Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.
Manual gearbox question!
-
- Newbie
- Posts: 23
- Joined: Mon Dec 11, 2017 10:37 pm
Manual gearbox question!
Out of interest, has anyone on here fitted a 6 speed box to a 2.5?
I'm finding my gearbox very short and wondered if a conversation to a 6 speed box was a solve!
I'm finding my gearbox very short and wondered if a conversation to a 6 speed box was a solve!
- ZedM
- Member
- Posts: 158
- Joined: Wed Sep 17, 2014 9:56 pm
- Location: Derbyshire
Manual gearbox question!
Personally I find the 5-speed perfectly matches the torque characteristics of the 2.5 M54. 3k revs at 70 mph - spot on. Happy in 5th at 1500 revs and pulls well right through the remainder of the rev range. BMW put a 5-speed with the 2.5 for good reason, although I'm sure both the 3.0 M54 and the 2.0 models both had 6-speed boxes and would think that maybe the 3.0 box would fit but might not suit the smaller engines outputs?? Someone with more knowledge will be along soon.
2003 Sterling Grey 2.5i SE, 17" Turbines and Falkens (no tramlining!), CDV Delete, Roof Motor Relocation by DLV.
- patriot66
- Lifer
- Posts: 3467
- Joined: Sun Jan 11, 2015 2:59 am
- Location: Mawdesley, Lancashire
Manual gearbox question!
My Zed is a 2.5i SMG. The gearbox is the same 6 speed manual fitted in the 3.0i. Perfect ratios for the 2.5i in my opinion although 6th is quite tall and I only really use it on dual carriageways/motorways. I'm not sure if the diff.ratio is the same for the 2.5i and 3.0i....maybe someone could clarify this.
Sterling Grey '03 2.5i SE / Infinitas Supercharger / S.M.G / Hardtop / Gloss Black 162s / Bilstein B4s / 3.0i Brakes / DLV De-Cat & Silencer / Rebuilt VANOS / Sonar 2Xcite Lights / Carbon & Alcantara Trim / M-Sport Seats / ...& Side Covers !
- Mr Tidy
- Legend
- Posts: 23608
- Joined: Wed Jul 02, 2014 12:18 pm
- Location: North West Surrey
Manual gearbox question!
I know what you mean OP.
My E46 is a 325ti so has the same engine and box as your Z4 (assuming it is a pre-facelift) so it also pulls 3,000 rpm at 70 mph.
This seems a bit high to me, but does have the advantage that if you want to pick up speed quickly on a motorway you don't really need to change down.
Having said that my nephew also had a 325ti, but his was a facelift model which got the 6-speed box and it was definitely more relaxed on motorways - more like 2,500 rpm at 70 mph IIRC.
I suppose in part it depends what you use it for - track days or B-roads blasts you're never going to need 6th!
My E46 is a 325ti so has the same engine and box as your Z4 (assuming it is a pre-facelift) so it also pulls 3,000 rpm at 70 mph.
This seems a bit high to me, but does have the advantage that if you want to pick up speed quickly on a motorway you don't really need to change down.
Having said that my nephew also had a 325ti, but his was a facelift model which got the 6-speed box and it was definitely more relaxed on motorways - more like 2,500 rpm at 70 mph IIRC.
I suppose in part it depends what you use it for - track days or B-roads blasts you're never going to need 6th!
Coupes because stunning!
Current - Silver Grey MC, Imola Red heated Nappa & carbon trim. Aeros, H & R Coil-overs, 224s, OE Strut brace, Nav, cup-holders, DSP Hi-Fi, pdc, cruise, MFSW, no CDV! E90 330i daily
Gone - Montego Blue
Gone - Ruby Black
Current - Silver Grey MC, Imola Red heated Nappa & carbon trim. Aeros, H & R Coil-overs, 224s, OE Strut brace, Nav, cup-holders, DSP Hi-Fi, pdc, cruise, MFSW, no CDV! E90 330i daily
Gone - Montego Blue
Gone - Ruby Black
- MACK
- Lifer
- Posts: 3600
- Joined: Mon Jun 15, 2015 11:38 am
- Location: Manchester
Manual gearbox question!
Not sure if it applies to the pre facelift Zed but on the 330i E46 when Bmw went from fitting a 5 speed to a 6 speed as standard the ratio's were basically the same 1-5 with 6th giving a more relaxed motorway cruise and slightly better fuel economy on a run.
Might be worth finding the stats for the zed and putting them into one of the online gear/diff ratio calculators to see what you will actually get from changing.
Might be worth finding the stats for the zed and putting them into one of the online gear/diff ratio calculators to see what you will actually get from changing.
Silver 05 3.0i SE
Mods inc - F/L Xenons Clear Ind Rear Lights M Sport Seats & Wheel Eibach/B4 3.64 DIFF (SOLD)
White E89 20i M Sport
Mods inc- B12 kit, M3 Arms, 18" Zito 935's with PS4's, Decat & Remap, Switchable Exhaust Flap (SOLD)
Mods inc - F/L Xenons Clear Ind Rear Lights M Sport Seats & Wheel Eibach/B4 3.64 DIFF (SOLD)
White E89 20i M Sport
Mods inc- B12 kit, M3 Arms, 18" Zito 935's with PS4's, Decat & Remap, Switchable Exhaust Flap (SOLD)
- Steve84N
- Senior Member
- Posts: 1828
- Joined: Tue Jul 21, 2015 1:00 pm
Manual gearbox question!
6th in my coupe is 76mph on the motorway at 3,000rpm.
The ratios are slightly shorter on the coupe than the roadster though for better acceleration, I think it's the final drive that's different.
The ratios are slightly shorter on the coupe than the roadster though for better acceleration, I think it's the final drive that's different.
C63 AMG Estate 6208cc
-
- Senior Member
- Posts: 1424
- Joined: Thu Aug 24, 2017 12:57 pm
- Location: Leamington Spa
Manual gearbox question!
I always find this site useful:
http://www.bokchoys.com/differential/GearRatios.htm
I think generally gears 1-5 are the same, but then 6th adds an overdrive for cruising. Bear in mind also the 3.0 has a longer diff than the 2.5, which will affect how all the gears feel. and a diff swap is a relatively easy thing to do.
http://www.bokchoys.com/differential/GearRatios.htm
I think generally gears 1-5 are the same, but then 6th adds an overdrive for cruising. Bear in mind also the 3.0 has a longer diff than the 2.5, which will affect how all the gears feel. and a diff swap is a relatively easy thing to do.
- Machine monkey
- Lifer
- Posts: 11310
- Joined: Thu Oct 04, 2012 12:49 pm
- Location: In the shire Oxfordshire
Manual gearbox question!
I think the bell housings are identical. And the engine architecture is the same. So yes it will fit no problem. I would imagine that they are the same length also. Worst case scenario you may need a 3.0l prop shaft as well.
- GuidoK
- Lifer
- Posts: 3171
- Joined: Tue Aug 17, 2010 1:37 am
- Location: all over the place
Manual gearbox question!
^5 box is shorter in lenght, so def. a 3.0 propshaft needed.
Also a new clutch might be needed, the early 5 speeds are 9 spline and all 6 speeds (and later 5 speeds) are 22.
I dont know if that also requires a new dmf.
Also a new clutch might be needed, the early 5 speeds are 9 spline and all 6 speeds (and later 5 speeds) are 22.
I dont know if that also requires a new dmf.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch
- Mr Tidy
- Legend
- Posts: 23608
- Joined: Wed Jul 02, 2014 12:18 pm
- Location: North West Surrey
Manual gearbox question!
That's interesting - is 76 mph based on GPS? My Coupe tends to be showing almost 80 mph at 3,000 rpm!
Coupes because stunning!
Current - Silver Grey MC, Imola Red heated Nappa & carbon trim. Aeros, H & R Coil-overs, 224s, OE Strut brace, Nav, cup-holders, DSP Hi-Fi, pdc, cruise, MFSW, no CDV! E90 330i daily
Gone - Montego Blue
Gone - Ruby Black
Current - Silver Grey MC, Imola Red heated Nappa & carbon trim. Aeros, H & R Coil-overs, 224s, OE Strut brace, Nav, cup-holders, DSP Hi-Fi, pdc, cruise, MFSW, no CDV! E90 330i daily
Gone - Montego Blue
Gone - Ruby Black
- Steve84N
- Senior Member
- Posts: 1828
- Joined: Tue Jul 21, 2015 1:00 pm
Manual gearbox question!
I'm running 245/40/18 which is a larger circumference.
Stock speedo over reads by around 2-3mph but with these tyres it's almost bang on against GPS.
Stock speedo over reads by around 2-3mph but with these tyres it's almost bang on against GPS.
C63 AMG Estate 6208cc
-
- Newbie
- Posts: 23
- Joined: Mon Dec 11, 2017 10:37 pm
Manual gearbox question!
Thanks for all the advice guys, really helpful info there.
I might look out for a six speed box to rebuild and gather the other bits up ready for a conversation.
I've got a couple of other priorities at the mo on my house so as soon as they are done I'll crack on.
Thanks again.
I might look out for a six speed box to rebuild and gather the other bits up ready for a conversation.
I've got a couple of other priorities at the mo on my house so as soon as they are done I'll crack on.
Thanks again.
-
- Lifer
- Posts: 5277
- Joined: Wed Feb 19, 2014 3:01 pm
- Location: NW London
Manual gearbox question!
NCS has some options for setting wheel size if the mileage is out.
3.0si Sport: F10 Illuminated ZHP, Retrofit Cruise, OE Stubby, Gaptech RCH+, Kenwood BT73DAB + Handsfree, HIDs, LED Sidelights, OE LED Number Plate Lights, Custom LED strip bootlight.
- Steve84N
- Senior Member
- Posts: 1828
- Joined: Tue Jul 21, 2015 1:00 pm
Manual gearbox question!
Good to know, I won't be playing around with it though as the car will no longer be mine by next Wednesday.
C63 AMG Estate 6208cc
- kis
- Lifer
- Posts: 4536
- Joined: Wed Jul 20, 2016 2:33 pm
- Location: Surrey / West Sussex Boarder
Manual gearbox question!
6th in my SMG (3.0i) sits at 2500rpm at 70mph
My E85 Z4 3.0i SMG
BMW Family History (past and present):
1 Series - E87
3 Series - E46 Coupe, E46 M3, E90 (x3)
4 Series - F36, F82 M4
5 Series - E34 (x2), E39
7 Series - E32
X5 - E53, E70
X6 - E71
BMW Family History (past and present):
1 Series - E87
3 Series - E46 Coupe, E46 M3, E90 (x3)
4 Series - F36, F82 M4
5 Series - E34 (x2), E39
7 Series - E32
X5 - E53, E70
X6 - E71