E36 BMW chassis parts list

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bttmotorsport

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Andrew_Frick

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Doivi Clarkinen
Keep in mind that 1996 and later M3's already have these reinforcements.

Dave thank you for your contributions. Any other tips you are willing to share based you experiences with Hintz car?

I remember seeing some pictures of a log being used as a suspension spring after a trailing arm failure. Was that just a case of stuff breaks if you hit something hard enough or is there some inherent flaw with multilink BMW stuff that caused the issue?

When you move the rear spring from its original place to coilover, it is more likely to break the shock mount in original trailing arm. Hardly ever seen it when using the original setup..

The only reason that the shock mount broke on Hintz's car was that the rear springs as supplied by Sellholm coil bound (fully blocked, actually) before the full travel of the shock. Surprising as I would have expected better from Sellholm but they were easily replaced with some Eibach springs with less turns and a couple of inches shorter block height. Album of the damage.

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Doivi Clarkinen

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bttmotorsport

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Andrew_Frick

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Doivi Clarkinen
Keep in mind that 1996 and later M3's already have these reinforcements.

Dave thank you for your contributions. Any other tips you are willing to share based you experiences with Hintz car?

I remember seeing some pictures of a log being used as a suspension spring after a trailing arm failure. Was that just a case of stuff breaks if you hit something hard enough or is there some inherent flaw with multilink BMW stuff that caused the issue?

When you move the rear spring from its original place to coilover, it is more likely to break the shock mount in original trailing arm. Hardly ever seen it when using the original setup..

The only reason that the shock mount broke on Hintz's car was that the rear springs as supplied by Sellholm coil bound (fully blocked, actually) before the full travel of the shock. Surprising as I would have expected better from Sellholm but they were easily replaced with some Eibach springs with less turns and a couple of inches shorter block height. Album of the damage.

Anyway it seems to be quite common reason for retirement in grF cars, who use coilovers, in Finland, Xtreme cup cars which heve the spring on original place, again dont seem to have that problem...

Grant you'e still suffering from what ever caused you to imagine your block was different from about 20 million others.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

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Andrew_Frick

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Doivi Clarkinen
Keep in mind that 1996 and later M3's already have these reinforcements.

Dave thank you for your contributions. Any other tips you are willing to share based you experiences with Hintz car?

Get beefy spare lower rear shock bolts, especially if using coilovers. Use red Loctite on them. If they loosen they tend to bend. I'm actually trying to get some studs machined to suit the coilovers but the bolts have been staying tight and not bending since using red lLoctite.

Don't forget to remove the restrictor out of the clutch hydraulic line (right at the slave cylinder) or you will wear clutches out prematurely. It's just a little restrictor that makes for smooth (but slow) clutch engagement on the street. In other words, it's impossible the dump the clutch on a stock Bimmer, you don't actually have direct control of the clutch engagement.

Get spare stub axles (the axle flange that goes into the rear diff) and replace them on a regular basis. This is a known weak point, the splines twist and eventually break. This is what put us out of the Nameless Rally last year.

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john vanlandingham

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bttmotorsport

When you move the rear spring from its original place to coilover, it is more likely to break the shock mount in original trailing arm. Hardly ever seen it when using the original setup..

I see this said--and repeated.. And I cannot begin to understand the reasoning since the spring does not create any stress, only the shock does.

Please explain.

OK, I'll try.
This seems far too basic of a principle to not get virtually instantly, so if I've got it wrong, show me where.
Like any good thought exercise, lets list the 'assumptions.'

1) Stock design has the spring and the damper in different locations.
2) The 'coilover' setup moves the spring mounts onto the damper, and mounts the damper in the stock locations.

For simplicity sake, lets look at a car at rest and understand what the suspension bits do.
Spring: This actually carries the weight of the car, but by the nature of being a spring it allows the suspension to move.
Damper: The role of the damper is to control the movement of the spring, and therefor the suspension.
So, at rest there would be very little, if any, pressure on the damper mounts but the spring mounts would be taking all of the weight of the car.

As a test, picture what happens to a car if:
- it has neither springs nor dampers installed. (Goes down to limit of mechanical travel)
- it has just dampers installed. (Goes down to limit of damper travel)
- it has just springs installed. (Goes down to normal ride height, but is bouncy as all hell)
- it has springs and a blown dampers installed. (Goes down to normal ride height, and is bouncy, depending on how blown the dampers are.)

So...

If we accept that the weight of the car is carried by the springs, when we change to a coilover design, removing the spring from the stock location and mounting it to the damper means we also move the weight of that corner of the car to the stock damper mounting points, a load they were never intended to carry.

I'll let the physicists amongst us figure out what sort of loading the damper mounts would see in motion if they were ONLY seeing the damper forces, but I think it is safe to assume, it would be a LOT less than the combined forces of the spring (corner weight) and damper.

or am I wrong...

---

First Rally: 2001
Driver (7), Co-Driver (44)
Drivers (16)
Clerk (10), Official (7), Volunteer (4)
Cars Built (1), Engines Built (0) Cages Built (0)
Last Updated, January 4, 2015

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john vanlandingham
Blame is for idiots. losers.

Morison. No. You glossed over what the damper does to accomplish its effect. Damping is the effect.
We call it dampin or dempening butt what it is doing---the only thing it is doing is slowing down the rate of change or movement..

It does this as we all know by forcing oil thru some little holes which are covered by a stack of ever smaller steel shims..


It takes energy to force the oil thru the hole---but not a lot, they're big holes



This forcing of the oil to lift that stack of still shims changes the kenectic energy of the moving suspension into heat.

The spring doesn't multiply force it just pushes back by whatever rate it is..Push a 175 in/lb spring this much it moves in a bit and take the force away and it pushes only whatever it is..

The damper changes things. The damper resists movement....and say you have a damper pilled with piss and one floppy 0.1mm shim there would be no damping, and not force on the dampers mounting on compression and only whatever the spring is pushing back, but not more.

Now damper filled with Canajian Tar Sand crude---and regardless of where the spring is, there would be serious ass stress on the shock mounting on compression...because in this case 100 in/lb spring in this position or 500 in that--- you see that THE DAMPER will resist movement.
The shit wants to move....it is the thing which SLOWS the movement that creates the stress

And it is always compression damping that is the stress because return is only xxxlbs of the spring..

It is the SHOCK controlling the spring that generates stress in proportion the the dampening it does.....


Now sometimes you have to stop thinking you can figure out shit from your own brain power and instead use your eyes....

Have any of you guys ever looked at the shock mounts on serious cars with coil over suspension?
Formula cars? Group B cars? Circle track cars...
Little flimsy thin mounts welded onto thin wall tubes. 10mm or 1/2" bolts for cars weighing from 1500-3500lbs that go 130-190 mph...

Use your eyes and understand... damper changes energy....creates stress--in accord with the internal valvling and oil.. And as it is velocity sesitive, try and collapse it instantaneously, there is astronomical force---unless you have chose your valving smartly---


(In the spring analogy: say you have a 20 lb/in spring. place it on the pad of a jack and now jack the car...what does it do? Nothing. just collapses. Release. What does it do? Nothing. just extends once the weight is off.
Place 1200 lb spring on jack, what does it do?
Nothing, it compresses 1/2" but then the car goes up... Release, Car goes down.
The spring doesn't create the stress it just collapses or it doesn't. And it just extends in perfect harmony with its nature.)

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Yes, I glossed over the effect of the damper, and I am fully aware of what it does.

Do we agree that the major forces on the shock mounts come under compression?

My point was that where the springs are attached separately, they take some of the load off the damper mounts as they are being compressed. (since the springs are 'pushing back' in concert with the dampers) When you move to a coilover, all of the 'push back' is going through a damper mount that wasn't designed to take the whole load.

Now, go to stiffer coilover springs (IE Pushing back harder) and more aggressive dampers and how could you expect the stock mounts to hold up?

Stiffer springs in the stock location at least means the damper mounts only have to take the increased stress of the increased damping. (and probably not all of that since the springs push back, on another area, as well)

---

First Rally: 2001
Driver (7), Co-Driver (44)
Drivers (16)
Clerk (10), Official (7), Volunteer (4)
Cars Built (1), Engines Built (0) Cages Built (0)
Last Updated, January 4, 2015

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john vanlandingham
Blame is for idiots. losers.

Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

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BJosephD
Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

There is no issue! It's too much smoking...

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Grant Hughes

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BJosephD
Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

Why would you need the adjustment? When the spring is in original place, you can change it in few minutes if for some reason car´s height should be altered... You can´t use the adjustment in coilover to modify the ride height either...

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bttmotorsport

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BJosephD
Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

Why would you need the adjustment? When the spring is in original place, you can change it in few minutes if for some reason car´s height should be altered... You can´t use the adjustment in coilover to modify the ride height either...

What are you talking about? Sure you can. Anyway, as long as you're not bottoming the the shock or spring it's not an issue.

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Doivi Clarkinen

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bttmotorsport

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BJosephD
Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

Why would you need the adjustment? When the spring is in original place, you can change it in few minutes if for some reason car´s height should be altered... You can´t use the adjustment in coilover to modify the ride height either...

What are you talking about? Sure you can. Anyway, as long as you're not bottoming the the shock or spring it's not an issue.

Of course you can, but that´s not the right way to do it.... as the spring ratio changes when you tight it to get the car higher, and if you plan to lower it, spring is "loose" over the shock... whic again is not the ideal situation at least... Some fine tuning could of course be done, but mainly you´d need change the ride height with length of spring..

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bttmotorsport

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Doivi Clarkinen

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bttmotorsport

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BJosephD
Seems to me the best way to adress the issue is to leave a spring in the stock location with an adjustment sleeve and run the fancy shocks????

Why would you need the adjustment? When the spring is in original place, you can change it in few minutes if for some reason car´s height should be altered... You can´t use the adjustment in coilover to modify the ride height either...

What are you talking about? Sure you can. Anyway, as long as you're not bottoming the the shock or spring it's not an issue.

Of course you can, but that´s not the right way to do it.... as the spring ratio changes when you tight it to get the car higher, and if you plan to lower it, spring is "loose" over the shock... whic again is not the ideal situation at least... Some fine tuning could of course be done, but mainly you´d need change the ride height with length of spring..

That's not how it works at all. The spring rate is the spring rate. The spring rate does not change as you raise or lower the spring perches. Really you're only going to be adjusting the ride height no more than about a couple of inches. Much more than that and you're going to need different length shocks anyway.

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DaveK
General wisdom on BMW forums is that if you had a 6-cyl you needed a medium case diff. Jari told me that most of the cars overseas keep the small case diff so that they have access to the higher ratios without getting into "M" parts. That was what prompted my supra diff swap and a 4.3, but I would never recommend the hassle of that swap to anyone after driving the car.

I'm not convinced that these cars need crazy high rear end ratios since the gears are a bit wonky. With a 4.44, I was launching the 328i in 2nd gear at 100AW and transits with 65mph speed limits sucked (1:1 5th gear). On stage, I used 2nd-5th gears.

I'd need to pull out a gearing calculator, but I sorta wonder if a low 3.xx would be nicer. Hopefully you'd be able to launch in 1st gear, and use 1st-4th on stage and then have 5th gear for transits.

If your car came with solid front discs (the 1995 and 1996 Ti models did), the quick upgrade is to the vented discs and rotors that all the other E36s came with (excluding the M3 since those won't fit under 15s). At hilclimbs they brakes don't see a ton of abuse, and at rallies I'm not going deep enough into the corners to really put the hurt on the stockers yet.

Dave

About the finaldrive still, here´s few clips to compare the car with 3 different finaldrives. Only technical modification between these is shorter gears, engine is std 3.0 inline six with maybe 150hp... All stages are in basically same area, so no crazy up/downhills... and all events are dark without pacenotes.

First it had std 3.63:



Then we got 4.22 in it:



And finally 5.12:



So as you can clearly see, shorter the finaldrive, way quicker and more agile car. Top speed difference, with 3.63 maybe 140mph, which cannot be never reached on stages, with 5.12, 100mph which in 90% of stages is enough.

Here's some calcs using the ZF gearbox (95 M3 and 96-99 328 & M3), BFG 195/70/15 tires, and the speeds listed are at 7,000rpm:

_______1st____2nd___3rd___4th___5th
______4.20___2.29__1.66__1.24___1.00

2.5____51____94____129____173___214
2.7____47____87____120____160___198
2.9____44____81____111____149___185
3.1____41____75____104____139___173
3.3____39____71____98_____131___162
3.5____36____67____92_____123___153
3.7____34____63____87_____117___145
3.9____33____60____83_____111___137
4.1____31____57____79_____105___131
4.3____30____54____75_____101___125
4.44___29____53____73_____97____121

My Compact had a S50 engine (240hp/225tq stock) and I've been running it with a 4.3 Supra diff for a couple years. The red 328 (190hp/206tq stock) has a 4.44 in it. Both motors are slightly warmed over with less restrictive intake and exhaust mods.

At our hillclimbs we use rolling starts, so you're typically moving at 10-20mph or so before you get the green flag. I'll start in 1st roll forward (since we're usually starting on an incline) and grab second and just wait till the flag drops and hammer it. At 100AW I found that there was no reason not to launch the car in 2nd gear. Both 1st and 2nd equal loads of wheelspin.

So, with both cars I effectively have a 4-speed gearbox that tops out in the mid-120s. So what I was trying to say earlier is that if you went with a 3.3 rear end, 1st gear would get you an extra 10mph (splitting the difference between 1st & 2nd gear with a 4.3), which might make it useable. 4th gear would top out at a slightly higher 131mph and you'd end up with a pretty comfortable 5th gear (3000rpm @ 70mph vs 3950rpm with the 4.3) for cruising on transits.

The other thought with these motors is that they've got pretty broad torque bands. These aren't peaky 4-cyl that need to be kept on boil to really move. I wonder if the slightly longer gearing (more mph per revs) could translate into less time wasted shifting?

Dave