S54 w/ 6 speed. Which diff

[grk325]

What diff are you guys running with your s54 with 6 speed transmission?


Sent from my Nexus 5 using Tapatalk

[Thujalvi]

Assuming we're talking about the Getrag 420, which has an 0.83 overdrive top gear, you can pretty much pick a ratio. I'd reckon pretty much anything between 3.64 and 2.93 should give a good balance of acceleration and low highway revs.

And of course you'll want an LSD.

[nando]

stock M3s come with a 3.62, many upgrade to 4.10s. personally I think a 3.73 would work pretty well, a little quicker but not too annoying. remember, you have 6 gears to play with..


2.93? whyyyyyy? the motor revs out to 8000rpm. it's not like you're going to run out of gear..

[nrubenstein]

stock M3s come with a 3.62, many upgrade to 4.10s. personally I think a 3.73 would work pretty well, a little quicker but not too annoying. remember, you have 6 gears to play with..


2.93? whyyyyyy? the motor revs out to 8000rpm. it's not like you're going to run out of gear..

I've currently got a 3.46 with the Euro motor. I'll be shifting that to the S62 car and probably sticking a 3.64 in.

With a 205/50-16, that's slightly more aggressive than stock M3 gearing. The 3.64 would be equivalent to a 3.91, 3.73 to 4.00, and a 3.91 equivalent to 4.20. The correction factor is 93% +/-, depending on the tire.

[The Dark Side of Will]

stock M3s come with a 3.62, many upgrade to 4.10s. personally I think a 3.73 would work pretty well, a little quicker but not too annoying. remember, you have 6 gears to play with..

2.93? whyyyyyy? the motor revs out to 8000rpm. it's not like you're going to run out of gear..

Because it makes plenty of low end thanks to the dual VANOS, so it can be turned slower for better highway mileage.

The E46 uses taller tires than an E30, so the same diff ratio results in shorter overall gearing.

[nrubenstein]

Because it makes plenty of low end thanks to the dual VANOS, so it can be turned slower for better highway mileage.

The E46 uses taller tires than an E30, so the same diff ratio results in shorter overall gearing.

My experience with the S54 is that it HATES that.

Also, what kind of idiot swaps in an S54 hoping for mileage?

[goarmy]

Probably a daily driver.. S54 guys that I know have gotten 20mpg running it hard between highway/street in the e46, that's not too bad..

[grk325]

Cool thanks for the input. I'm running 4.10 right now and I can say 1st to 3rd it revs way to quickly. I usually start off in 2nd gear during normal driving.

Sent from my Nexus 5 using Tapatalk

[Liquidity]

Because it makes plenty of low end thanks to the dual VANOS, so it can be turned slower for better highway mileage.

what kind of idiot swaps in an S54 hoping for mileage?

[nrubenstein]

Probably a daily driver.. S54 guys that I know have gotten 20mpg running it hard between highway/street in the e46, that's not too bad..

They are not getting 20mpg on ethanol gas running the car hard in combined driving.

And, again, my experience with the M3 (which I have owned one of for most of the last decade) is that it is not very sensitive to the revs you run while cruising. Traveling in 5th vs. 6th just doesn't seem to impact things noticeably.

[nrubenstein]

An M54B30 will do it better if you want low end torque and fuel economy.

[nando]

even better.. N52B30

[Wanganstyle]

Because it makes plenty of low end thanks to the dual VANOS, so it can be turned slower for better highway mileage.

The E46 uses taller tires than an E30, so the same diff ratio results in shorter overall gearing.

S54 HATES a really long final drive. S54 needs 3,62-4,10 to be in its happy place.

If you want to save gas with a S54 then a Hack ing it to The fucT type of beautiful conversion is probably also in the works with re-using the piston rings and cutting the intake cam with an angle grinder.

S54 needs revs; if you want to run a 2,93 you need to install a Turbo kit first.

[nrubenstein]

S54 HATES a really long final drive. S54 needs 3,62-4,10 to be in its happy place.

If you want to save gas with a S54 then a Hack ing it to The fucT type of beautiful conversion is probably also in the works with re-using the piston rings and cutting the intake cam with an angle grinder.

S54 needs revs; if you want to run a 2,93 you need to install a Turbo kit first.

It's an engine management issue, likely designed in to protect the rod bearings (high torque at low revs is very hard on them). The power available at normal revs with tall gearing would force you to shift into first gear all the freaking time in regular driving. Heck, before the Epic tune, it was a fair bit worse at low revs than my old S50US. An engine that is not exactly renowned for torque at low revs.

You don't need a LOT of revs, but you basically need to be over 2k. And staying over 2k with really tall gearing is a chore. And, again, the M54B30 will do a much better job of it.

[Wanganstyle]

It's an engine management issue, likely designed in to protect the rod bearings (high torque at low revs is very hard on them). The power available at normal revs with tall gearing would force you to shift into first gear all the freaking time in regular driving. Heck, before the Epic tune, it was a fair bit worse at low revs than my old S50US. An engine that is not exactly renowned for torque at low revs.

You don't need a LOT of revs, but you basically need to be over 2k. And staying over 2k with really tall gearing is a chore. And, again, the M54B30 will do a much better job of it.

agreed the S52 or m54 is a better street motor than S54; I ran it with 5 gears and 3,38 final drive and it annoyed me compared to a e46M3 with 3,62 or 3,91.