trickfc

I want to know what EGTs you have in different driving conditions for comparison. I have greddy guage w/ sender mounted about 2 inches from turbo in downpipe.

WOT at redline in 2nd - about 650 C
WOT redline in 3rd -about 700 C
cruising 70-80mph in 5th gear closed loop -about 750 C

My car runs rich. I will not dyno tune until I get a couple more things for my setup. Just want to compare.

Mike

RETed

Those numbers are actually about right.
Low gear WOT pulls are almost useless, as you don't get full engine load in the lower (i.e. 1st and 2nd) gears.
Try doing the pulls in 4th or even 5th if possible.
I'd bet they are a little higher.

In 1/4-mile drag racing, I was getting 720C at WOT through the traps.
On highway cruising, the EGT was hovering about 760C.

If you're watching the EGT on the highway, they will read a higher.

GReddy 52mm EGT
Probe in downpipe, RB 3"


-Ted

SwooshMan

I have the same gauge and my probe is in the same exact place, mines reading about 5500 at wot and 6000 while cruising

HAILERS

At 70mph or 3050rpm, I read.....1280 to 1300, in fifth.

jimmyv13

My numbers are a little higher than RETed's.

WOT in 3rd, 800-810C with 11.8-12.0 AFR
WOT in 4th, 810C with 11.8-12.0 AFR
cruising....800C, 3500RPM, 5th gear, 13.6 AFR
idle....450C, 18" vacuum@900 RPM


My AFR's are fine, but I'm a little worried about my high EGT's. The Apex'i probe is on the DP about 2" away from the stock turbo. I think my timing needs some attention, but I am unsure what to do with it. While cruising, I'm about 28' and under WOT it advances to 17'-19'. What can I do to get my EGT's down a bit?

Any comments are welcome. Thanks.

RETed

That's for a turbo right?
Yeah, it's too hot.
Your AFR's are too lean.

Are you using a standalone EMS?
Or an S-AFC?
For AFR's, shoot for 10.5 to 11.0 - your numbers are too hot.



-Ted

Piranha

Timing effects EGTs as well however, so he could be either too advanced or retarded.

jimmyv13

Yes, AE with an LT8.

My AFR's went up a bit with the cooler temps around here. Normally, they are in the low 11's under WOT.

RETed

Knock down the timing 2 degrees from 0 to max boost.
Jack up the fuel a little.
Get those EGT's under 800C.


-Ted

jimmyv13

cool, thanks Ted.

Advance or Retard the timing from zero to max boost?

I'll have some driving time tomorrow back and forth to school, I'll report my results.

RETed

Yeah, the areas you're not under significant load can run a lot higher ignition timing advance.
The ignition timing gets more important the more load you put on the engine - concentrate more on the "0 manifold" and up to all the boost load points.
So anything with 0 or + pressure, knock down the ignition timing 2 degrees.
Rule of thumb is to advance slowly up to peak torque and then flatten ignition timing to about 15-degrees total.
You said you're running 17 to 19, so that's a little bit too aggressive.
With a rotary, advancing the ignition timing does not increase power that much, so retarding it back a little doesn't hurt your power output that much.
The EGT's should drop significantly, and this should keep the engine happy.


-Ted

molehill

I´ve just bought two greddy EGT, and I´m planing to place them 2" after the exhaust ports, one for each rotor. Is this a bad place to place them? I would like
to be able to get one EGT for each chamber, and this is the only place I can think of
that will give seperate readings. If I place them so close to the exhaust ports what would the normal temp be?

- Oscar

RETed

If I had the money, this is exactly what I would do.
With the probes that close to the exhaust port, shoot for like 800C on the EGT gauges.
That should be absolutely safe.

Like in another post I said before, try to get the car on a dyno to actually see if the EGT is spot on for best power - this is the only way I can confirm what a good target EGT is for *your* engine.


-Ted

jon88se

Yep, Ted's right about that rule of thumb but I assume such little timing (15 degree plateu) is just a safe area for rotaries since I see 23 degrees advance holding after the torque peak when datalogging my GVR4.

In my FC, I see 700c @ redline WOT in third. Cruising @ 60mph I'm at a low 600c. I have the warning on the GReddy gauge set @ 750c. This is running 12-13 psi on the stock turbo, FMIC, stock injectors, walbro and Rtek1.5. The Rtek 1.7 will be here this week and my GReddy 720cc's are sitting on my desk hehe

molehill

Thanks for your reply! Now I can go ahead manufacture my manifold, I´m copying your and Higgis design, but building it devided. I´ve mailed Higgi and he seems to be pleased with it! Post pics when it´s done.

- Oscar

jon88se

Oh, and my probe is about 4 inches from the turbo in the downpipe.

jimmyv13

I have attached my timing maps, I pulled a few degrees out of everything above zero and added a crapload of fuel in the higher RPM's between 4-8PSI, but I'm still climbing up to about 780C EGT. My AFR's went down to low 11's high 10's. The static on my ECU is set to +5. What now....more fuel or pull more timing out?

jon88se

Take timing out.

Piranha

Uh, static is set to +5 on microtech cars because the pin is 5 degrees retarded. Otherwise, all maps will be 5 degrees back. Why would he take that out?

Personally, I don't think EGTs are all that accurate for a primary tuning device. I'd expect to use them more to detect changes than set things. AFR is a lot more accurate for burn.

jimmyv13

Well, the wideband in my car is borrowed from a friend and it will have to be returned very soon, so I'm trying to compare what happens with certain AFR's and the EGT.

Piranha

AFR goes up, EGTs go up. AFR goes down, EGTs go down, and then start going back up.

RETed

The big question is...do you feel a difference?


-Ted

jimmyv13

My AFR went down nearly a full point, and my EGT's only went down at most 20 degrees.

jimmyv13

Not enough of a difference for the butt dyno to notice...

RETed

Okay...
I would take out another 2 more degrees of timing across the board.
As long as the car is still running strong, keep taking timing out little by little.



-Ted