Ark Posted February 7, 2007 Share Posted February 7, 2007 OK, I've got a DEFI EGT gauge to install, and I want to mount the sensor in my downpipe (I know it would be 'better' placed in the manifold, but this is more accessible). Given that I have an un-blemished downpipe at home waiting for installation, I can kill two birds with one stone here... Anyway, where can I get a mounting boss to weld to the pipe, so I can just screw the sensor straight in? It should be a 1/8PT size. Thanks Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 7, 2007 Share Posted February 7, 2007 I can make you one. But I think you are crazy putting it in the downpipe, you mights as well sell it, or stick it in the fire at home to see how hot it gets Quote Link to comment Share on other sites More sharing options...
tooquicktostop Posted February 7, 2007 Share Posted February 7, 2007 I had a defi gauge positioned in the wrong place and the reading as a complete waste of time, it did look pretty though all lit up on in the dash but if you are going to spend that much on a gauge and fitting why not have it in the right place where it will tell you what your EGT are and if you have a problem, which is what it was designed for, mind has been changed now and does what it is supposed to, its worth the hassle Quote Link to comment Share on other sites More sharing options...
Rich Posted February 7, 2007 Share Posted February 7, 2007 stick it in the manifold for an accurate reading Quote Link to comment Share on other sites More sharing options...
Ark Posted February 7, 2007 Author Share Posted February 7, 2007 Is it a "turbos off" job to stick it in the manifold? Quote Link to comment Share on other sites More sharing options...
merckx Posted February 7, 2007 Share Posted February 7, 2007 Is it a "turbos off" job to stick it in the manifold? No, you can reach through . I remember CW saying you need a long dril and tap. Careful that the metal cutting don't stay in the manifold and go through the turbo. Quote Link to comment Share on other sites More sharing options...
paul mac Posted February 7, 2007 Share Posted February 7, 2007 i remember looking at this when i was BPU and wondered how the f**k Chris Wilson does this, top respect, take it to him and get it done proper Quote Link to comment Share on other sites More sharing options...
LeeT Posted February 7, 2007 Share Posted February 7, 2007 I believe Matt Harwood has/had a mate who used to do this for £40 which is an absolute bargain Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 7, 2007 Share Posted February 7, 2007 I charge 50 quid to fit these. Quote Link to comment Share on other sites More sharing options...
Pig Posted February 7, 2007 Share Posted February 7, 2007 So, whats the recomendation? in the turbo or the manifold? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 7, 2007 Share Posted February 7, 2007 Manifold runner, as near the ports as possible. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 7, 2007 Share Posted February 7, 2007 Of course if you fit it before the turbo you have the worry that when/if the probe tip breaks your turbo(s) will be knackered too. If you fit it as close as poss after the turbo you don't have that problem. Quote Link to comment Share on other sites More sharing options...
Ark Posted February 8, 2007 Author Share Posted February 8, 2007 Hmm, maybe I'll take it to the local motorsport garage who are also Defi dealers. Much as I'd like someone like CW to fit it, £200 of petrol to get £50 of work done doesn't make much sense... New question then: I want an AFR gauge too. Can this probe be mounted in the downpipe or is this another manifold jobby? Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 8, 2007 Share Posted February 8, 2007 Of course if you fit it before the turbo you have the worry that when/if the probe tip breaks your turbo(s) will be knackered too. If you fit it as close as poss after the turbo you don't have that problem. Now this does keep coming up as the reason for not having an EGT sensor/gauge (having it after the turbo is the same as not having it...) but how many have self destructed in the last four or five years? -Ian Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 8, 2007 Share Posted February 8, 2007 Hmm, maybe I'll take it to the local motorsport garage who are also Defi dealers. Much as I'd like someone like CW to fit it, £200 of petrol to get £50 of work done doesn't make much sense... New question then: I want an AFR gauge too. Can this probe be mounted in the downpipe or is this another manifold jobby? Nope, it's a middle of the centre section of the exhaust jobby -Ian Quote Link to comment Share on other sites More sharing options...
Class One Posted February 8, 2007 Share Posted February 8, 2007 Hmm, maybe I'll take it to the local motorsport garage who are also Defi dealers. Much as I'd like someone like CW to fit it, £200 of petrol to get £50 of work done doesn't make much sense... New question then: I want an AFR gauge too. Can this probe be mounted in the downpipe or is this another manifold jobby? Nope, it's a middle of the centre section of the exhaust jobby -Ian And there's a handily placed grommet under the gear selector to run it through as well. Quote Link to comment Share on other sites More sharing options...
foodfreak Posted February 8, 2007 Share Posted February 8, 2007 Hi Ian, I know of 4 tips that have gone, all have taken a turbo with them. One of them mine:) wouldn't trust one in a runner again John Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 8, 2007 Share Posted February 8, 2007 There are tips and there are Inconel tips. I onlu use Inconel in my engines, and they aren't radically expensive, either. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 8, 2007 Share Posted February 8, 2007 having it after the turbo is the same as not having it So you're saying that having that have an EGT probe mouted directly after the turbo gives you no useful indication of EGTs? Sorry but I don't believe it. Temps post-turbo are lower than they are pre-turbo but one is still able to spot above normal EGTs with a post-turbo sensor, surely? Isn't it just that the threshold for "Whoa! That's too hot" is at a lower temp than it would be with the probe mounted in a runner? but how many have self destructed in the last four or five years? Dunno how many but I've heard of it happening. With my luck, I wouldn't want to risk it. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 8, 2007 Share Posted February 8, 2007 I agree with Ian. What you really want to measure are temps in the combustion chamber. This can be done, and is done by serious tuners and manufacturers, but it's VERY expensive, and usually done alongside real time cylinder chamber pressure wave measurements. The further away from the chambers you probe the less accurate the results. Throw the dampening characteristics of a turbo into the equation and measurements after it are so time delayed and inaccurate as to be all but meaningless. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 8, 2007 Share Posted February 8, 2007 So are you saying that raised EGTs pre-turbo do not result in noticeably raised EGTs post turbo? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 8, 2007 Share Posted February 8, 2007 No, but the lag time is so signicant that by the time the raised temps are seen post turbo the piston ring lands will have probably already have collapsed. The turbos are massive heat absorbers, and act as thermal dampers. If you are happy post turbo fine, fit the thing post turbo, but it won't make it correct, or be much more than a dash ornament. Quote Link to comment Share on other sites More sharing options...
supra matt Posted February 8, 2007 Share Posted February 8, 2007 Very intresting thread guys could someone tell me where the best place in my set up would be? thanks Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 8, 2007 Share Posted February 8, 2007 Drill and tap the turbine housing of the turbo, centrally, close to its flange where the manifold bolts up, unless it's a divided housing. Quote Link to comment Share on other sites More sharing options...
supra matt Posted February 8, 2007 Share Posted February 8, 2007 thats where i was thinking thanks for that chris, Quote Link to comment Share on other sites More sharing options...
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