Turbos - General Question - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

05-19-2002, 16:13

Just wondering if someone can explain to me or point me into a good web site for info on the basics of turbo/superchargers. I understand that they are air compressors, but what sort of setup do they require and how do they add power?

I asked a while ago about adding a fan to the tennis raquet intake to increase flow and that was shot down, but what about one of those 12v tyre pump compressors that claims to be able to cope with all sorts of pressure? would rigging one of these into a CFI make any difference?

Thanks
Simon

CATman · 05-19-2002, 17:40

HAHAHAHAHAHAHAAHAHA, WHAT AN IDEA

05-19-2002, 18:02

hey CATMan, no pickin... I don't have one, so i can't try it, but i'd still like a description or link for info :)

XplodEd EA · 05-19-2002, 18:11

Basically a turbo is an air pump thats hooked up to the exhaust manifold. The flow of the exhaust gases turns a turbine which pumps air via tubing into the inlet manifold, the pressure of air is greater than atmospheric pressure.

I don't think an air pump of what ur describing is gonna be of any use. It wont be pumping enough air for the demands of the engine, with the turbo it keeps up with the demands of the engine as its pumping faster with more revs.

I hope that gave u some idea

Ed

NAPARM · 05-19-2002, 18:28

a turbo forces (hence the term "forced induction") more air into the engine, and more air in the same space equals more power.

05-19-2002, 18:31

yeah, cheers, but what I mostly wanted to know is what the point is. does the turbo give more power at teh same rpm as normally aspirated? how does fuel consumption compare? I'm guessing that the extra power comes from adding more fuel AND air rather than just more fuel.

I'll pick one up during the week and have a go anyway. what are the legality issues/insureance issues. something like this would be pretty easily removable - switched from the dash too.

Simon

Troutman · 05-19-2002, 18:32

To be honest, no matter how many times I have turbo and supercharging explained to me, it never makes any sense.

So you take use flow from the exhaust, and use that to force more air into the engine? The amount of power lost due to restriction on the exhaust should at least equal the power gain to my mind.

But oh well - if it works, it works!

old_mate · 05-19-2002, 19:05

Nah Jack, the turbo's turbine compresses the air by a huge about, the resistance created by the turbo in exhaust becomes insignificant (notice though that 2.5/3inch is pretty much the standard exhaust size if you run a turbo). If you run a intercooler, which cools the air after it leaves the turbo before it enters the inlet manifold, you do notice a pressure drop. In efficient air to air coolers (usually the big bastards you see in the front of VL's/rice) you usually aim to maybe drop half a psi of pressure......

turbo's are great cos they give power for free. They use an engines wasted exhaust gases to create more AIR pressure that gets fed into the Inlet Manifold. Its then your job to match that air with more Fuel. The more boost you use, the more fuel you have to put in. The only real downside to turbos is the heat-exhausts are so hot as it is, then have to get compresses as well, all in a crowded engine bay.....efficient cooling and Intercooling is a must.

A Supercharger is a little different. It runs off the motor's crank usually to create boost. Its hooked up much like a aircon compressor to the cars belt system. As the belt turns, it also then turns the supercharger, which then 'pumps' more air into the inlet manifold. They arent nearly as efficient as a turbo, because you have to create the more power by spinning the blower off the motor, however the boost created should be able to overcome this. The advantage-no heat is created.

Whats better? its a personal thing. Superchargers are easier to install, and are a fairly predictable device. You seem to be able to go a little more crazy with a supercharger before you have to modify pistons and ECU's and stuff. Can get away without intercooling pressurised air, but if you are running high boost it then becomes a different story. The turbo is more expensive, as you usually have to get a custom exhaust manifold made to drive it, you have more parts to but, such as wastegate (determines boost) Blow Off Valve (allows boost to escape when throttle snaps shut so boost wont go backwards into the still spinning turbo-a BAD thing), the use of aftermarket ECU is almost mandatory so it can supply extra fuel, then you gotta get pumps to supply fuel etc etc

Sorry for the long post, its a very un-professionally educated explanation, my own understanding of the topic (remember Im 18 and havent owned a turbo car, let alone know all there is to know about one) however many ppl have asked what a blower and turbo are and my explanation seems to get them on the right track. There are more complex issues like how you run a blower/turbo with a carb setup, etc etc, But I'll save that for another time kiddies.......

If im wrong on any pointers on this, please dont hesitate to publically humiliate me in letting me know.....I can only learn from being told!

Troutman · 05-19-2002, 19:09

That's for that matey. Would have to be the best description on the matter I've read :)

05-19-2002, 19:11

wow! great explanation! The info has been helpful although someone mentioned it a couple of posts ago - the more air you have in the chamber, the higher compression you get and thus more power.

Thanks all.

If I give it a go, I'll let you know what happens.

Simon