I'm sure lots of people may know this stuff but just in case it's not something someone hasn't thought of I figured it best to post this.
Everyone fears the dreaded heat and ringland failure. Of course this would be easier if we all just installed an EGT gauge and then we could monitor our changes with that. But lets get real. How many of you will tear everything apart to install one? exactly.
When tuning you should always be monitoring performance in some way. 60-100 times seems to be the most used. Now when tuning most people seem to tune spark until it sees KR and then they back it off 1 or 2 degrees. While I see the point of doing this people do this blind with no understanding of what is really going on. I decided to test this out to see how crazy I could get with it.
I was able to run about 28deg of timing on e47 before I saw KR. With that I could actually run 26deg with no KR problems. Everyone is probably thinking well damn that's good run it. Here is the problem. I saw the exact same performance of 26deg timing that I saw with 23deg timing. Absolutely zero change in my 60-100 times. I tested this multiple ways multiple times. The average was always the same. What I did notice was heat differences which was what I was actually trying to measure. I just needed to know the boundaries I was testing with.
Before people start testing like I do just know I do not recommend it. Use a more subtle approach to figuring this out for your setup.
I monitored my IAT's and IAT2's during all of this testing. Though I did not see increases in performance as timing went up, I definitely saw increases in both. I also know people are going to say IAT's cause higher EGT's, could it really be the other way around as well. Yes it can. Think of it this way, hot exhaust is flowing through the turbo, and cool air is flowing through the turbo. Heat does transfer. To what extent does this correlate to EGT's I have no clue. I do not have an EGT on my car so I wasn't able to see if the outcome was proportional in any way. I will not post what I think the safe zone is for the temperature rise is because I honestly don't know. I will say if your seeing 20-30deg increase on a single 60-100 pull then I would definitely be changing something. I don't personally let my tunes get that high. If I remember correctly my 26deg timing tune cause around 20-22 degree increase on a 60-100 pull and on the same tune with 23 deg timing it was significantly lower. After I do a log on a pull I always check this out to see what my changes did. No sense in an extreme heat increase but next to no gains in power.
All of these tests were done the same. Almost identical warm up time and cool down time before the next test. Similar heat outside. Only one pull done per drive. Same section of road. Etc.
While this is not an exact science for tuning and obviously I would highly recommend an EGT this should still help some keep a safer tune. It would be nice to see others try this so we have more data to go off of. I do not tune my customers to the extremes I tune my own vehicle so I have no test data from them. Ideally we would want to see data from someone with an EGT setup.
Also keep in mind that it is not just spark advance you should be monitoring temps with. After every change I make I monitor it just to see how it affected me from the last time. I used that as an example because it is easier to see the relationship.
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Originally Posted by MikeM173
