2nd Gen Non-Engine/Transmission E.G.T probe

[SHobbs]

I currently have my probe post turbo, I want to move it to the pre-turbo position. My probe requires a 1/4in. NPT tapp, it is an ISSPRO guage. Is there a size limit when drilling and tapping the exhaust manifold or is 1/4in. ok. If not where can I get a 1/8in probe that will work with my current guage or will any probe work.

 

[DanielH]

I saw a post on here not too long ago where somebody used a 1/4" tube X 1/8" compression pipe fitting and drilled it out to accept the regular probe. I drilled out a couple fittings to use on mine and I think they will work fine. (a lot smaller hole ) I haven't installed mine yet.

 

[John - K5AWO]

Geno's Garage has the probes very reasonable. Under 20 bux.

www.genosgarage.com



I would leave the probe you have installed and put a new one pre-turbo. Get the 1/8" version so you don't have to drill as big a hole. 1/4" will work fine too, but I prefer smaller holes.



All probes have the same output. The size is just a mechanical thing.

 

[rblomquist]

Ok guys I have my flak vest on so I'm ready to catch spears after posting the following statement; but here goes:



Why do you want to move it pre-turbo? By your signature you're not one of these guys that is pumping out over 500rwhp. IMO, having to use a pryo pre-turbo is overdone.



For me, the practicality of having it post turbo makes more sense as I use it multiple times per day for ensuring safe shutdown temps. On the flip side it's only a few times (at best) during a month's period that I neven get close to dangerous EGT (towing) and it's easy to add 500 degrees in my head to stay well within the safety zone. Some gauges even come with a danger zone (red) on the guage which starts around 900 degrees (for post-turbo use).



This has been beat to death a la trannies, air filters, oil and like about everything else it ends up "to each his own". Pre turbo is fine if that's what a person wants, to me it's kind of a fear monger thing within the TDR. Again, I'm looking at it from a practicality standpoint, the main thing is that you have guages.

 

[dpuckett]

I have drilled and tapped 2 manifolds with the 1/4NPT threads, with no problems. Both 1st Gens, though I dont think that would make any difference.



AS for pre vs post turbo placement, it depends on what your plans are BOMB wise. If you plan on adding a bigger air filter, and maybe a timing box only, keeping output under 250RWHP, then I'd say post turbo is fine for you. If you plan to go any higher than that, I'd put it pre turbo. On my (then) near-stock 1st Gen, I could hit 1400 going up a hill empty, making only 24psi boost. I had had the t-couple post turbo for a week or so, and never saw 900, at 28psi. How hot I actually was at 28psi, I have no idea, but I'd be willing to be it wasnt safe. 50K later on a PDR HX35 (which had 20K when I bought it used), I have had no problems. I just wait till it is BELOW 300; more like 250-275.



Daniel

 

[BTowler]

Post turbo can vary wildly on the readings, from 300-600 degrees differece. Pre turbo is more consistent and accurate. As far as monitoring egt's at shut down for turbo life, the better solution is to monitor turbo oil temps at the turbo, but this is a complicated job, I have not seen any kits for this so you have to piece it together and, , drill your turbo housing. Haven't gotten up the nerve to do it yet, maybe when I buy one of those high dollar aftermarket turbos! This does not replace a pyro, just supplements it for shut down temps.

 

[dalton4]

Don't totally trust pre or post turbo readings for shut down if the outside temp is hot and you've been working the engine. This is what I experienced in June, 2003 when on vacation in the lower 48. The temp was about 95 and I had stopped at a rest stop with the 10K# 5er in tow. The engine had been idling for about 4-5 minutes when I decided to check turbo and turbo exhaust elbow temps against my preturbo probe. Using an infrared temp sensor meter, I had the following:

Preturbo... 280F

Turbo... . 395

Elbow..... 225



The turbo was a heat sink compared to the other locations. I didn't time it, but it took about 10 minutes of idling before the turbo was below 300 degrees. Regardless of the EGT reading, my advice is to allow additional cool down time before stopping engine if the outside is hot and you've been working the engine.

 

[rblomquist]

Originally posted by BTowler

Post turbo can vary wildly on the

So can pre-turbo (if you're using it to monitor shutdown temp). It's the same concept, you get variance on one or the other.

 

[SHobbs]

I am planning on changing the housing from 12cm to 14cm and adding, hope I have the letters right, edm 1 or 1. 5. This is the only reason I want to move it.