3 (E38) engine swaps/conversion's rev limiting at 5,500RPM's

[turbo_bu]

For the E38's, does that mean you have to use a car OS then? From what I have read, GM did not make a Gen IV (E38) with a manual transmission since that is when they changed to the GMT900 chassis (2007).

[LastCall]

Bringing up an old thread from the dead. lol

I read where GMt308 fixed the tune, but does anyone know what was fixed specifically? I'm on the dyno now, and stuck at 5400 rpm. I've tried to change all rev limiters without any success. Anybody have suggestions?

[LastCall]

It was a pretty disappointing day on the dyno today. Did not get to make a run past 5500 rpm, regardless of what I changed the tune rev limiters to. Seems that idle allows the RPMs to climb higher, so not sure what that means. If you look at both APP an ETCTP, app stays around 95%. but the etc is cutting it down to 30-40% or less. What would cause this? I changed P1516 to not reported as I was getting the code and though it would be causing the issue.

It feels like a soft limit, and if I stay into the throttle, the ETCTP will fall down, RPMs will go to roughly 4,500 RPM. and then I can rev it back to 5400 rpm. It does not feel like a hard fuel cut off. And I don't think it is reduced power mode as the ETCTP will start working again without having to let go of the throttle and step on it again.

I disabled most of the throttle control tables/test, and some of the MAF/MAP rationality tests as well. Trying to eliminate things, I know this is not the ideal and right way.

Specs are an LS2 with a Maggie at 6 psi with E38 controller and 4L70 with T42 controller. I've attached the ecm and trans tune and three log files (one with basic info and another with ETC PIDs).

Here are the details about OS and hardware:

E38 ECM
08 Silverado OS - 12617631

T42 TCM (posted correct trans tune 09-26-16 @ 6:26 am PDT)
08 Silverado Trans OS - 24239927

Silver blade TB
2010 Camaro Pedal (APP)

[LastCall]

Issue has been fixed. The rev limit was because no transmission range switch was present, and the trans was defaulting to park/neutral tables.

Which brings me to my next question - with no range switch, does the computer ignore the idle in gear (drive tables)? Like coast down and in gear transition tables? Or is that driven off current gear in the trans?

[ScarabEpic22]

Ah that makes sense, I've been pondering this the past few days wondering why it was cutting out at 5500rpms. If you'd said 4000, I'd have immediately gone for P/N/gear selector.

Weird, with a T42+4L70E combo, that should be sending a VSS signal to the ECM. Is the ECM OS looking for a 4Lxx or 6Lxx trans?

[joecar]

Thanks for posting back.

[minytrker]

Issue has been fixed. The rev limit was because no transmission range switch was present, and the trans was defaulting to park/neutral tables.

Which brings me to my next question - with no range switch, does the computer ignore the idle in gear (drive tables)? Like coast down and in gear transition tables? Or is that driven off current gear in the trans?

I had 2 LS3/4l70 swaps that were done at the same time. They ordered 2 of everything, 2 430hp ls3's, 4l70's, standalone harness from same company, literally everything. One cut off at 5500rpm's and one didnt with the same exact tune in both. Swaps can do weird things I have learned over the years.