HI,was wondering especially for warm days would it be worth bypassing the coolant going through the throttle body,a mate of mine has done it on his intergrale but was wondering if it has being done on a coop as a way of reducing intake temps??? G

I know Nigel has done this. He says no negative effects at all.

James

oh ok, may give it ago, would be interesting to see if it makes a difference to the inlet temps .

I've done it too. I bought a metre of alu tubing (from B&Q) and fitted it across the fuel rail instead of the rubber hose. I reckon it does make a little difference - but as my inlet temp sensors are before the throttle then I can't measure the difference.

Chris

P.S I also polished up the ally pipe

I did this years ago to my 16v, not had any problems with it. The feed is generally for a lot colder climates where the throttle plate may stick due to the low temps.

The best compromise is to have a switched bypass that activates when the engine is above say 60 degrees and thereafter the throttle is bypassed.
Bear in mind it may throw your maps out a bit.

I have just found out about this little "mod" and will give it a go. Sounds like a bit of a free upgrade. Seems a bit odd to cool the air temps down with the intercooler then have it warmed back up again as 90C coolant courses though the throttle body. I found this link from another forum on a test on an Evo.

Any one got some pics of this mod??

If you look at the throttle body Marco you can see a pipe leading from the 'stat which goes into the right hand side of the TB. Another pipe comes from the left hand side and then crosses the inlet plenum and goes into the top of the expansion tank.

I tested this from a cold start and this pipe heats up with the rest of the coolant. So bypassing it either by joining the two pipes or by replacing both as Nobby has done is worthwhile. Not sure that there would be enough original pipe to join them, but they may *just* stretch to be able to join.

I shall have a look today!!

Good idea any way!!

I did this years ago - the two pipes WILL stretch so that you can join them with a pipe connector

I've suffered no ill-effects, even in deepest winter

Better get busy then!! Thanks people!!

Also did you block the feed into the throttle housing with some thing?
Or just leave it open/unblocked!!

just leave the throttle body pipe open - not a problem

Thanks!!

I believe the coolant is fed through the throttle body to avoid the risk of it freezing up and getting stuck. Very low chance of it happening but even one Toyota style accelerator incident is one too many.

The velocity and mass of air flowing through the throttle, I very much doubt you will gain anything from this mod on back to back testing.
The water is designed to heat the throttle housing to prevent icing, not heat the air going through it.

so there is no point to it!?

i just saw it as a heated throttle body meets cold air = warm air!!

but htinking about what your saying Jimbo... you have a point... so much air goes into it, i doubt it will have time to heat up!!

Most you boost pipes are next to a hot engine at about 80-90°C might as well insulate these.

What's best to use?

if there is heat in the throttle body there will be heat transfered to the inlet and then through you induction pipe work and i know this is a bad example but a sound one.

with air moving fast it will still get hot if the surrounding areas are hot as the air molecules will come in contact with heat and get hot physics 101 and just think of a hair dryer it has fast moving air going through only being in the hair dry for a split second per molecule but yet gets the air really hot and you press to cool button and the air goes cold.

the only real remidy to get colder air removing the water pipes from the inlet will help but not on its own you would have to move the battery into the cab or boot and move you induction pipework away from the engine.

But you have a red hot filliment in a hir dryer with a much larger surfice area, and the mas of air through the throtal body at 6000RPM is far far higher.


Not sure been looking about for something cheep and shiny on the out side, like pipe lagging only bigger.

Ummmm, a hair dryer is a 2KW device with a matrix designed to rapidly heat air so obviously that's what it's going to do.

A small water rail in a throttle body designed to prevent ice by using 86'C water isn't going to have the same effect no matter how much molecule science you throw at it. The throttle won't be at 86'C that's not what it's designed to do, it's designed to keep it above 0'C.

Do a back to back test on the rollers, I'll eat my own head if you notice a difference

I think you would be better off removing the pipes that connect to the throttle as weight saving. You see the 100g will give a lighter car which means it will be faster

Basically what I'm saying is even though the theory is correct it will make no difference in the real world and even if it does it will be so small it's pointless. I would be surprised if you noticed a 0.5C difference in air temp (which is less than the tolerance of the sensor anyway). In fact even doing a back to back dyno run wouldn’t be sufficient proof as you would not be able to keep anything constant enough to measure an accurate change.

I personally would leave this alone.

like i said bad example, the point is that air molecules rapidly heat and cool, so removing the heat source to the inlet will help a little maybe upto a few degrees but to get the full benifits like i have stated above you need to move all you incutcion pipe work away from heat sources and the best bit of kit on the market is a Cryo2 intake system fitting this alone is better than a charge cooler and more compact under the bonnet and with a fmic in place and the rad pipes from the inlet will greatly improve performance and reduce intake temps.

It can only lower the intake temps by removing it, so, ... get rid of it.

No need to go all theoretical about it.

sorry dink my geek glasses came oout of the cupboard