How did Steeda put 4.09 gears in a S650 that has no access to tuning?

[ThreePedalPlow]

I was under the impression that these cars had to have tuning unlocked before we could do gear changes. Does anyone have any ideas how Steeda swapped rear gears without tuning? Would it just throw the speedometer off a little or something?

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[robvas]

You can change some stuff with Forscan on the 2024's can't you?

3.55 to 4.09 would be like 15-20mph difference at the end of the 1/4 mile, their in-car videos don't have the speedometer off by that much

 

[CamustangSS650]

My guess is the car throws a wheel speed sensor code, and it doesn't matter for that track use, or they mocked them and the car never saw the speed difference.

Mocking works but the issue is that you will throw off the speedometer and mileage. For street use its an issue since you will rack up fake miles.

 

[tj@steeda]

I am not privy to what we did - but I'll ask our internal team to help weigh in.

Best,

TJ

 

[roket]

you are able to change the diff ratio with Forscan at this address

726-15-01

xxxx

****

xx--

in those 4 spots you can put any number between 0 and 655, aka any diff ratio beween 0:1 and 16.21:1
here are some common ratios
3.15:1 = 013B
3.31:1 = 014B
3.55:1 = 0163
3.73:1 = 0175
4.09:1 = 0199

 

[Dave2013M3]

I talked to Steeda they said they had no issues with the 4.09s and didn't use anything to adjust it.

 

[Dave2013M3]

you are able to change the diff ratio with Forscan at this address

726-15-01

xxxx

****

xx--

in those 4 spots you can put any number between 0 and 655, aka any diff ratio beween 0:1 and 16.21:1
here are some common ratios
3.15:1 = 013B
3.31:1 = 014B
3.55:1 = 0163
3.73:1 = 0175
4.09:1 = 0199

Is this in the BCM module, where exactly would you do this change. Could you give us an example?

 

[roket]

Is this in the BCM module, where exactly would you do this change. Could you give us an example?

that is the BCM. the address is listed and the numbers go where the stars are

 

[Dave2013M3]

that is the BCM. the address is listed and the numbers go where the stars are

Thanks, the screen shot is that from the S650 or an S550. I know some people are having issues with Forscan. A set of 4.09s is going to be one of the first mods I am going to do.

 

[ThreePedalPlow]

I talked to Steeda they said they had no issues with the 4.09s and didn't use anything to adjust it.

Sweet! I thought we would have to wait for tuning for that. I'm switching to a taller tire which is going to make my 3.55s worse than they already are. I'm hoping I can find someone near St.Louis that could build me a 4.09 setup if I could provide a donor or a brand new unit. I think Ford sells the 3.55 unit I already have below. I know I don't have the Torsen anyways.

 

[tj@steeda]

Yes - sorry, I did get a response from our team.

Manual transmission cars may act differently, we do not know yet ... we only did our Automatic.

We have ranged from 3.31, 3.55, 3.73 and 4.09 gears in our car. The only issue we have seen is the speedometer difference between the various ratios.

Hope that helps!

Best Regards,

TJ

 

[Darkness24]

Yes - sorry, I did get a response from our team.

Manual transmission cars may act differently, we do not know yet ... we only did our Automatic.

We have ranged from 3.31, 3.55, 3.73 and 4.09 gears in our car. The only issue we have seen is the speedometer difference between the various ratios.

Hope that helps!

Best Regards,

TJ

Thought that someone changed to a 4.09 gear & had some kind of problem, really don't remember what the issue was. Maybe it was a Manual & that would be the difference.?

 

[Mr Hyde]

Sweet! I thought we would have to wait for tuning for that. I'm switching to a taller tire which is going to make my 3.55s worse than they already are. I'm hoping I can find someone near St.Louis that could build me a 4.09 setup if I could provide a donor or a brand new unit. I think Ford sells the 3.55 unit I already have below. I know I don't have the Torsen anyways.

Is yours a base gt just asking? I have a base and it came with the torsen 3:55 its a 300a base gt unless there's a baseier base gt out there somewhere. I find the 3:55 kind a lacking though my wheel tire combo is only slightly higher than my old ones. Im not draging the car but was interested in swapping the gears out.

 

[CAYOTE]

I know this is an older thread, but I just put a set of 3.73’s in my 10r80 car. I have had no issues whatsoever. I haven’t changed anything in computer yet and speedometer is still correct according to gps. I went from 3.15’s to 3.73’s. I’m running ET street r’s and they seem to do pretty decent on the street.

 

[24 vert]

I know this is an older thread, but I just put a set of 3.73’s in my 10r80 car. I have had no issues whatsoever. I haven’t changed anything in computer yet and speedometer is still correct according to gps. I went from 3.15’s to 3.73’s. I’m running ET street r’s and they seem to do pretty decent on the street.

If the speedo isn't off despite the gear ratio change, that sounds like it's reading vehicle speed speed off of a front wheel ABS/wheel speed sensor. If that's correct, the speedo will only be off if front tire size changes.
Have you noticed any funny ABS behavior in hard stops or any other traction control/advancetrac issues.

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