BlaCkPlaGUE

Hey

Does it mean that the turbine is creating too much resistance becuase its not big enough? or does it mean that the compressor is building too much boost causing the turbine to create resistance?

Kind of confused here. What effects EGT's?

thanks guys.

atihun

Usually it's due to running lean or incorrect timing. Also possibly caused by clogged catalytic converters.

What readings are you getting?

XSTransAm

it means its a rotary

BlaCkPlaGUE

Heh.. None, im just curious, I don't even have a turbo
But yea you just confirmed it for me, exhaust gas resistance looks to be one culprit, along with ignition timing.

SO why do you need an EGT gauge ? Too high an exhaust gas temperature will result in coked turbo bearings? basically the gauge is to try and help save your turbos life if you notice the reading too high?

rx7tt95

Too much fuel will also yield high egt's. Confused yet?

BlaCkPlaGUE

hahha, yes I am now confused. It makes sense though, even though extra fuel helps prevent detonation, once it leaves the housing and enters a 600+degree manifold it ignites.
That is correct right?

But regarding turbo life am I right? as in the whole purpose of the temperature gauge?

thx guys.

Carl Byck

Basicly, any number of poor tuning choices, or too small an exhaust (turbo/manifold runner/exhaust itself) can contribute. It should be around 1600 in the manifold. I used to see ~1800* on my hybrid TII, it didn't last long LOL. Carl

eViLRotor

iTrader: (2)

I have this saved. Think RETed wrote it:

diabolical1

iTrader: (3)

insightful ... and that's the way i had learned it.

bingoboy

when dyno is not available ted will tune riding shotgun with a laptop and a good egt gauge.

Ottoman

I heard not to rely on the EGT too much.. it's just a ballpark figure...

i heard the EGT gauge doesn't respond fast enough to changes in temperature to be used accurately as a tuning device

it's more of another way to monitor Engine health rather then tune

Carl Byck

While it is true that it responds slower than a WB, it is absolutely required data to properly tune a car. It will not allow you to see a transient event that can break your motor, but as listed above, it will help you to arrive at proper timing, and AFRs. Think of it as a double check to a tuners common sense(is there such a thing ), it will ID situations where you are approaching an unhealthy combination, by going too far, ie way too much retard, or too much/little fuel. Notice either way you go with fuel can cause a power drop, an EGT will tell you which way you went too far. Carl

RETed

I tune 13B's just fine.
Just ask any of my customers.
The majority of them are *street cars*, which I only tune to 90% power anyways.
I tune them very conservative, and running them any rich would just foul spark plugs.
The last 10% I can get on the dyno, but the street tuning with the EGT is pretty spot on.
Case-in-point, I got the our 20B FC non-turbo tuned on the street, and once we got the car on a DynoJet, the tuning was spot on up to 6kRPM; the last 1,000RPM up to 7kRPM we gained another 5hp - everything under 6kRPM did not gain anything adjusting fuel or ignition timing on the Haltech E6K.


So why don't you tell all of us what is better?
Wide-band?
How do you adjust ignition timing with a wide-band?


-Ted

Ottoman

ur the first person I know that vouches and lives by just EGT tuning...

i see SOO many ppl with EGT gauges but don't here of them street tuning with it.. just "watching" it to make sure the car is in "normal operational parameters"

i'm not sayin ur wrong or lying.. it's just a first I've heard of...

I thought UEGO =A/F and Dyno=fine tuning +timing


U have a writeup or explanation on Tuning watchign EGT? What temp Range should u be targetting for example? or is that one of the tricks of the trade?

cuz if u can get a 90% tune with just a good EGT gauge.. **** the dyno and LM1 i'll order an EGT today!

books

iTrader: (8)

Let’s assume I am at the dyno, monitoring EGTs and maintaining proper AFRs. I would like to optimize my power at a particular rpm range. How is this accomplished?

1) Should I reduce timing until I lose power as EGTs lower and then increase timing as power and EGTs rise?
2) Once power levels (not drops) stop advancing the timing, at this point is this my optimum power timing?

For step 1) the reasons to retard timing and then advance are:
a) The initial timing may be either too advanced or already optimized
b) to establish a baseline EGT

During step 2) I am concerned you may not be able to see the power drop since the EGTs may be dangerously high. This is the rationale to stop advancing timing once power levels instead of power dropping.

Comments please.

Carl Byck

Pretty much, look at my post above in the thread an dyno tuning on an engine dyno. Basicly, fuel can be done on the street, timing, start at a known safe value, advance until you no longer are gaining torque, now back off a degree. I am not an expert tuner, Ted certainly has alot more experience than I do, but we pretty much agree on this one. Many old school guys learned to tune with an EGT before WB were available, like anything, with practice, and using all the auditory, and visual ques available, you can tune with just an EGT. Carl

books

iTrader: (8)

Thanks Carl,

I have read that thread a few times and selectively cut and pasted portions of it to a Word document. Since you mentioned it, I started to read it again and noticed this tidbit from Ted,
“This is why I said to run the car on a dyno and watch the EGT gauge.
Once the engine starts going into pre-ignition, you WILL see the power drop significantly.”

I was hoping for some confirmation that what I wrote was valid. I have altered timing a bit on the dyno while recording EGTs but have not experienced this “power drop” however I have not noticed significant gains either. Perhaps, I am not changing the timing enough.

I noticed Kan had said he accidentally ran advance as high as 40 degrees, I wonder if he was monitoring EGTs at that time.

RETed

If you have experience in piston engine tuning, advancing the timing does not affect rotary engines versus pistons engines.
This is one of the secrets.

Yes, there will come a point where the power will stop increasing, but advancing the ignition timing will not significantly affect EGT's.
This is where I back the timing down, cause why risk the engine when it doesn't make power?


-Ted

BlaCkPlaGUE

Just curious but we've had alot of guys in the second gen section with red hot turbo manifolds at idle, alot of people have recommended to check your timing becuase advancing it affects this.
Are these people wrong to suggest this?
I thought that you quoted on the first page that timing does affect EGT's. I know you mentioned that it doesn't effect it significantly, thats why I asked my question in the first sentence.
Just trying to clear things up, im now confused again

RETed

Oops, that didn't make any sense... :P

It should've said...

Advancing the timing does increase power gains like it does on most piston engine tuning.

You're going to hit a wall where advancing the timing increase power very little.
At this point I back the timing down to where the power is still highest, but ignition timing advances is smallest.


-Ted

books

iTrader: (8)

Thanks for that clarification, I thought you meant the opposite.

RETed

Aw crap, my typing is just going to hell... :P

Let's try this one more time!

"Advancing the timing on a rotary engine does not increase the power as much as it does on most piston engines."

Ok, I think that's what I'm trying to say!

Adjusting ignition advance on a piston engine will produce significant power gains.
Compare that to a rotary engine, the rotary engine might initially respond with good gains, but it hits a point where if you keep advancing the ignition timing, you get no significant gains in power.

This is where I back off the ignition timing, because why push the ignition advance if it makes no more significant power?


-Ted