bryan01 Posted May 19, 2008 Share Posted May 19, 2008 i'm installing a new-to-me turbo setup (that knot of a ss-tubular header that was JT's, 6-1 collector, etc). i've got a wideband (lc1) from when i had a megasquirt on the car (rb25), and now i've got an apexi fc ... once i get the turbo on and pipes piped it's going to the dyno my question is, should i drill and put in a bung (and plug it for now since i dont actually have the gauge/sensor) for an egt gauge now that everythings off? currently there are no gauges in the car, and i didnt have an egt before, but i'm thinking w/ the increased boost it's something i should look into. i've got a stock skyline cluster i'm going to wire in for the basic gauges, then add a few ... to EGT or not to EGT? if so, which runner (rb25, series 1) runs the hottest? i could put it after the collector, i searched and read about people putting them right after the turbo so that if the sensor broke it wouldnt ruin the turbo... ?? and a lot of people seem to say just to go w/ the wideband, or the wideband for tuning and the egt for street ... any experience w/ rb25 usage of EGt's out there? anyone know the range of temps for an rb25? also, if JT didnt need a egt w/ his setup, why would I? (he had a t4 running gobs of boost, and i'm adapting a large t3t4 for mine) ... Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted May 19, 2008 Share Posted May 19, 2008 Everyone I have seen have been after the turbo. I have one on my diesel and Id say I like it alot with towing especially. But Id say its a good idea to have one. Quote Link to comment Share on other sites More sharing options...
bryan01 Posted May 19, 2008 Author Share Posted May 19, 2008 Everyone I have seen have been after the turbo. I have one on my diesel and Id say I like it alot with towing especially. But Id say its a good idea to have one. well if i put it in later downstream of the turbo, then i don't have to worry about the shavings from drilling it going anywhere they shouldn't, and i can go ahead with my install right now ... mmm ... instant gratification ... Quote Link to comment Share on other sites More sharing options...
Nigel Posted May 19, 2008 Share Posted May 19, 2008 Everyone I have seen have been after the turbo. I have one on my diesel and Id say I like it alot with towing especially. But Id say its a good idea to have one. My understanding is that because you'll get a big temperature drop after the turbo, you're not going to see the true peak temperature. After doing a lot of reading on the subject, I settled on placing mine just before the turbo. This is on an L6 with short exhaust runners mind you. If you have a tubular header with long runners, then closer to the head, near a cylinder that may be known to run hotter might be better. Nigel Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted May 19, 2008 Share Posted May 19, 2008 Always pre turbo. Evan Quote Link to comment Share on other sites More sharing options...
stony Posted May 19, 2008 Share Posted May 19, 2008 13-18 inches from the exhaust port is what i have always heard. Most everyone i have ever seen installed is in the turbo housing right next to where it bolts to the exhaust housing Quote Link to comment Share on other sites More sharing options...
Warren Posted May 19, 2008 Share Posted May 19, 2008 Mine works great right where it is in this picture. Put a rag into the exhaust manifold throught the opening, stuff it in far enough that it won't get caught in the drill bit...drill and tap your hole, remove the rag and it takes all of the shavings out with it. None get anywhere near anything that would be hurt. Use a shopvac to vacuum out the manifold if you're really paranoid. Quote Link to comment Share on other sites More sharing options...
bryan01 Posted May 20, 2008 Author Share Posted May 20, 2008 so there seems to be just as many opinions around my place as there is here ... i called the shop that's going to be tig-ing my intake piping, and they said egt's are awesome (maybe they just thought i might get it from them, i dont know) but for a street application actually they said they usually install them downstream of the downpipe. they said it could give you a "mis-reading" on the street if you were just sitting at a stop light and it was in the manifold or close to the turbo (even in the downpipe apparently) because of how hot they get, and yes i said "well isnt that the whole point?" ... they said it just depends on what i'm doing with the car and since i dont plan on racing every day, putting it in the manifold wouldn't give an accurate reading of the load on the engine ... any thoughts? stony? do you even have an egt? (most reponses were "i've seen" what are you guys actually doing?) i guess the shop is saying that for an all out racing application you'd be more concerned w/ a peak temp but w/ a street application you'd be more concerned w/ over all load and heat across the board, but not including the crazyness (high heat) that's going on near the turbo? zdrifter, know anything about all the egt's you've seen after the turbo? all aftermarket? were they put there for ease of install or because of wanting to read the temp there over somewhere else for some reason? warren, i have a 1/2" adapter plate between my turbo and my manifold, i'd be cool if i could fit the sensor in that, but i think the plate might be to thin for that. also along w/ that and where stony was saying to put it, install the sensor in the turbo itself? if it's so close to the exhaust side of the turbo, upstream of the turbo, wouldnt that affect flow into the turbo? or at the very least wouldnt the air be moving so fast and violently that it would increase the risk of a broken sensor ending up in the turbo? anyone ever hear of this actually happening? (i read a few posts during a search that people were worried about this with sensors pre-turbo). Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted May 20, 2008 Share Posted May 20, 2008 Mine is at the #6 runner. That cyl is the one most likely to run lean due to my front facing intake manifold. I had it there on my RB and my Z. I have used mine for tuning, and think its accurate. Its nice to have during cruising to see if you can dial in more timing etc.. Evan Quote Link to comment Share on other sites More sharing options...
Nigel Posted May 20, 2008 Share Posted May 20, 2008 i called the shop that's going to be tig-ing my intake piping, and they said egt's are awesome (maybe they just thought i might get it from them, i dont know) After I installed my WB02 gauge, I hardly ever look at my EGT gauge anymore. The only time I really pay much attention to it is when I'm letting the engine cool down (I typically wait until the temp drops below 1,000F IIRC before I shut it off), or to keep an eye on it for excessively high temps. It's somewhat helpful for ignition timing, but as for Air/Fuel tuning, the WB02 can't be beat. but for a street application actually they said they usually install them downstream of the downpipe. they said it could give you a "mis-reading" on the street if you were just sitting at a stop light and it was in the manifold or close to the turbo (even in the downpipe apparently) because of how hot they get, and yes i said "well isnt that the whole point?" ... they said it just depends on what i'm doing with the car and since i dont plan on racing every day, putting it in the manifold wouldn't give an accurate reading of the load on the engine ... How does it not give an accurate reading of the load on the engine??? Maybe they're right, but I'd really like somebody to educate me as to why. The further you put the probe from the engine, the greater the heat loss, especially if it's after a turbo, and therefore, less accurate. I'd be worried that you'd have a false sense of security thinking that the temps are ok, but if you've lost a few hundred degrees (I've read that under certain conditions, there can be as much as a 500deg F difference before and after the turbo!) by the time it reaches the probe, you could be in trouble. The real question is what do you hope to get from the installation of an EGT gauge. I've had one in my Z for 7 years, and I like I said, I hardly ever look at it. The values are open to a lot of interpretation, and it's very difficult to compare from one engine to another, particularly if the probes are mounted in different locations. To get the most from an egt gauge, it would be best to have a probe for each cylinder to watch for differences between cylinders. However, for the average user, their best use is as a safety warning against excessive temps. But then, what is excessive? As for the probe affecting flow into the turbo, the probe is quite small, so it's not going to have any impact. Also, I've yet to hear of one breaking off. Unless you buy a really crappy quality one, the odds of a stainless probe breaking are very remote. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
Warren Posted May 20, 2008 Share Posted May 20, 2008 I put mine there so I'd know what temperature the exhaust was as it was entering the turbo, collectively from all cylinders, just as a general reading so to speak. The idea was to know the turbo was seeing. This also comes in handy when leaning out the motor during long cruises on the interstate to know when you're getting a bit too lean, even with a wide band O2 onboard. As far as it interfering with the flow, it doesn't really stick down into the airflow as far as you might think, so the disruption, if any, is slight. With regards to parts breaking off, or being injested into the turbo, it's unlikely, as the part that is in the airflow is more or less solid, as shown here: That's not to say that it hasn't, doesn't, or won't happen, but I've never personally heard of it. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted May 20, 2008 Share Posted May 20, 2008 I have had mine just like Warren's when I had the L6 motor. I now have a duel band AutoMeter EGT gauge, so I put one probe in #3 runner, and the other probe in #6, as shown, right up against the ports... Quote Link to comment Share on other sites More sharing options...
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