Ego/ Egt placement, Before or after Turbo?

[Aspire SVT]

any thoughts on where to install an o2 and egt in regards to the turbo. was thinking after to not disrupt exhaust flow in manifold. thought possible though would be best for longevity to be before the turbo to be notified of any problem of temp or afr before it reaches turbo. any thoughts

[sasquatch]

put the egt sensor where all the exhaust runners collect. so somewhere about 1 inch or closer away from the turbo flange just make sure you have enough room to get the wrench on lol... for the O2 sensor put that about 4 or 5 inches away from the turbo on your down pipe.

[Aspire SVT]

im now running my eg temp gauge in my stock manifold and my wideband downstream to get a baseline of my temps and my afr's. my egt sits at around 750-775 at idle. and on a 3rd gear pull it went to around 1200 with the afr around 13.8-14.3, this is with the temp bung placed in the stock maini at the collector where all the runners collect (where the main heat shields front center lower bolt went). this is with a stock air intake stock timing, plugs and gaps and stock downpipe, no catalyst, free flow exhaust. im trying to get a baseline of normal temps so i know what to try to duplicate with the turbo. did a search about it but ended up turning up my own thread lol. im gonna look on hmt and google too. thanks. im back on it and getting close. all i have left is a lower support bracket for the turbo and make a lengthened jumper harness for the o2 since its in the turbo dp now when its on. . intake piping done, manifold done and coated downpipe done, air cleaner done, oil line done, coolant inlet and heater return tube reroute done and looks factory(because it is...junkyard score!!!) i'll get pictures. thanks

[Aspire SVT]

So ive browsed on over to the hmt forum did some research and have come to the conclusion that these are normal temps for my engine. It also reinforced sasquatch's response in putting the temp probe before the turbocharger as i have found that some people have put it in the downpipe after the turbo and it does not instantaneously read cylinder temps because hey theres a turbo in the way. i understand that cylinder temp varies and is not a given set of temps for a certain engine, their are a few variables to consider such as wear, temp probe placement, exhaust and intake configurations, combustion chamber type. I have also learned that it has been an incorrect practice to tune by temperature as an engine that is passed stoich in the lean direction may also show a cooler temperature and can have disasterous results (i had no intention of using that practice just thought i would pass it along). Obviously the best way is to have an individual temp probe and wideband per cylinder to quickly identify an issue as it appears but i just dont see this to be needed on a 5 psi intercooled street car on my budget. So far ive had a few days to drive it in an almost stock configuration (stock intake, exhaust manifold and downpipe, timing, 2.25 catless exhaust) with the wideband and the egt in conjunction to get an idea of this engines normal temps and how they vary based on drive patterns. at a warm engine idle, it sits at just under 800f, in normal city driving it ranged anywhere from 900-1200f and would increase under a load and decreases during a shift (which shows the gauge has a decent reaction to a fast temp change). i had a chance to take it on I80 the other day and i did a pretty hard 3rd gear pull to about 55-60 mph and it went to 1400F and that was the highest it went, not a common practice but i wanted to see what happens. I know that, installing a turbocharger inline with the manifold and my very unrestrictive 2.25 exhaust will probably slowdown the temp variance will probably retain more heat in the cylinders and the manifold along with the increased backpressure. maybe i wont have my low end bog anymore from my too big exhaust...!! i have placed the temp probe in identical locations in both of my manifolds so that will not play a variance in my readings. Im glad i have a base line now and a range to keep in mind of what is normal.