LSD upgrade, any thoughts
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Category: Technical & Model Specific Forums
Forum Name: BMW ///M Power
Forum Discription: Ask your BMW M Power Technical Questions here (M1, M2 hybrids, M3, M5 & M6)
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=30484
Printed Date: 05-May-2024 at 11:29
Topic: LSD upgrade, any thoughts
Posted By: M3Kris
Subject: LSD upgrade, any thoughts
Date Posted: 16-May-2006 at 12:41
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Hello (e30)M3 race and trackday experts, I am having my diff done because it started making noise. Now my thinking is while they are at it I can as well have it upgraded from 25% to 40% Lslip. But, what would it get me. I use the car for track days and to get to them and for the occasional drift practice. Any thoughts on this? Thx, Kris
------------- M3 1990 |
Replies:
Posted By: 215DMX
Date Posted: 16-May-2006 at 14:55
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Drop, JON90 a PM, he's got some 40% slip rings in
his. Mine are still sitting on the shelf........ |
Posted By: M3cK
Date Posted: 16-May-2006 at 15:03
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M3Kris Is your noise an 'offbeat rotational droning' ? I think mine has got a prob! Does anyone know rough costs for having a standard one rebuilt.? ------------- '89 E30 M3 Made in Munich |
Posted By: M3Kris
Date Posted: 16-May-2006 at 16:37
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M3CK,
I have the wining noise, first when the diff oil was warm, now at all times. In NL and Germany they quote around 300 Euro for rebuilding the standard diff with normal wear. What is the mileage on yours? ------------- M3 1990 |
Posted By: M3cK
Date Posted: 16-May-2006 at 16:40
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Just gone 100k (m)
------------- '89 E30 M3 Made in Munich |
Posted By: M3Kris
Date Posted: 16-May-2006 at 16:44
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Mine has just over 100k m as well....recent oil change did not improve anything so have to go the rebuilding way. ------------- M3 1990 |
Posted By: M3cK
Date Posted: 16-May-2006 at 16:49
Snap! 
------------- '89 E30 M3 Made in Munich |
Posted By: Eamo
Date Posted: 17-May-2006 at 05:24
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Kris
Very worthwhile upgrade is changing the diff ratio as well Assuming you have a standard car you will have a 3.25 diff. Change this to a 3.64 and it will make a world of differnece. Thats what I did with my Cecotto. ------------- |
Posted By: jpboost
Date Posted: 17-May-2006 at 05:59
| My diff rebuild (std) cost me around £150. I'd assume a little bit more (+£50? labour on top of the extra parts) if upgrading to 40% slip rings. |
Posted By: M3cK
Date Posted: 17-May-2006 at 12:46
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Eamo Is the recommendation to change to a 3.64 (40%?) diff so it's better for track use.....or.....better all round in and more in character with the car.? (If you know what i'm trying to say!) Thanks for the figures 'jpb' ------------- '89 E30 M3 Made in Munich |
Posted By: M3Kris
Date Posted: 17-May-2006 at 13:42
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Eamo, I now have 3.25 which seems to suit the Spa racetrack and Ring. When I drive in Germany it is max if possible and then the standard gearing gives max revs at 250 kph on the clock. For shorter gearing I opt for 205-50 tyres. But what will be the advantage of having the 40% LSD, can I accelerate harder out of corners? The diff upgrade would be around 400 euro + some 150 for worn bearings etc.
------------- M3 1990 |
Posted By: M3DTM
Date Posted: 17-May-2006 at 16:17
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????? Can someone please explain? John ------------- A properly sorted E30 M3 is still 'King of the Ring' |
Eamo wrote:Posted By: Eamo
Date Posted: 17-May-2006 at 17:26
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Upgrading your standard 3.25 diff to a 3.64 diff will vastly improve acceleration up through the gears however it will lower your top end speed by 10/15mph.
depending on what tracks you visit most can determine the best ratio diff to be used i.e. if the track is short, twisty with short straights then a 3.91 is perfect for you. However the down side to this is that your top end speed will reduced to around 120mph. I found that the acceleration with this diff to be fantastic but road use was not nice as the car was at high revs most of the time. the 3.64 while not having as much acceleration as the 3.91 was still a huge improvement over the 3.25 and a perfect compromise for regualr track and road use. If however you have a evo2 or se which have a 3.15 diff, a 3.46 diff from the 320is would be a sensible upgrade. ------------- |
Posted By: Eamo
Date Posted: 17-May-2006 at 17:29
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sorry - also meant to say that hardcore m3 track guys will depending on the track change diffs based on the track they are going to ------------- |
Posted By: M3DTM
Date Posted: 19-May-2006 at 04:02
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Eamo, I normally drive my car to the circuits which means on the motorway it normally does 4000 rpm (with standard 3.25). How much will that be with the 3.64 fitted? John ------------- A properly sorted E30 M3 is still 'King of the Ring' |
Posted By: Eamo
Date Posted: 19-May-2006 at 04:27
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JOhn
In that scenario I think you'll be hitting arond 4800rpm instaed ------------- |
Posted By: Eamo
Date Posted: 19-May-2006 at 04:31
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Actually John try this http://www.diffsonline.com/techinfo/...Calculator.xls - online diff calculator
Just enter wheel size, gearbox ratio and diff ratio ------------- |
Posted By: M3Kris
Date Posted: 19-May-2006 at 05:05
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Got my final quote for a reman diff with 40% LS and Z3M cover, total 580 euro ex. VAT. John, Which tracks are you visiting? ------------- M3 1990 |
Posted By: falkster
Date Posted: 19-May-2006 at 06:04
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Eamo where will I get the ratios for the standard gearbox please? ------------- Z3M Roadster (gone....just...but not forgotten...yet) E30 M3 (Toy) Alfa 147 (just gone) BMW 330d (new work horse) Daimler Double 6 (no idea yet) |
Posted By: Eamo
Date Posted: 19-May-2006 at 06:12
here ya go boss http://www.s14.net/specplus/comparisons.html - click link ------------- |
Posted By: falkster
Date Posted: 19-May-2006 at 06:18
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Only place I didnt look!!! Thanks mate ------------- Z3M Roadster (gone....just...but not forgotten...yet) E30 M3 (Toy) Alfa 147 (just gone) BMW 330d (new work horse) Daimler Double 6 (no idea yet) |
Posted By: M3DTM
Date Posted: 19-May-2006 at 07:25
I'm on the Mainland, but hope to visit some circuits in the UK... John ------------- A properly sorted E30 M3 is still 'King of the Ring' |
Posted By: M3Kris
Date Posted: 19-May-2006 at 11:08
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John, so am I, south of NL, it is called Belgium! I would also like to visit some UK tracks but I can hardly manage the ones over here...car to repair, family needs attention...etc. Do know of any trackdays coming up soon? What did you prepare on your M3 for trackdays? Thx, Kristian
------------- M3 1990 |
Posted By: Mike 90 M3
Date Posted: 19-May-2006 at 11:36
Here you go mate. (4000/3.25) x 3.64 = 4480 rpm Rocket science ------------- If everything seems under control, then you're just not going fast enough.... 
|
Posted By: DAWIEM3
Date Posted: 19-May-2006 at 14:35
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My feelings on this in brief are Track only car - 3.91 or shorter depending on circuit. Trailered everywhere. Track car / occational road use 3.73 Track / road car use on the ring, and driven there - 3.64 Road car occational tracked - 3.46 Road car driven by a an OAP - 3.25
Its basically all down to what the car is used for, your driving style, how hard you drive, engine mods, tyres etc. 40% updrade will work well in all cases except if you are an OAP, as your reactions my be a bit slow to catch it if it bites. Regards,
Dave ------------- E30 M3 Road car ( Now in Hongkong ) E30 M3 Track Car S14 2.0L 2002 in progress E30 C2 2.7 Alpina E36 M3 3.2 EVO |
Posted By: M3DTM
Date Posted: 19-May-2006 at 14:57
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Although this was not my topic thanks for all the reactions, particularly Dave. @Kristian, You could try Zandvoort next Friday, the 26th of May. This is organised by the BMW Drivers Club ( http://www.bmwdriversclub.nl - www.bmwdriversclub.nl ). They always charge around € 125.00 for a trackday at Zolder, Spa, Zandvoort, or Assen. There is another club called Tracktime (set up by a group of doctors/pharmacists) which organises days at Zolder and Zandvoort and you could always go to the Nordschleife (although I would recommend on weekdays only). I would really love to do some trackdays in the UK, particularly Donington, Bedford and I think it's Castle Combe. As for trackday preparation, there are some guys on this forum who seem to have gone all the way. Their cars (i.e. E30 M3s of course John ------------- A properly sorted E30 M3 is still 'King of the Ring' |
) are a lot more interesting than mine. Mine is a basic 200 bhp model with standard rev limiter and still standard diff, Wilwood brakes now changing to AP 4 pots, yellow Koni shocks with Koni springs, Eibach stabilizer, camber plates, Sparco Pro2000 racing seats and Sabelt 4 point harness and rear cage from a German manufacturer (sorry forgot the name, not Wiechers or Matter).Posted By: DAWIEM3
Date Posted: 19-May-2006 at 15:09
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John,
We all started somewhere, and grew with our cars. That way your driving skills improve with the car and you don`t end up taking it back home on a low bed. You are doing it the right way, safety first, handling, braking, and then the additional power. I would add Oulton Park to your list of UK circuits. Regards,
Dave ------------- E30 M3 Road car ( Now in Hongkong ) E30 M3 Track Car S14 2.0L 2002 in progress E30 C2 2.7 Alpina E36 M3 3.2 EVO |
Posted By: M3Kris
Date Posted: 19-May-2006 at 16:33
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Dave, What is an OAP? John, what kind of camberplates do you use; I just upgraded to Gr N suspension and am looking for some advice on camber plates.
------------- M3 1990 |
Posted By: M3DTM
Date Posted: 19-May-2006 at 17:08
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Hopefully this link still works... http://img172.imageshack.us/img172/1401/veerpootm3a6ke.jpg" target=_blank veerpootm3a6ke.jpg? 1401 img172 img172.imageshack.us http:>http://img172.imageshack.us/img172/1401/veerpootm3a6ke.jpg else at the bottom of this topic... http://www.bmwcarclubforum.co.uk/forum_posts.asp?TID=30420&PN=2 - http://www.bmwcarclubforum.co.uk/forum_posts.asp?TID=30420&a mp;a mp;a mp;a mp;PN=2 John
------------- A properly sorted E30 M3 is still 'King of the Ring' |
Posted By: piers66
Date Posted: 20-May-2006 at 04:10
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Kris
OAP = Old age pensioner Try Motorsport Engineering (Bill Fiddler)for height/camber/castor adj. topmounts (p/n 1228) - approx £235 + VAT (or your equivalent) for a pair. 00441257453777 Alternatively Roger at Muzzimotorsport (Austria) 00436765006172 Cheers Piers ------------- piers66 |