shift points of a zr2
Moderator: F9K9
shift points of a zr2
i orderred a Power programmer today and I am wondering what people are using with 31" tires..or if anyone knows what setting is close to what the zr2 shifts like?
[size=75]05 Sierra LLY "Silver Bull"[/size]
-
HenryJ
- Admin K Elite
- Posts: 12705
- Joined: Tue Oct 01, 2002 9:14 pm
- Location: Ontario, Oregon
- Contact:
Re: shift points of a zr2
Justin wrote: what setting is close to what the zr2 shifts like?
Oooh! ooooh! I know this one 
Use no shift firmness setting and no changes to the shift points, and save your money if that's what you want for shifting....the ZR2 is exactly the same as ours
"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving! - ThunderII KE7CSK
then are the zr2's bad on the highway? my shifting is harsh in and out of final gear. It is also underpowered at any low or steep grade on the highway 
hence the shifting down (revving up to 2500-3000 rpm then back into final down to 2000 rpm when incline passes)
i am wondering if the zr2 does the same?
hence the shifting down (revving up to 2500-3000 rpm then back into final down to 2000 rpm when incline passes)i am wondering if the zr2 does the same?
[size=75]05 Sierra LLY "Silver Bull"[/size]
-
HenryJ
- Admin K Elite
- Posts: 12705
- Joined: Tue Oct 01, 2002 9:14 pm
- Location: Ontario, Oregon
- Contact:
You guessed it!
I have a friend with a 2001 Highrider (RPO ZR2) and took his for a drive to compare. He had been complaining about the same mushy shifts and the lock unlock of the converter while climbing small grades.
I put mine back to stock and used my HPPIII on his . Let him drive it for a week. I'm glad he brought it back, He really didn't want to go back to stock after a taste of the shift firmness!
So moral of the story: If you adjust only the VSS (vehicle speed Sensor) calibration for the increased tire size (31") you will be exactly the same as the ZR2.
EDIT:I do need to say that I think that the stock final ratio of ours with the 29" tires and 3.73:1 rear gearing is actually better than the 31"/ 3.73:1 the Z's have stock. Mine seemed to have a bit more "get up-n-go" than his Highrider, stock. Even though the crew weighs 400lbs. more.
After the switch to 31" tires it was a draw.
They should have had a 4.10 ratio option available for them.
Yours is probably worse than usual right now , if you speedometer is uncorrected.
The PCM uses the VSS as one of the determing factors for the correct shift point.
I have a friend with a 2001 Highrider (RPO ZR2) and took his for a drive to compare. He had been complaining about the same mushy shifts and the lock unlock of the converter while climbing small grades.
I put mine back to stock and used my HPPIII on his . Let him drive it for a week. I'm glad he brought it back, He really didn't want to go back to stock after a taste of the shift firmness!
So moral of the story: If you adjust only the VSS (vehicle speed Sensor) calibration for the increased tire size (31") you will be exactly the same as the ZR2.
EDIT:I do need to say that I think that the stock final ratio of ours with the 29" tires and 3.73:1 rear gearing is actually better than the 31"/ 3.73:1 the Z's have stock. Mine seemed to have a bit more "get up-n-go" than his Highrider, stock. Even though the crew weighs 400lbs. more.
After the switch to 31" tires it was a draw.
They should have had a 4.10 ratio option available for them.
Yours is probably worse than usual right now , if you speedometer is uncorrected.
The PCM uses the VSS as one of the determing factors for the correct shift point.
"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving! - ThunderII KE7CSK
