e32 740il 6-Speed Manual Conversion

[moroza]

The best way to start sorting out ride height, if you're trying to keep OE-ish rates: next time you're on the highway and not in a hurry, swing by a DOT weigh station, ignore the puzzled looks they might give you, and get a front and rear axle weight, ideally with nothing in the car but fuel. Then refer to what by now is getting compiled into one giant useful spreadsheet. Or if your goals are moderate and desire to increase rate nonexistent, just send stock springs to Cannon with instructions to squish the middle coils by the desired drop amount.

Oversteer, really? Are you sure the tires are actually breaking traction, or if just feels like the rear is steering a bit more when you roll on the throttle? The latter is well and good and normal, the former is not.

Increased rear ride height not only increases rear camber (less negative, more vertical, less grip), but has a non-negligible effect on front caster, increasing it for easier steering at the cost of less straight-line stability.

You seem mostly happy with the OE clutch and flywheel setup, but if the stars align such that you're in the PNW when my E34 544iT project is running, go for a drive with a UUC E31 conversion flywheel and see what you're missing. Only in the worst conditions - dead of summer, traffic, AC, just driven hard, radio off - is very minor idle rattle audible from inside the car, and that's with ~250k on the engine and trans. I have an audio recording of the previous owner doing a WOT-to-redline 2nd and 3rd gear pull in this car... with all four open downpipes.

[m60power]

The best way to start sorting out ride height, if you're trying to keep OE-ish rates: next time you're on the highway and not in a hurry, swing by a DOT weigh station, ignore the puzzled looks they might give you, and get a front and rear axle weight, ideally with nothing in the car but fuel. Then refer to what by now is getting compiled into one giant useful spreadsheet. Or if your goals are moderate and desire to increase rate nonexistent, just send stock springs to Cannon with instructions to squish the middle coils by the desired drop amount.

Haha yes, funny you mention this, I've been considering doing that after I found out how much corner scales cost lol. And I don't care to mess around with making a contraption of wood boards to use some bathroom scales and math...

And yes you guessed correctly, suspension calculations for wheel rates, ride frequency, roll couple and whatnot are getting thrown into a spreadsheet to get a ballpark estimate for handling of the chassis.

Oversteer, really? Are you sure the tires are actually breaking traction, or if just feels like the rear is steering a bit more when you roll on the throttle? The latter is well and good and normal, the former is not.

Increased rear ride height not only increases rear camber (less negative, more vertical, less grip), but has a non-negligible effect on front caster, increasing it for easier steering at the cost of less straight-line stability.

Yes it's oversteer in that off-throttle, into the corner, the rear steers slightly more than the front (tires aren't fully breaking traction yet, probably just higher slip angle at rear) and the car feels like it rotates into the corner at a tighter amount of "yaw" angle than it would be if the tires evenly followed the radius... If I roll on the throttle mid-corner the rear does in fact fully break traction into a slide or drift. This behavior is with the brand new tires too. Yeah probably not 'good', but definitely more fun.

Ah crap, by 'reduce' the rear camber I meant reduce the amount of negative camber from nominal. So increase towards positive camber; I now realize I worded that terribly!

You seem mostly happy with the OE clutch and flywheel setup, but if the stars align such that you're in the PNW when my E34 544iT project is running, go for a drive with a UUC E31 conversion flywheel and see what you're missing. Only in the worst conditions - dead of summer, traffic, AC, just driven hard, radio off - is very minor idle rattle audible from inside the car, and that's with ~250k on the engine and trans. I have an audio recording of the previous owner doing a WOT-to-redline 2nd and 3rd gear pull in this car... with all four open downpipes.

Hell yeah! If I'm in the general area I will for sure let you know. I've been wanting to do more hiking/camping in the north west, the closest I've probably been to your area is lake tahoe and the black rock desert. Yes I believe it, one of my top choices, actually I think it was my ideal choice, for the clutch and flywheel situation was originally the e31 280mm flywheel paired with a sprung clutch disc. From what I remember the flywheel was still available from BMW and a pretty reasonable price too. I am very happy with the OE 540i clutch/flywheel at the moment, however I also know that in time that dual mass flywheel will start to get problematic, rattle, and 'shudder' the driveline when taking off from a standstill...

[m60power]

Some more photos with the E38 'Style 4' wheels on the car:

e32_1.jpg e32_2.jpg e32_3.jpg

[m60power]

e32_4.jpg e32_5.jpg e32_6.jpg

[moroza]

Too tall, but the style works well. Those were a close second choice behind ye olde Style 5's when I switched to 16":



So you're running H&R rear and stock front springs? From what I understand, that too will bias the chassis towards oversteer.

The E31 flywheel is still available, but the clutch is not. One solution is having old ones re-lined. Another involves a disk from some Ford. Someone may have done it already, but all I have is rumors, the hardware (some of it still installed in the car), the intention, and sooner or later will make the time to either see it through or see it fail.

[m60power]

Your touring looks awesome! It's super clean too! Personally, I would ditch that black paint on the wheels for some more contrast to the rest of the car; i think a silver, shadow gunmetal silver type thing, or chrome would look pretty good. Front ride height looks perfect, but rear looks like it could be just a bit lower however it's tough to tell from the angle of that photo and the unevenness of the ground surface. I really need to solve the ride height situation on my car, it's the one thing really bothering me (at least in the aesthetics department).

Thank you for pointing me to Cannon, I might go with them to compress my stock springs, although I do actually want a slightly higher spring rate (15-25%) than stock; I think you mentioned Cannon will also make custom springs, correct? My goals are a conservatively lowered ride height front and rear, and slightly sportier spring rates, although I might just be overly picky with the spring rate aspect in search of 'perfection'

Yup those H&R 750iL springs are still on the rear, and the front springs are stock along with the rest of the front suspension bits. Definitely interested in what you end up finding out with the clutch for the 280mm E31 flywheel.

[moroza]

Thanks! I rarely can keep the exterior that clean, mainly because my house is two miles from the nearest pavement, but the interior stays within a few notches of Showroom (it's very hard to photograph, but there are a couple in my Soundproofing thread). If you saw me in person, the overdone black would make more sense, but yeah, I'd've wished for a bit more contrast too, just didn't want a whole silver lip and had no other ideas. The rear is indeed a bit too tall, mostly because that's the minimum ride height at minimum SLS pressure - with inadequate damping - but also because those tires are oversized: 215/60R16.

E34 Sport/MTech and most aftermarket lowering springs have rates ~50% over stock. If you just want 20% or so, I'd look into OE springs for some other BMW. E32 front springs are physically interchangeable with E34, E30, E28, at least later E24, and probably some others. A few of them are listed in the spreadsheet, some measured first-hand.