Using shorter drag radials cause any problems??
#11
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
Shift points (at least on the 2k+) are based on both rpm AND mph. Smaller tires mean you shift sooner, taller tires mean you shift later (and possible to late, hitting the limiters). For those at bonniefest 05 they saw this on BADSSEi.
#13
Senior Member
Certified Car Nut
But the stock PCM in this 95 SLE will not know he is going a different speed than the VSS indicates, and shift like normal, even though you are actually going slower.
#14
DINOSAURUS BOOSTUS
Expert Gearhead
Originally Posted by jwikoff99
But the stock PCM in this 95 SLE will not know he is going a different speed than the VSS indicates, and shift like normal, even though you are actually going slower.
#15
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by jwikoff99
But the stock PCM in this 95 SLE will not know he is going a different speed than the VSS indicates, and shift like normal, even though you are actually going slower.
#16
Senior Member
Certified Car Nut
Originally Posted by Rogue
It wont shift like normal, it will shift based on its normal programming.
Do you mean late/early in relation to RPM or actual MPH? If the car doesn't know the tire size has changed, why would it shift at a different RPM?
#17
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by jwikoff99
Originally Posted by Rogue
It wont shift like normal, it will shift based on its normal programming.
Do you mean late/early in relation to RPM or actual MPH? If the car doesn't know the tire size has changed, why would it shift at a different RPM?
#18
Senior Member
Certified Car Nut
So, if it normally shifts at 5500 rpm, WOT, at 45 mph (just an example), then you change the tire size, wouldn't it still think you are going 45 mph, WOT, at 5500 rpm and shift at the same time?
What don't I understand?
What don't I understand?
#19
Senior Member
Posts like a Northstar
Join Date: Jan 2003
Location: Northern KY
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by jwikoff99
So, if it normally shifts at 5500 rpm, WOT, at 45 mph (just an example), then you change the tire size, wouldn't it still think you are going 45 mph, WOT, at 5500 rpm and shift at the same time?
What don't I understand?
What don't I understand?
#20
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by jwikoff99
What don't I understand?
For example if your moving at 20 miles in first gear and floor it the PCM calculates that to shift at 5800 your speed should be 50 mph with your stock tire size. With smaller tires your speed will reach 50mph (according to the VSS) before 5800 (probably 5600 or so dependng on amount of tire change) and the shift will occur early.
In the same scenario if your moving at 20 mph and you floor it the PCM calculates that to shift at 5800 you should be 50 mph with your stock tire size. With larger tires your speed will reach 50mph (according to the VSS) at say 6000 instead of 5800. If your limiter is set to 6000 your going to bump it.