Can I get a difinitive answer on EGT probe location? - Page 2

White Devil · 02-21-2008, 09:10 AM

There are a lot of theories on this one...people say it gets less fuel, some people say that it's because the exhaust has the longest distance to travel, so there is more backpressure redicing the scavenging effect of that cylinder. It's just one of those wi4erd things about the motor...

It's not a huge difference though, actually, in the grand scheme of things, it's a very small difference, hardly even noticeable.

One of my buddies is a Subie Mechanic and this is what he had to say about it.

06BlUEBOY · 02-21-2008, 09:19 AM

Like one dude said run it on the up pipe that what i was told!

boozy04 · 02-21-2008, 09:49 AM

cylinder 4.

White Devil · 02-21-2008, 09:54 AM

like I said Up Pipe FTW

someone i know just blew a ringland on piston 1 cause of running too lean. He did not have egt but if he did and had it in the UP he might of seen the temp rise. If he had it tapped into the #4 runner he would of never seen it.

Regardless he is in the process of rebuilding another motor he will probably blow up.

helifreak · 02-21-2008, 10:07 AM

Was that on the new, I think Axis stage 4, motor he just built?

White Devil · 02-21-2008, 10:12 AM

no that was on his stock STi.He hasn't built isht yet he is still trying to get the money to do it. No matter what he puts together he will end up blowing it.

blustile2240 · 02-21-2008, 06:19 PM

guys.... I think were all beating the dead horse... I say put it near the collector before the up-pipe. I have heard horror stories when mounted too close to the turbo, but also have heard about "inaccurate readings when cylinders get isolated"..... so, the only compromise I can think of is at or around the collector! just my 2 though... no haters please

xrocket21 · 02-23-2008, 08:10 AM

Well, I put it about 5-6" from cyl 4.

I don't feel like this ever got the definitive answer I was looking for, but I guess it is one thing where there isn't a single "right" answer as i thought. Oh well. We will see how it goes.

Thanks for all input.

helifreak · 02-23-2008, 08:23 AM

Do you even need an egt sensor if you have an A/F anyway? The A/F sensor I would think would be a better indicator since: lean=Hotter & rich=cooler cylinder temps. As long as the A/F is where it needs to be there shouldn't be any issues with cylinder temps.

***ToeKutter*** · 09-01-2008, 08:33 AM

Quote:

Originally Posted by helifreak

Do you even need an egt sensor if you have an A/F anyway? The A/F sensor I would think would be a better indicator since: lean=Hotter & rich=cooler cylinder temps. As long as the A/F is where it needs to be there shouldn't be any issues with cylinder temps.

Sorry for reviving this, but I am curious about this exact same issue. Do you need EGT if you have A/FR probe? IMO, they basically tell you the same thing, except that AFR does it it far greater detail. However, I read some tuner resources that tell you that EGT is a MUST! (How to Tune and Modify Engine Management Systems by Jeff Hartman). Not sure if they were quoting it as a MUST, assuming you don't have a AFR or in addition to it.
Thanks for the input!

merrill0007 · 09-02-2008, 04:35 AM

header all the way. its a pretty easy install took a little over an hour (a friend is always recommended). take you time drilling and taping

LuVJuGGs · 09-02-2008, 02:43 PM

Quote:

Originally Posted by merrill0007

header all the way. its a pretty easy install took a little over an hour (a friend is always recommended). take you time drilling and taping

How the heck did you drill and tap so fast...did you remove the header? if not what about the metal shavings?
Surely there was something on the inside

bluedemon_II · 09-02-2008, 08:09 PM

Well you can drill and tap it in under an hour but it wont be that pretty. Also if you have an A/f in the car then you don't need to have a EGt but it helps. So all in all you can run the 2 gauges and see how the Fuel changes affect your exhaust gas temperatures and know when the mixture is to far gone to the lean side.

Pitcherman · 09-02-2008, 08:38 PM

Putting it in the up pipe won't show that much of a difference if once cylinder starts to go lean, by the time you notice it will probably be too late, if you are using the EGT to help monitor a lean condition in the cylinders then buy an egt gauge made for aircraft that can monitor all four cylinders make sure to get one for a 12v system), otherwise put it by whatever cylinder you want and use your wideband O2.

Tgui · 09-02-2008, 08:45 PM

Quote:

Originally Posted by helifreak

Do you even need an egt sensor if you have an A/F anyway? The A/F sensor I would think would be a better indicator since: lean=Hotter & rich=cooler cylinder temps. As long as the A/F is where it needs to be there shouldn't be any issues with cylinder temps.

Timing, AVCS, etc can play a major role in EGTs.

02-21-2008, 09:10 AM	#16
White Devil Banned Car: 07 Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? There are a lot of theories on this one...people say it gets less fuel, some people say that it's because the exhaust has the longest distance to travel, so there is more backpressure redicing the scavenging effect of that cylinder. It's just one of those wi4erd things about the motor... It's not a huge difference though, actually, in the grand scheme of things, it's a very small difference, hardly even noticeable. One of my buddies is a Subie Mechanic and this is what he had to say about it. This ad is not endorsed by this member. Please register or login to hide this ad.

02-21-2008, 09:19 AM	#17
06BlUEBOY Junior STI Driver Car: 06 Subaru WRX STi Bl Fav Mod: Perrin 35r comin soon... Location: South Carolina Area Posts: 71 Join Date: Apr 2006 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? Like one dude said run it on the up pipe that what i was told!

02-21-2008, 09:49 AM	#18
boozy04 Grassroots STI Racer Car: 07 OBP STi Fav Mod: Valentine 1 Location: NW, Indiana Posts: 516 Join Date: Sep 2005 Trader Rating: (3)	Re: Can I get a difinitive answer on EGT probe location? cylinder 4.

02-21-2008, 09:54 AM	#19
White Devil Banned Car: 07 Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? like I said Up Pipe FTW someone i know just blew a ringland on piston 1 cause of running too lean. He did not have egt but if he did and had it in the UP he might of seen the temp rise. If he had it tapped into the #4 runner he would of never seen it. Regardless he is in the process of rebuilding another motor he will probably blow up. Last edited by Majin : 02-21-2008 at 12:47 PM.

02-21-2008, 10:07 AM	#20
helifreak Junior STI Driver Car: WR Blue 05 Sti Location: Dallas, TX Posts: 135 Join Date: Jun 2007 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? Was that on the new, I think Axis stage 4, motor he just built?

02-21-2008, 10:12 AM	#21
White Devil Banned Car: 07 Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? no that was on his stock STi.He hasn't built isht yet he is still trying to get the money to do it. No matter what he puts together he will end up blowing it.

02-21-2008, 06:19 PM	#22
blustile2240 STI Driver Car: 05 STi Fav Mod: tein Location: Boston, MA Posts: 239 Join Date: Jun 2006 Trader Rating: (3)	Re: Can I get a difinitive answer on EGT probe location? guys.... I think were all beating the dead horse... I say put it near the collector before the up-pipe. I have heard horror stories when mounted too close to the turbo, but also have heard about "inaccurate readings when cylinders get isolated"..... so, the only compromise I can think of is at or around the collector! just my 2 though... no haters please

02-23-2008, 08:10 AM	#23
xrocket21 The Next Petter Solberg Car: 2005 STI Fav Mod: Methanol Location: Boston area Posts: 935 Join Date: Feb 2005 Trader Rating: (5)	Re: Can I get a difinitive answer on EGT probe location? Well, I put it about 5-6" from cyl 4. I don't feel like this ever got the definitive answer I was looking for, but I guess it is one thing where there isn't a single "right" answer as i thought. Oh well. We will see how it goes. Thanks for all input.

02-23-2008, 08:23 AM	#24
helifreak Junior STI Driver Car: WR Blue 05 Sti Location: Dallas, TX Posts: 135 Join Date: Jun 2007 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? Do you even need an egt sensor if you have an A/F anyway? The A/F sensor I would think would be a better indicator since: lean=Hotter & rich=cooler cylinder temps. As long as the A/F is where it needs to be there shouldn't be any issues with cylinder temps.

09-02-2008, 04:35 AM	#26
merrill0007 Amateur STI Driver Car: grey 07 wrx STi Fav Mod: magnaflow exhaust Location: Portsmouth Posts: 41 Join Date: Feb 2008 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? header all the way. its a pretty easy install took a little over an hour (a friend is always recommended). take you time drilling and taping

09-02-2008, 08:09 PM	#28
bluedemon_II Grassroots STI Racer Car: 04 Sti Wrb on Silver Location: Hatillo, Puerto Rico Posts: 501 Join Date: Jul 2007 Trader Rating: (0)	Re: Can I get a difinitive answer on EGT probe location? Well you can drill and tap it in under an hour but it wont be that pretty. Also if you have an A/f in the car then you don't need to have a EGt but it helps. So all in all you can run the 2 gauges and see how the Fuel changes affect your exhaust gas temperatures and know when the mixture is to far gone to the lean side.

09-02-2008, 08:38 PM	#29
Pitcherman Village Idiot Car: 04 JVP STi Fav Mod: Blitz NUR Spec R Location: B.F.E, Texas Posts: 7,960 Join Date: Apr 2004 Trader Rating: (3)	Re: Can I get a difinitive answer on EGT probe location? Putting it in the up pipe won't show that much of a difference if once cylinder starts to go lean, by the time you notice it will probably be too late, if you are using the EGT to help monitor a lean condition in the cylinders then buy an egt gauge made for aircraft that can monitor all four cylinders make sure to get one for a 12v system), otherwise put it by whatever cylinder you want and use your wideband O2.