so i emailed rotary performance (rx7.com) about my EGT purchase. they suggest the downpipe, NOT the manifold. this is good, b/c i didn't want to go tapping into my wastegate or something and screw everything up.



now its just a matter of finding out what size the tapped hole needs to be. the directions are quite unclear on the tap size...

measure it

i dont have a dial caliper.

Just find a nut that is the same size and thread pitch and drill the hole and have the nut welded to the top of the hole. Kind of like the bung for the O2 sensor.

good idea, but i dont have a welder. i have a tap and drill, but no welder. i'll get it in, just a matter of time

egt is bs.

why do you say that?

the downpipe probably isn't thick enough to tap... the nut welded on is probably best.



the manifold *is* better. but alot harder as well. and if you have an S5. you'd need 2 gauges...

the DP might be too thin to tap. welded on nut is probably best.

egt are just a rough measurement of the air/fuel ratio....

Get a wideband o2....

what about timing?



mike

i'd rather have both, my EGT is now in the DP from the previous owned but i'll be moving it to the manifold. Make sure you get an NPT tap

what is an NPT tap. i got another reply from RP, rocky said to find a nut that fits as home depot and tap that size in my downpipe

and dont say its worthless, i just spend $160 on it, lol

for that much it adds HP, lol

i'd rather screw up a $160 downpipe than a $450 manifold anyway

what kind of EGT do you have? the threads for EGTs are usually a pipe thread (NPT) meaning that they taper. Let me know what EGT you have and i'll let you know what tap size you need for the sender. I still suggest you put it in the manifold. You can do this by drilling while the car is idling before it gets hot, just be careful under there. Use a high enough speed on the drill to keep the shavings small and they will blow out of the turbine and through the exhaust.

i could, but i think i'll just stick with the RP suggestion, no harm done. its all relative anyway, for my car at least. if i know the normal operating downpipe EGT, then relative highs and lows compared to this temp should give me a good idea of if i'm lean or rich, assuming no major changes in heat transfer have taken place.



I have the GReddy 2" EGT gauge. They dont look like they taper, though. However, the nut welded on the DP is sounding like a good idea, i might just hit up midus and have them drill a hole and weld the nut on for like $10.

putting the EGT in the downpipe will decrease the response and not give you an accurate reading. They probably told you that because they don't want to be responsible for you screwing up your turbo. I on the other hand don't care, I'm only going to suggest the correct way to do it.

1/8 npt



egt is quite important for all the tuner and road racers out there. you can have perfect a/f ratio, and have an egt too high and can still pop your motor.



as for location, down pipe, manifold, or turbing hsg, all don't matter that much. Its just what your numbers are referenced off at. If you are comparing, dp to dp temps, you should tap yours into the dp. the closer to the exhaust port the higher the temperature will be, and slightly faster response as well.

Also keep in mind rotary exhaust gas temp can sometimes exceed the max reading on some guage, so it is necessery to move it further away from the exhaust port (like in the downpipe) so that the probe don't melt.



* happens a lot on DSMs, when they tap it into 1st runner *

that means the timing is too advanced or too retarded



mike

"1/8 npt" tells me very little. that's what the directions say, but neither my metric or SAE tap peices say that size. i'm going to lows tomorrow, that will fix things. i'll just get a nut that fits and either tap a hole that size, or if that doesn't hold, i'll just go to midus to get it welded on.

NPT stands for National Pipe Thread. Your SAE and Metric tap and die sets will not have this normally. You have to buy a seperate tap to do this. You also will have to tap out the nut you will be using as well because it also will be SAE or metric thread. NPT is pipe thread wit a taper to it. One the nut is welded in place tap them together, this will give you the required taper needed for the probe to stay in place. The reason they use pipe thread is that it will stay locked in place better with the high temps that the probe will endure, other wise it may loosen under all the heating and cooling cycles it will encounter in the life of the probe.

well, i guess i am going to have to go to a muffler shop or some other place to get this done. oh well, one tap, shouldn't cost too much.

EGT's are a good thing to have when you get to tune your car on a dyno. The dyno usually will have a wideband O2 for you to use. But one of these tools alone isn't half as good as using both of them together.

I know for a fact that Sears sells 1/8 NPT taps and it'll be less than $10.. If you tap the manifold or the ex housing you will need to remove them or you have the possibility of metal shavings falling down in to the ex port and doing some serious damage... If you put it in the front pipe you'll get inacurate reading and it will also show what is going on too late... The best place is in the ex housing, but then you also risk it breaking off from heat and running the end of the sensor threw your exaust blade.. Having a EX temp gauge is a great thing, but when put in the front pipe (the safest place) you don't get the best performance of the guage and in the ex housing or manifold you get the best performance, but risk it comming apart and distroying the ex wheel of your turbo or even worse falling back in to the ex port and blowing the engine... It's a damned if your do damned if you don't kind of thing...



also the reason the ex housing is the best place is because you will get a hot reading when you go rich due to the left over fuel combusting in the manifold and ex housing, you won't really see this in the front pipe because the ex temp drops dramaticly once it leave the turbo..



IE.. running lean you may get a 920'c reading in the ex housing, but only a 740 in the front pipe..



running perfict you may have a 820'c in the ex housing and get a 710'c in the front pipe..



running rich you may have 1000'c in the ex housing and a 750'c in the front pipe...



It's much easier to see 100 and 200'c temp difrences than 10 and 20'c temp difrences on the gauge and when you do minor tunning adjustment you will also see 10'c temp changes in the ex housing, but you won't be able to see the 1'c temp change in the front pipe etc...

hmmmmmm?

scum...

You all got me interested now on this Wide Band O2 deal. Obviously the WBO2 takes precedence over an EGT gauge, but I am curious about A/F meters. If you have a WBO2 installed, does that make a A/F meter useless? Or is there some actual use for it with the WBO2?



Greg

The new techedge kit uses the Bosch sensor which is not scarce like the NTK sensor has become. The sensor for this kit is 100 bones. Cheaper than the NTK sensor in its hayday.



IMO a wideband is a much better tool than an EGT. Have you seen V2.0 from techedge? We are talking A/F logging, RPM logging, temp logging? How does that compare to the EGTs peak hold?



Check out the specs. If you can build the DIY kit you will be miles a head. I had hardly no electroics experience but I was able to build a v1.0 with no major problems. It was a thrill to be able to build the unit/display.



Give techedge a look man. http://wbo2.com/



James