The semi-Comprehensive M60b40 into E30 swap Q&A

[bmwmech1]

i saw that, but i'm still confused towards the 6spd. he said e39 flywheel has to be used for the 5spd, but does that mean an e34 one would work with the 6?

Hey man, I thought I'd jump in and clear up some of your confusion... THE main difference between the 2 transmissions, besides the extra gear is the input shaft diameter and number of splines. The 6 speed was used in the E34 and E39 so either flywheel will work for the 6 speed, you just need the proper 6 speed clutch kit diameter for the flywheel you are using. The 5 speed proper clutch kit, with the correct shaft diameter and spline count only comes in a 240mm diameter friction disc, which negates being able to use the E34 6 speed flywheel which uses a 265mm diameter friction disc. You can use an E34 5 speed flywheel from an M60B30 or an E39 540i flywheel from an M62B44, which both utilize the 240mm friction disc diameter. Clutch kit for the 5 speed should be sourced as a E36 328i or E39 528i clutch setup, in whatever stage of performance you choose. Plenty of options out there. As far as lightweight flywheels go, either size can be used for the 6 speed, only the 240mm diameter unit for the 5 speed. The E34, 265mm clutch/flywheel setup will only work for the 6 speed. Bruce has a pretty comprehensive breakdown on what fits and what doesn't, we'll see if he chimes in.

Hope this helps...

Garey

[Jean]

E34 6speed is still a massive dual mass pos.

[mkcman17]

i saw that, but i'm still confused towards the 6spd. he said e39 flywheel has to be used for the 5spd, but does that mean an e34 one would work with the 6?

[Jean]

http://www.r3vlimited.com/board/showpost.php?p=2828526&postcount=46

[mkcman17]

sorry if i've missed this, but which flywheels need to be used with which trans?

[Jean]

Those manifolds are $404 new EACH. There's gotta be a better way to source those headers.....

Ideas?

Ebay, I bought one side for $89 with the cat ;)

[Garageaholic]

Those manifolds are $404 new EACH. There's gotta be a better way to source those headers.....

Ideas?

[BruceBe]

The whole idea behind gearing is to keep the engine in an RPM range that maximizes the "area under the curve" - the power curve. This allows the engine to do the most work in propelling the car forward. So, for an engine with a very narrow power curve (high peak HP, but quickly rising and falling off), then the gearing is selected to keep the engine operating in that narrow band. This would require more gears/shifts than an engine with a flat torque curve and generous HP curve.

The examples you give could be completely valid - for the particular track. At another track, the short-geared car would run out of RPM, or, coming off a particular corner, the short-geared car could find itself running out of 2nd gear, and bogging 3rd, as it's heading on to a long straight. Well-funded teams will keep data for each track, and change both transmission and diff ratios accordingly.

Both the 5 and 6-speed boxes have about the same gear ratios, 1st thru 5th, with the 6-speed adding a .83:1 6th gear. Unless you were competing on a track with *really* long straights, and you optimized the diff ratio for the length of straight, I don't see a very significant advantage for this particular six-speed with the V8.

-Bruce

[Mr Two]

The main reasons I've been considering a 6 spd heavily:

They seem to be more common than 5 spds. I've seen many of them listed for sale but not many 5spds.

Ltw flywheel prices are fairly similar - you don't seem to end up spending that much more for a 6 spd setup. UUC makes one with a 13lb wheel and a performance organic clutch for $1599, VAC makes one with an OEM M5 clutch for $1500 at 13.5lbs. Since you need an e39 flywheel with the 5spd, JBR appears to go for $800 and clutch kits are $400 or so, right?

The extra weight is in a good spot - near the middle and down low.

It would let me get both a higher top speed, and faster acceleration compared to a 5spd setup when paired with the right diff, + the higher ratio diffs can use all different kinds of clutch setups that are off limits to the 2.93 and 2.79. 40% lock sounds nice.

Brucebe, you are undoubtly more experienced in this matter than I am, speaking of gearing for track use. Surely the car will still do quite well with long gearing, but assuming the same top speed and no wasted shifts on a given track, wouldn't the 6spd car be significantly faster? The only knowledge I'm going off of is watching some Best Motoring video of an S2000 with 4.33 gears as opposed to stock 4.10s gaining a significant lead over the stock car, more so than the difference in driving skill would make possible, and seeing my friends B16 powered Civic hatch running some extremely fast times around the local track partially due to the transmission he built for it - it had such short gearing but since the track had a relatively short straight he made the most out of every gear and took down some much more powerful cars with only 170whp.

[FunfGan]

I'm running a 2.93LSD in theory only right now, since the car only sits in the shop and stare back at me, so I'll report back once it actually runs, lol!

Garey

Thanks! Haha. Feel free to chime in anybody else, trying to get this stuff saturday :p

[bmwmech1]

Diff size/ gearing with 5spd? The threads I've read say even a 2.95 is a little high, but I can get a great deal on a 3.25...

I'm running a 2.93LSD in theory only right now, since the car only sits in the shop and stare back at me, so I'll report back once it actually runs, lol!

Garey

[FunfGan]

Diff size/ gearing with 5spd? The threads I've read say even a 2.95 is a little high, but I can get a great deal on a 3.25...

[dothadance]

room for turbo?? :D

[bmwmech1]

Garey - did you find a collection of OEM bits that make the shifter a bolt-in? Just curious - I'm pretty happy with what we've come up with, but I'll almost always defer to the factory, when the parts will fit.

-Bruce

Haha, I've not gotten to that point yet. I had heard that the E28 stuff may work, but I can't confirm. I was just planning on shortening the E34 stuff to the right dimensions. I guess I should have said that in my post you quoted, so as not to confuse anyone... it's an "almost" bolt-in affair, Lol! I was more referring to the trans mount and DS being OEM stuff... forgot about the shifter.

Garey

[BruceBe]

The nice thing about the 5 speed is it is a completely bolt-in affair, using off the shelf parts.
Garey

Garey - did you find a collection of OEM bits that make the shifter a bolt-in? Just curious - I'm pretty happy with what we've come up with, but I'll almost always defer to the factory, when the parts will fit.

-Bruce