Ideally, where is the best place to put the two sensors? I assume EGT would be as close to the head as possible where all four cylinders could be read. But do I want a probe pre-turbo?
O2, 2-4" after the turbo in the downpipe?
Matt S.
<a href="http://www.cardomain.com/id/kindofcavy"><img src="http://img61.exs.cx/img61/8537/J-Sig8b.jpg" alt="Image Hosted by ImageShack.us" /> </a>
Built not bought, check that!
well your not going to read all 4 accurately unless you have 4 guages, its best to put it as close to the head on just one of them, o2 sensor should be 18 inches away from exhaust port
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
stewart warner says to put there probes POST turbos...autometer dont give a rats ass. then again that goues along with their @!#$ty gauges too. but i wont get into that.
shifted told me the #3 cylinder is the most telling on our cars for some reason but i think id put it post turbo...thats where mine is going at least
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
i dont think youd have much of an issue puttiing the EGT sensor after the turbo, it would just take slightly longer to get an accurate reading. once the piping was good and hot though, it should be fine. the closer to the exhaust ports though, the better the temp. sensitivity and the quicker the response on the gauge would be.
Well, hypsy, I'm not sure where Ron got that. Has he tested it? Regardless, relying on one cylinder is relying on one cylinder. Get a bad plug, bad injector... not willing to base my engine on 1/4 of it.
Rob, although that is where my EGT is now (I'm redoing my exhaust, so probably moving the sensor if need be), I can only imagine the heat the turbo pulls from the system. Even more so when you consider that I've water cooled mine.
And, Prime, isn't 18" a bit far of the sensor? Learn something new everyday.
Just looking for the best solution.
Matt S.
<a href="http://www.cardomain.com/id/kindofcavy"><img src="http://img61.exs.cx/img61/8537/J-Sig8b.jpg" alt="Image Hosted by ImageShack.us" /> </a>
Built not bought, check that!
I have my EGT probe in the collector area of my manifold, pre-turbo. How do you know how much heat the turbo is removing? Too much of a variable for me.
My O2 sensor is about 2 inches away from the turbo outlet. Works perfect for me.
O noes!
most wide band sensor want to be farther away from a turbo because of the heat , i know inovate sells a heat sink to keep the o2 cooler
alot of people say the #3 on the 2.4 cause for some reason its the first to go lean
but like some one said have 1 in each port is the best
hmmm...looks like i got a new spot to mount mine when we FINALLY finish my exhaust tomorrow. YEAH!
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
^ you going to be at import wars tommorow?
anyways. with the s/c reflash you will notice a high egt. so dont get scared. That is what it is in the programming. (protomec told me , and he knows everything).
i say forget that egt stuff and save up for a wideband.
If I had my way id have 4 EGT guages one as close to the head as possible, anything else is just 1/4 of the real picture or totally off, the 18 inches from the exhaust port is per summit racing and PLX, which is a maker of wideband sensors, you will also find the stock 02 sensor is about that far as well
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Word, I'll go there with my 02 sensor. Thought about measuring the stock on, but I'll take your word for it (since I don't have a stock exhaust anymore).
Jake, WB would be nice, but what's the point with the GM program? What am I going to adjust? This car gets $0 more thrown at it.
Matt S.
<a href="http://www.cardomain.com/id/kindofcavy"><img src="http://img61.exs.cx/img61/8537/J-Sig8b.jpg" alt="Image Hosted by ImageShack.us" /> </a>
Built not bought, check that!
if you put it after the turbo you'll be reading the temps after the turbo has used a good bit of that thermal energy, so your temps are going to be lower.
Whats important is that wherever you put it you know what temps are acceptable for that range. A more efficient turbo however will lower the EGT's even more because it will be able to use the thermal energy in your exhaust more effectively.
if you want the actual temp, measure pre turbo, if you want it after the turbo has used what it wants, more of an efficiency temperature, put it after the turbo.
The only way to get a consistent measure reading is to measure pre turbo
-Chris
hypsy wrote:stewart warner says to put there probes POST turbos...autometer dont give a rats ass. then again that goues along with their @!#$ty gauges too. but i wont get into that.
shifted told me the #3 cylinder is the most telling on our cars for some reason but i think id put it post turbo...thats where mine is going at least
I have never had a problem with autometer gauges as well as mot of my friends. but thats our experiences.
Matt like they said behind one exhaust port is the ebst for an EGT gauge, wideband goes down from the turbo
LE61T PTE6262 Powered 
I have my wideband maybe 18"-20" away from the turbo... Its the innovative.
