Best suspension for Daily Driver / Backroads Dancer 135i

[titium]

Originally Posted by tjswarbrick

I have the Black / Race Powerflex RSFB Inserts. With those, E92 M3 FSB, Koni Yellows, and Swift Spec-R's, the floaty feeling is all gone.
Frankly, the only problems I have with the suspension as it stands now is it's a bit too low (tires are swallowed up inside fenders by about 1/2 inch) and it really hits hard over sharp bumps that impact the full width of the vehicle. Not sure if the suspension is bottoming out, but that's what it feels like.
I did get Z4 rear and "shortened M3" (E36, I think) front bump-stops.

With the extra weight of the vert you really need to go for either the coil over conversion on the koni's or switch to a off the shelf coilovers.

Trying to get BMW performance springs to work for an application they weren't designed for won't work well imo. Running shorter bumpstops isn't ideal either unless you can ensure that the springs and shocks stay within their "usable range" under full compression, if they don't then you will permanently deform the spring resulting in sag and ultimately a lower ride height. Which may have been that has happened with your original swift spec r springs.

[tjswarbrick]

They haven't gotten lower.
I've just been putting the car to a lot more various uses.
Driving around today, the Swifts and Konis really are wonderful.
They just get to be a little much when I have sensitive passengers.

[Gangplank]

Getting closer to a decision.

[ASBSECU E93]

This is my subscribed DOT.

[a4nut]

I'm going to weigh in here with a vote for the Ohlins coilover setup from Harold at HPA. A few months back I was planning to buy the m performance suspension, and he recommended I go with the Ohlins. So I took his advice, and added...

- M3 front control arms
- whiteline rear subframe inserts

I had them installed about 3 weeks ago, and I have to say it's perfect for a DD. Even on the garbage roads in Ohio! Taught without being harsh, no floating or bouncing, and the rear end stays put. In a word, brilliant. Matched with my PSSs and it handles nearly as well as my R53 JCW with the JCW suspension. I'm perfectly satisfied with the purchase. And while I don't have any canyons to carve around here, the highway ramps and backroads are just chewed up and spit out.

You will love this setup. Do it

[ShocknAwe]

More and more in love with my setup every day. TCK SA with 7k/12k swift springs, isolators, dinan mounts, M3 arms, sperical toe arms, rsfb inserts, diff lockdown, and oddly a temp solution which I may make permanent, bilstein HD dampers on the back.

[Gangplank]

Another vote for the Ohlins R&T. Installed it last weekend. At this point after my research & reading reviews the kits I'd consider are ohlins & the TC Kline SAs.

[tjswarbrick]

E88 135 'vert. Dinan camber plates (dialed to -1.6deg), shortened M3 front and Z4 rear bump stops, Swift Spec-R springs (201 lbs/in front, 503 lbs/in rear) and Koni Sport (yellow) shocks. Dampers are currently set about 1/4 of the way from full-soft. Also M3 FSB and polyurethane RSFB, but I doubt those have much effect on my issue.

Harsh, jarring response to sharp-edge transitions (expansion joints, and square-edge potholes) is getting to me. And to my passengers. Also, crawling over parking lot speed bumps because something hits on the way back down.

Just found this on a motorcycle suspension tuning website:

BACK END KICKS STRAIGHT UP:
SHOCK – Generally caused by too little or not enough rebound damping. Slow rebound damping 1-2 clicks. Note: In some applications rebound affects compression damping. Adding too much rebound stiffens the shock damping, decreasing rebound too much softens the shock damping.

I love the roll control and responsive handling provided by this setup, but don't have much suspension tuning experience. Can any experienced suspension guys speak to my best first course of action being: crank down the rebound damping more tightly? Bring it about to middle of the range - both F&R? Or go beyond that?

Also - rears are only adjustable at full compression. What's the best/easiest way to achieve that on the back of a 135i? (Other than paying somebody to do it.) Do I need to do a full shock removal? I do have two floor jacks.

[tjswarbrick]

I can't believe I've been living with my overly stiff suspension for about a year, and all it needed was an hour of thought, elbow grease, and adjustment.

Last time I tweaked it I couldn't find the little Koni adjuster, and used vice-grips. Worked fine, but I had the "firm" and "soft" directions mixed up in my head!

Tonight, I got the strut braces out of the way and backed the front dampers back to full soft. Instead of ~ 3/4 turn from soft, driver's side was 1.75 turns. Passenger was 2.25!

Set them at 1/2 turn from soft, buttoned it back up, and went for a drive.
What a difference.
Front end felt just a little bit loose. Overcooked it into a turn (let's say accidentally) and it just held on and jetted through. Had been expecting a touch of understeer.

Headed for an expansion joint that send my daughter and her volleyball teammate into fits. The patched it! So - no test.
Went to my next favorite cowl-shaker. Big thud and rough slam from the rear end, but just a mild shudder in the front! World of difference.

Went home, adjusted it again - to one turn from soft. (I think it's closer to 1.25 on the driver side.) Headed out for my next-favorite set of body-slammers. One caught me by surprise and kicked up the tail, but the front just absorbed it. Next few really had nearly no effect on the car. Just bumps in the road. Amazing!
25mph speed humps are no problem. Parking lot speed bumps must still be taken at a crawl, but the hit at the end isn't nearly so crashy as before.

I was planning to test 1.5 and 2.0 turns from soft, but time got away from me and I am too happy with the current setting to worry about it. If I tracked the car with any frequency or lived in Germany or some other state where road maintenance is actually a thing I might go for 1.5 turns from soft. As it stands, for my current conditions, 1 turn is perfect.

The only other thing that made anywhere near this much difference was replacing the worn-out front MPSS with new ones.
Hopefully that, and moving from a 245/35 to 255/35, will cure the rear. If not, I guess I'm on to a DIY on rear shock removal in a month or so.

In the meantime I can, once again, unequivocally recommend the Swift Spec-R's and Koni Sports! Just don't crank 'em down to full hard.

[Mandinca]

Originally Posted by titium

With the extra weight of the vert you really need to go for either the coil over conversion on the koni's or switch to a off the shelf coilovers.

Trying to get BMW performance springs to work for an application they weren't designed for won't work well imo. Running shorter bumpstops isn't ideal either unless you can ensure that the springs and shocks stay within their "usable range" under full compression, if they don't then you will permanently deform the spring resulting in sag and ultimately a lower ride height. Which may have been that has happened with your original swift spec r springs.

Damn, wish I'd seen this before I put them on my vert. BMW PS is horrible over the bumps although I attribute some of that to the RFT's I have on.

[tjswarbrick]

Car is in the shop for suspension work. As good a time as any to swap in a set of springs.

Car won't be heading to the track for the foreseeable future, is daily commuter, and also canyon carver when I get the time and inclination.
Keeping the Koni Sport (yellow) dampers.

Swift Spec-R currently mounted are too low, and perhaps a tad too firm.

Stock M-Sport currently in storage are too soft, and I wouldn't mind getting a little bit of drop from there.

What's the general concensus here :
T2/T3 BMWP springs?
T3/T4 BMWP springs?
Eibach Pro Kit springs?
Need to get a set ordered today.

[tjswarbrick]

No takers?

Update:
Mechanic said the upper strut broke! I don't have a pic, and don't know what that means exactly, but he doesn't have a distributor for Koni so asked me to buy a replacement. With the Koni Lifetime Warranty and Advance Replacement option, I'm hoping to have something to him in the next couple of days.

As far as springs:
In my previous research I came across T1, T2, T3 and T4 Front (P/N 31336788891, 8892, 8893 & 8894) at N/A, 146, 160, and suspected 195 lbs/in., respectively.
T1, T2, T3, T4 and T5 rear springs (P/N 33536788898, 8899, 8900, 8901 and 8902) at 390, 420, N/A, suspected 495, and perhaps 560 lbs/in., respectively. (Some of these may be specified for 3-series, but someone, somewhere talked about installing 'em on a 1. Estimating spring rates gets kinda sketchy when you start getting out of the standard fitment options.)

BMW does not list a Performance Suspension spring for my convertible (or any E88 that I could dream up and search.)

Swifts are 201 (F) and 503 (R) lbs/in. Frankly, too stiff for DD on my roads, with my passengers. More importantly, the longer I drive 'em (on for 2.5 years now) the more I realize they really drop the car too low.

Eibach has an E88 fitment! (P/N 2091.140) It is NOT the same as their E82 setup, but crosses to the Pre-LCI 328i E92 coupe. Which makes sense from a weight standpoint. Trouble is, I can't locate Factory or BMW P numbers for the springs on the E92 328, for comparison, either.
These Eibach Pro's are specified as lowering the 328i 1.0"(F) and .8"(R), and going down .8"(F) and .5"(R) on a (sport-suspension-only) 135i.
2097.140 E82 set specifies 1.2" drop F&R, which is well on the way to more that I want.

The E92/E88 ride height sounds perfect to me. I know they aren't linear, and I thought that bothered me. But since the car will never see a track, I've decided to treat is as the soft-top that it is (and recognize that it's over 100k mi) and stop wailing on it at every possible opportunity, and all reviews I've seen of Eibach springs with Koni shocks have been quite positive.
So I have a set of those on their way to my mechanic.

Will report back here after installation and I get the chance to drive 'em for a bit.

[tjswarbrick]

(Double Post)

[rowsdower]

I have Eibachs and Koni yellows with a few thousand miles (about a thousand track miles). I can’t compare to Swift or BMWP, but compared to stock Sport, it’s noticeably firmer. I would have preferred Bilstein dampers but the Konis are fine. The drop is not too bad (my car is a 128i though).

[duder13]

Here is my 135i with the Bilstein B12 setup (Bilstein B8 with Eibach Pro Kit springs.) I do have Dinan camber plates on the front, which I believe add a 1/4" in height.

[tjswarbrick]

Thanks guys.
It may just be the photo angles, but rows' silver looks like the perfect height. duder - is that cashmere? - car looks 1/2 between there and my E88 with the Swifts.

Some before's with the Swifts:





Eibachs are on the way, so I hope I made the right choice! (Not worried - I'm confident it'll be better than either stock/stock or koni/swift for me.)
Advance Replacement Koni Sport is also on the way to my mechanic...

(Evidence of need for shock replacement

[duder13]

Originally Posted by tjswarbrick

Thanks guys.
It may just be the photo angles, but rows' silver looks like the perfect height. duder - is that cashmere? - car looks 1/2 between there and my E88 with the Swifts.

Yeah, my B12 kit does look a little lower than on that 128i, especially considering I have the Dinan front camber plates.

Wow, I can't believe that Koni blew like that!

p.s. yep, it's Cashmere Silver Metallic.

[rowsdower]

For the record mine has Dinan plates too. The apparent drop of the cashmere car compared to mine may be an illusion caused by difference in wheel diameter. My wheels are 17” and I’d guess duder’s wheels are 18s - duder can you confirm?

[duder13]

Originally Posted by rowsdower

For the record mine has Dinan plates too. The apparent drop of the cashmere car compared to mine may be an illusion caused by difference in wheel diameter. My wheels are 17” and I’d guess duder’s wheels are 18s - duder can you confirm?

A ha! You're correct, I have 18" wheels. Great point.

[tjswarbrick]

I, too, have Dinan camber plates.
And 18's.
17's should provide same tire OD, but perhaps there is some optical illusion work going on there.

[oneBIGtoe]

Understand that bmw does not list the PS for the e88. But it does not make a lot of sense to me considering the spring rates are similar if not the same for some of the aftermarkets. Also, some of the coilover and spring companies list same part# for both e82 vs e88. Not convinced about the PS not suitable for e88. But I do believe you can get better options considering the price.

There is some interesting info about spring rates on the TCkline site and specifically for the 1er.

[rowsdower]

Originally Posted by tjswarbrick

I, too, have Dinan camber plates.
And 18's.
17's should provide same tire OD, but perhaps there is some optical illusion work going on there.

Yes the OD should be the same. When looking at the car though, the top of the wheel is 1/2" further away from the fender on 17s vs 18s so it looks a little taller.