Assembling some digital panel meters to measure various temps - charge temp, coolant, temp etc. but lacking experience with thermocouples and how to insert them in the appropriate places. The one I'm most stuck on is EGT - getting a sensor that wont melt is easy but how on earth do I get it into the exhaust if it comes without an adaptor? Perhaps I can buy just an EGT sensor? I know John Banks is an electronics whizz maybe he (or anyone else) can educate me a bit??

 

Easiest way is to get a boss turned out of stainless in u r local machining shop with a smaller diameter at the front(or buy one off the shelf with suitable thread if available).
Drill the downpipe to suit the small diametere of the boss and weld the boss onto the downpipe Job done. If u use the autometer probe the boss needs the threads on the OD.

Pete

 

Just completed a similar job but using SPA supplied type K thermocouple (very similar to most used in industry).
These devices usually fit via a 'gland' that has 1/8" NPT male thread.
Therefore a suitable hole needs to be drilled (watch out for swarf getting into the the wrong places) and a boss with an internal 1/8" NPT thread welded on preferably not brazed though. For the intercooler the base near the outlet can simply be drilled and tapped to the correct size. Do this with the intercooler off the car so that the swarf etc. can be blown or washed out. Use a small amount of non setting pipe sealant on the threads when fitting the glands.
This means that the thermocouples can be removed at any time and a blanking plug screwed in their place. Ensure that the glands / plugs do not protrude into the exhaust/intercooler too far as this will cause a hot spot and or gas flow problems.

 

I would want EGT before the turbo if possible, but was not happy to drill a hole in the turbo housing as I wanted a temporary setup. Some argue the best place is about 8-10cm from the outlet of your preferred hottest cylinder - the debate rages on, but #3 on the rear drivers side seems to be some people's preferred candidate. There are heatshields in your way and you ideally would take the victim to be drilled off the car as otherwise you could potentially get shavings into your turbo If I tune my car any further I will fit EGT, but all I have for now is intake temp thermocouple which is the easy one to do and is removed with no traces.

On I-club there is a search facility (try factory forced induction forum) and there are several pages with pictures on how to install various temp sensors.

The problem with thermocouples is that they need sometimes large and expensive meters with another thermocouple inside. There is a chip the AD595AQ which would give you a voltmeter type output which you could then link to an analogue display with a new face or ripping the gubbins out a cheap DVM is possibly easier. Or there are commercial ready made solutions with "instructions".

 

Thanks for advice guys