Tired of lowered car

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dks
Posts: 29
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Tired of lowered car

Post by dks »

Hi guys, I'm after some suggestions.

I'm sick and tired of my car being too low.

I've got a 12/87 Highline imported into Aus from the UK. The PO put on some 17" style 42 knockoffs with 235/45s.
It had ...662 front springs - so this makes it a Tropical Spec (whatever that meant for the UK).

I got some Eibach springs and billy sports. The overall ride was quite firm but not too bad - no complaints from the better half re ride.
I think the car is about 30-40mm lower than standard.

After a dozen years or so like this I reckon I've had enough of smashing the front spoiler in car parks and gutters, scraping the exhaust over speed bumps and hitting the front spoiler on those 3-4m long speed humps the local council likes here in Brisbane.

I quite like the look of the lowered stance of the car - the top of the tyre is the same height as the wheel arch - but that's the cause of the problem!

I've seen Brucey's table of springs etc but not sure where the Eibachs fit into the lists.

Some alternatives that seem obvious are
- go back to the 662 springs and use B4/touring shocks (don't really know the difference)
- go back to the 662 springs and use HD shocks
- get some 024 or 904 springs and use HD shocks

I think I'm leaning towards 662s/HDs and then if its too high get some 024s or 904s.

Anyone got any other suggestions.
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Brucey
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Re: Tired of lowered car

Post by Brucey »

since the damping rates are similar between the sports and HDs you might was well try the new springs with the extant shocks. You probably need new (internal to the insert at the front) bump stops anyway, so you could choose those to match the new ride height better anyway.

The big differences between the sports and HDs are the shock travel; it is longer in the HDs and shorter in the sports. It is only shorter in the sports shocks so that (shorter, stiffer) springs don't become dislocated on full droop. The maximum roll and negative travel in the shocks are different but in normal driving I think you would be hard pushed to tell the difference between HD and sport shocks if standard springs are used with them. Sports rears have more perch height settings so allow a fairly wide range of springs to be fitted.

A suggestion is that it might be best to get M635CSi front springs; this gives about 1/2" lower than stock suspension at the front. Any standard spring (they differ in free length not stiffness so much) may fit the rears with the perch height adjustments on offer. You have little to lose by trying this anyway.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
brickwhite
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Re: Tired of lowered car

Post by brickwhite »

I would go for the Stock springs and HDs. Or Msport springs if you can find them.

Maybe a taller tire and smaller wheel may smooth out bumps too. 16" wheel and 225/50 or 205/55 tire.
Last edited by brickwhite on Wed Oct 31, 2018 12:47 pm, edited 1 time in total.
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Brucey
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Re: Tired of lowered car

Post by Brucey »

this photo shows the difference in sports and HD shocks at the rear

Image

from this it is quite clear that the sports shocks can be used with standard springs and indeed offer a wider range of ride height adjustment. The only thing that you are losing is ~1/2" of negative travel. You would probably notice this on a racetrack but not on the road.

As I mentioned earlier damping rates are similar. Identical at the rear but not quite identical at the front, however they are very close indeed.
Bilstein E28 5 series 82-88, E24 6 series 83-on
rebound / compression force at 52 cm/sec

Newton pound-force
N lbf (0.2248 x N)
------------ ------------------
Front:
P36 0243 Sport 2900 / 950 652 / 214
P36 0233 HD 2860 / 650 643 / 146
P36 0239 Comfort 1790 / 650 402 / 146
Rear:
B46 0607 Sport 1605 / 805 361 / 181
B46 0608 HD 1605 / 805 361 / 181
B46 0610 Comfort 1590 / 770 358 / 173
from here http://www.unofficialbmw.com/e28/suspen ... mbers.html

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
dks
Posts: 29
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Tired of lowered car

Post by dks »

Thanks for your views.

I'll see how the high the 662s make the car and then make a call re the alternative springs.

I guess the M635 springs is the 31 33 2 225 115 (I run about 32 points)
and Mtech springs, the 31 33 2 225 646.

I'll have a bit of a look around to see what I can find - they might be a little troublesome to find.

thanks again

...Dave
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TN_M6
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Re: Tired of lowered car

Post by TN_M6 »

Other options might be some thicker spring pads or simple spacers on the strut mounts that allow you to use what you have but gain some height. IIRC there were spring pads for cars going to countries with poor roads and maybe find them in the e30 parts bin listing for the front since it's all the same. In the rear are you up on the highest spring perch for the Sports yet? Is that enough?

Personally I see so many cars or pictures that have gone soo low, some stupid low. I scrubbed my front air dam a time or two even before I 'lowered' my M6. Lowering for me was no more than 13-17mm and I still need to be careful. I can almost get a hand between the top of the tire and fender and I think that's about right.
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slofut
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Re: Tired of lowered car

Post by slofut »

Like Brickwhite said, tires make a lot of difference in ride and handling. A bit more rubber on the rim in a better quality tire would help the ride and maintain good handling. I prefer 16" wheels on these cars personally. Dunlops have been good.
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Brucey
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Re: Tired of lowered car

Post by Brucey »

FWIW if you try to use lowering springs but adjusted to give near-standard ride height (via perch adjustments or packing at the front), you need to be careful that you don't end up with the spring going coilbound in bump; it is pretty much touch and go at the back with a standard setup and a lot of aftermarket springs have narrower gaps so less travel per unit length of spring.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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