Suspension recommendations please

[Peter Coomaraswamy]

Looking for some advice on ride quality and what has worked for folks on the forum. Currently I have all new suspension and bushings, basically everything under the car. I Have the CN springs, and Bilstein HD’s with CN’s negative camber plates and I’m running 225/50/16’s all around with no clearance problems. I have the stock (39 yr old) sway bar up front and no sway bar in the rear. I only have about 100 miles on the car since its release from the “hospital”. Everything feels tight when cornering, but the car does not feel “well planted” in corners. I know this is rather vague and I’m not trying to make a race car out of this thing. Suspension parts are not cheap, so rather than doing a trial and error I thought I would ask you all for some input.

Thanks

 

[alanmcg]

need more

you are right, 'well planted' is too vague. need more specifics to help you - do you mean excessive body roll? looseness in the steering wheel? side-to-side differences in the shocks/suspension? etc.

with stock frnt sway bar and none in back, im suspecting you mean excessive body roll.

 

[rsporsche]

Peter,

please remember these cars are 40+ years old. they don't drive like a modern car. also remember that when the x5 came out, the stock x5 beat the times around the nurburgring that the factory CSL race cars did ... at least that was the advertisements said. there have been a lot of advances in suspension geometry and technology. so the question you need to answer is what is the car doing that makes it seem unplanted?

that being said, it is hard to judge the setup over the internet. a few questions - did you upgrade all of the bushings to polyurethane? did you replace the swaybar bushings? i suspect that no rear swaybar might have something to do with it. if you put the entire CN pkg on the car (bilsteins, springs, etc.), you might consider a new set of swaybars + bushings.

 

[bavbob]

If you look at the rear of your car, you should have all the trimmings for a sway bar (welded brackets for bushings and links), my 72 Bavaria does. It was an option most did not take. I just picked up the rear bar from the dealer with the hardware for about 90 dollars, got Ireland Engineering poly links for 45 bucks. Let you know if any difference.... Can we live vicariously through you......Suspension Techniques larger than stock sway bar pair is about 240 dollars.

 

[Nicad]

What tires and alignment settings are you running?

 

[Sven]

Peter - it seems to me you really have only a few options left to try (for street driving, non racing):

1) using firmer polyurethane bushings, 2) installing the 28/22 mm front/rear sway bars, 3) front strut tower brace, and/or 4) changing the type of tires you are running. You are past the point of stiffening the body with welds.

I would try #2 first as a complementary upgrade to the CN shocks and springs. Tires also make a difference to road feel/grip.

At some point it's not going to get any better.

 

[TodB]

Suspension

I have your set up along with a front strut brace and adjustable sway bars front and rear. I hammer it pretty good every now and then and I find it neutral and predictable. I also have a friend who races Grand AM and he mentioned that it was extremely well planted. Probably not suitable for repeat track days but I hope to take it to one or 2. Very streetable.

I started with the lower rated Dunlop tires but traded up for Direzza Starspecs which I also have on my E28. Made a huge difference. Probably too much tire for a Coupe...

As others have mentioned, check your bushings and replace as necessary. Make sure your diff mount is up to the task and not swimming in its mount. This is a common area to become compromised and may need reinforcing. I believe that Coupeking sells a weld in part.

 

[E911]

Balance....

You've made adjustments in spring rate and camber and now need to bring your sway bars up to balance out what you've done. Lots of options but in the end you want to end up with a bigger front bar and a rear bar too.

If it were my street car I'd keep stock bushings and use a 635csi front bar (or equivalent) and a stock E9 rear bar. Simple, quiet, durable and not green or red or...

 

[Peter Coomaraswamy]

Ok, thanks, and yes, I was defenitely too vague; I would say excessive body roll and not enough feedback through the steering wheel It feels like if I keep the wheel cranked in a turn the car will just roll over (of coures it might). Point taken about it being an older car and so I'm trying to get the best I can get without going completely "ape" on this thing. I forgot to mention that I do have the front strut bar (CN) and all the bushings have been replaced though with original not poly and I did not add any camber adjustment to the rear. I'm running fairly tame Bridgestone tires so my thought would be to put on a heavier front sway bar and paint it black, add the rear sway bar and see how she does. Since I'll be doing the change and addition does the forum suggest, with the set up that I have, that I use other than rubber bushings on the sway bars. It seems like a fairly easy project so I should have some feedback soon.

Thanks

 

[rodspock]

Peter,

I have a very similar set-up to yours and my car sits very well on the road. It performed surprisingly well on a club run in company with an E92 M3, M135i, 1Ms and a hotted up E46 330Ci. However the devil is in the detail...

Assuming that your alignment is correct (front and rear - I used adjustable bushings for the rear) and your sills are structurally sound. I would start with the front sway bar. There were two types on the E9s. The smaller is 19mm in diameter, while the larger is about 22mm.

The sway bar is easy to check and relatively easy to change - but the front hangars can be a pain.

Cheers,

Rod

 

[Nicad]

I have Star Specs on my Miata. Quite amazing on that application, but I don't think it might be as suited to an an E9 ( (Just a hunch). They are terrible in cold weather (lower than 50f). On my E46 and E36 ( Both with large sway bars), Michelin Pilot Sport 2's were by far the best performing tires from a feel and control point of view. I bought Conti DW Extreme for my Coupe (haven't tried them) and just installed them on the E 46 wagon and I am a disappointed compared to the Michelin. The steering has diminished feel IMHO. Hopefully the Coupe is better suited to the Conti.

It would be nice to see all the suspension combinations in this thread. One thing I would want in my setup is the ability to be unflappable on a bumpy road the way BMW seems to have built their reputation. I think you need wheel travel for that.

 

[rsporsche]

i have bridgestone re-11 tires on my coupe in the staggered 16" sizes. amazingly good tires. i was going to buy the conti extreme contact dw, but bridgestone offered an incredible deal at o'fest in birmingham ... and i bought them and had them installed cheaper than i could buy the conti's from tirerack (not installed).

my point, i've got bilstein's, lowering springs + (unknown make) swaybars front + rear. it drives nice, but it is numb compared to the very precise handling of my previous e30 m3, my previous (highly modified) 2002 and most certainly my porsche - part of that comes from the steering, part from the geometry.

i think the way to get a significantly better handling coupe would require progressive springs, better bushings and balanced with the size of the swaybars ... or by moving toward coilovers, but all of this will take a lot of testing of spring rates and general testing. so i agree that it would be really good to publish what we have on our coupes ... but i suspect that it is going to be difficult to be able to sort it out unless the same person was driving all of the different cars on a similar course. and most of all, this could cost lots of money to sort it out.

 

[Gazz]

Has anybody tried a shop that prepares historic racers, preferably of course CSLs or even Bavarias? They would have been through the trial and error process and it may simply be a matter of winding back the race set up for a street application. I.e. less camber, less spring rate etc.
I'm no suspension expert so there may be something fundamentally wrong with this approach.

 

[rsporsche]

korman comes to mind. my 2002 had their clubsport suspension, and it was perfectly balanced. it was stiff though. definitely the best driving 2002 of the 3 that i have owned. but i can tell you that they don't use progressive springs on the coupe setup.

perhaps Mario Langsten (VSR) has experimented - i would trust his advice in a heartbeat.

 

[E911]

IMO, for a street coupe you want a little more camber, a little less height, a little more spring rate and a lot more front sway bar- combined with fresh factory bushings you'll have a car you can push hard through the turns with minimal roll and still have the compliance to feel like you're driving a classic luxury sport coupe.

The great thing about these cars is that a set of lowering springs (or cut springs) gives you 3 out of 4... Add big front bar and then go drive the tires off it.

The E9 power steering unit is quite good but will never give you the precise feel of a rack n pinion or the CSL CR box... It's something you have to accept as part of the experience.

 

[Nicad]

IMO, for a street coupe you want a little more camber, a little less height, a little more spring rate and a lot more front sway bar- combined with fresh factory bushings you'll have a car you can push hard through the turns with minimal roll and still have the compliance to feel like you're driving a classic luxury sport coupe.

The great thing about these cars is that a set of lowering springs (or cut springs) gives you 3 out of 4... Add big front bar and then go drive the tires off it.

The E9 power steering unit is quite good but will never give you the precise feel of a rack n pinion or the CSL CR box... It's something you have to accept as part of the experience.

Good points, and Scott, I would bet Duane's car (with Mario's setup) is about the way I think I want mine. It certainly looks composed in track photos.

 

[Peter Coomaraswamy]

Another question then, I have an '85 633 donor car, if the front sway bar is the larger diameter can I use that one? Do sway bars get "tired"? I have allot of $ in the car- nothing compared to the time in it, but a couple hundred, 3-4 hundred more to make it ride like a proper automobile would be worth it. If however the consensus is that a correct fitting sway bar from a 633 with a larger diameter would give me the identical results then I have no objection to saving the money. Also, if anyone knows if the rear sway bar would fit then added bonus for me

Thanks-

Also, I will document everything and get the printouts from the allignment shop just as a point of reference for the forum and do all the measurements once I feel it is "correct". Again, I realize, and agree, that it is an objective feeling- unless of course I can get it on the local track and beat my time in the Shelby.

 

[HB Chris]

Only early e12 based e24 bar will work, it's 23mm. Euro Csi had option of the 23mm or standard 17mm.

 

[Peter Coomaraswamy]

based on the feedback

I installed the heavy duty sway bars. Quite a difference in that there is very minimal body roll and I don't feel like I'm going to tip over when I go around corners.

Next question; I think the feeling that is still not quite right is that when I make a turn-left or right- say at about 30 MPH I get very little "resistance" in the steering. In the other cars I drive there is an amount of push-back that contributes to the road feel. With my set up it feels like it wants to turn TOO easily- I don't know if that makes sense? in-put most welcome!

 

[DerSchwede]

Only early e12 based e24 bar will work, it's 23mm. Euro Csi had option of the 23mm or standard 17mm.

Euro CS and CSi all went from 17 to 23 mm in the end of August 1973.