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BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > Ohlins



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      03-04-2013, 08:56 PM   #1
melenkae90
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Ohlins

Anyone know how low ohlins can go? And are stock spring rates to soft to run aggressive wheel fitment?
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      03-04-2013, 09:48 PM   #2
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Apparently not too low. You have to use SWIFT springs to get lower on Ohlins R&T
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      03-05-2013, 02:00 AM   #3
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Quote:
Originally Posted by melenkae90 View Post
Anyone know how low ohlins can go? And are stock spring rates to soft to run aggressive wheel fitment?
The standard Ohlins rear spring rates are far too soft, and are this rate beacuse of the soft subframe bushes. So yes, too soft for aggressive wheel fitment.

How low do you want to go?

You can adjust so the front arch lower lip about level with the tyre top edge, and the rear tyre is fairly well up into the arch.
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      03-05-2013, 04:18 AM   #4
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Quote:
Originally Posted by Techevo View Post
The standard Ohlins rear spring rates are far too soft
Too soft for what? The race track maybe, but for road use I find them just fine thank you.
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      03-05-2013, 04:21 AM   #5
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Quote:
Originally Posted by Techevo View Post
The standard Ohlins rear spring rates are far too soft, and are this rate beacuse of the soft subframe bushes. So yes, too soft for aggressive wheel fitment.

How low do you want to go?

You can adjust so the front arch lower lip about level with the tyre top edge, and the rear tyre is fairly well up into the arch.
Ya i kinda figured the spring rates were on the soft side. I dont want to slam my car or anything like that just enough so it looks good. Only thing is wheels im getting are aggressive and i dont want the rim to hit on my fenders ya know
Ive been researching coils and these are getting great reviews and i dont know what will be best for my setup?
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      03-05-2013, 08:44 PM   #6
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Quote:
Originally Posted by Phil325i View Post
Too soft for what? The race track maybe, but for road use I find them just fine thank you.
Good for you, but with passengers and luggage the car will be pretty well riding on the bump stops.

Also, if you work out the suspension frequencies, the front/rear ratio is completely out of wack. Standard, it has a rear bias of 6.7%, the Ohlins standard rates create a forward bias of 34.6% and this ruins the balance of the car.

If all you want is to bimble about, then it's fine (and you could have saved £1000 and fitted Koni's and Eibachs for an even comfier ride)

If you want any sort of decent dynamics on the road, then the rear rates are far too soft.

I run an E91 (my shopping/tow car) and have used Koni yellows/Eibachs, then Ohlins with the standard rates, 343/672 and 400/800.
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      03-05-2013, 08:57 PM   #7
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Quote:
Originally Posted by melenkae90 View Post
Ya i kinda figured the spring rates were on the soft side. I dont want to slam my car or anything like that just enough so it looks good. Only thing is wheels im getting are aggressive and i dont want the rim to hit on my fenders ya know
Ive been researching coils and these are getting great reviews and i dont know what will be best for my setup?
It will rub with aggressive wheels, with any kind of weight in the back.

The standard fronts with 672 rear swifts is a really nice setup. You'll preferably want uprated subframe bushes with these springs.

The Ohlins dampers are very, very good.
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      03-06-2013, 02:50 PM   #8
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I noticed that the kit for the E92 M3 comes with the same front spring rates as the non M but much stiffer rear rates:

SPRING RATES:
Front: 60 N/mm (343 lbs/in.) Rear: 120 N/mm (685 Lbs/in.) M
as opposed to 60 N/mm front and 70 N/mm Rear for non M.
I wonder what the reasoning behind this is, is the lower rate based on the softer subframe bushings for the non M or do you think it's just that the M3 rear set up is different?
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      03-06-2013, 03:41 PM   #9
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My educated guess as to why the non-M has lesser rear spring rates vs the M3 is because the non-Ms don't come with LSDs from the factory.
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      03-06-2013, 06:40 PM   #10
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Quote:
Originally Posted by CJ421 View Post
My educated guess as to why the non-M has lesser rear spring rates vs the M3 is because the non-Ms don't come with LSDs from the factory.
That, aswell as the M3 uses much stiffer subframe bushes allowing harder spring rates. Higher rate rear springs and soft subframe bushes will cause the subframe to be 'levered' away from the chassis, causing even more subframe movement and the unsettled feeling it gives.
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      03-06-2013, 07:10 PM   #11
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Quote:
Originally Posted by Techevo View Post
That, aswell as the M3 uses much stiffer subframe bushes allowing harder spring rates. Higher rate rear springs and soft subframe bushes will cause the subframe to be 'levered' away from the chassis, causing even more subframe movement and the unsettled feeling it gives.
That's a very good point.
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      03-06-2013, 11:49 PM   #12
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Quote:
Originally Posted by melenkae90 View Post
Anyone know how low ohlins can go? And are stock spring rates to soft to run aggressive wheel fitment?
Ohlins are designed for ~20mm lowering. Some cars may see more lowering. Beyond that, you will need to replace the Ohlins springs with Swift of proper length and rate.
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      03-06-2013, 11:52 PM   #13
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Quote:
Originally Posted by Techevo View Post
That, aswell as the M3 uses much stiffer subframe bushes allowing harder spring rates. Higher rate rear springs and soft subframe bushes will cause the subframe to be 'levered' away from the chassis, causing even more subframe movement and the unsettled feeling it gives.
The reason is that the deflections caused by the high rate springs aren't and can't be controlled by the rear dampers.
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      03-07-2013, 02:11 PM   #14
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Originally Posted by HP Autowerks View Post
Ohlins are designed for ~20mm lowering. Some cars may see more lowering. Beyond that, you will need to replace the Ohlins springs with Swift of proper length and rate.
can you buy these without springs? and put swift springs on to save some cash?
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      03-07-2013, 02:13 PM   #15
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Quote:
Originally Posted by melenkae90 View Post
can you buy these without springs? and put swift springs on to save some cash?
Yes, you certainly can.

Shoot me a PM and I'll reply with prices.
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