High Exhaust Gas Terperatures(EGT's)

[Dzaster]

The skinny:

- EGT probe mounted post turbo(~4-5" after turbo)
- AFR is stoich or slightly richer, never lean
- Timing is 10 BTDC(stock), with 4 degrees advanced in EMB, only advanced in vacuum.

Okay, so I seem to have always been experiencing higher/rising EGT's while cruising. Sometimes see around 1100-1150 then I let off--slowly climbs.

I thought I had solved this high temps problem when I ported my turbo and manifold, but apparently not. It's still present.:(

Something that might have a play on timing is that I installed flat top pistons instead of pistons with say .5mm domes. I didn't think that would be enough to merit much advance for ignition timing. Nevertheless, it is advanced via the EMB.

So far my research on this has suggested that high EGT's are commonly caused by lean AFR and timing to far retarded. I don't think I suffer from either. Anybody have any other ideas?

I will be looking to pickup another EGT kit.

[Accord2nrz]

Actually 1100 to 1150 is not that high in my opinion. at a high my engine is registering 1300 the low end i stay around 1000. So i'd wager your right around the money spot. Depends how cramped your motor is, the temp of the air charge going in, how high your coolant is. If you hook in an obd 2 reader you can see what your coolant temp is.

[Dzaster]

I don't have an OBD2 reader. My car is OBD1, can I get an OBD1 reader? Will reserach this as I just seen a mention of the OBD2 reader to read base timing changes--another member here, in another thread.

And so this is post turbo probe mounting then? Either way, I am getting a better EGT. Mine seems to work intermittently, but APPEARS to read fine when decides to work.

I know we talked about steppers in another thread, I may look for one with a stepper or just go with a prosport. Don't you have a prosport EGT Lin? If so, content with it?

Thanks

[Accord2nrz]

I love my prosport, incredibly accurate and yes its post turbo, by about 6 - 12 inch.

[Dzaster]

I'm sold! Prosport does seem like bang for buck stuff. I just got an oil pressure gauge by them and it's nice for the price.

[Dzaster]

Curious, what Prosport did you go with--the regular or the peak and hold ones. Peak and hold cost a little more but seem to have the stepper motor that Turbineguy was suggesting is good to have in a gauge.

[sventhemac]

I have been looking at the prosports also. Nice to hear some good things about them. Going for the peak and holds, for after run comparisons with the EMU.

[Matt87]

Dude you need to fix that. 1100-1300 egts all the time is not normal!!!! Mine sticks around 640-750 degrees at just crusing and under boost 950-1100 on E-85 which burns cooler lol.

Also when I was on pump gas my EGT was around 850-1000 crusing and 1100-1150 tops going up hill/ under boost. You have a problem.

Dzaster- Adjust your map. Instead of 14.7 afr's while crusing make it 13.0 or 12.5 that will keep it down. Keep me updated..

[Dzaster]

Actually matt, what you share about your EGT numbers while you were running on pump gas, don't sound to far from what I'm experiencing.

I'll look to perhaps richen it up, but the thing is I can try and richen it up in the EMB, but the ECU, still operating in closed loop, will simply correct it back to stoich.

However, this is a great read. HERE (http://www.sdsefi.com/techegt.htm)

I just ordered a Prosport Premium EGT gauge with the stepper motor. I'll report back.;)

sven, that is the one I picked up, peak and hold. I have that feature on my boost gauge and it is a great feature. You can check it on the go--while driving. Not sure I'll need it on the EGT so much, but it'll have it.

[CG10DET]

try adjusting your ignition also to see if you can bring it down with that.

[Turbineguy]

What you guys are experiencing with your EGTs is completely dependant on several factors. Probe placement is the biggest variable. 1500-1600 is actually pretty normal for forced induction if the probe is placed right after the head. Post turbo will never give accurate readings due to all the heat absorbed from the exhaust stream by the turbo and pre turbo exhaust hardware. If you want to see how much it varies leave your probe in the same post turbo spot and put a turbo blanket on the snail. There will be a noticable rise in your EGTs. The other thing is that you absolutely need to have a wide band along with EGT in order to determine whether EGT spikes are related to AFRs or to timing. EGTs will be highest at the point of highest VE which corelates to the highest cylinder pressures.

[Dzaster]

I have a wideband, and since the ECU is working in closed loop still the area where I thought was high EGT's is actually spot on stoich and is in cruise. When I get into boost it'll either drop or not go any higher. I've not experienced excessively high EGT's while in boost. My high EGT's are always off boost.

[maxgtr2000]

Hmmm. Use your egts off boost as a reference. Like Turbine guy said egts will be different from vehicle to vehicle because of probe placement. Close to the head is more accurate, then you use the closed loop driving egts as a reference for everything else. On my car there is almost 4 ft of pipe before the turbo, and this is considered short for a maxima, trust me. My egt probe is almost another foot from the turbo. Going up hill my egts read 800-900f. Regular crusing is 650-760ish. Boost is 850-1080. Some other factors that will effect egts are exhaust size and coolant. The bigger and more free flowing the lower the egt reading because the gases flow out faster, also coolant effects chamber temps. I personally am using 70/30 distilled water and antifreeze with Redline Water Wetter. Some people do but I wouldn't run 50/50 water anitfreeze in a turbo vehicle. I would run more water in hotter climates and you can always change to ratio to higher antifreeze in the winter if needed. If you are knocking off boost that would be a concern but if there are no adjustments from the emanage until you are transitioning into boost then the egt readings might be normal for your car. Another thing is if the turbo is too restrictive to the intake when not under boost you will have high egts.

[Dzaster]

That is exactly what I run for cooling system mix even with water wetter. I'm thinking it may be just how my motor runs, but also considered if it might be backed up at turbo. My motor is a bit less displacement than the cars this motor came on stock--1500cc as opposed to 2000cc. 3" exhaust, no cat, glasspack, muffler.

It's gotta just be normal or as good as it'll get with this setup.

[sventhemac]

Cool deal man I will be picking up a few gauges when I get home. Boost, EGT, And probably OIL pressure. I have a spot for 3 gauges.

[Turbineguy]

Higher EGTs at cruise can indicate several possiblities. One would be retarded timing. The other thing may be your open loop AFRs. One of the reasons for richer than stoic is that the extra fuel helps with cylinder cooling. You may be able to run a leaner mixture while retarding the timing and bring up the open loop EGTs and get better cylinder pressure as a result. The best way to do this is to set your open loop AFR and start with a safe initial timing setting and then advance it slowly and watch EGT, AFR and knock. The butt dyno may be able to tell you if your going the right way but the best way obviously would be a roller dyno. Don't forget that too lean and too rich will both spike the EGTs as well as any kind of detonation as well.

[Dzaster]

Okay so here is a vid of a couple easy pulls.

Pulls Video (http://dl.getdropbox.com/u/766008/New%20EGT.wmv)

Order in the pillar pod: top(closest to camera) is the new EGT gauge, the middle is boost, and the furthest one AFR. The one on the dash is oil pressure.

Just figure I state what they are so there's no confusion. Anyways, I'm not sure what to make of this--whether EGT's are normal or too hot or what. Either way, AFR's are really pretty good once I get in boost and it seems to stabilize right around 1200*F. Again, probe is mounted post turbo. The knocklite, I am not too sure if it's setup properly still. I have a couple things to give attention to that might be giving me faulty readings on that. I just shot the base timing and it's 10*BTDC as is normal on my motor.


This is what my ignition map looks like. It's about 1 degree of timing pulled per 1psi of boost.
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/Ignitiontiming82509.png


And a couple of peak moments in the pulls.

Around 9psi boost
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/pull1.png


Also around 9spi boost
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/pull2.png


Does that look to be too much timing being pulled? I'm afraid that at this moment, I have no way of determining what my ECU is doing in terms of timing adjusment outside of the EMB. One more thing, I do have the water meth still setup to engage somewhere around 6psi and 4000RPM.