New Supercharger... do I really need an EGT gauge?

Sep 23, 2009
Hurst, Texas
The installation of the supercharger has led me to learn more about my '96 than all the twelve years (or so) that I ran it un-supercharged. Virtually all of this new fancy learnin' came from the Forum (where else?).

I see that some (but probably not a majority) owners of supercharged 1FZ rigs have EGT gauges... I have read with great interest (and bleary eyes) their variances in exhaust gas temperatures.

I use my 'Cruiser as my 'daily driver,' but being retired, 'daily driving' doesn't amount to much. We will use the 'Cruiser for occasional towing of our 3,500 travel trailer. We will never do any rock crawling!

I have a Scangauge II installed... so, do I really want to go to the trouble to install an EGT gauge? What say ye?

I guess while I'm at it, I should ask about the advisibility of installing a boost gauge.

Thanks to all who make this Forum such a fantastic resource for us more-or-less-newbies!!

Dec 7, 2005
From having a supercharger on my 4runner, I have a dual EGT (its a V6) and an AFR gauge. I think if I were to be towing I would be using the EGT the most, but as it stands I tend to watch my AFRs more. Boost is worthless unless you want to know your supercharger stopped working. I'm thinking that would be something you would notice from excessive throttle input though.

For what its worth, I'm putting an EGT, AFR and ODBII gauge on my junk before even boosting it.

If it is between the two, EGT will give you more valuable information than boost. If you're thinking no gauges at all, that is strictly your call. I always say knowledge is power though.
Sep 15, 2008
53402, Racine, WI and 92111 San Diego, CA
Really not needed.

Boost really isn't needed anyways since it will never change.

If anything, I would add a wideband gauge. Since the ecu and fuel control I'm assuming is all stock, there's not much you can do to tweak timing.

I don't know if you can hook up something like an old school Apexi ITC (Ignition Timing Controller), but that would allow you to tweak timing at certain RPM ranges.

Strap it to a dyno, find out what your air fuel ratio is at, tweak ignition timing to peak torque without any knock and you're done.

At that point you really don't need any gauges because everything is tuned and wouldn't be subject to change.
Aug 31, 2009
Orinda, CA
An EGT is a very useful tool for tuning an engine.

That said, I wouldn't bother installing any extraneous gauges. Just keep an eye on your temp gauge and enjoy your supercharger. You don't need another gauge to cause unneeded stress. Are you going to have six gauges w/ six probes in each exhaust port? Are you going to react quickly enough if there's a sudden spike in EGT? I'm not trying to be rude, but sometimes too much information presents it's own problems.

If you install anything, add an idiot light that flashes when your knock sensor goes off. If it starts flashing, back off the throttle.
Mar 27, 2003
Lompoc, CA
I'm with these guys, too much info can make you crazy. Of my EGT, Wideband AFR and vacuum/boost gauges, I think the most useful info is probably vacuum. I back off the throttle on long hills when the EGT passes 1550, and that would be impossible to WAG without the gauge, but I don't really know if 1550 is a good "whoa" point - why not 1500 or whatever... My truck has always run higher EGTs than most folks', but with no pinging and AFR numbers in the high 10s to mid 11s all the way to 1600 deg, I'm no longer as neurotic about it as I once was. And when I had the head off at 160K, there was no sign of burnt valves or pistons. I just need to get the temp gauge mod done - that's real value. Just my two cents. Mack
Nov 27, 2003
It was explained to me the value of a egt gauge:

basically, the egt is your first, most immediate sign that something is overheating. It allows you to immediately monitor/adjust for high temps or see that something is wrong.

coolant/engine temp (scangauge) will start to heat up afterwards. So the chain would be:
engine heating--->egt-->engine heats up enough to heat coolant-->water temp

I am with you, hesitant to add a lot of gauges. I don't want to deal with the wiring and have a explosion of gauges all over the place.
But, if you want to know what is going on egt/boost/vac is valuable info.

I believe for towing, this may be very important. If I were you, I would get the egt. Even if it is temporary so you know what is going on while you tow over familiar ground to get a baseline.

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