6-speed manual swap into e36 m3

[MauiM3Mania]

When we did the six speed swap, a used 3.91 was located, was cheap and fit on the palette with the Getrag, driveshaft and etc. It's hardly useless, yeah... you get into second gear half way through the intersection if you are trying to not gather attention, but it is enjoyable for any level of driving beyond granny style.


As Jonathan said, the euro/S54 engines simply have the rpm range that allow it to work. Keep in mind, I don't have interstates to deal with. If I were to do it again and if the circumstances allowed, a 3.73 would have been my preference.

[kevinwilly]

When we did the six speed swap, a used 3.91 was located, was cheap and fit on the palette with the Getrag, driveshaft and etc. It's hardly useless, yeah... you get into second gear half way through the intersection if you are trying to not gather attention, but it is enjoyable for any level of driving beyond granny style.


As Jonathan said, the euro/S54 engines simply have the rpm range that allow it to work. Keep in mind, I don't have interstates to deal with. If I were to do it again and if the circumstances allowed, a 3.73 would have been my preference.

I had a hard choice. I've ended up with a 3.64, a 3.73, AND a 3.91 in various configurations sitting in my garage. I was rebuilding a diff for this project and had to decide which gearset I wanted to use. I chose the 3.64 because it's going to be a daily driver and I get onto the interstate quite a bit. Maybe the 3.73 would have been the better choice, but who knows? i can always build another one. I have all the parts except a diff housing, and those are dirt cheap to pick up. Maybe if I get bored this winter I'll build one. Maybe.

[MauiM3Mania]

Once you build the 3.73 (40% lock up please), ship it west. LOL

[kevinwilly]

Once you build the 3.73 (40% lock up please), ship it west. LOL

I was talking about building one up for a guy here locally. I said with parts and labor I'd give it to him for 700 bucks. He seemed to think that was insanely high. But just the gearset and LSD carrier are worth 250 or so. Then new bearings are about 75-80 bucks, plus some seals and whatnot. It would only take me an afternoon since I have a shop press and tons of leftover shims, so I was only going to charge a couple hundred in labor and clear some extra parts out. He didn't think it was worth it. If I get it built, I'll be selling either that one or my 3.64. SO stay tuned.

[jvit27]

FYI a 3.64+6spd cruises a hair below what a 3.23+5spd does on the highway; a 3.73 is just a hair over. There isn't much between them, pick one and be done.

For S50/S54 I recommend:
3.64 if you do interstate
3.73 if you don't care
3.91 if you track the car

FWIW the 3.91 will rev a bit higher in 6th than 3.23 in 5th. And for reference a 3.46 with 17's will be nearly identical to an E46 M3 with 18/19" wheels and the stock 3.62 gearing.

Personally I take my cars on trips, so highway MPG and civility is a factor in my decision but over the years I have also grown to appreciate the compromise of the stock gear sets the factory chose for both cars... my 3.23+6spd is perfect. E46 could be a little shorter since I run 19's, maybe a 3.91 in it's future but it's not a priority. Choosing a gear set for the track is circumstantial, but most of the differences in actual speed/acceleration are negated on the street by wheel spin, earlier shifts, narrower power bands, etc. An extreme example of this goes in the opposite direction where the big HP F/I guys actually go to a taller 2.93 or even 2.79 to stay in boost longer.

When we did the six speed swap, a used 3.91 was located, was cheap and fit on the palette with the Getrag, driveshaft and etc. It's hardly useless, yeah... you get into second gear half way through the intersection if you are trying to not gather attention, but it is enjoyable for any level of driving beyond granny style.

As Jonathan said, the euro/S54 engines simply have the rpm range that allow it to work. Keep in mind, I don't have interstates to deal with. If I were to do it again and if the circumstances allowed, a 3.73 would have been my preference.

I'm sure it's fun once you get going! I'd 'put up with' a 3.91 where you are too :P

[Braymond141]

I run my 6-speed with a 40% locking 3.38, but I was also boosted. This was a really nice combo for handling the power and excellent highway economy. With the S54 swap I was thinking 3.64 or 3.73, whichever is more affordable to buy.

[bmdubbayoo]

a lot of great info in this thread...

is there a place to source a used 6spd ZF GS6?

[kevinwilly]

a lot of great info in this thread...

is there a place to source a used 6spd ZF GS6?

There's not like one "go to" place. There's a few forums members that part out cars regularly. Forums, craigslist, junkyards, etc. m3forum probably has more active classifieds for the e46 m3, so I'd recommend heading over there. Bimmerforums is better for e36 stuff.

I've got a guy that parts out stuff in NJ. I got my S54 from him. Not sure what he charges for a manual, but if you PM me I can get you his name and number IF you are serious about buying. The engines he sell at VERY reasonable prices. Same with interiors. So I'd imagine the transmissions are a good price, too.

[Ex36]

I was talking about building one up for a guy here locally. I said with parts and labor I'd give it to him for 700 bucks. He seemed to think that was insanely high. But just the gearset and LSD carrier are worth 250 or so. Then new bearings are about 75-80 bucks, plus some seals and whatnot. It would only take me an afternoon since I have a shop press and tons of leftover shims, so I was only going to charge a couple hundred in labor and clear some extra parts out. He didn't think it was worth it. If I get it built, I'll be selling either that one or my 3.64. SO stay tuned.

Glad I wasn't that local guy--what a cheap bastard!

[MauiM3Mania]

Glad I wasn't that local guy--what a cheap bastard!

It takes all kinds.

[kevinwilly]

Glad I wasn't that local guy--what a cheap bastard!

Well, I'd give it to you for cost if you wanted it. But only because you're so pretty.

[Auto Parts Guy]

I have the 420G in my M3 with the 3.38 diff. Perfect combo IMO. I concur with the noise at idle when warm especially with the AC on due to the lightweight FW but I don't mind it. My M5 is the same. If I would have found a nice ZF 6 speed before I picked up the 420G, I wouldn't have thought twice about putting it in.

[adamnur]

I have the 420G in my M3 with the 3.38 diff. Perfect combo IMO. I concur with the noise at idle when warm especially with the AC on due to the lightweight FW but I don't mind it. My M5 is the same. If I would have found a nice ZF 6 speed before I picked up the 420G, I wouldn't have thought twice about putting it in.

Do you wish you had gone with the ZF? I didn't really know the 420 was considered "clunky" until now.

Sent from my SM-G935W8 using Tapatalk

[Braymond141]

The 420G is very good with a stock flywheel and clutch. Very easy to swap in too.

[Auto Parts Guy]

Do you wish you had gone with the ZF? I didn't really know the 420 was considered "clunky" until now.

Sent from my SM-G935W8 using Tapatalk

Not at all. I like the clunkiness (er, don't mind it). Reminds me of a racecar.

[JuCo]

Great information in this thread. Thank you all who contributed. I am seeking to locate a 6 speed ZF or Getrag to mate to my 210mm 3.15 differential I have for my Turbo M3. If anyone in this thread could provide me details of whom I can contact to seek a transmission with warranty I would gladly appreciate it.

[Baby ///M3]

I have a six-speed unit from the E46 M3 paired with a 3.91 diff. But my supercharged E36 is making around 380rwhp or so.

This combo is not as bad as some may think considering that I do equal amount of city/highway driving on my E36 (although it's not driven very often). Despite the lower gear ratio, I actually find myself shifting less driving around in the city, as I can just leave it in the fifth gear without shifting as long as I am not going slower than 20mph. 1st gear is still very useful going up a steep driveway and driving around in the parking lots.

Does anyone know how different ratios would impact the way a supercharged E36 accelerates? I had a hard time keeping up with a stock late model Mustang GT off the line this other day because I had to shift to 3rd even before we broke the speed limit.

Jon

[Braymond141]

I have a six-speed unit from the E46 M3 paired with a 3.91 diff. But my supercharged E36 is making around 380rwhp or so.

This combo is not as bad as some may think considering that I do equal amount of city/highway driving on my E36 (although it's not driven very often). Despite the lower gear ratio, I actually find myself shifting less driving around in the city, as I can just leave it in the fifth gear without shifting as long as I am not going slower than 20mph. 1st gear is still very useful going up a steep driveway and driving around in the parking lots.

Does anyone know how different ratios would impact the way a supercharged E36 accelerates? I had a hard time keeping up with a stock late model Mustang GT off the line this other day because I had to shift to 3rd even before we broke the speed limit.

Jon

In my opinion you're geared too short for the power and low rpm the S52 has. With an 8k rpm redline, shorter gearing makes a little more sense. 7k comes up too quickly and I'm sure you're fighting traction. Try a 3.38 or a 3.45/6. I ran a 3.38 with the S52 around the same power as you. 60mph should come up just as 2nd gear redlines iirc. Boosted cars need taller rear ends to take better advantage of the power, plus it will help with traction too.

[Baby ///M3]

Thank you very much for your comments and feedback.

What ratio are you currently using for your six speed now? I originally bought the 3.91 diff to go with my automatic transmission and didn't bother to switch it out when I replaced the auto with a manual box. I must not have driven the car hard enough, as I rarely spun the rear wheels even with this setup.

Since I am running 18in wheels, which somewhat alters the ratio, I wonder if I can still hit 60mph with a 3.46 or 3.64 ratio diff. A 3.38 would be a less costly option but I wonder how it compares with the 3.46 or a 3.64 unit with a six-speed tranny.

Jon

[Butters Stoch]

What's an Euro 6speed worth now a days ? I have one, debating on tossing it in. But if I break it, replacing it could be tough. I've broken a few transmissions so far, so I'm thinking about other options that are more readily available.
What do people pay for a decent euro 6spd ?

[Braymond141]

Thank you very much for your comments and feedback.

What ratio are you currently using for your six speed now? I originally bought the 3.91 diff to go with my automatic transmission and didn't bother to switch it out when I replaced the auto with a manual box. I must not have driven the car hard enough, as I rarely spun the rear wheels even with this setup.

Since I am running 18in wheels, which somewhat alters the ratio, I wonder if I can still hit 60mph with a 3.46 or 3.64 ratio diff. A 3.38 would be a less costly option but I wonder how it compares with the 3.46 or a 3.64 unit with a six-speed tranny.

Jon

The S54 going in will get paired with a 3.73 or 3.64 differential. Same clutch upgrade to 40% lock I did on the 3.38. I'm told the 3.46 is also a good choice with the lighter E36 and NA. I may run the 3.38 if I cannot find either in time. Eventually the S54 will see mild boost with a Vortech Ti charger. I may re-evaluate the differential choice at that time.

Maybe look for a 3.45. I believe they are cheaper than the 3.46. Upgrades can be had through Thayer http://thayermotorsports.com

[Baby ///M3]

Butters Stoch: I not not sure about the euro six-peed but you should be able to do an E46 six-speed conversion, including labor for less than $2k.

Braymond141: Compare to a N/A S52, does a supercharged S52 alter the appropriate ratio for the diff? I was thinking about getting a 3.46 but wonder if I'll see a big improvement by going with a 3.64 unit.

Jon

[Braymond141]

Butters Stoch: I not not sure about the euro six-peed but you should be able to do an E46 six-speed conversion, including labor for less than $2k.

Braymond141: Compare to a N/A S52, does a supercharged S52 alter the appropriate ratio for the diff? I was thinking about getting a 3.46 but wonder if I'll see a big improvement by going with a 3.64 unit.

Jon

I'm not sure what you mean by altering the ratio. The shorter the gearing the quicker that boosted motor is going to rip through the gears. Right now you are wasting the acceleration capabilities with the 3.91 and 380whp. 3.46 is what I would do if I were you. You should gain some traction control and not lose any off the line grunt.

[Baby ///M3]

Sorry. What I meant to ask was given the same six-speed transmission, would a boosted motor require a different diff ratio in comparison to a N/A motor.

You've already provided an excellent answer on point. Thank you!

Jon

I'm not sure what you mean by altering the ratio. The shorter the gearing the quicker that boosted motor is going to rip through the gears. Right now you are wasting the acceleration capabilities with the 3.91 and 380whp. 3.46 is what I would do if I were you. You should gain some traction control and not lose any off the line grunt.

[Braymond141]

Sorry. What I meant to ask was given the same six-speed transmission, would a boosted motor require a different diff ratio in comparison to a N/A motor.

You've already provided an excellent answer on point. Thank you!

Jon

First through fifth are identical on the 420g compared to the 310z/320z 5speed. Because you have that extra gear a 3.45-3.64 is more tolerable. A 5speed owner may want to go 3.23 or 3.38 to keep fuel economy.

Someone running lower boost and a 6speed might like 3.64-3.91 differential more.