Goblin

What range are you guys getting in your EGT's?

I've got a T-78, and all that that implies, with no cats and a GReddy PE.

Cruising in whatever gear, around 2500rpm, and 100-300mmHg, I tend to stay at around 800-825 degrees (C).

Kick that cruise up to 3000rpm, same pressure/vacuum range, and I see 850, sometimes climbing to 890 (at which point I back off the throttle for a bit and it cools back down).

This is all MUCH hotter than it used to run with the twins. I expected it would get hotter, but should it be this hot?

I've been playing with fuel there trying to get it down (PowerFC), but I'm not getting any real results temperature wise. I'm not making very large changes, though. The A/F from the J&S (when it decides to give me a solid value when cruising) is right around 12:1, tending towards the rich side more often than not.

What's the way to cool it down? More fuel in that range? Less fuel? Less advance?

And what's a reasonable target number? 700?


Thanks in advance for help. This tuning stuff is still new to me...

Taz

iTrader: (1)

First of all, where's your egt sensor?
I have a TO4. My probe is about 2" from the turbine in the downpipe.
Cruising (Part throttle) temp is 760-840. WOT, I've seen up to 900, but only when racing. At part throttle the O2 sensor (if working properly) is actually leaning the car to get better millage. Once the car goes WOT (wide open throttle) the ECU disregards the O2 sensor and richens the mixture to whatever has been programmed. In my car while at PT with temps around 840, once I go WOT the temp actually lowers to about 760, and gradually starts to climb with each gear - which probably is an indication of a weak link in my fuel system. What size injectors are you running?

Ketone

While cruising I see 680 or so but when hittin 20 + psi I can see it go up to about 880-900 but it's cool.

I have the Apex ETG gauge with the probe mounted about 2 inches away from the turbine in the down pipe...

Goblin

That's right about where my probe is, too.

I've got stock 550 primaries, and secondaries bored out to 1300, with the fuel pressure raised 1:1 with boost psi (I think it's set at 1:1, anyway... Could be higher...)

So, it sounds like the temps I'm getting aren't that far out of the norm.

Last night I added %15 more fuel across the board at 3000 rpm, and now when cruising it's rock steady at 800 degrees. Maybe it doesn't matter, but it makes me feel a lot better seeing my actions finally have a result, and not seeing that temp guage walk towards 900 when I'm not even on it.

Thanks for the replies.

sokudo

mine runs at about 1000c at full boost and throttle. about 700c crusing. my sensor is in the exaust housing of the turbine

crispeed

My EGT probe is in the manifold about 6 inches away from the exhaust port and I get around 890 to 900 deg. celcius max at full throttle in high gear at 30 psi at 9000 rpm.

crispeed
87TII
9.20@150mph

SPOautos

Why did you mount it so far away? I thought it was supposed to be more like 2" away

Thanks,

silvr94r2

iTrader: (3)

I've heard from a few people in the biz that the EGT should be before the turbo and best in the collector. Is this right or wrong or close? Makes sense but what do I know.....

crispeed

I mounted it there because that's where the collector is and also because that's where I get the best results!

crispeed
87TII
9.20@150mph

AJC13B

A collector for the exhaust manifold? Before the turbo?

crispeed

YEP!

crispeed
87TII
9.20@150mph

silvr94r2

iTrader: (3)

Unless you have a cast manifold that is.....otherwise there would have to be some sort of collector before the turbo. I didn't think there was one after the turbo

That is the best place to mount the EGT to get the most accurate measurement.....from what I've been told

sokudo

most people i know put it in the exaust housing of the turbine. the housing is cast so it is thick enough just to drill and tap and put the sensor in.