother trying to make it go fast?

Mate, I know there's major problems where you are now. No need for comment like that.

B2TF, it's good you've bought up something like this, because later on, I'm looking at boosting the ute, but don't know which way to go. Any other bits of useful information would be great right now.

[dansedgli]

Originally Posted by Mike Gayner

Oh yeah that's why you see so many turbo charged top fuelers, right? :rolleyes:

Why would you want to bother boosting a Focus? I mean, they're an okay car for a shopping trolley but why would you even bother trying to make it go fast?

haha Ive got a mini that is going to be turbo and run 13's for approx $2K worth of engine!

[dansedgli]

Originally Posted by Ghia5L

With your car being an auto, I suspect that it'll change gears before a turbo has a chance to really spool up (depending on how highly strung a setup you have)

Nope! There is more load in first gear, it will spool fine if it is the correct size.

I would not supercharge a car if turboing was an accessible option. The ability to upgrade is the major reason. If the turbo is correctly sized lag will be minimal.

My falcon has a 700hp turbo on it and it gets boost at 2000rpm. :sm_headba Mine is auto as well.

But if I had a V8 and was after forced induction I would supercharge just becuase you can get off the shelf kits for the windsor and that helps when you want to get it all engineered and passed emission testing.

Arent off the shelf turbo kits available for the focus?

[FRDXR6]

I reckon a turbo focus would be pretty cool, theres heaps of small fwd drive cars geting around with turbo's its just a matter of finding a kit for one or getting it custom built - proabaly looking at 4-8k mark same as boosting a falcon?

[The MaDDeSTMaN]

Does anyone disagree with what I wrote, or did I have it about right?

[Steffo]

Originally Posted by Mike Gayner

Oh yeah that's why you see so many turbo charged top fuelers, right? :rolleyes:

Why would you want to bother boosting a Focus? I mean, they're an okay car for a shopping trolley but why would you even bother trying to make it go fast?

Top Fuel are obviously rule-limited to roots type. It is an effort to slow them down. Roots are the most inefficient form of forced induction. You get 'contstant boost' but you also get extreme levels of heat and extreme levels of parasitic loss. It takes 800hp to drive the supercharger on a Top Fuel dragster - that's an 800hp power gain alone from going roots -> turbo, if they were allowed to, they'd all do it.

As for why would you bother boosting a Focus... it's a small light car, it doesn't need much power to be exceptionally fast. The Focus weighs 1218kg (2680lbs) with a full tank of petrol... now lets add, say, a 100kg driver (1318kg or 2900lbs). With 190kW (255hp) and assuming you get a good run, that's a 13.7 - 13.8 @ 95 - 100mph. So on average, low 14's, from a little FWD hatch. Power/Weight is a good thing. It needs only 300hp to run 13 flat. What's a big, heavy Falcon do with 300hp? 350hp and its running 12.3 - 12.4's etc etc.

Turbocharging is definitley the way to go, Roots yeilds too much heat and parasitic loss, and extreme expense and difficulty to intercool properly, Twin-Screw is the same, just not as bad.. and Centrifugal is only really good if you wish to be different or have little to no underbonnet space. It's simply a crank driven turbocharger. Centri's are really screwed because they get the deficiencies of a Supercharger and a Turbocharger rolled into one package. You get the parasitic loss of a Supercharger (being crank driven), yet they need to spool up, just like the turbo, so you lose the whole "constant boost advantage" that Superchargers have.

Besides, a properly setup turbocharger system will have little to no lag, and make bucketloads of power from low rpm to redline.

[loxxr6]

Ok to further things a little I will be honest and say I am doing my homework on a suitable boost application for the Focus. It's only a 'what if' at this stage but I would like to know as much as I can about it.

It seems it's the funny season for forced induction (esp turbo's) with everyone wanting to do it (me included lol).

I'd also recommend the turbo. You'll prob find a lot more info re turbo'ing the car versus s/c'ing and like other's have said, you're prob better off.

Here's the link for procharger (i'm guessing this is what was being discussed earlier)

http://www.procharger.com/

[Perana]

It depends a lot on what you want as well... if you want a flat and fat torque curve go for a Positive Displacement Supercharger... otherwise i would go for a turbo as im not a fan of centrifugal blowers...

There are quite a few forced induction kits avaliable for the Focus. I know Ford Racing have a PD kit avaliable and so do Cosworth.

BTW I am putting a PD supercharger on my Zetec engined Escort in the future.. as far as intercooling I will be using a water to air intercooler which is much easier to package in a tight engine bay than a normal air to air intercooler... but is more expensive.

[Biggoggs]

Originally Posted by The MaDDeSTMaN

I think a turbo would make more sense - it's what I would go for personally. Reason being that you can drive around at low revs and not have the turbo spool up, so then it'll be as if there is no turbo there, so no fuel econ hit as well as it still being nice and easy to drive.

I'm not sure about this, but I would have thought the exhaust pressure was still spinning the turbo up, but not enough to make boost? I agree with what you're saying though, if I'm below 3,000k I wouldn't be `hooning' and need extra power anyway. :

Personally, I think a supercharger is more suited to a 6 or 8 then a 4, and I'd personally prefer to be able to drive off boost if I want to as you can with a turbo. But I hope I've been helpful in telling you what I'd consider the advantages and disadvantages of each are.

There's a famous turbo six you might be aware of, it's called the GT-R Skyline, and it goes pretty hard. The Saleen has a twin-turbo 7L(?) v8, and that also goes pretty hard.
You could also say a V8+forced induction=crazy amounts of power, which also = insurance cost & labour cost & materials cost...

[Racecraft]

yes a supercharger for a V8 as you only need one... THrow in the v configuration and you'll spend twice as much on goodies....

[b2tf]

Thanks heaps for all the info guys, please keep it coming.

From what you've all said it sounds like a Turbo is a better way to go, Supercharged sounds nicer :P but if a Turbo is a better choice who am I to argue.

Yes Focus off the shelf Turbo kits are available however I dont know much about them or where to even get them - if possible I dont want to have to import stuff myself, Id rather buy it all and get it fitted at the same place if possible. InFocus Motorsport.com.au say they have one coming but there arent many details about it beyond that.

Now realistically what I am looking at for a project like this? I am aiming on a budget of $3k or as close as possible, I think this may be a little unrealistic?

Also, would the use of a Unichip/Aftermarket ECU be required for this sort of thing? I want it to be as simple as possible.

[The MaDDeSTMaN]

Originally Posted by Biggoggs

There's a famous turbo six you might be aware of, it's called the GT-R Skyline, and it goes pretty hard. The Saleen has a twin-turbo 7L(?) v8, and that also goes pretty hard.
You could also say a V8+forced induction=crazy amounts of power, which also = insurance cost & labour cost & materials cost...

Yup, I was just meaning that I think a supercharger is more suitable for a 6 or 8 then for a 4, due to the power being sapped from the engine just to run it - obviously, a 4 has less power then a 6 or 8 to start with, so IMO you don't want to have anything sapping power on a 4 if you can help it.

Of course, turbos can also suit 6s (Typhoon, XR6T, Skyline and MANY others) and 8s (although it's obviously more of a pain to fit a turbo or twin turbo on a V config engine if it doesn't already have one), and an amazing amount of power can be made.

As has been said, it all depends on what you're after.

Oh, and the reason I made such a deal of fuel economy was because, unless I'm mistaken, one of the reasons for back2thefutura buying the focus was because it was more economical to run then the Falcon he previously had.

[b2tf]

Originally Posted by The MaDDeSTMaN

Oh, and the reason I made such a deal of fuel economy was because, unless I'm mistaken, one of the reasons for back2thefutura buying the focus was because it was more economical to run then the Falcon he previously had.

Thats correct. Also wanted a newer car lol.

Sounds like Turbo is the way to go - actually i remember hearing about a Turbo Focus in Adelaide which I think may have been done by CAPA? Does anybody have any details on it? Ive emailed them but I only did it last night so I dont expect a reply just yet.

[MRJUCY]

Ultimately I beleive the autorotor twin screw superchargers are the best form of forced induction as they are more efficient & produce much lower boosted air temps & power loss. They also produce almost constant boost yet have a by pass so on light throttle no boost is entering the engine & it drives & has the ecconomy yet as soon as you stomp on it the by pass closes & you have full boost.
Kenne-Bell makes some great setups with these but unfortunately for you not the Focus so I'd recomend a setup that has already been tried & tested rather then going to the time & expense of coming up with your own solution

[Biggoggs]

Well, although biased, Google turned up this;
http://turbochargedpower.com/Turbo%20vs%20Blowers.htm

Now realistically what I am looking at for a project like this? I am aiming on a budget of $3k or as close as possible, I think this may be a little unrealistic?

Also, would the use of a Unichip/Aftermarket ECU be required for this sort of thing? I want it to be as simple as possible.

a) Probably, b) probably. Forced induction isn't cheap, and your Focus will likely become a bit thirstier. Not sure about the ECU, it's a good idea (along with turbo timers etc, might be a system to cover all the above), but I'm pretty sure it'd be quite a bit over 3k. Call a few tuner shops if you don't want to do it yourself, and get some prices.

[Racecraft]

3k might get you the turbo and some plumbing NEW...

If you are budgeting on 3k B2TF spend alot of time on research, the Focus is 2l, so look around and ask questions on what type of turbo guys are using, the specs of the turbo wether its for a Ford or not the specs will be very close if you stick to EFI 2ltr stockies.

Keep your eyes on EBay or even the ForSale sections of some of the ricer forums, Boost Crusin', Silvia etc for a cheaper kit someone is offloading.

The only thing you'll have to purchase Focus specific (if your not a dab hand at welding)is the manifold.

[Steffo]

Originally Posted by MRJUCY

Ultimately I beleive the autorotor twin screw superchargers are the best form of forced induction as they are more efficient & produce much lower boosted air temps & power loss. They also produce almost constant boost yet have a by pass so on light throttle no boost is entering the engine & it drives & has the ecconomy yet as soon as you stomp on it the by pass closes & you have full boost.
Kenne-Bell makes some great setups with these but unfortunately for you not the Focus so I'd recomend a setup that has already been tried & tested rather then going to the time & expense of coming up with your own solution

No screw-type supercharger will ever be as efficient as a turbocharger.. the extra heat and parasitic loss is inveitable. Just read the site Biggoggs listed.. they've got it spot on.