TECH TALK - ask your technical car questions

[PSZeTa]

bike engines rev ALOT higher.

yes, but thats mainly because the bike's engine is alot smaller

F1-engines deliver 800bhp with 2400cc and can do over 18k rpm.

How's that?

[boganbusman]

Bikes also weigh a LOT less, so dont require the torque that a car engine needs.

yes, but still, its a big difference. And im only discussing the engine here....

Yes we are talking about the engine, but you need to consider what the engine is being used for.

[RVD]

bike engines rev ALOT higher.

yes, but thats mainly because the bike's engine is alot smaller

F1-engines deliver 800bhp with 2400cc and can do over 18k rpm.

How's that?

thats because theyre only designed to run for 2 races, and they're extremely expensive (extremely heavy-duty materials), way too expensive to build into your average supercar....

[boganbusman]

Well we've answered your question.

Bike engines make more power because they don't need much torque. When you build an engine you have to make a compromise between power and torque, and the major deciding factor is how much weight you need to push around.

[RVD]

thx again, and ive got jet another question....(hope u dont get bored...)

how does a rotary engine work?

[boganbusman]

Read the whole thread, we've already answered that one.

can anyone explain me how the rotative engine from mazda rx8 works

http://auto.howstuffworks.com/rotary-engine.htm

[RVD]

Read the whole thread, we've already answered that one.

can anyone explain me how the rotative engine from mazda rx8 works

http://auto.howstuffworks.com/rotary-engine.htm

dang, srry

[RVD]

whats the difference between a supercharger and a Turbo???

i know a turbo slams more air into your engine, which makes the fuel burn more efficiently and better ( right??) but i dont know what a supercharger exactly does

[xHaZxMaTx]

Turbochargers use the exhaust from the car to spin the blades that force air into the engine.

Superchargers are spun by a belt connected to some part of the engine, I don't remember.

...I think.

[darknight788]

yes superchargers are connected via belt to the engine that spins a turbine mounted usually on top of the engine, the downside to a supercharger is it robs HP and the good side is it makes instant power. however instant power can be achieved with twin turbos by having one small turbo and one large turbo you will make boost throughout the entire rpm range. single turbos generally do better on smaller engines b/c they make most of their power in the higher rpm's. superchargers generally do better on bigger engines b/c they make most of their power in the lower to mid rpm ranges

[Driv2Slow]

basically- superchager: brings air into engine. turbo: gets rid of extra, uneeded waste via exhaust

[PSZeTa]

Biggest nonsense I've ever heard.

[darknight788]

@ Driv2Slow superchargers and turbos both bring air into the engine, and on a turbo charged vehicle the exhaust is not really waste because without it the turbo would not work . and all cars no matter what get rid of uneeded waste via exhaust

[boganbusman]

There are different types of superchargers too.

The ones you see stuck on the top of the engine are usually a Roots or screw type blower, and you can also get centrifugal superchargers that look just like a turbo, except without the turbine housing. There are still even more different types, but those are the most common.

Supercharging will generally produce more torque in the lower rev range, but they still increase max power in the top end. It is also usually cheaper.

Turbocharging will generally produce more power in the higher rpm range, although it varies greatly on the size of the turbo.

[xturbo]

also, which of both consumes more gas? the turbocharger or supercharger???

[boganbusman]

also, which of both consumes more gas? the turbocharger or supercharger???

For everyday driving a turbo would probably use less, because it doesn't kick in until you reach higher rpms. When you are driving flat-out, both will use lots of petrol, but there are too many variables to say which will use more.

[darknight788]

youd think a supercharger would consume more gas because it is engine driven and therefor robs horsepower, a turbo just runs on exhaust gases not robbing any horsepower

[boganbusman]

But a turbo can still use loads of petrol, for example an Evo FQR400 gets 4mpg when you drive it hard.

[steelsnake00]

by having one small turbo and one large turbo you will make boost throughout the entire rpm range.

Not entirely true, a TT system usually cuts down the lag before boost is supplied, rather than removing it completely.

[darknight788]

yes thats what i mean your are not going to cut lag down to nothing you would have to have a very small and light turbo but you can get it pretty close with complementing twins with VVG

[steelsnake00]

True.
Well, it is possible to remove lag totally; there have been several ways, one of which involves retarding the engine timing so far that the main combustion is when the exhaust valves are open; this increases density and pressure in the manifold and kicks the turbo into life
Unfortunately, unless you want 500-mile intervals between turbo changes as 0mpg, it isn't exactly the way forward.

[darknight788]

hmm yes that would be bad, since most cars/trucks are not twin turboed id say the best thing to do is have a VVG turbo that gives good low end and good highend at the same time, its better than blowing up turbos every 500 miles

[vanyots]

Check the new VW Golf GT 1.4 TSI:
Technical highlights

It combines supercharger and turbo with direct fuel injection.

[steelsnake00]

Apparently, the VW Iroc (New Scirocco) is going to have a 261bhp version of the 1.4 TSI engine.

[darknight788]

GAWD that thing is going to be so quick superchrager/ turbo combo sounds kinda cool IMO