Shownomercy

iTrader: (1)

3bar SD open loop dyno tune on motor currently.

Tune was done with a crappy old alternator, and I would assume very low voltage.

Few weeks after dyno tune, I installed a new high output alternator, and now header primaries are glowing at idle.

Related?

1slowbusa

iTrader: (8)

What is your afr? Can you at least give us a log to review?

Shownomercy

iTrader: (1)

14-15 at idle, I can try to pull a log off it. Do I need a credit or anything for that?

1slowbusa

iTrader: (8)

What software are you using? If it is hpbtuner and you have connected before then no. Give us more info n the car as well. Example, motor, trans, make, model, year....

Shownomercy

iTrader: (1)

OK I will try and scan it tmmr morning.

1995 Z28 LT1, PT7675 turbo, 3bar HP tuners OS, 4L80E trans..

Nothing matches what the car should be at this point

Ed Wright

iTrader: (1)

Glowing header tubes are most always late timing. Higher voltage fattens the engine up. That lowers EGTs, which won't make the header primary tubes glow.

Shownomercy

iTrader: (1)

Well only other change was tossing header wrap on the crossover, stumped.

Shownomercy

iTrader: (1)

What would cause this to happen all of a sudden though, can't really think a new alternator and system voltage being higher would change timing curves...?

I do not think its mechanical cause I have good vac at idle and both banks are doing it not just one primary or two.

The tuner seems to think it is mechanical and I will pull a plug this afternoon but any ideas here or things to toss past the tuner? I think a 2 volt change in system voltage would change injector offsets but I dunno tuning stuff.

Ed Wright

iTrader: (1)

Unless the injector voltage offset table is seriously screwed up, that won't be it. It would have to be almost undrivable lean to make the headers glow.

Shownomercy

iTrader: (1)

How about an excess of false knock, could that cause a lazy spark curve to be retarded to the point of glowing primaries?

Ed Wright

iTrader: (1)

Late timing caused by anything would do that.

jimmyblue

iTrader: (11)

Whether your headers "glow" depends somewhat on
the viewing conditions as well as the fueling. I've
seen chromed headers glowing with a decent idle
mixture, with the shop lights off. Lights on, you
wouldn't notice.

I do not see any actual AFR readings reported so
it's hard to say anything useful.

06X6spdGTO

iTrader: (6)

Vacuum leak???

Do you have access to a wideband?

Shownomercy

iTrader: (1)

Wideband is showing 14-15 area but its in downpipe after turbo, both banks are glowing though.

Uploaded a scan file

T/A KID

iTrader: (12)

Your only at about 4-5 degrees of timing, need to increase that considerably.

Shownomercy

iTrader: (1)

Any reason why it would suddenly have such low timing..?

Ed Wright

iTrader: (1)

Some "tuners" pull the timing way back at idle to stabilize idle RPM. That certainly makes for red pipes. That is dumb as hell. One well known tuner asked me once why I thought he was seeing so many hot headers. He was using something like 10 to 12 degrees at idle, and zeroing out the idle speed correction spark tables because he didn't like to see the timing move around at idle. I told him it was the late timing at idle. He pretty much told me he thought the timing no stable at idle was just wrong, and there had to be another cure.
:-)
If your not seeing knock retard at idle (a tuning issue ) or a screw up in a temp correction table, it was likely the tuners choice. Alternator won't do it.

Shownomercy

iTrader: (1)

It doesn't show any KR, but I can verify. Just am very sure I couldn't have missed glowing headers previously... So idk how this is all of a sudden now

Ed Wright

iTrader: (1)

Not likely mechanical. More likely you just didn't notice.

Shownomercy

iTrader: (1)

Oddly comforting

I emailed my tuner and mentioned why it has such low timing.