Why is the throttle body heated?

[frankiej]

Why is the throttle body heated? How does it effect performance/drivability? What does it do?

Thanks for reading,
Aaron

[d6dph]

It's for severe climates iirc, Not 100% sure why tho. Don't really want to make a tit of myself

[E30Mark]

It's to stop it icing up in cold climates! Because of the effect of drawing in large volumes of cold air through a reduced aperture it chill's the TB potentially icing it up. Had a VW Golf ages ago that used to cut out on long motorway trips didn't realise the warm air pipe to the airbox was missing, so the carb used to ice up.

Never known a TB to actually ice up in this country though...

[frankiej]

Then, I could cap that off and not worry about it with any problems? I don't plan on road tripping to the artic any time soon. Mine has started a slow, steady drip.

[bmwe30mtech]

You shouldnt need this function in Italy i wouldnt guess! I have never heard of a TB icing up, even in really cold climates. Carb engines are far far more prone, hence why they have warm air pipes even on small engines.

A drip from whereabouts?

[d6dph]

It's to stop it icing up in cold climates! Because of the effect of drawing in large volumes of cold air through a reduced aperture it chill's the TB potentially icing it up. Had a VW Golf ages ago that used to cut out on long motorway trips didn't realise the warm air pipe to the airbox was missing, so the carb used to ice up.

Never known a TB to actually ice up in this country though...

I thought it was that but didn't want to look silly if I got it wrong

[E30Mark]

Who say's i've got it right...

frankiej disconnect the water pipes and link them together, it might make a 0.1% difference on performance!

[gooner1]

Why not just leave them attached, not as if they are causing a problem is it?

[daimlerman]

Back in the early '70s when I was tuning an 850 mini,I bought it a one and a half inch SU carb.I was told that this would need a heated inlet manifold to work properly.My Daimler has a heated inlet manifold as well.Current thinking is that cold air is denser(sp?) that warm air,so as I am piping air from outside of the engine bay into the 2.7's TB I have removed the water pipes that heat it.So far I have had no icing problems.I think that the theory regarding carb. fed engines is that the fuel is helped to vapourise by the heating.

[HairyScreech]

well in theory they are heating the inlet charge as it enters the engine.

[Rosc0PColtrane]

You shouldnt need this function in Italy i wouldnt guess! I have never heard of a TB icing up, even in really cold climates. Carb engines are far far more prone, hence why they have warm air pipes even on small engines.

A drip from whereabouts?

Would need it in North Italy.

[Rosc0PColtrane]

It's to stop it icing up in cold climates! Because of the effect of drawing in large volumes of cold air through a reduced aperture it chill's the TB potentially icing it up. Had a VW Golf ages ago that used to cut out on long motorway trips didn't realise the warm air pipe to the airbox was missing, so the carb used to ice up.

Never known a TB to actually ice up in this country though...

I thought it was that but didn't want to look silly if I got it wrong

You're fully capable of looking silly without getting this wrong, you had nothing to lose Dave!

[d6dph]

Shut it.

[Nelly]

@ Dave's expense

[zaust]

What Neil said. ↑↑↑ lol Plus you will proberly notice a sharper throttle response once done due to the colder air intake...

[Brianmoooore]

Back in the early '70s when I was tuning an 850 mini,I bought it a one and a half inch SU carb.I was told that this would need a heated inlet manifold to work properly.My Daimler has a heated inlet manifold as well.Current thinking is that cold air is denser(sp?) that warm air,so as I am piping air from outside of the engine bay into the 2.7's TB I have removed the water pipes that heat it.So far I have had no icing problems.I think that the theory regarding carb. fed engines is that the fuel is helped to vapourise by the heating.

I was tuning minis in the early seventies as well, daimlerman! Carbs did indeed ice up in the winter! Reminds me of the time, when travelling home from Uni at 4 a.m., my throttle jammed wide open in the middle of Guildford. (No M25/M3 in those days!). Had to drive on the ignition key, and every time the ignition was turned on there would be an enormous backfire.
Everyone in Guildford was awake early that day!

[binxy69]

I disconnected mine on my 325 4dr with the intent of getting coldest possible intake using a ram air kit and some mods. Never had any problems with it. Just joined the two pipes together with some gas piping and two jubalee clips.

[daimlerman]

Back in the early '70s when I was tuning an 850 mini,I bought it a one and a half inch SU carb.I was told that this would need a heated inlet manifold to work properly.My Daimler has a heated inlet manifold as well.Current thinking is that cold air is denser(sp?) that warm air,so as I am piping air from outside of the engine bay into the 2.7's TB I have removed the water pipes that heat it.So far I have had no icing problems.I think that the theory regarding carb. fed engines is that the fuel is helped to vapourise by the heating.

I was tuning minis in the early seventies as well, daimlerman! Carbs did indeed ice up in the winter! Reminds me of the time, when travelling home from Uni at 4 a.m., my throttle jammed wide open in the middle of Guildford. (No M25/M3 in those days!). Had to drive on the ignition key, and every time the ignition was turned on there would be an enormous backfire.
Everyone in Guildford was awake early that day!

The only time that I experienced carb. icing was in the winter of '70,I delivered the girlfrend of the day to her home somewhere in the Bristol area and tried to drive the mini back to RAF High Wycombe.It was in January and bloody cold!!(leans on walking stick)we do not get winters like we used to!!

[gareth]

the GT twin choke weber on my mk2 escort 1300 used to ice up when it was snowing. it was funny, it would ice up on the first choke leaving idle and the second choke working fine. made for fun trying to control a rwd car in the snow with nothing between idle and full throttle!

[Heyho]

The throttle body isn't really on the coolant circuit to prevent icing, but to prevent condensing of the blow-by gases fed into the housing via the breather pipe. It stops the oil and water vapors congealing and blocking the feed hole.

I doubt there would be any discernible difference with it disconnected. I blanked mine off when I had my 520i, as it was leaking, and I couldn't be bothered to fix it.

[frankiej]

Wow, I didn't expect so much traffic on this thread. Thanks a lot everyone. Yeah, as I said before, mine has got a drip. It looks like I'll be tapping my two hoses into each other and going from there. It kind of bothers me that it warms the intake charge any ways. That seems a little anit-productive to me.

[daimlerman]

IIRC it's 8mm internal diameter hose,I bought a short length from the local motor factor.You can eliminate two joints that way...

[frankiej]

IIRC it's 8mm internal diameter hose,I bought a short length from the local motor factor.You can eliminate two joints that way...

That's the same idea that I had actually. I suppose that great minds DO think alike.