Superchargers and Blowers

[zerfetzen]

What's the difference, or is there any?

[Oldschool]

Generally speaking, a turbocharger gets it's boost by the exhaust gases spinning up a turbine.  That turbine then is attached to an impeller that blows pressure to the induction side.  Turbocharger = exhaust gas driven.  Turbos have an off idle lag that a blower does not have---but great gains have been made in reducing this "turbo-lag"
A blower is driven by a belt or gears from the crankshaft. The crank turns the blower which has implellers that force air/fuel into the induction side.  Blowers do not have the same off idle lag as the turbos, but they in turn use engine horsepower to turn the blower.  While there are many exceptions to this rule, generally---blowers are more widely used in drag racing applications and turbos are used where instant "off-idle" response isn't so important.   (Turbo guys---I know that there are a lot of very fast cars running turbos at the drags---don't flame me---I did say there are many exceptions---hehe)  Just my take on the difference between the 2......        

[Killer_Mopar]

Well since Oldschool explained turbos and blowers, I will explain superchargers. Generally speaking when someone refers to a supercharger then they are talking about a belt-driven device that is mounted at the front of the engine (like an alternator, compressor, or power steering pump). Blowers are mounted on top of the engine (where the intake manifold is) and turbos are mounted right after the exhaust manifold. Anyway, a supercharger has a lot of the characteristics that a turbo has except that it doesnt have as much lag. Superchargers are nice because they come as kits and usually fits under the hood, however they have parasitic losses just like a blower and are not used in high-boost applications. Forced induction is a huge topic that is a lot easier to explain with pictures, diagrams, and charts....so if you want to know more about the advantages of a certain type then your best bet is to go to a place like howstuffworks.com

[heminut]

Supercharger=Blower, they both refer to the same thing and the names are interchangeable. A CENTRIFUGAL supercharger/blower bolts to the front of an engine like an alternator or powersteering pump. A ROOTS style supercharger/blower bolts onto the intake manifold. Both are belt driven. The centrifugal unit usually blows through the carb, and the roots style usually draws through the carb.

A turbocharger is basically a centrifugal supercharger with an exhaust driven turbine attached to it to turn it rather than using a belt, and they are usually set up to blow through the carb.

[willhaven]

I've heard that turbo lag can be significantly reduced with a twin or sequential turbo setup. You also have to make sure you're using the right size turbos for the job.

I guess turbos aren't more widely used because they require more fabrication work. My best guess anyway.

[JimCuda]

I would like to see a supercharger setup that is ready to go for a small block under or at 2k. You wouldn't think there would be such a price difference between turbos and superchargers.Much like everyone knows, one works of a belt (SC) and the other works off exhaust (T). The devices seem to be close in match Centrifugal Superchargers and typical turbos (T25, T28, T3/T4's).

However the cost is much greater for that of the centrifugal superchargers. Do a quick search on ebay will show you a Turbo will range from $130 (used) to ($500) new, where as a Centrifugal will range you well (and I do mean well) beyond that amount.

I'm still looking around for an affordable supercharger setup for my small block.

[wart1de]

Cost and difficulty ( fabrication, fitting etc ) are the reasons people don't often use turbos on v8s. Superchargers are just so much easier to install.

As far as turbo lag goes, the bigger the turbo, the more lag. Like Willhaven said, you can use two smaller turbos instead of one big one to try and reduce lag. Huge intercoolers ( which you see on ricers ) also cause some lag. The majority of ricers out there have intercoolers which are much bigger then they need and this causes lag/performance loss but they think it looks good to have a cooler sticking out the front of the car so they keep it. That or they have no idea!

At the track where your launching at 3500rpm+ theres no such thing as turbo lag because the turbos are already up to speed from the get go. It is on the street that you may notice some lag when the engine rpm is low. Acceleration will be slow until the turbo starts to spin at the required speed to pump air into the engine. However, with todays turbo technology and a good setup you won't notice much lag even on the street. In saying that, a poor turbo setup ( wrong size/type of turbo/intercooler/pipes etc. ) may have lag which is unbearable. Much like putting a set of fully ported 340/360 heads on a stock 318 bottom end.

[wart1de]

However the cost is much greater for that of the centrifugal superchargers. Do a quick search on ebay will show you a Turbo will range from $130 (used) to ($500) new, where as a Centrifugal will range you well (and I do mean well) beyond that amount.

I think the reason the turbos themselves are cheap in comparision is because the japs have flooded the world with them.

[cuda340shaker]

It wouldn't be too hard to find a vortech or paxton supercharger used on e-bay or craigslist for cheap. There's TONS of Mustang and Camaros out there that have had them on and been wrecked. Make some brackets and fab up some intake piping and there you go. You can buy a carb hat from vortech or ati.

I like turbos better myself, due to the fact that they don't run out of steam at the top end. Also, on a decent V-8 the lag would probably go un-noticed with the right sized turbo because the torque is greater than in a 4 banger. I have an SRT-4 with a big turbo, and it starts to spool around 2200 rpm and I get a full 22psi by 3500. If I want more I just push a couple of buttons on the boost controller and there it is.  I can also make my car have different boost levels depending on what gear I'm in to maximize traction. You cant do that with a supercharger. You have to play with pulleys and belts, which is okay, but you're still limited to what you can do.

[wart1de]

The guys winning the dyno competitions in Australia are running twin turbos over superchargers.. They are making 1500HP+ at the wheels from small blocks.

[JimCuda]

got a link on the twin turbo guys?

 

[zerfetzen]

Thanks guys, this is a great discussion!

[wart1de]

This is the homepage of the guy that seem'd to have started the twin turbo craze.. Unfortunately he crashed his car into a wall and is no longer with us.. but his family have kept his website up.

http://www.twinturbov8.com/