Upshift Light - ZR-1 Net Registry Forums

Toranamat69 · 08-18-2013

Looking at the LT5 wiring diagram for the 1990 models, it shows pin B13 as the 'Upshift light'

I never connected this when I put the LT5 in my Torana but I am doing a heap of changes to it at the moment and sorta like the idea of a shift light on the dash.

Does this output just trigger a shift light on the dash and if so, what RPM does it light up?

Matt

LGAFF · 08-18-2013

Funny, I just read about this in the supplemental book. I always assumed the upshift was for fuel economy but in the ZR-1 its actually for max power/accel.

I might have this backwards but the manual says there is a 200rpm difference in the dash reading to the actual RPM. So as I understand it the light comes on at 5800RPM when the dash reads 6K RPM. On a stock motor they stated this is the best RPM for shifting.

I had shot a note to dominic asking if this could be just modified to come on at 7200RPM

Toranamat69 · 08-18-2013

Ha Ha that was going to be my next question - can you get that reset to what ever RPM you want.

LGAFF · 08-18-2013

I am not sure if its controlled by the ECM or the CCM

efnfast · 08-18-2013

"It is better to have the world think you a fool, than to open your mouth and remove all doubt", but here goes anyway. I thought it was a fuel effiency thing, that's why Marc H disables the annoying thing?

Kevin · 08-18-2013

Quote:

Originally Posted by efnfast

"It is better to have the world think you a fool, than to open your mouth and remove all doubt", but here goes anyway. I thought it was a fuel effiency thing, that's why Marc H disables the annoying thing?

not unless peak fuel efficiency is also near peak hp at WOT. I actually want marc to put mine back in

LGAFF · 08-18-2013

Thats the skip shift....the upshift is traditionally a fuel efficiency play on most cars, but apparently on the Z its not used for that......or so the manual says

1990 quasar blue · 08-18-2013

It does both. Under full throttle it lights for optimum acceleration. However, when cruising say in fourth gear at steady throttle it will come on to help you optimize fuel economy. Im pretty sure the updated portion of the gm code turns it off and not personally done by Marc. He turned mine back on and raised it to help accommodate my current mods. It can only be set so high though and I honestly cant remember what that is at the moment. Maybe 7200 but don't quote me on that. Xfire probably knows for sure.

08-18-2013	#1
Toranamat69 Join Date: Oct 2004 Location: Brisbane, Australia Posts: 37	Upshift Light Looking at the LT5 wiring diagram for the 1990 models, it shows pin B13 as the 'Upshift light' I never connected this when I put the LT5 in my Torana but I am doing a heap of changes to it at the moment and sorta like the idea of a shift light on the dash. Does this output just trigger a shift light on the dash and if so, what RPM does it light up? Matt

08-18-2013	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Upshift Light Funny, I just read about this in the supplemental book. I always assumed the upshift was for fuel economy but in the ZR-1 its actually for max power/accel. I might have this backwards but the manual says there is a 200rpm difference in the dash reading to the actual RPM. So as I understand it the light comes on at 5800RPM when the dash reads 6K RPM. On a stock motor they stated this is the best RPM for shifting. I had shot a note to dominic asking if this could be just modified to come on at 7200RPM __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-18-2013	#3
Toranamat69 Join Date: Oct 2004 Location: Brisbane, Australia Posts: 37	Re: Upshift Light Ha Ha that was going to be my next question - can you get that reset to what ever RPM you want.

08-18-2013	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Upshift Light I am not sure if its controlled by the ECM or the CCM __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-18-2013	#5
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,479	Re: Upshift Light "It is better to have the world think you a fool, than to open your mouth and remove all doubt", but here goes anyway. I thought it was a fuel effiency thing, that's why Marc H disables the annoying thing?

08-18-2013	#7
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Upshift Light Thats the skip shift....the upshift is traditionally a fuel efficiency play on most cars, but apparently on the Z its not used for that......or so the manual says __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-18-2013	#8
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Re: Upshift Light It does both. Under full throttle it lights for optimum acceleration. However, when cruising say in fourth gear at steady throttle it will come on to help you optimize fuel economy. Im pretty sure the updated portion of the gm code turns it off and not personally done by Marc. He turned mine back on and raised it to help accommodate my current mods. It can only be set so high though and I honestly cant remember what that is at the moment. Maybe 7200 but don't quote me on that. Xfire probably knows for sure. __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19