Question for guys who actually have the the Roush Kit

rollingshi59

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I had this discussion with Roush about going to a bigger tire. It’s not about the speedometer being off a bit, it’s the 10R80 transmission will be shifting improperly if they don’t change the tire diameter. They said if you have a manual transmission it only would affect the speedo a bit.
Great info thanks. my case, its A10. Best best bet would probably be sticking with street set up.

Btw, in 1st gear. mine won't shift to 2nd untill it hits 2k rpm( driving slowly after a cold start). Is it supposed to be shifting like this?
 

Azul Assasin

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I had this discussion with Roush about going to a bigger tire. It’s not about the speedometer being off a bit, it’s the 10R80 transmission will be shifting improperly if they don’t change the tire diameter. They said if you have a manual transmission it only would affect the speedo a bit.
I can see that being the case if the tire size was like 3% or more. A 305/45r17 is only 0.4% bigger than stock pp tires. 305/35r19 is only 1% smaller than stock pp tires.
 

Proshop

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I had this discussion with Roush about going to a bigger tire. It’s not about the speedometer being off a bit, it’s the 10R80 transmission will be shifting improperly if they don’t change the tire diameter. They said if you have a manual transmission it only would affect the speedo a bit.
Only diameter not width thou right?
 

hossman

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Only diameter not width thou right?
Yes diameter. In the Roush calibration they use revolutions per mile.

For example my 19 Roush Stage 3 runs 275/35/20 on the rear and it’s 753 revolutions per mile. If I go to 305/35/20 on the rear it’s 731 revolutions per mile.


As quirky as the 10R80 can be, getting it dialed in wouldn’t hurt.

You can always get buy a J2534 pass through device and download the Roush Diagnostic Tool for free and you can change the tire size yourself in the calibration, data log the car and even flash calibration updates from Roush instead of dealing with the dealership.
 

Proshop

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Yes diameter. In the Roush calibration they use revolutions per mile.

For example my 19 Roush Stage 3 runs 275/35/20 on the rear and it’s 753 revolutions per mile. If I go to 305/35/20 on the rear it’s 731 revolutions per mile.


As quirky as the 10R80 can be, getting it dialed in wouldn’t hurt.

You can always get buy a J2534 pass through device and download the Roush Diagnostic Tool for free and you can change the tire size yourself in the calibration, data log the car and even flash calibration updates from Roush instead of dealing with the dealership.
Long past the Roush calibration so I guess I’ll just let my tuner know if I change diameter of the wheel and I’m sure they can adjust accordingly.
 

Matthewstorm

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yeah i'm sure there are plenty of people that run it. just in my opinion its deleting something that was purposely put there.
I have the UPR dual CC made specifically for Roush.
 

brucelinc

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I have used various diameter tires over the past 3 1/2 years and never had an issue with shifting or shift points. Granted, the difference in diameter was not huge but I am a bit skeptical about the need to make adjustments unless there is a significant difference.
 

WOTPULLS

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I have asked this to UPR before and was told that the line being blocked is the vacuum line not the drain line so there shouldn't be an issue.
The vacuum line IS the drain line. its the ONLY line in the bottom of the bowl.
 

rollingshi59

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Great info thanks. my case, its A10. Best best bet would probably be sticking with street set up.

Btw, in 1st gear. mine won't shift to 2nd untill it hits 2k rpm( driving slowly after a cold start). Is it supposed to be shifting like this?
Could any owners with a10 chime in with my tranny question? Kinda feels like it shifts higher compare to bone stock calibration, driving around town 5~15 mph and it shifts hard. If I try to drive bit faster it will go to 2nd before 2k rpm.

it also makes louder rattle (piston slap possibly?) As rpm rises in first gear. (Before it warms up)

Normal characteristics?
 

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Could any owners with a10 chime in with my tranny question? Kinda feels like it shifts higher compare to bone stock calibration, driving around town 5~15 mph and it shifts hard. If I try to drive bit faster it will go to 2nd before 2k rpm.

it also makes louder rattle (piston slap possibly?) As rpm rises in first gear. (Before it warms up)

Normal characteristics?
Unfortunately it sounds about right for the Roush calibration. Aftermarket tune will fix that thou.
 

gtcs20148

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Could any owners with a10 chime in with my tranny question? Kinda feels like it shifts higher compare to bone stock calibration, driving around town 5~15 mph and it shifts hard. If I try to drive bit faster it will go to 2nd before 2k rpm.

it also makes louder rattle (piston slap possibly?) As rpm rises in first gear. (Before it warms up)

Normal characteristics?
So I have noticed with mine that when I am normal Drive mode, the shifts seem to be correct and not harsh at all. When I am in Sport or Sport + mode, the shifts are really harsh and I sometimes get the bucking between 2nd-3rd and 3rd-4th. If I am WOT and it is shifting I really don’t notice any issues. Seems to only be with partial throttle positions. I have really just gotten used to it until my warranty is up and then I will go custom tune. From what I have seen the Roush Calibration does shift higher in the RPMs and is harsh.

As far as the rattle, mine has it too until it warms up. Also had it before I put the Supercharger on. Mine is a 2021.
 

Proshop

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So I have noticed with mine that when I am normal Drive mode, the shifts seem to be correct and not harsh at all. When I am in Sport or Sport + mode, the shifts are really harsh and I sometimes get the bucking between 2nd-3rd and 3rd-4th. If I am WOT and it is shifting I really don’t notice any issues. Seems to only be with partial throttle positions. I have really just gotten used to it until my warranty is up and then I will go custom tune. From what I have seen the Roush Calibration does shift higher in the RPMs and is harsh.

As far as the rattle, mine has it too until it warms up. Also had it before I put the Supercharger on. Mine is a 2021.
Mine is the same. I think it 2021’s that have these issues for the most part.
 
 
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