Lowering Spring Advice Needed!

dj_efk

dj_efk

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Hi guys,

I need some advice on front springs. I followed the exact formula as recommended by Bill Cutler in this thread:

http://www.e9coupe.com/forum/showthread.php?p=34788#post34788

The rears are Kings that I imported from Australia and work great with just the right stance / stiffness I need.

However the fronts (Peddars 2120) haven't worked for me - The ride height is about an inch too high, plus the springs are not stiff enough: The car dives under hard braking and I can ground the tyres on my wheel arch liners over speed bumps etc.

Bill's pics link in the original thread now doesn't work so can't show you all what I'm looking to achieve in terms of ride height, but if you check out my car now and imagine it coming down an inch or so (or so the car is either completely level or leans forward slightly) you will get where I'm going with this.

What springs can I buy that will give me what I want (lower ride height, stiff enough to give a fairly comfortable ride without excessive dive or grounding ??


http://i828.photobucket.com/albums/zz206/dj_efk/BMW/bm15.jpg
http://i828.photobucket.com/albums/zz206/dj_efk/BMW/bm3.jpg
http://i828.photobucket.com/albums/zz206/dj_efk/BMW/2800CS_2.jpg
 
More information please

I think you're describing several issues:

1. Nose dive- usually brakes and shocks. Inertia causes this. The fix is a balanced braking system and shocks that have a rebound or compression rate equal to what you desire. So if you know what you have that info might help point to a direction to proceed with. For example your rear shocks may be fine on compression; but soft on rebound when the brakes are used hard where the front takes most of the action.

2. Springs- you've mixed a set. Usually springs are load dependent and can be linear or progressive. So if you know what the spring rate is in terms of pounds; that would help. For instance, 400 might be the right combo as in LaJolla's sets here in the states. Race cars might need 600 for a given condtion.

3. Spring height-ride height- when lowering, the front goes through a camber change; this normally requires a fixed camber plate that re-aligns the suspension geometry. Ireland Engineering sells both fixed and adjustible. You should consider this mandatory as the car will exhibit bad behavior otherwise.

4. Tire / wheel offset rub- what are you running? Where is the rub- outside, inside, strut? For example, if a strut bearing is bad, the strut insert insn't sitting correctly, etc. several reasons for tire rubbing and geometry change.


I hope this explains a bit and would be happy to offer a further opinion with a bit more info. My best suggeston though is a matched set of springs of the proper type for what you want to accomplish.
 
Hi 61,

Thanks for the detailed reply.


61porsche said:
1. Nose dive- usually brakes and shocks. Inertia causes this. The fix is a balanced braking system and shocks that have a rebound or compression rate equal to what you desire. So if you know what you have that info might help point to a direction to proceed with. For example your rear shocks may be fine on compression; but soft on rebound when the brakes are used hard where the front takes most of the action.
.
Click to expand...


I have standard brakes and standard spax shocks on the back. The front springing is generally way too soft hence why I believe the nose diving to be at least partially caused by this.


61porsche said:
2. Springs- you've mixed a set. Usually springs are load dependent and can be linear or progressive. So if you know what the spring rate is in terms of pounds; that would help. For instance, 400 might be the right combo as in LaJolla's sets here in the states. Race cars might need 600 for a given condtion.
.
Click to expand...

I have indeed - as per previous post I followed Bill's setup to the letter but I haven't achieved the same ride height as him, nor is it possible I have the same spring rate, as his car is running 16's too. This leads me to think that either Pedders shipped the wrong springs or Bill maybe didn't quote the right part number. My car is riding at least 30mm higher than his judging from the pics of his car (which are now moved from photobucket hence can't show you what I mean).


61porsche said:
3. Spring height-ride height- when lowering, the front goes through a camber change; this normally requires a fixed camber plate that re-aligns the suspension geometry. Ireland Engineering sells both fixed and adjustible. You should consider this mandatory as the car will exhibit bad behavior otherwise.
Click to expand...


Good point - I see Carl Nelson sells cheaper ones - Does anyone know if there's any difference in quality / ride height / end result? Understand IE's ones to add 6mm to the height which obviously I'd need to take into account.


61porsche said:
4. Tire / wheel offset rub- what are you running? Where is the rub- outside, inside, strut? For example, if a strut bearing is bad, the strut insert insn't sitting correctly, etc. several reasons for tire rubbing and geometry change.
Click to expand...

I'm running 205 / 55 / 16's, they are actually rubbing on the (Jaymic) wheel arch liners and although I'm not sure, probably the arch lips on lock over large bumps.


61porsche said:
I hope this explains a bit and would be happy to offer a further opinion with a bit more info. My best suggeston though is a matched set of springs of the proper type for what you want to accomplish.
Click to expand...


Right but the point I'm making is that I don't know who, apart from the above named suppliers, would do springs that are slightly lower / stiffer than the standard 30mm / 10% stiffness options. I was wondering what others have tried that have achieved a little more drop than this without the tyre clearance issues etc.

Any pointers appreciated.

Thanks
 
"I'm running 205 / 55 / 16's, they are actually rubbing on the (Jaymic) wheel arch liners and although I'm not sure, probably the arch lips on lock over large bumps."



I have the same problem with my 16" wheels, Carl has camber plates to fix that, I am ordering a pair soon for myself.

My chrome on the wheel arches has gotten bent twice, scared to ruin it....
 
I hadn't heard of arch liners. Do they help to protect the tires from damage ? I did a quick look on Jaymic site and didnt see them.
 
I would call H&R Spring. If they no longer make the application ( they do for 02s and early sixes still), perhaps they could provide the technical bits to have a set properly made. For a 2" drop you may be talking of coilovers. I do know the springs and shock rates relate to each other for it to work it's best.

Arch liners- they are just a means of protecting the opening. I have Volvo liners on the front. Modern cars have them; which is what you see behind the wheel. It's just an added protection against water, rocks, and helps in the prevention of rust.
 
Liners

Seems to me that prior to the last update to the tech info portion of the site there was a detailed explanation as to the install of the Volvo front inner fender liners...I no longer see this. Opinions varied as to whether the liners protected this area or could be a detriment...
trapping water and corrosion unseen until too late. I no longer rip down logging roads with abandon (in city driving makes me nervous these days) but when I did, cleaning out the wheel arches was no fun.
 
Arch liners- they are just a means of protecting the opening. I have Volvo liners on the front. Modern cars have them; which is what you see behind the wheel. It's just an added protection against water, rocks, and helps in the prevention of rust.

I agree, probably 75% of our coupe’s rust problems start from the lack of full fender skirts in the front wheel wells. I have made stainless pieces to seal off the upper fender skirt lip and the door post area but consider them a so so fix at best, the real answer is a full fender skirt that covers all of the car in the wheel well area. I could make them but I would need a good month or more some winter because you have to drop out the front suspension and make the bucks in the wheel wells. Once the bucks are made (the hard part) you can remove them from the wells and they are then your guide for shaping the metal skirt, the easier part of the job because you are now working outside of the wheel wells like a gentleman. The way things are going on the movie production flatbed I’ve been working on I doubt it will happen this winter. ~ John Buchtenkirch
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Hi guys,

Where in Europe is it possible to buy lowering springs for e9?
 
RTHLSS1 said:
Hi guys,

Where in Europe is it possible to buy lowering springs for e9?
Click to expand...

Carl Nelson ships to Europe, but shipping alone will be in the $300 range..
Jaymic in UK has a -30mm lowering spring set.
If it's of any help, you can buy H&R e12 -40mm springs from ebay.de for a reasonable price, but only fronts, the e12 rear springs won't fit the e9.

Here's a pic with the H&R -40mm front springs (just installed, so might settle down a little bit) and some unknown rear springs that I found lying around.

IMG_1353.jpg
 
Thanks! But I am looking to get lower since I would like to fit BBS 18" style 5 rims ...
 
RTHLSS1 said:
Thanks! But I am looking to get lower since I would like to fit BBS 18" style 5 rims ...
Click to expand...

Then you probably need adjustable coilovers to get it dialed in just right, I know GAZ-shocks in UK sell coilovers for the e9 .
You need to send them your struts, or buy a pair of struts in UK and have the seller send them straight to GAZ for modification.

Price wasn’t crazy last time I checked, and I know lots of guys in Sweden use GAZ in their track cars with good results.
I’m probably going with their coilover-kit later when/if I feel I need it.
 
Gransin said:
Then you probably need adjustable coilovers to get it dialed in just right, I know GAZ-shocks in UK sell coilovers for the e9 .
You need to send them your struts, or buy a pair of struts in UK and have the seller send them straight to GAZ for modification.

Price wasn’t crazy last time I checked, and I know lots of guys in Sweden use GAZ in their track cars with good results.
I’m probably going with their coilover-kit later when/if I feel I need it.
Click to expand...

Great info - would it be possible to foward me their mail?
 
Have you considered to get your E9 springs and shocks set up from BMW. They would be the right spec designed for your E9. I believe these parts are still available from BMW classic and a BMW workshop can install.
And less risk than the hit and miss after market options.
 
Mal CSL 3.0 said:
Have you considered to get your E9 springs and shocks set up from BMW. They would be the right spec designed for your E9. I believe these parts are still available from BMW classic and a BMW workshop can install.
And less risk than the hit and miss after market options.
Click to expand...

Since I am lowering the car original springs from BMW do not help me much.
 
18" wheels will be a nightmare to fit and make your car ride like sh1t. To retain some ride compliance 16" is the largest rim size to go for.

My car has a Carl Nelson front end - as above he shipped to the uk. Expensive but worth it.
 
dj_efk said:
18" wheels will be a nightmare to fit and make your car ride like sh1t. To retain some ride compliance 16" is the largest rim size to go for.
Click to expand...

Nightmare sounds a bit dramatic. One doesn’t stick 18’s on a car that originally came with 14’s without expecting to tinker a bit. There are several forum members running 18’s. I think the limited number of e9’s on 18’s has a lot to do with owner preference and little to do with fitment or harshness of ride.

RTHLSS1 said:
Thanks! But I am looking to get lower since I would like to fit BBS 18" style 5 rims ...
Click to expand...

Assuming that you are referring to factory 18” BMW (bbs) RC061 and RC062, I don’t believe that you will have fitment problems with rolled fenders and some tire stretch. The 8” fronts are ET20, same as the 17” version that is successfully run on several member cars. The 9” rear are ET24. Vince is running 17x9 RC’s at ET26 on his e9 and they clear the fender and the suspension. You would be 2mm closer to the fender and it will be a bit tight. You will probably want to research tire brands that work well with tight clearances.
 
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