EGT & E85

[CarPsyco84]

I just got done tweeking the tune on my car last night... at 30 psi I was running 25 degrees up at 7k and beyond and 22degrees by 5k, and it was still gaining hp I just started getting chicken. I found that running in the upper side of 11's to low 12's AFR the low level knock count that used to show up at lower 11afr went away. Maybe that 15 degrees is somewhat late which would make it run hot in the exhaust side?

[turbotalon1g]

Well as much as everyone thinks its dumb or a waste, I will be purchasing an EGT gauge.

In addition to, WB, oil psi, water temp, boost and trans temp.

[goodhart]

Just read this post from Robert at FP on facebook and it reminded me of this old thread.

Not sure if it's useful to anyone, but the old man knows his shit so I figured I'd post it just because.

Back in the "DAY" (the 90's) we all had Greddy EGT guages and we never let them go above 850C for even a instant for fear of our engines melting away like the Wicked Witch of the West with a bucket of water on her. Today most people don't think they even need a EGT gauge since they have widebands, and that has a lot of implications.

First of all, the whole time we thought we were "tuning" with our EGT gauges, we were actually just making sure our parts didnt melt. Today we are all much more sophisticated and do our tuning with our widebands, many of us not even bothering to fit EGT gauges or even measure EGT at all. This makes perfect sense from the tuning perspective, because after all, you can't tune a ECU very well off EGT anyway.

What we overlook when we make this decision is that the typical "safe rich" tune supplies more fuel than can be burned during the power stroke and the typical "safe timing" is really retarded timing which puts even more of the combustion occurring during the exh stroke instead of the power stroke. Well you may already get where I am going with this... If there is a bunch of "safe rich fuel" left over for the exh stroke and the timing event was 4 degees later than it should have been then what you got there inst safe at all, you are doing the jet engine blowtorch routine inside the manifold, and your EGT which you are not measuring is getting absurdly high, easily reaching or exceeding 1000C without much trouble.

Inconel turbine wheels can tolerate operating at about 800-850C without being damaged, but flashing up above that for any real length of time will affect the material and make it weaker. each time it happens the material gets more and more weakened until the point where the tips just start to melt off. This imbalances the turbocharger and starts to put a lot of abnormal loading on the bearings which accelerates wear... all of this terminates when the turbine blades and or the turbine side bearing simply yield and break apart.

Couple things to take away from this note:

1) your EGT is important and you should know that your tuneup does result in a safe EGT.
2) turbochargers, particularly ones that cost less than $10-$15 thousand dollars, cannot deal with constant EGT above 850C.

[Shane@DBPerformance]

I run EGTs on road race cars whenever possible. You need to try to run a safe tune on a track car like that due to the extended beating they take, but a safe tune with low timing = higher EGTs, which can end up melting the turbine wheel on a car that goes 20+ min straight.

[evotuner]

I saw this too very good write up. Ron just had a car in his shop with an EF3 that went way lean and needed a rebuild because the exhaust wheel was dicked and the hotside even cracked. Map's turbo builder said he hasn't seen anything like this. The hotside was white

[EclipseGST]

I saw this too very good write up. Ron just had a car in his shop with an EF3 that went way lean and needed a rebuild because the exhaust wheel was dicked and the hotside even cracked. Map's turbo builder said he hasn't seen anything like this. The hotside was white

A guy tried tuning my friends 1g for him saying he knew what he was doing.... Used an SAFC1 with a narrowband o2, unplugged the knock sensor and went to work. The exhaust looked like it had snow in it. Turbo wheel melted right off the shaft. Poor guy just paid the kid $5500 to build the car for him and only got like 50 miles out of the car total. Toasted the motor and all.

Ooops!

[evotuner]

^lawsuit? lol

[Goat Blower]

Good luck with that.

[EclipseGST]

The guy blamed everything on the PCV lines coming out of the valve cover, saying they collapsed. Also blamed it on the stock turbo being not good in the winter!

Clearly the guy is an excellent tuner! I wonder if he applied for that position at MAP! lol

Lawsuit really isnt worth the trouble or money/time. The guy doesnt have anything to his name and already owes about $20k in back child support so taking him to court would get my friend nothing.

[Kracka]

Anyone can call themselves a professional tuner, I would say stating that 1 in 10 actually is would be generous. What's the worst right now are all the guys on national forums claiming to be e-tuners.