325i close ratio gearbox

[lsdinnz 0]

Need a close ratio gearbox for 87 M20 325i

[BM WORLD 1285]

you can use a getrag 220 from a e36 .

i have one for sale

[lsdinnz 0]

What E36 is it from, I am still a tad confused about what fits what?

[BM WORLD 1285]

What E36 is it from, I am still a tad confused about what fits what?

any model 316i 318i 318is 318ti 316ti 320i 323i 325i all use a getrag 220 box

328i and 3L m3 use a zf box though , but they will also fit onto a m20 engine

why do you need a box like this , is it for racing etc??

[lsdinnz 0]

Its for Targa, standard box always seems to be either revving its nuts off in 2nd or chugging in 3rd on twisty stages

[huff3r 347]

Its for Targa, standard box always seems to be either revving its nuts off in 2nd or chugging in 3rd on twisty stages

Would a shorter ratio diff fix that?

[lsdinnz 0]

An off the cuff reply would be that irrespective of the final drive you would not change the gear ratios between gears just overall top speed, happy to stand corrected on this, it would mean that 1st and second etc would be lower geared but the gap in ratios would be the same. Having used true close ratio boxes in other rally cars I don't think a lower diff ratio will fix the root issue.

[CamB 48]

That's right - it won't. You'll still have big gaps between gears compared to a proper close ratio box.

There is a getrag (245? I think) available for M20 engines, with a dog-leg first gear that's a proper close ratio box with a slightly taller first gear and 5th gear is 1:1 (ie the same as a normal 4th gear). They're rare, desirable and hence expensive.

The later ZF ones from E36 are reasonably close ratio - 1st gear is kinda short by comparison to the proper close ratio boxes but the remainder are reasonably close together. Since you no longer would have overdrive top gear you'd need to change to a suitable shorter diff (multiply your final drive ratio now by 81% to get a rough idea).

Edited March 21, 2011 by CamB

[BM WORLD 1285]

a good gear calculator

select your tyre size , gearbox type , diff ratio etc etc

http://members.dodo.com.au/~wawawa/revs.htm

[lsdinnz 0]

Thanks for the link.

I think that while I know I can play around with the final drive it won't get me what I want.

My understanding from what I saw when I searched was that I can use a Bellhousing from a E28 528e M20 and then I can use this with a 265/5 close ratio box. The problem with this is that I found three different bellhousing part numbers listed for a E28 528e M20, talk about confusing.

[BM WORLD 1285]

some of the early e21 323i and e30 323i had the close ratio box with the seperate bellhousing.

but they are all rare and old now and have crappy shifter systems etc

better to go with a e36 box , easier to find and replace etc

either the Getrag or ZF will do.

maybe even the 6spd ZF units from the 3.2l m3 or 330i and newer e46 plus models etc

or just get more power to over come your problem

[CamB 48]

The 6spd - didn't think of that. You (lsdinnz) could keep your final drive as top gear is an overdrive. 1st gear would be very short but all the gears in between would be good.

I have one I should probably sell - good price (as I got it for a good price), and it comes with shift cradle and propshaft.

Someone should correct me if I am wrong, but the ZF's mentioned and the 6spd don't mount on quite the same angle when on an M20.

(and a late edit - while you can probably find the right M20 bellhousing for a getrag 265, the short ratio one from the M3 is also rare and expensive).

Edited March 21, 2011 by CamB

[BM WORLD 1285]

The 6spd - didn't think of that. You (lsdinnz) could keep your final drive as top gear is an overdrive. 1st gear would be very short but all the gears in between would be good.

I have one I should probably sell - good price (as I got it for a good price), and it comes with shift cradle and propshaft.

Someone should correct me if I am wrong, but the ZF's mentioned and the 6spd don't mount on quite the same angle when on an M20.

(and a late edit - while you can probably find the right M20 bellhousing for a getrag 265, the short ratio one from the M3 is also rare and expensive).

correct all the later gearboxes (m50 m52 m54 ,m42 ,m43 m44 etc) will sit on a sleightly different angle , so you will have to modify or make a gearbox mount and you may also have to bend the gearshifter a bit .

[lsdinnz 0]

Thanks for all the advice . Just want to clarify;

• all the mentioned boxes will bolt straight up with out reworking the bell housing?
• What clutch and pressure plate is used, the M20 one?
• Does the starter motor bolt straight on?
• If the box is tilted at an angle is it away or towards the driver side, does it affect gearchanging as the linkage is at an angle irrespective of the gear lever position.
• If the gearbox is at an angle will that cause any lubrication issues
• When you say an angle how many degrees roughly?

CamB; The 6 speed you mentioned, is it a close ratio? what is it out of? I would be interested if its not going to be a headache to have installed and maintain. Will it handle being flogged for 5 days in the Targa?

I live up in the USA but the car is in Auckland at Bavarian, A 265/5 box up here in good condition goes for ~USD$3000.00 - $4000.00

[CamB 48]

I don't know re: the angle of the gearboxes. I can work it out if I think about it. I'm pretty sure it tilts the box away from the driver and recall its about 15 degrees. I believe you use M20 flywheel etc and its matching starter motor, but I am not sure and I've never done it before. I know people convert E36 to M20 single mass flywheel this way.

The 6spd box is out of an E36 M3 and should withstand any punishment an M20 can create (nothing substitutes for sympathetic driver though), and its the same ratios (approx) as the 5spd ZF mentioned earlier (and in that calculator link) but with an overdrive 6th gear so with your current diff it would be like having a slightly shorter 1st and 2nd and then 3 more gears to reach your current 4th gear (so 4 gears where you have 3), plus an overdrive. I don't know if it fits in an E30 tunnel (I believe yes, but not by much - Ray @ HellBM fit one into a Z3M) and don't know if being on a slight angle is bad for lubrication.

If the car's at Bavarian, ask Ernst - he'll have an opinion on what is and isn't a good idea.

I paid ~$1750 for the box and that's what I'd want for it - includes box, gearstick cradle, cross member and propshaft (you might need to get a custom propshaft made with the front of the E36 one and the rear of an E30 one). I think it even has the slave cylinder still attached.

(another late edit - I'd be most concerned to work out whether the box fits on an angle ----> there's internet evidence it fits when behind an M50/S50 but not an M20).

Edited March 22, 2011 by CamB

[BM WORLD 1285]

just use your old flywheel clutch starter etc no need to chnage that . you may have to use a different thrust bearing to get the correct clutch height travle etc .

one from a m20 e21 320i 323i will do .

just the bottom 3 small bolt holes dont line up , but not that important and could be redrilled if you relly wanted to bother.

the main 4 big bolts line up fine also the starter motor etc

[Silver Fox 43]

The 6 speed fits the E30 fine, we run one in the E30 race car behind the M54B30 with no mods.

We also use the light M20 flywheel with a custom clutch plate and std pressure plate, with a M20 starter.

Edited March 22, 2011 by Silver Fox

[hotwire 352]

The 6 speed fits the E30 fine, we run one in the E30 race car behind the M54B30 with no mods.

We also use the light M20 flywheel with a custom clutch plate and std pressure plate, with a M20 starter.

A starter that works sometimes aye David

Sorry, back on topic

[HELLBM 1560]

Can do you a ZF 328/M3/M Coupe 5 spd. box or a Evo M3 6 spd box installed if required. Maybe there is something you could do stateside for me.

[lsdinnz 0]

Thanks for the info all, going to talk to Ernst and then go from there will let you know what I ended up with.