Over 46* ignition advance

[sjgrimsley]

First off, I am running an 0411 PCM with a 2003 Corvette Coupe base tune to control a super mild 406 sbc and 4L60e transmission.
406 SBC with the following mods:
Patriot Performance Freedom series 190cc heads, 64cc chambers
Holley EFI single plane manifold
Holley 36lb/hr injectors
Edelbrock ultra low profile intake elbow
GM DBW 78mm throttle body from 2000 Tahoe
GM 85mm MAF with screen from 2000 Tahoe
8 individual ignition coils from 2000 Tahoe

Custom grind camshaft: 196/216 @.050" .414"/.470" 116LSA-4.5*

Obviously I am using EFI Connection's 24X conversion package. My PCM was originally from a 2002 V6 Silverado, did a write entire with 2003 Corvette Coupe tune file. So, computer wise, we can just call this an '03 Vette coupe with the MAF failed for VE tuning.
FWIW I have successfully done a CASE relearn with it.

Currently I am trying to optimize part throttle timing, particularly in light load cruise areas.
For some reason I have hit a ceiling at 46* advance. I'd like to reach 50* in these light load areas.
That might seem excessive, but remember this is an old sbc with old slow burning chamber designs.

Am I missing some simple little thing that I'm going to look dumb for? Is there an internal limit in the PCM or a limit in the scanner?
I have searched high and low only to find nothing about this situation.
If anyone can give some advice or point me in the right direction, I'd really appreciate it.

I'll post my tune so someone can hopefully find something I have missed.
Thanks in advance! (pun intended)

Custom Cam 406 MAF.hpt

[SSUte01]

I can't speak for that particular OS, but I've noticed on many 0411 OS that there is some sort of limit of 40* no matter what the table is and what adders are applied. I am assuming this is a similar case, just of a value of 46*. I raised it a long while back and I was never able to figure out the reason nor does it bother me all that much to continue to pursue it. Would be good to know why though.

[sjgrimsley]

I'd hate to think I've hit a ceiling of 46* advance. There is quite a bit of room to improve the cruise areas as far as what the engine wants. I wonder if this is something that can be altered in the tune at a deeper level than the editor can reach? Maybe Chris could chime in with a few words.

[sjgrimsley]

Bump.

[2xLS1]

I opened a 03 Vette file with TunerCat and found your answer.

[SSUte01]

Well, there you go, I figured there was some kind of limit that we were not exposed to. Thanks for sharing, now the ability to modify it organically would be nice, a low priority I'd assume, but nice all the same. Cheers

[sjgrimsley]

Well thanks a ton for pointing that out. Had a feeling it would be something like that. I'd like to be able to bump that up. Being able to command advance that high may not help LSx guys out any but it sure benefit guys like me running older small blocks with these new pcms. I'm gonna have to make a request for that. Thank you for sharing.

[2xLS1]

I've seen that set as high as 60 on truck calibrations. I could change it for you with TC if you want to ship me your PCM. Just pay for shipping both ways. As long as you do a new read after I change it it should stay there with other changes you make. I'm in OKC OK.

[Bill@HPTuners]

In the meantime shoot support your .hpt file and I'll see what we can do about adding the constant.

[sjgrimsley]

Double post.

[sjgrimsley]

Thanks for the offer 2xLS1, I think I'm going to send Bill my tune and see what he can do. I really can't remove the PCM from my car since it's my daily driver and sees about 60-70 miles a day. Lol

Bill, email sent. Thanks!

[Bill@HPTuners]

new 2.24 build up with this constant added

[sjgrimsley]

Awesome! Thank you man.