EGT's

[dsiegel360]

I've seen it posted many times, that observing the EGT's is an important part of the tuning process.

What are the temperatures we need to stay within?
What does a typical EGT curve look like?
What does a common lousy EGT curve look like?

Thanks....

[beepbeep]

Most important stuff in my book is keeping AFR in check while running recomended ignition timing. That usually keeps EGT's within margins per definition.

It's when you start fiddling with EFI (by delaying ignition to spool turbo, anti-lag and like) that monitoring EGT's comes handy. 930 headers are long so they keep EGT's at turbo low. It's hard to say what EGT's are OK as it varies from turbo to turbo and depends on how long headers you run but I personally wouldn't dare run hotter than ~870-ish deg. C at head exhaust port, aircooled heads and all.

Actually, I wouldn't run heads hotter than 220 deg. C (alloy goes soft) and TIT much more than 870 deg. C. (those old turbos usually don't like it).

There are OEM cars that run 950 deg. C TIT but they are watercooled (both turbo and heads).

But generally, I find AFR's and ingition first priority. EGT's usually take care of themseves with typical plain-vanilla 930 compontent (OEM headers, CIS, 0.7-1.0 bar of boost etc.)

If you start doing custom work and piling up the power, EGT might be worth looking at.

[DonE]

My EGT's, as measured on an engine dyno during break in and initial tuning, were 1475 F, 6200 rpm, 12.0 - 12.2 AFR. That was measured about 2" from the exhaust port on all 6 holes on my EFI conversion.

I don't think tuning these cars with an EGT (even as a reference) is all that helpful. AFR's and torque (timing) on the dyno are more effective.

[dsiegel360]

Thanks guys, that's the info I was looking for.

If anyone else wants to add anything......