EGT & E85

[turbotalon1g]

I was wondering if anyone had some insight to this, from what I know egt maybe a lot more useful now with the use of E85.

E85 is a lot less prone to knock and I've talked to a few people and they even a single egt probe kit is better than nothing.

I'm not looking to make uber HP, but I just want to be safe.

I am also ready to buy gauges and I don't like to buy twice.

[aaronspeed]

A EGT was a poor mans Wideband. Now that a wideband is so cheap why waste your money. Most of the time it is useless without a wideband. Just get a wideband and a logging device.

[turbotalon1g]

Oh wow, i should of been ready for this.
As you can tell it was early/late when i posted this, hence teh lack of info.

I'm not a noob, I have tuned all of my cars just fine.

If you nothing to say, but EGT is old school well get lost because I don't care, pushrods are old school and they still rock.

Back on topic, if you have done tuning with E85 you will notice that you can run insane timing on top of already high boost.

Case in point, 2 cars ago my motor would barely take positive timing while in boost it would knock to hell on pump gas, even on E85 it was a bitch, but once spending a shit ton of time with it I was able to get into the high teens for timing and even low 20s with no knock.

If you have tuned with E85, I want your opinion on using an EGT gauge not that its a waste and old school.

I believe there are users on here, that have already experimented with E85 and measuring EGTs with scary results, seeing easily over 1700F on a pull with AFRs in the mid 11s and timing at a modest mid teens (15ish i believe).
This has probed me toward a EGT gauge along with the fact E85 is just too knock resistant that I feel heat is one of the major characters in determining its limit.

[aaronspeed]

I use E85 in my 725whp Twin Turbo daily driven Mustang and have used a EGT in tuning and it will tell you nothing more than compared to a Wide-band. Why do you think every Dyno uses a wideband and not a EGT to tune. If you put a EGT in every exhaust port and can tune your injectors individually then you have something to tune, but putting a EGT probe in one port or at the down-pipe will tell you nothing without pulling spark plugs. Your better off going the quick and easy route and use your wide-band. I did not post to teach but to give a quick response. I have seen 200 -300 degree difference in each cylinder of my 5.0 and I am sure the way the exhaust ports are made on the 4g63 it would be the same when under boost. Borrow a Thermo Laser temperature gun that goes up to 2000 degrees and point it at the header after you take the car a quick cruise and see the difference between header tubes and then think about the difference when driving under boost. You always tune for the hottest cylinder so why not just use a wide-band since your taking a average reading. Another issue just to mix it up a little, I have seen my E85 range so much that it is like buying 93 octane and getting 89 octane. You always tune for a safe average. It is like tuning with Meth/Water injection and you run out. Either your tuning computer knows what to do or you blow your engine.

[turbotalon1g]

Post taken from another user on DSMlink:

"Well, here is what we know about E85:

1. Because it dramatically cools the intake, the final combustion temp is at least 100* if not 200* cooler than gasoline with all other conditions being equal.
2. Combustion temps rise when timing is retarded and fall when timing is advanced. A properly tuned E85 setup will have significantly advanced timing (over gasoline) thus reducing the combustion temps even more.

It is hard to believe that anyone is really seeing 1700+* on E85 unless they are running their timing too low, their WB is inaccurate, or their EGT gauge is innacurate. Many people (myself included) have accidentally screwed up the global setting with E85 and went full throttle with a/f ratios north of stoichiometric without causing any damage. It is VERY hard to believe that someone could be producing 1700* EGTs at only 11.5:1. If that were the case, then we would have melted our pistons.

We've all heard of guys melting parts on gasoline - anyone ever seen that happen with E85? "

[Shane@DBPerformance]

We use EGTs on road race cars, but not really in a way to save or do anything for the motor. Having an EGT probe on each cylinder is great for tuning with systems that can do individual cylinder trimming and power tuning, but most people, including the cars we do, usually only have 1 or 2 EGT probes. On the road race cars, we are most playing with the tunes to try keep the EGTs down enough to keep the turbo from melting. Road race cars never get a rest and the EGTs can build up to some high temps that eventually take out the turbo exhaust wheel. Having to slow down and come to a stop on the street once in a while is usually enough to keep a turbo alive forever on a street or drag car. 20+mins straight of beating with no stops can be a little hard on things and it can be hard to keep the EGTs down while at the same time running a safe tune for the motor at high boost.

I have 2 EGT probes and a wideband on a road race Evo. There is 1 probe in each bank of the twin scroll runners going to the turbo. They are wired to the factory ECU and the driver can log everything I need to know at the track using Evoscan and email the datalogs from each session.

[Shane@DBPerformance]

It is hard to believe that anyone is really seeing 1700+* on E85 unless they are running their timing too low, their WB is inaccurate, or their EGT gauge is innacurate. Many people (myself included) have accidentally screwed up the global setting with E85 and went full throttle with a/f ratios north of stoichiometric without causing any damage. It is VERY hard to believe that someone could be producing 1700* EGTs at only 11.5:1. If that were the case, then we would have melted our pistons.

We've all heard of guys melting parts on gasoline - anyone ever seen that happen with E85? "

Pistons do not melt from 1700 degree EGTs.

E85 spools turbos faster because of why? Guess what more of that stuff that spools turbos faster can do to EGTs.

[aaronspeed]

Now that is the correct method of use for the EGT. Subaru has a EGT probe from the factory for the same reason. I enjoy tuning my Subaru cars because from the factory they have a EGT and a Wide-band and makes tuning much easier since everything is interfaced with the factor ECU.

[Archertsi]

About a year ago I came to the conclusion that I wanted to run an EGT along with my wideband for multiple reasons.

1) No matter where I search, I everyone runs a different AFR on E85. So how lean can we run it? It doesnt like to knock, so the next possible way to damage the engine is to melt it down. EGT gauges will help you to know where to stop leaning it.

2) Egt can help you dial in timing. Not enough timing can cause high EGT's because fuel is still burning as it passes the probe. While lower egt's, may equal not enough. While always watching AFR's

3) While pushing 150-300 hp per cylinder on these engines, they are being highly maxed out. Data is key, the more the better and if you can afford it, it can NEVER hurt to have more Data.

4)While AFR's may be correct, EGT's can still be high. Things heat soak, engines heat up while doing a pull.

Example: http://www.streetfire.net/video/toyota-supra-blows-engine_202983.htm

Turbotalon1g: I'm with ya, it can never hurt to have that gauge. It WAS old skool, but I really think these will make a come back. Old skool also considered 400 hp insane, now we easily double that. A WB02 that cannot tell what fuel you are running is not as accurate as you think. While temperature is still temperature.

[turbotalon1g]

^Thanks man.