Upgrade path for a 'grand touring' focused 135

[atr_hugo]

I liked the title of d k's thread so much that I plagiarized it, please forgive me d k.

What I'm looking at is determining the best way to upgrade the existing 135i to deliver a car that She Who Must Be Obeyed and I will use for travel in the next few years. It is a 2013 135i, pretty much loaded M-Sport, with Nav, PDC, H/K audio, black leather interior, and 6MT.

I previously owned an '08 135i that was totalled in July of '16. At one time on the '08 I was running an E93 M3 front swaybar, Koni FSDs, and Conti ExtremeContact DWs and eventually Michelin Pilot A/S3s (not for snow but for the expanded temp range of the tire compound - I have a set of wheels with real snow tires mounted for the mid December, mid March timeframe).

The new car has PPK installed and no suspension work yet. In addition it's still running the run craps. I will not go back to the runflats. I will probably opt for the Pilot A/S3 + (probably 225/40 front, 255/35 rear), again for the expanded temperature range - we intend to travel to heavily visited sites outside of summer months (too many whippersnappers in the way in the summer ; -).

The problem right now is the M-Sport suspension is at best 'clunky', it can be downright unsettled at times. It also seems to be overmatched by the PPK at times - got a good launch off a light the other day and watched TC light up on smooth, dry asphalt at about 5K in second gear; what the heck, over?

So the suspension needs to be revamped knowing that my combined spring rate will drop when I ditch the Bridgestones. I had a decent experience with the FSDs but am wondering if a Bilstein B12 kit wouldn't be as effective. I am agnostic about vendors/brands, I just want something that is agile and doesn't beat up my wife's bad back.

These are the goals:
- agile, comfortable, quick
- enhanced turn in, steering feel
- clean up sloppy rear sub-frame
- reduce NVH in suspension (clunks currently)

How should I go about meeting these goals? The wisdom of this community would be greatly appreciated. Thanks!!

[asbrr]

Originally Posted by atr_hugo

<snip>

These are the goals:
- agile, comfortable, quick
- enhanced turn in, steering feel
- clean up sloppy rear sub-frame
- reduce NVH in suspension (clunks currently)

How should I go about meeting these goals? The wisdom of this community would be greatly appreciated. Thanks!!

It's always good to start with clear goals. I concur on fixing the RSFB, you could do 2 piece poly like Whiteline or go OEM M3, will have no real negative impact in ride quality (run craps are a much bigger difference).

I can comment on the B12, and I will make this generalization about Bilstein dampers (sticking to non-adjustable kinds). I like them, they are built great, have excellent body control and high speed damping characteristics. But in the 3 instances (3 different cars) that I've had them, the small day to day bumps are definitely felt. I went with the B12 kit from stock M-sport, and on a choppy road with small imperfections, you do feel them. It does however deal with bumps very quickly. So Bilsteins have a certain "feel" to them that I've found is consistent over the years and across different cars. I happen to like it and didn't mind the small bumps coming through a bit more.

Koni based suspensions in my experience will soften those small bumps a bit better (obviously if you adjust them to full hard, then you're going to feel it). A few folks that have had them said this, along with some rides I have had in cars (not done to my own car unfortunately so take with a grain of salt).

From what I hear/read, the Ohlins coilovers are also ones that can strike a very nice road feel/ride balance due to their more expensive design and valving, assuming you adjust them properly.

Best advice I can give you is to try and meet up with anyone in your area with the suspension setup, that's truly the only way to tell....good luck with your reading/research.

[atr_hugo]

absrr, thanks! I hadn't thought of the two piece rear sub-frame bushings, merely the inserts, good catch!

I have spent some time driving vehicles with Bilstein setups (first I remember was the Ford Lightning on a press trip - they went from dual tube to Bilstein monotubes and the ride was better as well as cornering, actually autocrossed the stinking Lightning in a parking lot of Six Flags over San Antonio - didn't absolve the truck of gross lean in tight corners though : -). I have liked what I've felt. Interested if anyone can compare them to the M-Sport suspension.

The FSDs are pretty good, and given the role that the car will perform (no track days) shouldn't be overwhelmed - but (there's always a BUT) I have to keep the ride height fairly stock and finding a stiffer spring that won't lower the ride height too much could be difficult. I know with the FSDs, stock springs, and non-runflats the '08 135i was a bit floaty at times - especially over undulating freeway.

[The Wind Breezes]

For best ride quality I would keep spring rates and damping near stock. Replacing the stock bushings will go a long way toward getting rid of slop, but keep in mind the ride quality will at very best not improve.

If you're not doing track days, be realistic about the extent of how you'll push the car. I have a lot of track experience and surprised various, theoretically better, cars when my 135 was totally stock, runflats included. If you want to go fast in anything other than a straight line, mods won't help you whatsoever unless it's in the driver's seat. And it sounds like you're looking for comfort on long fast drives, so a good alignment, good (quiet) tires and stock suspension is probably what the doctor ordered. If you want to go really wild you can install air suspension, which is super freaking comfortable, but that will be a lot of money and / or effort.

Always keep in mind that your stock car will easily go fast enough to kill you or other road users, and / or get you put in jail or have your license taken away. You really don't need performance suspension mods for street driving.

[atr_hugo]

Originally Posted by The Wind Breezes

For best ride quality I would keep spring rates and damping near stock. Replacing the stock bushings will go a long way toward getting rid of slop, but keep in mind the ride quality will at very best not improve.

Right. My spring rates will go softer without run flats. My biggest complaint currently with the stock suspension is the 'crashing' over even minor pavement imperfections. In the '08 135i the Koni FSDs pretty much eliminated that but felt a bit floaty over undulating pavement, which, rightly or wrongly, I ascribed to too soft springs.

And it sounds like you're looking for comfort on long fast drives, so a good alignment, good (quiet) tires and stock suspension is probably what the doctor ordered. If you want to go really wild you can install air suspension, which is super freaking comfortable, but that will be a lot of money and / or effort.

Drove a RR Wraith on a press trip and it was just about perfect, could be a bit stiffer for my tastes but well controlled and delightfully smooth. They use an air suspension. Biggest draw back on a 135i is intrusion into cargo space.

Always keep in mind that your stock car will easily go fast enough to kill you or other road users, and / or get you put in jail or have your license taken away.

Yes indeedy - with the PPK the 135i is faster than the E39 M5 I drove years ago. Biggest problem with driving fast is you're not in a vacuum, it's not just yourself on the road. My '08 135i was totalled after I managed to stop for some yutz who decided to stop and backup on an Y-split of an Interstate and the right rear quarter of my car was smacked by some uninsured kid paying more attention to his cell phone than traffic.

I generally try to be extra cautious of where I push the car knowing its limits are probably (who am I kidding, it is ; -) beyond mine.

Thanks!!

[John_01]

To keep the suspension comfortable its better not to drop the car too low. IMO, a lot of the harshness occurs due to limited suspension travel, and lowered ride height will make it worse. Aftermarket springs generally reduce the suspension travel which means the car will rest heavily on the bump stops a lot of the time. I am not saying the stock springs are ideal from a performance point of view, but they are a decent option if you are looking at ride quality. There are a number of people with stock springs who add a E92 M3 front sway bar to keep the body roll under control.

I have the Koni sport adjustable struts and shocks on my car and they are comfortable if you keep to low stiffness settings such as 0.5 or 0.75 turns from full soft.

[Dackelone]

Ditch the run flat tires.
Ditch the stock springs and shocks - since they were tuned for the "stiff" RFT's. I would go with Koni's and a mild lowering spring(30mm's). Bilstein shocks are also nice... but they can be a little stiff/hard traversing bumps or seams in the road.

And lastly change the rear subframe bushings to the M3 units. This will keep the rear axle points straight in the turns and get rid of that rubber band feeling in the rear of the axle. It will also cause you to make less steering inputs just driving straight down the road on a bumpy road.

[asbrr]

OP - the "floaty" feel you had is more a function of poor / weak dampening and movement in the subframe than anything else. One more thing to add - check out the Dinan rear shock mounts, they supposedly add 10mm of additional travel in the rear and take out the slop from the factory mounts. This helps prevent the suspension riding on the bumpstops during "normal" driving situations.

I think a mild upgrade in the vein of:
- RSFB upgrade (full bushings, not the inserts!)
- Ditch runflats
- Your choice of a mild spring upgrade (too bad Dinan doesn't make their springs for our cars anymore), coupled with a quality damper of your choice (Koni, bilstein etc)
- Dinan RSMs

Should end up with a reasonable enough ride while being sporty and well controlled....

EDIT: Sorry, one thing we haven't mentioned is the BMW Performance Suspsension (shocks + springs). They only lower the car maybe 10mm at most, springs are not as strong as some of the aftermarket ones, comes with improved dampers. If you removed the runflats, did the RSFB, this might be a good setup for you

[MightyMouseTech]

The RSFB are a must, get the M3 version.

As for tires, I would avoid the A/S3. I had a set as my intermediate tires, very noisy and harsh ride. My SS ride much better, and are significantly quieter.

A good quality damper like Koni or Bilstein paired with a slightly more aggressive spring, maybe the OE performance springs. After installing a set of KWV3 on my Civic, it has shown me just how bad the stock dampers are on the 1er. When I switch back to the 1er, I feel like I am driving a Buick with blown shocks. How do they manage to be too soft and too stiff at the same time?

[lowbudgethero]

My current setup was to get exactly what OP was describing: dinan springs/and bmw performance shocks with control arms. Performance shocks are hard to find at a good price now, so I'd go to adjustable konis or the FSD + dinan springs.

[juld0zer]

Originally Posted by MightyMouseTech

The RSFB are a must, get the M3 version.

As for tires, I would avoid the A/S3. I had a set as my intermediate tires, very noisy and harsh ride. My SS ride much better, and are significantly quieter.

A good quality damper like Koni or Bilstein paired with a slightly more aggressive spring, maybe the OE performance springs. After installing a set of KWV3 on my Civic, it has shown me just how bad the stock dampers are on the 1er. When I switch back to the 1er, I feel like I am driving a Buick with blown shocks. How do they manage to be too soft and too stiff at the same time?

By being so soft they bottom out perhaps? I was appalled when i first got my 135i. Roads here are pretty crap and always under repair or upgrading. 95% of the time it's just me and my gf in the car and we are pretty average weight, if anything a bit on the light side. Boot is almost empty. Even with conventional tyres it was crashy.

For a month i pinched a full set of 17" wheels donated by a new F20 (shod with Goodyear efficientgrip 225/45R17 RFT). With my Bilstein B8 and BMW performance springs it was quite comfy. The car would easily get its tail out where the 245/35R18 PSS would've been finsle though - as expected!

[The Wind Breezes]

Subframe inserts will help too for a fraction of the cost and effort. They take maybe an hour to install for the average home mechanic, two hours if you take a break and haven't done it before.

[Gangplank]

- Ditch the run flats
- Rear subframe bushings or inserts
- M3 control Arms & good alignment
- Rear differential brace (got it from a forum member look for the eliminate wheel hop ad in classifieds)

Those 4 made a world of difference in the ride quality. I had planned on getting the BMW Perf. Susp. but after these mods decided I could wait another year or two until I wear out the sport dampers.

[gjm120]

Originally Posted by juld0zer

By being so soft they bottom out perhaps? I was appalled when i first got my 135i. Roads here are pretty crap and always under repair or upgrading. 95% of the time it's just me and my gf in the car and we are pretty average weight, if anything a bit on the light side. Boot is almost empty. Even with conventional tyres it was crashy.

For a month i pinched a full set of 17" wheels donated by a new F20 (shod with Goodyear efficientgrip 225/45R17 RFT). With my Bilstein B8 and BMW performance springs it was quite comfy. The car would easily get its tail out where the 245/35R18 PSS would've been finsle though - as expected!

How does the B8 / BMWP Spring combination work out? I'm looking at that b/c I like the lesser drop of the BMWP springs and the price of the B8's vs BMWP dampers.

[atr_hugo]

I'm looking at tires too - they will not be run-flats. I have had really good luck with Michelins over the years (from a feel and responsiveness perspective). Geez, I think the Fiat 128 I owned had Michelin Xs on it from the factory (which I soon replaced with BBS wheels and Pirelli CN36s - overtired the car, it was slow to begin with but sheesh after the CN36s went on it couldn't get out of its own way ; -). I think I've driven almost some model of every major maker's tires. Preference is Michelin.

I've opened up to thinking about all seasons when Michelin introduced the Pilot A/S 3. Actually ran a set on the '08 135i and liked them. Never ran them in snow, but the tread compound was optimized for less than hot temps and I do most of my driving in those conditions. (Work gets me summers off. : -)

So . . . one thing I know is that wet braking is extremely important to me. And I hopped over to TireRack and looked at Max Performance Summer, and Ultra Performance All Season and lookie here!?! A Pirelli? You gotta be kidding me!

[Bimmer-Bob]

I didn't see anything in the thread about how much you were looking to spend - that makes a huge difference.

I've gone through a few different suspensions on this car - the stock M-Sport, then Bilstein PSS9's, and finally Ohlins. I've played with a few different spring rates, a couple of different sway bar sizes, and several sets of tires. I've done the stock RSFBs, the Whiteline inserts, and finally the full poly Whitelines.

I think before you do anything else to the suspension, you should try the Whiteline inserts. They're not as good as the full poly bushings, but they are like an 80% solution, and at $45 plus a couple hours of your time, they have to be one of the biggest (if not THE biggest) bang for your buck mods out there. I only wish I had done them sooner - depending on your needs, you might find you're okay with leaving everything else stock.

As far as coilovers, I can concur that the Bilsteins err on the side of harshness. Sure, there's body control and it feels sportier than stock, but you will feel the road more, and not always in a good way. The Ohlins are head and shoulders above them, but offer (paradoxically) a ride that is better than stock, and handling that is much better. The downside is they are pretty pricey. Supposedly they need rebuilding every 20,000 miles, too - although I've done more than that without any perceived degradation in function, or any weird noises or leaks.

I wouldn't mess around with sway bars until the end - they're more of a finishing touch than a starting point. I really liked the addition of a larger rear bar when I finally got one, but it went in at the same time as an LSD with a shorter final drive. I wouldn't have necessarily touched the rear bar otherwise.

[BimmerAg]

Originally Posted by atr_hugo

I'm looking at tires too - they will not be run-flats. I have had really good luck with Michelins over the years (from a feel and responsiveness perspective). Geez, I think the Fiat 128 I owned had Michelin Xs on it from the factory (which I soon replaced with BBS wheels and Pirelli CN36s - overtired the car, it was slow to begin with but sheesh after the CN36s went on it couldn't get out of its own way ; -). I think I've driven almost some model of every major maker's tires. Preference is Michelin.

I've opened up to thinking about all seasons when Michelin introduced the Pilot A/S 3. Actually ran a set on the '08 135i and liked them. Never ran them in snow, but the tread compound was optimized for less than hot temps and I do most of my driving in those conditions. (Work gets me summers off. : -)

So . . . one thing I know is that wet braking is extremely important to me. And I hopped over to TireRack and looked at Max Performance Summer, and Ultra Performance All Season and lookie here!?! A Pirelli? You gotta be kidding me!

Not that I don't believe the data, but conditions must have been different for the summer vs all-season tires...why are the all-seasons better in every category except dry stopping distance?!?

[atr_hugo]

Originally Posted by BimmerAg

...why are the all-seasons better in every category except dry stopping distance?!?

Exactly!! Have I missed a revolutionary development in tire compounding? I tend to trust TireRack, and these are the objective numbers - the same set of vehicles for testing IIRC. Startling results to me.

I love Michelin tires, have always enjoyed the tactile sensations in the steering wheel from them. Kinda meh about Pirelli as a brand, but whoa!, the P Zero All Season Plus might (emphasis on MIGHT ; -) be worth a try. They may actually cure some of the harshness I complain about now.

[atr_hugo]

Originally Posted by Bimmer-Bob

I didn't see anything in the thread about how much you were looking to spend - that makes a huge difference.

Don't remember, sold some NVIDIA stock recently that I'd bought at $20 a share (breaking the family rule to buy high and sell low ; -). So I think unless I go absolutely nuts with parts & labor I should be fine. I think a $3K total bill may be doable. But it all has to go past the finance committee (She Who Must Be Obeyed).

I've gone through a few different suspensions on this car - the stock M-Sport, then Bilstein PSS9's, and finally Ohlins. I've played with a few different spring rates, a couple of different sway bar sizes, and several sets of tires. I've done the stock RSFBs, the Whiteline inserts, and finally the full poly Whitelines.

I think before you do anything else to the suspension, you should try the Whiteline inserts. They're not as good as the full poly bushings, but they are like an 80% solution, and at $45 plus a couple hours of your time, they have to be one of the biggest (if not THE biggest) bang for your buck mods out there.

That's good to hear!

As far as coilovers, I can concur that the Bilsteins err on the side of harshness. Sure, there's body control and it feels sportier than stock, but you will feel the road more, and not always in a good way. The Ohlins are head and shoulders above them, but offer (paradoxically) a ride that is better than stock, and handling that is much better. The downside is they are pretty pricey. Supposedly they need rebuilding every 20,000 miles, too - although I've done more than that without any perceived degradation in function, or any weird noises or leaks.

Can the Ohlins be kept to a minimal drop, near M Sport ride height? I don't want to lower the suspension more than an inch at most.

[d k]

Originally Posted by atr_hugo

I liked the title of d k's thread so much that I plagiarized it, please forgive me d k.

Imitation is the deepest form of flatery lol.

If anything, maybe we can pick up info from each thread?

Mine is here: http://www.1addicts.com/forums/showthread.php?t=1398406

As for running DW, they are pretty crappy tire.
I did an event (FR Shootout) on those and they sucked.

I did the Super Lap Battle on RE71-R and they were awesome!

[Bimmer-Bob]

Originally Posted by atr_hugo

Can the Ohlins be kept to a minimal drop, near M Sport ride height? I don't want to lower the suspension more than an inch at most.

It's hard for me to compare the Ohlins kit directly to stock, because I went for M-Sport, to the Bilstein PSS9s (which were very low, almost too low, even at the highest setting) for a couple of years, and then to the Ohlins. I did find that the Ohlins were sort of the reverse of the PSS9s - even at the lowest setting, I thought the car sat too high. Not higher than stock, mind you - probably about the same or a little lower. But coming from the too-low Bilsteins, it was hard to go back to what I thought was too high.

One thing to consider is that the Ohlins kit is actually designed for the E9x 3 Series, and is marketed as "also fits" the 1 Series, so it really is designed for the heavier cars, so maybe that's why I thought my 128i sat too high. Your slightly heavier 135i might sit just right, especially if you don't want too much lowering in the first place.

I have since gone to shorter, stiffer linear race springs because I wanted more control of spring rates for autocross, but for a street-driven car I think the Ohlins-supplied springs would be fine.

[c1pher]

I haven't done any suspension work other than replace the OEM tires with Michelin A/S3+. I was 50/50 between these and the PSS, but decided to go with them since they have a wider operational temperature range, have longer life and grip almost as well as the PSS. They were maybe $50 cheaper, so that was really a non-issue. I am very happy with the A/S3+. They are very quiet, ride great and grip much better than the Bridgestones. I think they are worth checking out. I also took the opportunity to upsize to 225/40-18 front and 255/35-18 rear. I feel like I still have good feedback, but honestly haven't pushed them as hard as I'd like yet except in the acceleration department.