GavinL Posted November 4, 2001 Share Posted November 4, 2001 Question for those with EGT gauges, where do you have your probe installed ? Having had a bit of a scout round on the US lists and there appears to be no consensus. Choice looks to be between the manifold and on the downpipe. Any advise greatly appreciated Quote Link to comment Share on other sites More sharing options...
Guest Supragirl Posted November 4, 2001 Share Posted November 4, 2001 I believe ours is on the manifold...Chris Wilson fitted the probe didn't take him very long, and he has got all the right equipment for it. Quote Link to comment Share on other sites More sharing options...
Branners Posted November 4, 2001 Share Posted November 4, 2001 The best location is naturally in the manifold pre-turbo. This has inherent fitting problems in that you either have to take the turbos off to do the work, or have a specific process which ensures none of the swarf gets in to the manifold where it would make its way in to the turbos. As a cheaper alternative you can get a probe taped in to the downpipe and work on the principle that you need to be at least 100-150degrees below the normal recommended EGT limits. JB Quote Link to comment Share on other sites More sharing options...
Doughie Posted November 4, 2001 Share Posted November 4, 2001 from what i've heard, the EGT probe needs to be as close as poss. to the combustion chamber in order to give an accurate reading. Even putting it in the downpipe will give a lower reading due to exhaust gases cooling slightly. but i'm no expert. Gav - i'll try to find a post by Chris Wilson and post the text up here. Quote Link to comment Share on other sites More sharing options...
GavinL Posted November 4, 2001 Author Share Posted November 4, 2001 cheers Stu (Edited by GavinL at 12:05 pm on Nov. 4, 2001) Quote Link to comment Share on other sites More sharing options...
Guest Supragirl Posted November 4, 2001 Share Posted November 4, 2001 Yes on the exhaust manifold, Chris W did an excellent job fitting it. Quote Link to comment Share on other sites More sharing options...
GavinL Posted November 4, 2001 Author Share Posted November 4, 2001 Quote: from Supragirl on 12:08 pm on Nov. 4, 2001[br]Yes on the exhaust manifold, Chris W did an excellent job fitting it. I read on the US site that on the pipe coming out of number 6 piston is the best place. However the end of the exhaust manifold sounds like the easiest. Quote Link to comment Share on other sites More sharing options...
Doughie Posted November 4, 2001 Share Posted November 4, 2001 Chris Wilson on EGT install : > On a MkIV is it possible to put the probe in top of the first section of > downpipe after the cast manifold, or is that just too far away to get a good > reading? If you mean AFTER the turbos this is no good. The turbos take a lot of heat from the exhaust gasses and also act as thermal dampers. You must probe before the turbos, as near to the ports as possible. Pro dyno sessions on new engine configs will probe each port individually for mixture and EGT. and C.Wilson again on EGT temps (these are in FAHRENHEIT, not Celsius !!) About 1000 is fine idle pottering temp, 1400 is getting pretty warm, sort of hard running temp, 1800 plus is meltdown time ;-) All in degrees Fahrenheit. Quote Link to comment Share on other sites More sharing options...
GavinL Posted November 4, 2001 Author Share Posted November 4, 2001 Quote: from Doughie on 12:14 pm on Nov. 4, 2001[br] Chris Wilson on EGT install : > On a MkIV is it possible to put the probe in top of the first section of downpipe after the cast manifold, or is that just too far away to get a good reading? If you mean AFTER the turbos this is no good. Hmmm...confused now, doesn't that contradict what CW did to Martin's and Emma's car...or am I being my normal dim self? Quote Link to comment Share on other sites More sharing options...
Doughie Posted November 4, 2001 Share Posted November 4, 2001 think Chris W. is saying that the EGT probe should be tapped into the exhaust manifold as close as poss to the cylinder head/block, before the turbos and before the downpipe. (to be honest i'm not even too sure where the turbos *are* in this whole arrangement ! does the exhaust partly go to the turbos and partly down the downpipe ? Who are you going to get it done for you Gav ? Quote Link to comment Share on other sites More sharing options...
Doughie Posted November 4, 2001 Share Posted November 4, 2001 some more info from others about EGT maximum temps. Arnout and Justin both say "950 deg. Celsius is absolute MAX." (950C = 1742F). also: "925 max. is preferable which is 1700F." and from Nathan : Does anyone know what the 'safe limit' is for EGT's on a MK4? My gauge is plumbed in before the turbo on the manifold if that makes any difference to readings. >> Hi Paul, Well, my recommendation is 950 deg.C. My personal highest is 925 and that was flat out from 2nd to just changing into 6th. It may have gone a bit higher in 6th but I never got the chance. I'm happy that for the amount of time I am ever likely to be in 6th the EGT's would be fine, though I would like to do a re-test on a stinking hot day just to be sure. If it does start creeping up to say, 975 for any sort of real time I may need to use intercooler water spray (a use for the headlight washers I 'spose!) , or as a last resort, water injection. Cheers, Nathan. (Edited by Doughie at 12:47 pm on Nov. 4, 2001) Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted November 4, 2001 Share Posted November 4, 2001 The exit of cylinder No.6 would be the best place for the EGT probe as it is the hottest point (EGR). However mounting it there would be pretty involved. Ours is mounted just after No.1 exit close to the join with the No.2 runner. It took CW hardly anytime to do the tapping and mounting at this point. I did mean to take some pic's but sort of forgot chatting etc. I think nearly all the guys in the states who have mounted their's in the downpipe have regretted it. Quote Link to comment Share on other sites More sharing options...
GavinL Posted November 4, 2001 Author Share Posted November 4, 2001 Quote: from Doughie on 12:38 pm on Nov. 4, 2001[br] Who are you going to get it done for you Gav ? Leon with a bit of luck. I fancy making up an instrument panel for my glove box. I was going to put a boost gauge and my DSBC in there. In the light of recent revelations on the MKIV fueling issue I would add a EGT gauge with (remote warning light ) as well. Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted November 4, 2001 Share Posted November 4, 2001 I can defenitely recommend the 'Peak Warning' type gauge. The other morning i was doing my commute to the station and the boost peak led came on, and was enough to catch my eye and make me check the reading. Could save a few heartache's!! Quote Link to comment Share on other sites More sharing options...
Ring Master Posted November 5, 2001 Share Posted November 5, 2001 Dont forget, each cylinder runs at slightly different temps, so you either need to take a reading from the cylinder that runs the hottest (#3 "I think") or take a reading from all 6. Now 6 EGT's gauges would be awesome, especially if you bought from Shop!!, but I guess tapping into a place where you get a reading from all 6 is cheaper. My probe was originally fitted by CW, but Ash wasnt impressed by the mounting point and has moved it. Quote Link to comment Share on other sites More sharing options...
Simon Posted November 5, 2001 Share Posted November 5, 2001 ...... My probe was originally fitted by CW, but Ash wasnt impressed by the mounting point and has moved it. So where is it now then?? Quote Link to comment Share on other sites More sharing options...
GavinL Posted November 18, 2001 Author Share Posted November 18, 2001 Moved to the top as Chris is now on the list. Quote Link to comment Share on other sites More sharing options...
Guest Ash Posted November 19, 2001 Share Posted November 19, 2001 It was not so much that I wasn't "impressed" with it. Maybe that is an unfortunate choice of word. Obviously, Chris is working within the boundary of a customer budget and I was quite impressed with his ingenuity in finding a point that was relatively easy to get to (thus making for a cheap install) and would do the job required of it. However, as Justin's turbo system had to come apart anyway, one of the things we did was to re-site the sensor. Yours, J Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 20, 2001 Share Posted November 20, 2001 Quote: from Ash on 1:08 pm on Nov. 19, 2001[br] It was not so much that I wasn't "impressed" with it. Maybe that is an unfortunate choice of word. Obviously, Chris is working within the boundary of a customer budget and I was quite impressed with his ingenuity in finding a point that was relatively easy to get to (thus making for a cheap install) and would do the job required of it. However, as Justin's turbo system had to come apart anyway, one of the things we did was to re-site the sensor. Yours, J Thanks Ash, for sure, a probe at the confluence of all the cylinders is ideal, perhaps JUST behind a 6 probe set up :-) But as you say, one needs to take practicality and costs into this, removing the whole turbo assembly to fit an EGT probe is just not on for most people unless the whole affair is off for some other reason. Probing a single cylinder near the port is certainly better than probing the down pipe post the turbos. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.