I would imagine like most other cars, it would be fine, but cause a speedometer discrepancy. It should be able to be fixed with a tuning device. Ive done that on mustangs plenty of times.
Changing the rear gearing on 6AT
Hello all,
I'm wondering if anyone will be changing the rear gearing for the 6AT. I can hit something like 72 in 2nd gear, and I think it's a bit much. Looking forward to having someone try this and see if there are any issues with the ECU when it's geared like a 6MT.
Blighty mentioned that I'd be the first do this this in my other thread about the 6AT, but I thought I'd ask independently just to make sure.
-Justin
I'm wondering if anyone will be changing the rear gearing for the 6AT. I can hit something like 72 in 2nd gear, and I think it's a bit much. Looking forward to having someone try this and see if there are any issues with the ECU when it's geared like a 6MT.
Blighty mentioned that I'd be the first do this this in my other thread about the 6AT, but I thought I'd ask independently just to make sure.
-Justin
1 - 20 of 89 Posts
The differential is the same as the first Gen cars you have plenty of options to change the final drive.
Vehicle speed is measured off the rear wheels so it does not affect your speedometer and since the final drive is after the gearbox it wont know you've changed anything so no software changes are needed.
Vehicle speed is measured off the rear wheels so it does not affect your speedometer and since the final drive is after the gearbox it wont know you've changed anything so no software changes are needed.
72 mph in 2nd? By my calculation on OEM gearing, that’s 8500rpm
I know the AT gearing is less aggressive and does get well over 60 in 2nd. But not sure how much. I cant find the gearing specs for AT
You're correct. It's actually 66.72 mph in 2nd? By my calculation on OEM gearing, that’s 8500rpm
by my calculations, using the 4.3 out of the 2017+ manuals would be most ideal at least for 0-60. I plan to do the swap very soon actually...
Have you done the swap yet? Considering it for my auto as well. If so had it messed with any of the eyesight features at all?by my calculations, using the 4.3 out of the 2017+ manuals would be most ideal at least for 0-60. I plan to do the swap very soon actually...
I haven't for that very reason, but I do want to do it if it doesn't mess with anything. There's another thread where we discussed it further to that end.
Sounds like it's time to find a buddy with a 6MT and do a parts swap for a day to see if it dies lol
Easy and simple, i'm sure
Easy and simple, i'm sure
I'd love to know your results, I've been toying with the idea of doing the same thing. 3rd is just so dang long. That said, I also don't want to go quite as short as the manual gearing as I do drive the interstate a fair amount and appreciate the low revving when cruising at 80+ MPH.
I've done the calcs and for someone wanting the best 0-60 (in two shifts by 7400rpm) and while maintaining decent highway mileage the 4.3 is the best bet (so long as it doesn't mess with EyeSight).
What are the RPMs at, like, 65 in 6th?I've done the calcs and for someone wanting the best 0-60 (in two shifts by 7400rpm) and while maintaining decent highway mileage the 4.3 is the best bet (so long as it doesn't mess with EyeSight).
I was doing some calculations earlier as well and I think you're right. I've noticed it's a lot harder to find a Y58 diff (4.3) than it is a Y38 (4.1) though there are a few out there. I doubt the 4.1 would make a big enough difference. Someone needs to be the guinea pig for eyesight lolI've done the calcs and for someone wanting the best 0-60 (in two shifts by 7400rpm) and while maintaining decent highway mileage the 4.3 is the best bet (so long as it doesn't mess with EyeSight).
Based on what I'm seeing, about 200 RPM higher so around 2,200What are the RPMs at, like, 65 in 6th?
I should start a gofundme to buy a diff for this lolI was doing some calculations earlier as well and I think you're right. I've noticed it's a lot harder to find a Y58 diff (4.3) than it is a Y38 (4.1) though there are a few out there. I doubt the 4.1 would make a big enough difference. Someone needs to be the guinea pig for eyesight lol
yup, 2204 @ 65mph, 2543 @ 75mph etcBased on what I'm seeing, about 200 RPM higher so around 2,200
There's a Y58 near me for sale pretty cheap but the casing has some damage so I guess that's no help to me
That's because only manual 2017+ cars got the 4.3, so there are FAR less of them lol. They're not cheap either, at around $600, plus new driveshaft seals, but at least case+diff swap is an option because buying just a diff for install into a case is far more.I was doing some calculations earlier as well and I think you're right. I've noticed it's a lot harder to find a Y58 diff (4.3) than it is a Y38 (4.1) though there are a few out there. I doubt the 4.1 would make a big enough difference. Someone needs to be the guinea pig for eyesight lol
What aspects of EyeSight would cause concern that a change in rear axle ratio would affect it? @ZN8 above mentioned that vehicle speed is determined by the wheels.
1 - 20 of 89 Posts
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