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intake air temps?

Posted: Tue Nov 20, 2007 11:20 am
by buzzard
reading of 45C on vagcom

this is never right is it.---- its 5C outside.

currently lookin for a boost prob.
done a log 003 for maf and this seems ok. 215g/s for standard car
but 115 log --boost actual and required is all over the place.
think i might have a leak appeared.
will check all the usuals.
(feelings of ticking time bomb.)

RE: intake air temps?

Posted: Tue Nov 20, 2007 1:00 pm
by CliveH
It's possible if you're not getting proper cooling.

Can you post your logs up please?

RE: intake air temps?

Posted: Tue Nov 20, 2007 7:26 pm
by shineydave
whereabouts is the inlet temp measured?, if it's after the intercoolers (as i would think makes sense) then the air has been through the turbos so it's not surprising it's warmer than ambient

Posted: Tue Nov 20, 2007 9:29 pm
by Jarv
I'm watching this thread with interest as I am very keen to find out what intake temp levels other SMIC equipped cars are running.

On my FATS run after my dyno session at Thorney on Saturday, I got a peak intake temp of 45 degrees, bang on what you got Buzzard. I also had my intake temps logged on my dyno session, and it peaked at over 90 degrees due to the inability of the fans to get sufficient air through the SMIC's.

I'd also like to know a bit more about what is an acceptable variance between actual and specified boost, and what the causes and consequences are of exceeding the recommended variance. Be interested to see your logs to see if your variance is similar to mine.

Posted: Tue Nov 20, 2007 11:56 pm
by CliveH
The Intake Air Temperature Sensor (G42) sits after the intercoolers (in the inlet manifold), which is why such high temperatures are being observed (as Dave says, air cooled after being through the turbos).

During the FATs runs at Thorney, typical IATs were in the range of 29 to 45C on the K04/RS4 cars.

Posted: Sun Nov 25, 2007 1:33 am
by buzzard
sorry for the interlude guys but i’m off my feet at the mo.
and yes...you’ve guessed it.
she is back on form.(always the same when your trying to draw a conclusion or a diagnosis of any kind)
temp logs were an average of 30 down to 26 on wot and can only think that heat sink caused the 45C temp.... but interestingly coming down hill for a while on overrun you would expect the temps to fall (reduced forced induction temps and all) but temp still stayed at 28-30)
boost figures for aquired and actual have also returned to within a smidge of each other so
seems that my boost prob has also vanished..and as before the air flow is 215g/s(normal for stock)

i hate speradic faults....

(have to let it develop)
i do run a cheese style air filter box though(full of holes) and i think that this is definately more suseptable to heat sinking than a standard airbox...if the turbo fairy comes i’m going to improve the intake for this reason..

Posted: Tue Jan 08, 2008 5:08 pm
by Blue_Thunder
buzzard wrote:interestingly coming down hill for a while on overrun you would expect the temps to fall (reduced forced induction temps and all) but temp still stayed at 28-30)
Once the inlet manifold gets warm, would this affect the measured IAT?

The last time I ran FATS in my K04'd S4, I think my IAT's were around the high 40's.