Coilover spring rates

Wed Dec 02, 2009 9:49 am

Cheers Theo! Great document. I'll have one of my mates look some prices up!

The KW's I was considering were the V2's which run full coilovers at the rear. I've asked KW if they will supply an adjustable damper for the rear to use in conjunction with the OEM spring location. Basically an adjustable V1 kit. We'll see how it goes.

Wed Dec 02, 2009 8:44 pm

bullwinkle wrote:Cheers Theo! Great document. I'll have one of my mates look some prices up!

The KW's I was considering were the V2's which run full coilovers at the rear. I've asked KW if they will supply an adjustable damper for the rear to use in conjunction with the OEM spring location. Basically an adjustable V1 kit. We'll see how it goes.

KW V2 is NOT a rear coil over. It's a ballon type spring with a height adjuster on top with a single shock. There is no rear coil over from KW for the E30 in any variant.

Thu Dec 03, 2009 11:56 am

Thanks Uwe (and Theo), I stand corrected!

Having sourced some prices for the GRP N bits and bobs (not too bad but being a bit new didn't realise I'd have to convert the front struts adding £££'s to the equation

) I think the KW set-up is probably the one for me right now.

Thanks again for the pointers chaps

Thu Dec 03, 2009 9:09 pm

bullwinkle wrote:Thanks Uwe (and Theo), I stand corrected!

Having sourced some prices for the GRP N bits and bobs (not too bad but being a bit new didn't realise I'd have to convert the front struts adding £££'s to the equation ) I think the KW set-up is probably the one for me right now.

Thanks again for the pointers chaps

sorry me again

you do NOT have to convert you front struts to run Grp N springs. There are two types of Grp N springs. A coil over version and a set for the standard front struts.

Fri Dec 04, 2009 9:45 am

Hey Uwe. What I really wanted to run was the height adj front struts. I appreciate that I can probably run with the springs and damper inserts but height adjustability is important for me, more for set-up and corner weighting than looks. My initial wish was to have a complete GRP N set up but I dont really want to start converting to 5 stud to do this.

It's very hard to decide what to do, especially with my current lack of knowledge on the E30.

Incidently, in the photo of your set up (earlier in the post), are those helper or tender springs in the back? Also, what spring rates are you using up front?

Thanks in advance.

Fri Dec 04, 2009 6:29 pm

I run 140N front and 180N rear with collapsing helper springs.
Springs are KW wide wound coils race springs (---> E X P E N S I V E!)

You can buy a kit from GAZ and convert your 4 lug struts into coil over, no need to get 5 lugs.
Cost £45-50 and some welding. Just cut the bottom spring platform off and weld the threaded tube on the strut, job done. Search for DIY coil over, there are a few threads.

You can also use springs from www.dfaulknersprings.com

Tue Dec 08, 2009 9:55 pm

Great thread guys!!! Excellent arguments from both camps.

I currently run KW V2's and was considering retrofitting a rear coilover into my E30 (probably a KW unit). I think the major conclusions, after reading this thread and equally considering both arguments is;

1) Rear coilovers are possible, and in use in many E30's without issue,
2) There is much thought that without reinforcement, the factory towers will fail (so much argument must stem from somewhere).
3) Coilovers with reinforced towers is the way to go!!

Wed Dec 09, 2009 7:13 am

UweM3 wrote:I run 140N front and 180N rear with collapsing helper springs.
Springs are KW wide wound coils race springs (---> E X P E N S I V E!)

You can buy a kit from GAZ and convert your 4 lug struts into coil over, no need to get 5 lugs.
Cost £45-50 and some welding. Just cut the bottom spring platform off and weld the threaded tube on the strut, job done. Search for DIY coil over, there are a few threads.

You can also use springs from www.dfaulknersprings.com

Have you a link for the Gaz coil-over conversion jobbies?

Wed Dec 09, 2009 12:24 pm

In the front we are running 1000lbs springs on a BMW E36 Sachs Group N strut, H&R Sway bar. In the rear we're running 650lbs on a coilover on custom made dampers.

The shorter damper is the custom one the other is a rear group N damper modified to accept coilover.

Wed Dec 09, 2009 12:28 pm

Oh, I might add that our rear strut towers are reinforced just to be safe, and they tie into the cage.

Wed Dec 09, 2009 5:14 pm

Ahh, I've seen those pics before. Your on bimmerforums.com! Good to see you on here too. Two questions about your front subframe, What size rose joints have you used to connect your lower arms to the subframe and how much have you lowered the front roll centre?

Mark

Thu Dec 10, 2009 8:23 am

Hey there.

With our new subframe and roll center spacers we have moved it a total of 9cm. I unfortunatey haven't taken any pictures as of yet of the new parts.

Ummm, I can't remember off hand what the rod ends are but they are from FK Bearings and the inner id is half inch (12.6mm if I remember correctly).

Thu Dec 10, 2009 4:06 pm

Could you get some pics up please?

I thought that the rod end bearing would have been a lot bigger than 12.6mm more like 16mm?

Have you modified the front subframe to make it more compact or just replicated something simmilar to the DTM one? Also have you raised the rear (lollypop) mount too to alow for anti dive?

Thu Dec 10, 2009 6:44 pm

Let me scratch about for some pictures. I although I'm not sure if I do have yet.

I can't remember the loads off hand but the bearings I'm using are that they use on the Nissan Dakar off road cars on their lower a arms. So they are plenty strong (but then the price is also plenty strong).

Our original subframe wasn't as good as it could be as the inner pick up wasn't raised at all. Now we have just replicated a 92 DTM front subframe.

The rear mount has also been changed to one that is identical to the 92 DTM rear mount as well. Using our original lollipop we weren't sure if it could withstand the increased vector forces. So we just went with what is proven and nothing better than an actual BMW Motorsport part.

Thu Dec 10, 2009 9:30 pm

Sounds good to me. I'm in the replication process at the moment, not so easy when you've not got a DTM car in front of you. Any pics or usedfull measurements would be greatfully recieved

Fri Dec 11, 2009 12:41 am

You got any a link to your build? Seems pretty interesting.

Luckily my friend owns the ex Will Hoy BTCC championship winning e30 m3 that I can take measurements off of.

What measurements are you looking for? I will gladly help where I can.

Fri Dec 11, 2009 8:13 am

Yes mate, the link is at the bottom of my sig. That's really handy on the BTCC front, any plans to replicate the adjustable ARB's?

I'm not too sure on measurements atm, you don't need them till you need them. Could you PM me your email address if I needed to get hold of you?