[exigentxyz]

I recently bought a 2021 230i automatic/ coupe, which I believe has a final rear drive axle ratio of 2.81; and need specific recommendations on changing the final ratio.

The goal is to bring the 0-60 time down into the 4 second range.

Would locating a whole unit from another model that will bolt up, be easier or will it be simpler to replace the ring & pinion with 3.46 or even 3.91 gears?

An example might be the 2019 M2, which I think is a 3.46, but will it bolt up?

Thanks

[aerobod]

Originally Posted by exigentxyz

I recently bought a 2021 230i automatic/ coupe, which I believe has a final rear drive axle ratio of 2.81; and need specific recommendations on changing the final ratio.

The goal is to bring the 0-60 time down into the 4 second range.

Would locating a whole unit from another model that will bolt up, be easier or will it be simpler to replace the ring & pinion with 3.46 or even 3.91 gears?

An example might be the 2019 M2, which I think is a 3.46, but will it bolt up?

Thanks

Don't forget there will be coding required to prevent "Drivetrain Malfunction" and limp mode issues, together with other system adjustments to correct for wheel sensor mismatch issues due to the gearing change, besides the mechanical work.

The rear axle carrier mounts should be the same to the body, but the driveshaft and output shafts are different as is the axle carrier on the M2. If you use the M2 electronically controlled diff, the control module, wiring and coding is also going to be needed.

[XutvJet]

M2 differential won't work because it's electronically controlled. You'll need an LSD which there aren't LSD options for your 230 smaller differential. Swapping in an M235/240 differential would be pricey because you'd need to modify the driveshaft and add the M235/240 axles and hubs and probably a whole host of other things. You're talking $4K+ in parts alone.

Adding a 3.46-3.91 ratios would make your 230 a total mess. Your car is already geared really deeply with the auto. You can't rely solely on the rear axle ratio. You have to consider all the ratios in the transmission. Simply put, your 230 already has a ton of torque multiplication and is already ideally geared for maximum acceleration. You 230's problem is engine power.

You'd be better served by selling the 230 and picking up an M235 or M240, especially xdrive if 0-60 if your fancy. It would be cheaper in the end as both those cars do 0-60 in the 4s stock and can easily go into the 3 second 0-60s with an xdrive and a tune.

[exigentxyz]

I appreciate frankness.

Initially I did attempt to find a M240 for sale, and my local dealership did a search for one, however apparently there is a shortage of most 2 series east of the Rocky Mountains now and nothing in the pipeline.

They found a few on the west coast but I was unwilling to pay the shipping, so that is on me.
I guess now I need to look at what other performance upgrades are available?

Is there a consensus on ECU chips or flash for the 230?

Again, thank you very much for your candor.

[morphomeman]

Unwilling to pay the shipping, but willing to pay a small fortune to try to do the impossible!
I envy you, man.

[exigentxyz]

Yes, expectations and outcomes ... so now I need to make lemonade

[PeanuKeeyes]

I just spoke with someone about this recently. Have you looked into the Quaife lsd’s? They can provide a solution if you get in touch. It’s going to be very expensive however.

As for engine tunes... I wouldn’t touch these 4 poppers if you’re planning on owning the car for a long time or outside of warranty. That said, you might be ok with a more modest tune using Bootmod3. That seems to be the favored platform these days. Expect increased wear on components and change oil less than every 5k miles, but if you’re not adding 50+hp, you should be ok on mostly stock components. Upgrade charge pipe though for sure if you do any tuning.

The 228/230’s are solid handling cars out of the box if spec’d with the performance suspension/brakes. If you’re looking to chirp your tires on the regular, keep on the hunt for the M240. It has a closed deck engine, it is a more robust design in terms of its power plant and you don’t have to hunt for the performance suspension spec as they all come with a good setup in that regard.

[RoundelM3]

Originally Posted by exigentxyz

Is there a consensus on ECU chips or flash for the 230?

There have been no "ECU chips" since the 1990s...there are "piggyback" tuners as well as flash tunes, but on a B48 engine, I'd stick with something mild. I have a JB+ on my wife's 228i and it makes a noticeable difference in power, but fuel economy and reliability are maintained.

[exigentxyz]

Thank you for the information PeanuKeeyes.

Your right, that they do have one listed on their website (converted from Pounds to $2,326.93) for manual drive.

I didn’t call them about a LSD specifically for an automatic; I assume that if they could build one it would probably cost a lot more than that.

Exchange QUAIFE LSD Differential
Make : BMW Series : 2 Series (F22/F23)
Application : 230i Manual, drive 7603750/1
Description : Exchange QUAIFE LSD Differential
Parts : £1,395
Fitted : £1,679

[dradernh]

Originally Posted by exigentxyz

Thank you for the information PeanuKeeyes.

Your right, that they do have one listed on their website (converted from Pounds to $2,326.93) for manual drive.

I didn’t call them about a LSD specifically for an automatic; I assume that if they could build one it would probably cost a lot more than that.

Exchange QUAIFE LSD Differential
Make : BMW Series : 2 Series (F22/F23)
Application : 230i Manual, drive 7603750/1
Description : Exchange QUAIFE LSD Differential
Parts : £1,395
Fitted : £1,679

https://diffsonline.com/bmw-f2x-230i-differentials.html