All times are UTC

 




Post new topic  Reply to topic  [ 8 posts ] 
Author Message
 Post subject: BMW Haynes gearing...
PostPosted: Sun Jan 05, 2014 9:59 am 
Offline
User avatar

Joined: Wed Dec 18, 2013 9:45 am
Posts: 57
Name:
Location: Barnsley
Just took the rear cover off the Sierra diff that came with my Haynes. Looks like it has an LSD and is a 3.62.

I was bored so thought I'd work out the gearing using my BMW 323i gearbox.

Using 205/50/15 tyres and revving to 7Krpm the max speed in each gear will be-

1st 31mph
2nd 53mph
3rd 80mph
4th 109mph
5th 133mph

Seems quite reasonable to me and fair to say it won't be exploring the upper limits of 5th too often, but will give a 4krpm cruising speed of 76mph.
The engine's going to be a nice torquey 2.8 M52 that will rev to 7K but realistically it's not going to be spending much time up around there, unless I have a death wish!! I reckon 1st gear might be pretty much redundant for all but the quickest of getaways or the steepest of hills.

If I go for a 3.14 it'd hit 61mph in 2nd and be doing 3600rpm @ 80mph but have a theoretical top speed of 153mph!!
It would be a better option but I'm not going to bust a gut (or the bank) to get one.


Top
   
PostPosted: Sun Jan 05, 2014 2:39 pm 
Offline
Site Moderator
User avatar

Joined: Sun Dec 02, 2012 3:59 pm
Posts: 1016
Name: Bruce
Location: Biggleswade
I did some calculations on mine and came up with similar conclusions regarding first gear, it'l probably get used for fun purposes only :lol:

forum/viewtopic.php?f=9&t=306


Top
   
PostPosted: Sun Jan 05, 2014 5:12 pm 
Offline
User avatar

Joined: Sun Dec 02, 2012 3:27 pm
Posts: 34
Name:
Location: Tydd St. Mary
This is the easy way http://www.catherineandken.co.uk/sti/tyres.html a simple gear calculator. Change the diff ratio, click and new speeds in all gears, simples

Sent this then looked at your calculator :roll:

_________________
Be Lucky Mike.


Top
   
PostPosted: Sun Jan 05, 2014 6:39 pm 
Offline
Site Moderator
User avatar

Joined: Sun Dec 02, 2012 3:59 pm
Posts: 1016
Name: Bruce
Location: Biggleswade
Cheers Mike, your one's better as it does all 6 gears :D The one I used only did 5.


Top
   
PostPosted: Sun Jan 05, 2014 8:00 pm 
Offline
User avatar

Joined: Wed Dec 18, 2013 9:45 am
Posts: 57
Name:
Location: Barnsley
I used this one-

http://www.endtuning.com/gearratios.html


Top
   
PostPosted: Sun Jan 05, 2014 9:20 pm 
Offline
User avatar

Joined: Mon Dec 17, 2012 11:22 pm
Posts: 330
Name:
Location: Coedpoeth N.Wales
Got the Sierra diff.How do I find the Ratio :?: Is it a code on the casing :?:


Top
   
PostPosted: Sun Jan 05, 2014 9:55 pm 
Offline
Site Moderator
User avatar

Joined: Sun Dec 02, 2012 3:59 pm
Posts: 1016
Name: Bruce
Location: Biggleswade
Everything and more than you ever needed to know :lol:

http://www.super7thheaven.co.uk/Sierra_ ... fferential


Top
   
PostPosted: Mon Jan 06, 2014 7:04 am 
Offline
User avatar

Joined: Wed Dec 18, 2013 9:45 am
Posts: 57
Name:
Location: Barnsley
Quote:
Got the Sierra diff.How do I find the Ratio :?: Is it a code on the casing :?:
If the ally tab's gone missing from the outside then you'l have to take the cover off and it'll be written on the crownwheel.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 8 posts ] 

All times are UTC

 


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron

Copyright 2016: Roadster Builders

 

Powered by phpBB® Forum Software © phpBB Limited