VauxSport - Vauxhall advice and chat forum

deek · Joined: 11 Dec 2006 Posts: 186

i want to put my airflow metre on the boost side instead of the intake side,as it has a couple of benifits to me but what are the problems that will efect performance by doing so?
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wayne451 · Posted: Wed Feb 21, 2007 9:56 pm Post subject:

It's also known as a hot wire sensor I believe so I am sure that putting it on the hotter side where gasses are compressed won't be ideal for it as I suspect it would reduce it's life expectancy!

Why do you want to do it? Confused

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stupink · Posted: Wed Feb 21, 2007 10:03 pm Post subject:

It "works" but i'm not sure on the longterm inplications, I would think the constant bombardment with oily crap probably enough reason not to do it.

deek · Joined: 11 Dec 2006 Posts: 186

shouldnt be any oil not for a while anyway as the turbo is brand new and iv no breather pipe into intake either,will eventualy be goin aftermarket managment anyway so not to worried about long term
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1/4m 13.7@107mph in my 97 vectra arctic

tathan · Joined: 11 Oct 2006 Posts: 3792 1997 Vauxhall Corsa

it won't work on standard management, and if you're going to aftermarket, chances are you will be dropping it anyway.
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chip · Posted: Thu Feb 22, 2007 1:34 am Post subject:

Would definately need a total remap, if you just move it and try and use the existing phase chips or whatever it will be a mile out on the fuelling.
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Under 400bhp makes baby jesus cry.
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Nova - 457bhp - Mid Engine - RWD - GT35 - Autronic SM4

wayne451 · Posted: Thu Feb 22, 2007 1:41 am Post subject:

Chip, I wanted to throw fueling in earlier but felt it out of my depth.

Am I right in thinking that as it is judging both temp and air quantity that it would cause it to run leaner? question

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I wish I had been lumbered with a BMW to impress the ladies as opposed to my massive cock.

tathan · Joined: 11 Oct 2006 Posts: 3792 1997 Vauxhall Corsa

It works by heating a wire, you've already said that. It judges airflow by how quickly the wire cools (because resistance changes). If the inlet temps are 60deg and compressed to twice atmospheric, it'll be miiiiiiiiiiiiiiillleeesss out.

The wire won't cool enough I'd imagine, even the denser charge won't save it, so it won't see enough air and will run massively lean.
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chip · Posted: Thu Feb 22, 2007 1:55 am Post subject:

Wire will still give a meaningful value I would expect, just not the same meaningful value as on the other side of the turbo, with a remap im sure it would be fine.
_________________
Under 400bhp makes baby jesus cry.
(so my boost leak at the jamsport day must have had him sobbing like rich j williams watching a chick flick)

www.totalvauxhall.co.uk

Nova - 457bhp - Mid Engine - RWD - GT35 - Autronic SM4

wayne451 · Posted: Thu Feb 22, 2007 1:57 am Post subject:

Cheers Tath, I was right! Thumbs Up

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I wish I had been lumbered with a BMW to impress the ladies as opposed to my massive cock.

tathan · Joined: 11 Oct 2006 Posts: 3792 1997 Vauxhall Corsa

It'll still change with airflow yeah, but the variance in inlet temps might cause problems?
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Haynzee: 'oh if using bender like mine...'

chip · Posted: Thu Feb 22, 2007 2:09 am Post subject:

If the air temp sensor is moved up with it, it shouldnt be a million miles out, but it would still need a remap for certain to work properly.
_________________
Under 400bhp makes baby jesus cry.
(so my boost leak at the jamsport day must have had him sobbing like rich j williams watching a chick flick)

www.totalvauxhall.co.uk

Nova - 457bhp - Mid Engine - RWD - GT35 - Autronic SM4

stupink · Posted: Thu Feb 22, 2007 12:55 pm Post subject:

The airflow meter has a temperature sensor before the hot wire IIRC, so wouldnt be too fussed about the temperature change. The car will run with it there, and run "ok" but unless you physically HAVE to put it there for fitment reasons I would leave it pre-turbo.

MarkyG · Joined: 15 Nov 2006 Posts: 657 Location: Newcastle

resolution of the sensor will be shit, and the temperature of the air will be increasing with boost, unlike pre turbo when its always more or less the same.
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deek · Joined: 11 Dec 2006 Posts: 186

it is partly for fitment reasons,would stu at msd be able to remap to work better there?
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1/4m 13.7@107mph in my 97 vectra arctic

wayne451 · Posted: Fri Feb 23, 2007 12:55 am Post subject:

If you plan to go to aftermarket management, why waste 600 quid or so on mapping an ECU which will have an extremely small pool of potential buyers, it's not like everyone has their AFM post-blower so you will be lucky to sell it on, especially as it is far more specific than a generic off the shelf chip.
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I wish I had been lumbered with a BMW to impress the ladies as opposed to my massive cock.

Stuart · Posted: Fri Feb 23, 2007 9:58 am Post subject:

even manufacturers dont have the afm post turbo...

a more modern AFM would be better that isnt a full on hotwire monster unit that we have at the moment, but you'd need to recalculate the transfer function for it to read accurattely
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