for past generation evos, what is the normal egt temperature at idle, and at high boost? what is too high and will show detonation. this is for need to know info so i have a starting point in a few weeks.

 

Hi,

I am not sure why the EGT's would be any different between an EVO or a 1993 Talon with a 4G63, but I want to learn the differences and why. My EGT's are as follows for comparison. The thermocouple is located 3" out on the number 1 exhaust runner.

Idle - appoximately 1100 degs F
65 mph (3000 rpm) approximately 1300 degs F
Full boost for me at the track (21psi) with a test pipe through the traps at around 106 mph EGT hits around 1580 degs F on race gas.

Hitting (but not exceeding) 1600 deg through the traps is considered the "sweet spot" by many tuners. Running the engine over 1600 deg F will start melting stuff. How do these numbers compare with the EVO's?

Speedlimit........

 

WIth an EGT probe mounted in the manifold, anything over 900c is usually caused by retarded timing as a result of knock. Anything below 900c is rich and not making as much power as you could be. So 900c is the sweet spot.

EGT at idle and cruise is irrevelant. The ECU has full control while in closed loop operation. As long as your O2 sensor voltage is cycling normally, the ECU is happy with what is going on.

Look at O2 voltage primarily up to about 4K rpm (2G DSMs like .94ish volts depending on octane) and then turn your focus to EGTs at higher rpm to red line.

Mike W

 

Hi Mike,

Thanks! Nice to have an expert pop in!

I am aware of the A/F and O2 relationships relative to lean and rich and EGTs. I was as curious as the original poster concerning tuning points and comparisons with EVO owners. You point is well taken concerning ECU closed loop operation at cruise and idle.

I purposely keep EGT below 1600 deg F (rich) because I am a wimp. Some of us 4 times a year to the track DSMers don't have the confidence to push the car to 1650F.(900C).

By the way, concerning your pecking order for cars at a club DSM meet from a previous thread. The Frankensteined 88 Hyundai Excel with a 4G63 turbo motor/tranny swap should have been moved to the page with used Yugos. And the 1G AWD Turbo moved up.

Speedlimit..........

 

Hi all-

I am putting an EGT sensor on my Evo. I had planed to put it in the exhaust manifold after cylinder #1. Then some one mentioned that the thermocouples can break off and damager your turbo. Has anyone heard of this happening?

Erik

 

I have never heard of it happening, but I suppose it's possible if you get a really low quality probe. EGT is definitely recommended if you're going to be cranking the boost and toying with fuel mixtures

 

Anything is possible for sure. If you are not brave enough to put it where the other kids do, you'll have to guess on how much cooler the exhaust gasses are further down stream. With out a way to look at actual knock, it will be a bit of a crap shoot. Typical down pipe temps are 750c at WOT but I have never tested it specifically. I have never NOT installed an EGT sensor in the manifold, but then again we only install GReddy EGTs.

Mike W

 

Make sure that you play it on the safe side, if you 're planning on tuning with just an EGT. I just feel that you need some sort of datalogger to see what is going on.

But then again its your car, and if your car and you can do whatever you want.

my .02

 

You can call me a wimp if you want, but I always keep my girl running rich so I don't blow up.... But then again, that's why I run consistant mid 12's with 133,000 original miles on the stock internals!! Keep it rich and you'll stay rich.. That's how I see it...

 

I will run a GEMS rally implant with full datalogging so that should be fine. How much are the Greddy probes can they be had without the gauges?

Erik

 

is 1400 F bad on track days...

 

I typically install the EGT 2" off the supposed hottest exhaust port. On my twinturbo 240z seeing 1600F was common at 20psi and pump gas. A few of my GN friends would see 1650F on their street/strip setups. I think your advice is spot on.

 

Looking at the Evo 4G63 motor from the front of the car, which cylinder runs hottest?