Terminology

[TiG]

I hope this provides some amusement for you all, but i've got bugger all idea what Zak was going on about here....

"yes.....the heat from the exhaust manifold will RUIN cold air intake.... its a hard job though.....do it OFF the car.....

when cars have Cross Flow heads......ie exhaust mainfold on one side, inlet the other....the heat isn't a problem....

but ....when onew influences the other to such an extent.....the induction temp suffers badly.

Get it shielded right fown to under the car.....it'll help performance"

Maybe i need a crash course in car terms
Analogys to computer parts is more than welcome....

TiG

[[GSV]Trig]

A cooler CPU is better than a hotter CPU, this is likable to the induction temperature...

If your case temp is high your CPU will be higher as result, same with induction...

[kaillum]

Originally posted by [GSV]Trig
A cooler CPU is better than a hotter CPU, this is likable to the induction temperature...

If your case temp is high your CPU will be higher as result, same with induction...

nicely put there Trig.... couldnt have put it better meself.

[TiG]

i kinda got that one, Trig, i was looking for a little bit more detail.

"Cross Flow heads" etc is more what i'm interested in understanding...

TiG

[sdp]

Cross flowed heads:

This are where the inlet manifold is on one side of the engine and the exhaust is on the other side, there is usually one branch per cylinder. Some cars, such as the mini have both manifolds on the same side of the engine, in the case of the mini the exhaust manifold has 3 branches (the middle cylinders share the middle branch iirc) and the inlet manifold has two branches, each one feeds a pair of cylinders. Obviously, the cross-flow head is more efficient. The 5 port design of the mini saves a lot of space in a cramped engine bay but the two manifolds are right on top of each other so the induction system gets blasted with heat from the exhaust manifold.

I'm still learning too though There's a diagram of a crossflow design here Click on engine and then its halfway down the page.

Look at this pic and you can see the inlet is right on top of the exhaust manny.

/Got a horrible feeling all that's wrong

[Lowe]

Why induction temperature is important...

Induction is the intake of air. An engine needs air, and the best possible temp of air being taken in, is as cool as possible. The reason comes down to a simple bit of physics.

The cooler the air is, the more dense the air becomes. The more dense the air is, the more oxygen it contains. The more oxygen it contains, the more fuel we can add to the mixture in the engine. The more fuel we add the more power we get out the engine.

So, in simple terms:

Cold air induction =

So.. Zak was saying, if you can stop all the heat getting out from the manifold, then the air being sucked in from under the bonnet will be cooler.

On a side note, this is why forced induction is really kewl. The turbo/supercharger is basicly a compressor which makes the air super dense. As before, the greater the density of the air the more fuel we can add, leading to a bigger .

[TiG]

Thanks Lowe and SDP, i didn't make much of those pictures and i hate the term manifold, but i think i understand a lot more.

TiG

[Zak33]

Originally posted by Lowe
On a side note, this is why forced induction is really kewl. The turbo/supercharger is basicly a compressor which makes the air super dense. As before, the greater the density of the air the more fuel we can add, leading to a bigger .

BIGGEST PROB....TURBOS ARE HOT.....cos they are spun by EXHAUST GAS.....which is wickedhot.....and that causes the Turbo casing to be red hot...that makes the induction air hot

hence an INTERCOOLER to chill the air again....

[[GSV]Trig]

Speeding up the air also makes it hot, turbo's are bad tbh, you want N/A power all the way

[Russ]

yea but you have nos to cool the heat the turbos create

[Lowe]

Originally posted by Russ
yea but you have nos to cool the heat the turbos create

Err, not quite...

To cool the intake charge, you use water injection. And yes, that's exactly what it says on the tin. You have a small fine mister added along the pipe where the air induction line and water is misted in. This cools the hot air down even further, meaning you can play around with the ignition timing even more, and really wack the boost up to silly levels. Of course it only lasts as long as your water bottle lasts so you have to be careful.

NOS however is a catalyst, it helps the fuel burn more efficiently.

[Big RICHARD]

The decomposition of N20 at high temperatures (above 400 deg.C) is explosive.

The higher the temp the more vigorous the decomposition. the decomposition is exothermic, meaning once it starts it get hotter and hotter and faster and faster and more and more explosive!

Plus as Lowe says, it acts as a catalyst for the fuel.

[Russ]

nos its actcually dangerous tho is it? didnt think it was explosive unless used incorrectly????

[Big RICHARD]

It's what's used as 'gas and air' in hospitals.

In high concentrations it poisonous. It's explosive in certain conditions.

See here

[Russ]

ah, so it isnt actually flammable but it works as an igniter. I was under the impression that when its heated it splits, so the oxygen aids the burning, now i know that the nitrogen ignites it all. great stuff

[Big RICHARD]

When it is heated it does split in to oxygen and nitrogen. (You get twice as much nitrogen as oxygen)

This oxygen then helps the petrol burn better. The splitting part is also explosive, so it gives even more of a boost.