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lowering advice for a 320 coupe ??
Posted: Tue May 13, 2008 6:56 pm
by sumo_e36
As above really, i have a 320 coupe with standard non m-tech suspension and i want to lower it enough so that a set of 15/16's would sit nicely in the arch. what kind of a drop would i belooking at for this , 80mm at the front ?? . although its just a 320 and i wont be tracking it or anything just yet, i dont just want a spring kit but coil overs are way out of my price range, has anyone any suggestions or ideas.
Also if i was to get a kit (springs and shocks) for a 325 would they fit or is the shocker mounted different on the rear with it being drums
Cheers James
Re: lowering advice for a 320 coupe ??
Posted: Wed May 14, 2008 2:21 am
by stevotheevo
-80mm is extreme, it'l bang around all day long and most likely rip the sump off.
-60/40 would be more suitable.
325 shocks wont work as the front legs on your car are a different diameter (too small)
Re: lowering advice for a 320 coupe ??
Posted: Wed May 14, 2008 2:27 am
by Jhonno
325i kit wont fit as you have 45mm front struts
Re: lowering advice for a 320 coupe ??
Posted: Wed May 14, 2008 3:25 pm
by Gibson
60/40 like mine, its on sixteens and i think it looks spot on

Posted: Wed May 14, 2008 8:17 pm
by sumo_e36
ok then 60/60 might look quite ok , can anyone recommend a make of lowering kit (shocks n springs or coilovers if dirt cheap) thats good quality and low cost cos i'm doing the car on a budget and i know nothing about suspension kits and brands.
Posted: Wed May 14, 2008 9:39 pm
by DavieP
sumo_e36 wrote:.... can anyone recommend a make of lowering kit (shocks n springs or coilovers if dirt cheap) thats good quality and low cost cos i'm doing the car on a budget ....
You'll need them to be cheap, because if you drop the suspension that low, you'll need the money to pay for uneven tyre wear. Keep your fingers crossed about meeting speed bumps as well - when in a fight with oil sump covers, the bumps usually win

Re:
Posted: Thu May 15, 2008 10:46 am
by pnd
35 mm is the best option for practicality go for a good brand of matched shocks and springs eg eibach bilstein h+r.
Re:
Posted: Thu May 15, 2008 11:15 am
by Gibson
Yea 60/40 can be a bit low.... i took the sump out on mine the other day but then again i do drive like a cock, if your gentle over speed bumps it should be fine...
i wouldnt reccomend 60/60 it makes it look like you have half a ton of bricks in the boot.... they look nice sat down on the nose a bit.
as for tyre wear you will need eccentric rear bushes for the front lower arms and the back doesnt seem to wear too badly, just make sure your bushes are all in good shape and it shoulb be ok.
upside is that little bit extra camber makes it handle fantastically round the twisties.
mine is on Koni adjustable dampers and i have no idea what springs its running. but they are cracking dampers, can be wound all they way up for smooth road or track use or loosened up for normal pot-holed roads. they were put on in 2004 so they have done four years without any problems and still look in tiptop condition. cost around £500-£600 for the set i think, according to the receipts i have.
Re:
Posted: Fri May 16, 2008 2:29 pm
by dann-p
I've got a 320 coupe an wanted to uprate the suspension on a budgetm her's what I ended up with:
-Dropped 35mm front and rear on progressive springs (go for H&R)
-Bilstein gas shocks
-Polybush front ARB mounts, with new ARB links, also polybushed
-Fitted rear ARB from 325 as 320's don't have one as standard - definately get one, mine cost £15 in total for everything from one of the many outstanding members of this outstanding forum and made a difference
-Wishbone bushes changed for polybushes
Now it handles like a go-kart and loves being thrown into the bends.
The polybushes are from superflex not powerflex as I found them to be cheaper and their service was fantastic (sent back the front ARB mounting bushes twice as I ordered the wrong ones - twice, what a novice!. Didn't charge return postage either time). Weren't too bad to fit either.
On a poor road surface it can feel a bit firm with the wishbone bushes, but overall a decent ride.
So you can get good handling with not much cash and a bit of effort. The car is capable on both road and track.
Re:
Posted: Fri May 16, 2008 4:07 pm
by Andyboy
80mm is stupidly low - don't even go there.
35mm is low enough. It will drop it enough without the thing running on the bump stops or cracking the sump on speed humps (which is very easy). I've used Bilstein B-4 gas shocks which are cheaper OE ones but are still a lot stiffer than standard Boge, especially old high mileage originals. I used Eibach springs and I can assure you they are a lot stiffer than standard - the coils are about 2mm thicker for a start.
As a result, the car handles a lot better but still has a nice ride. I've yet to fit a 325i rear anti roll bar - I have one saved but am waiting for a 320i/325i Convertible front bar to go with it. I found that fitting a 325i rear bar to a 320i with the original front bar made it more understeery.
Re:
Posted: Fri May 16, 2008 4:11 pm
by Jhonno
I found that fitting a 325i rear bar to a 320i with the original front bar made it more understeery.
Odd.. Should do the opposite

Re:
Posted: Fri May 16, 2008 4:25 pm
by Andyboy
Really?
I wonder why cars with the rear anti roll bar are fitted with a thicker front bar then?

Re:
Posted: Fri May 16, 2008 4:43 pm
by Jhonno
to balance the handling out.. by just adding a rear roll bar it'll still have the soft front one which was designed for no rear roll bar and so the balance will shift to oversteer
you want a quell understeer you stiffen the rear roll bar sofen the front, and visa versa..
Re:
Posted: Fri May 16, 2008 5:01 pm
by citizensnips
sorry to semi hi jack but can the 320 front be upgraded to the thicker struts?
Re:
Posted: Fri May 16, 2008 5:04 pm
by Jhonno
yes
Re:
Posted: Fri May 16, 2008 5:22 pm
by citizensnips
does it need top mounts changing? i assume this is covered somewhere on the site,
seems as i'm still welding up holes i've not started to research suspension changes
Re:
Posted: Fri May 16, 2008 6:49 pm
by Andyboy
Jhonno wrote:to balance the handling out.. by just adding a rear roll bar it'll still have the soft front one which was designed for no rear roll bar and so the balance will shift to oversteer
you want a quell understeer you stiffen the rear roll bar sofen the front, and visa versa..

Okay.
I fitted a 325i rear anti roll bar to my gold 4 door 320i and it didn't like it much around Crofts tighter corners so I disconnected it. Once disconnected it would try to go sideways when taking Sunny Out under trailing throttle. That's oversteer, not understeer!
BMW had problems with the early E21 understeering - so they increased the front anti roll bar from 22 to 23.5mm. Maybe they were wrong?
Re:
Posted: Fri May 16, 2008 7:03 pm
by Jhonno
citizensnips wrote:does it need top mounts changing? i assume this is covered somewhere on the site,
seems as i'm still welding up holes i've not started to research suspension changes
no it doesnt..
Re:
Posted: Fri May 16, 2008 7:05 pm
by Jhonno
Andyboy wrote:Jhonno wrote:to balance the handling out.. by just adding a rear roll bar it'll still have the soft front one which was designed for no rear roll bar and so the balance will shift to oversteer
you want a quell understeer you stiffen the rear roll bar sofen the front, and visa versa..

Okay.
I fitted a 325i rear anti roll bar to my gold 4 door 320i and it didn't like it much around Crofts tighter corners so I disconnected it. Once disconnected it would try to go sideways when taking Sunny Out under trailing throttle. That's oversteer, not understeer!
BMW had problems with the early E21 understeering - so they increased the front anti roll bar from 22 to 23.5mm. Maybe they were wrong?
Furry muff
Its a complicated topic i guess, and BMW will know far more than me on it.. That was just a general rule, but i have heard that due to the suspension design on on the e30 that stiffening the front end can reduce understeer as it maintains geometry and camber better, but i thought that lay in the springs as a stiffer front roll bar can unload the inside front, me thinks when i get time i should read up on it all

Re:
Posted: Fri May 16, 2008 7:07 pm
by Jhonno
i have seen auto-x (ers) in the states un hook the rear roll bar all together claiming better turn in also, guess due to lower speeds and weight transfer or something
Re:
Posted: Sat May 17, 2008 11:36 am
by dann-p
Fitting a rear ARB from a 325 to my 320 didn't make it understeer at all, but my front end is completely polybushed so it's nice and stiff and should maintain its steering geometry.
It has definately reduced body roll though, which I suppose it should given what its called!!!
Maybe i've just been lucky that everything i've fitted works well together. We'll see how she goes at the Nurburgring in June.