sorry for the ignorance (i wasn't the one that installed my zeitronix in the first place). which ground wire would you be referring to?

 

It's a good general rule. If you stay below 1600*F you are probably "safe". Does that mean you have a good tune? No.

To make matters more complicated, the EGT "limit" depends on time; your exhaust valves and turbines can survive very high EGT for extremely short periods due to thermal inertia.

The EGT limit also often defines the tuning limit for an engine- many times you'll cross 1600*F before reaching the maximum engine output. Pulling timing and adding boost can sometimes make even more power but requires you to go over 1600*F. I have no freaking clue if this happens often on Evos, so don't try it at home, kids! But I know it happens on some other cars and a higher EGT limit allows those cars to make more power on lower octane fuels.

I guess just keep it below 1600*F if you want to conservative, and 1700*F if you want to be agressive. Anything about 1700*F and you had BETTER know what you are doing. IMHO anyway ...

-Adrian

 

mine are from 740 to 800c on normal freeway driving and not flooring it. if I floor it from 1 through 5th it around 880 to 890 at around 21.4 - 22.00 lbs of boost 22 in fifth only. if i'm cruising on the freeway and your egt's are close to 800c and I drop from 5th to 4th my egt's will go over 900c I've even had spikes over 1000c for a split second(scary to see) but, it only happens when i put a heavy load on the motor( going up hill and dropping a gear to speed up) the egt is good to have cause it will help you decide when to back off when flooring it. I was told to keep it under 900c to be safe. this is a really good question.

 

We have run in the 985-1000C range when tuning for power. 1800-1850F.

For road racing long period of time you want cooler EGT's however.

 

I like to keep it around 900c on a long run/pull.

 

*update*

found out that my sensor went bad. i got sent a replacement from zeitronix. i took out the old one and noticed that the very tip of it was gone. :O (should i be scared?)

anyway, my car is reading EGT's once again, however, how accurate is the zeitronix?? i drove 30 min in the rain on the freeway. i did not even go past 70mph and didn't boost any thing higher than 6.5psi. i check my peak as i am approaching my exit for the hell of it and i see 1186 EGT??? that can't be possible can it? my peak read: lambda was 0.71, AFR was 10.5, Boost was 6.5, EGT 1186.

something isn't looking right. anyone have ideas? thanks.

 

Don't look at peak. It means very little. You need to log with a laptop to see what is truly going on. Most Evo's peak to 1250C when timing is being retarded so peak means nothing in relation to tuning or condition.

 

thanks for the info mr. TTP. i feel a little better now. most answers i've gotten from people were "if your car is running fine, then don't worry". i wasn't really satisfied with that type of answer. heh

 

Absolutely True.... EGT's are a balancing game between A/F's and ignition timing. EGT's tell me nothing but that the engine is still running. The only thing that they can tell you while tuning is if you monitor each individual cylinder one cylinder that reads much different from the rest would indicate a problem.

Back in the day it was common place to tune by EGT's but this was before the advent of good reliable high speed A/F meters. Always refer to your Air/Fuel mixtures (thermal management) and ignition timing (cylinder pressure) these are the two most important things you need to consider while tuning. EGT's are just to misleading.

You can have to rich a mixture but to little ignition advance and your EGT's can be through the roof. Or you can have to lean of a mixture with to much ignition advance and your EGT's can show to cold.



Chris Macellaro

 

you're saying that this statement is true? i'll be honest and say that my car feels and runs fine, but i always thought that there were possibilities of damage taking place without the driver knowing it. that's what i'm mostly afraid of.

this is a bit off topic and i know people have debated this a lot, but is there anything wrong with tuning on a dyno vs. on the street? my car was tuned on a dyno and i keep getting comments from other people saying that i should have gotten it tuned on the street. they say that dyno tuning is just for numbers and if i were to race another evo with less mods than me but tuned on the street then my car would get beat easily.

sorry for all the stupid questions...

 

You did not ask stupid questions friend.

I am sorry I did not make myself clear. I was talking about TTP Engineering's response being true.


I hope this does not turn into a or a contest.



To answer your question about dynotuning.

After I am done with the car on the dyno I always take the car out for the stuff that can not be done on the dyno (or easier to do off the dyno) like acceleration enrichment vs. TPS rate of change, coast down A/F's and Ignition Timing, sometimes cold starting, and just to double check the maps out on the street to make sure there are no issues with the calibration.

But here are the indisputable facts...To properly load cell tune all the maps you must have two things from a dyno. 1 you have to be able to hold the vehicle steady state. And 2 you must be able to see the changes made in real time.

Example: I bring the car up to 3500 rpm and hold the manifold pressure at 77 kpa with the dyno. Now I can hold the car there and make changes to that load cell fuel or timing until either the car overheats or I finish making the required changes to the calibration. This is hard to get all areas of the map in the fuel tables like this on the street. Although not impossible (a lot of guys out there get there fuel maps very very close like this). It is safer, easier and faster to attain the needed load cell ranges on a load bearing dyno then on the street or track.

Now Ignition timing is a whole different story. To PROPERLY SET IGNITION TIMING values in each individual load cell YOU MUST USE A DYNO. I am not talking about WOT this is what a lot of people can do at the track and get almost dead on. But to actually tune the vehicle properly in all attainable load cells again this must be done with a dyno. Lower to middle load cells are much too often overlooked by many tuners and more so with street tuning.

Let me explain. What I said earlier about the 2 things you need from a dyno, this is what I am referring to. Place the vehicle in one load cell on the dyno and advance the ignition timing until maximum torque has been realized on screen then go to the next cell and so on. You may gain half a foot/pound or you may gain 25 foot pounds but the truth is you can not feel 3 foot pounds on the street so how do you set ignition timing for maximum torque in every cell on the street? You can't period and if someone tells you that you do not need your car on a dyno for a proper calibration they are a LIAR. Your calibration can not be accurate or thoroughly complete with out some form of load cell tuning.

This is so often overlooked on street cars and I can not understand why. I tuned a Mustang about 6 months ago and when he came to the dyno the car was getting 8mpg and after I finished load cell tuning the maps the car now gets 22mpg. In addition he picked up 30 to 50 foot pounds of torque throughout the midrange. He said the car had completely different street manners and this was because fuel and timing were completely optimized on the dyno.

Ask yourself if you are going to spend money on a service would you not want the most you can gain everywhere in the calibration?




Chris Macellaro

 

This is of course, if tuning with a full standalone. ECU reflash and many other piggybacks do not either have timing cell adjustment capability or MAP based tuning. Some can be street or track tuned with no ill effects. For the full standalone I agree with the statement requiring a steady MAP and rpm position on the dyno.

 

Ah I knew I was forgetting something yes standalones but not specifically. GReddy Emanage and the XEDE to name a couple allow this type of mapping also.

And yes I agree unless heavy modifications have been made most of your mapping of the factory ECU's do well with the closed loop mid-range stuff.



Chris Macellaro

 

krillin, if you didn't get you EGT probe installed not too long ago, you should make sure that they installed the probe correctly. If it is too deep or too shallow, this may have lead to premature breakdown of the EFT sensor.

 

It is hard to screw up an EGT install unless the probe is manufactured too long for the port.

It is likely the peak is reading correctly. We know a thing or two about the Zeitronix product.