Engine/Transmission (1998.5 - 2002) 1/8 or 1/4 for pyro probe?

[V6power87]

I ordered the Westach combo gauge and forgot to specify the size thermocouple I wanted. Is one better then the other?

 

[GFoley]

I don't think one size is any better than the other. Someone else offered this a long time ago:

Start with the smaller one first. If you mess it up you still have a chace to redo it at 1/4 the second time. Use an adapter if necessary.

I thought that was a good piece of advice.



GLF

 

[Joel Richards]

I have had both - the 1/4" and the 1/8". Problem with the 1/4" was that it reacted **extremely** slow - and I tried two of them just in case the first one was bad. When I say slow, it had about a 6-7 second lag time in response. I now have both the pre and post EGT guages at 1/8" and am extremely satisfied.



HTH

-Joel

 

[V6power87]

Thanks guy's. I guess it really does not matter, on my '93 I had an Isspro pyro and it had 1/4 inch pipe. Oh well, I just wanted to make sure I was not getting the "oddball" size.

 

[WadePatton]

I've not tried the 1/8 size but my 1/4 is not slow. The pyro needle swings almost as fast as the boost gauge.



I don't think that all 1/4 NPT thermocouples are that slow.



I like the big one. Less likely to melt it clean off!

 

[RJOL]

I've had my Westach combo (boost/egt) in for about two years. Unless they have changed the kit, it came with a 1/8" probe. Don't think it would make any difference if it is 1/8" or 1/4"... Have fun...

 

[MikeR]

The gauge reading isn't affected by the fitting size... the probe is the same for both.



I have installed lots and lots of gauges, and I simply like the big coarse threads of the 1/4" for this type of install because of the high temp area.



-Mike

 

[DEZLPWR]

My manifold is currently tapped for 1/8 NPT. I am looking to get an Isspro EVA pyro that only comes with a 1/4 NPT. Can the 1/8 NPT be tapped to fit a 1/4 NPT, and if so, how difficult is it?

 

[JR2]

The size of the thermocouple will effect the reaction time of the gauge... the size of the fitting makes no difference. I have had both size thermocouples and can tell you that you want the 1/8th size. When I had the 1/4 I would see 900 degrees max, when I switched back to 1/8 I would see 1500 degrees. This was on the same strech of road on the same day (about 1 hour between runs).

 

[JJW_ND]

Westach 1/4 are very good probes

I have had a 1/4 probe with a Westach combo for over 5 years now. It will rise as fast as the boost if fuel heavy enough. Can even make it peg the 1500 degree limit. This is based on a pre turbo install.



IMO, Westach probes are very responsive and very accurate.



My only problem is I like full swing gauges. Does anyone know if a Westach probe could be used with Issopro EV gauge?



Great service from Geno's by the way.



jjw

ND

 

[ZEEEW]

I think that as long as you use the same type of thermocouple, type"J" or whatever it is, the size shouldnt matter. I have a 1/4" and my guage reacts quite slow. Little bro has a 1/8" and he can hit 1300 at the end of the driveway, it reacts very quickly.

 

[WadePatton]

Hewitt

My pyro is a Hewitt Industries 1/4 and it swings just as fast as the Boost--well almost. It goes to 1500 in a hurry on WFO runs. I think a 1/8 Hewitt would do the same.



MLNSHO (my limited not so humble opinion)

 

[V6power87]

Well, when I got home today the Westach gauge was here. Looks to be very nice!!



I can't wait to put it in this weekend to see how it works.