E88 handling delima

[SteveAZ]

So I bought an '08 E88 a few days ago, researched it some but honestly, this car was such a good deal that I fired on it figuring if I didn't like it, I'd just flip it.

Problem is I really like the car, don't care for the handling too much. Given I live in Arizona the convertible makes sense. But this thing is stock and with the 17" wheels and current tires feels like I'm driving a cadilac...hate that! Granted my comparison is slightly biased as our other 2 cars are a G37s and a Mini Cooper S (also convertible) and my last "fun" car was an S2000 which frankly didn't handle nearly as well as the G or the Mini and this car kind of reminds me of it from a handling perspective, not the cushy ride.

Anyway, so my question to you guys, I don't mind putting some money into this car if it'll improve the handling but will it? Right now I can't tell if there's frame flex or it's just the wheel/tire package and stock suspension. Both of which I don't mind replacing. Any of you upgrade those items on a vert and had good results?

Thanks

[BrokenVert]

Long story short - yes it's the suspension and tires.

Get yourself an E93 M3 front sway. It costs $200 and you can install it in your driveway in about an hour.

Drive a bit with that intyalled. If you start to like the way it feels a bit more then you can start to justify spending more money on much more drastic changes

[JimD]

I think you can make it handle well. My e88 has the sport suspension. A key difference, at least for me, is the seats. They have adjustable side bolsters that really help to keep you in place in spirited cornering. It seems like that would be expensive to change on yours. Wheels/tires should help it a lot and you can change springs/shocks etc. but if you get it cornering well, will the flat seats bother you? That would be my key caution.

Jim

[135Pats]

Im quite happy with how my vert handles, it has the m package and performance suspension... if you want to improve it drastically, coils and sway bars are the way to go. It will be much stiffer through the twisty stuff.

[Simsims]

Originally Posted by SteveAZ

and my last "fun" car was an S2000 which frankly didn't handle nearly as well as the G or the Mini

[SteveAZ]

Thanks for the replies, good point about the seats, not looking to autocross it but you're right, they're pretty flat.

As for the M3 front sway bar, sounds like a good start. Are people just ordering them from the dealers or is there a better source? Is most of the M3 suspension compatible with the 135?

I verified the tires today and they are the Goodyear Eagle LS2 runflats and virtually new, so I'm guessing what I'm picking up on isn't that much to do with the tires.

I need to get the alignment done and was thinking I may throw on springs prior since they're also cheap. I see a lot of people are changing out their "S" springs, is that because they leave a lot to be desired or because they want the lower ride height. If I can get a set cheap and it'd be worth it, I'd do those as well.

Thanks again,
Steve

[Greenkirby21]

Originally Posted by SteveAZ

Thanks for the replies, good point about the seats, not looking to autocross it but you're right, they're pretty flat.

As for the M3 front sway bar, sounds like a good start. Are people just ordering them from the dealers or is there a better source? Is most of the M3 suspension compatible with the 135?

I verified the tires today and they are the Goodyear Eagle LS2 runflats and virtually new, so I'm guessing what I'm picking up on isn't that much to do with the tires.

I need to get the alignment done and was thinking I may throw on springs prior since they're also cheap. I see a lot of people are changing out their "S" springs, is that because they leave a lot to be desired or because they want the lower ride height. If I can get a set cheap and it'd be worth it, I'd do those as well.

Thanks again,
Steve

Edit: Nevermind, you have a 135i. I was gonna say get wider tires and sport suspension.

You can get the m3 front sway from dan@unitedbmw

[1speedbike]

Originally Posted by SteveAZ

Thanks for the replies, good point about the seats, not looking to autocross it but you're right, they're pretty flat.

As for the M3 front sway bar, sounds like a good start. Are people just ordering them from the dealers or is there a better source? Is most of the M3 suspension compatible with the 135?

I verified the tires today and they are the Goodyear Eagle LS2 runflats and virtually new, so I'm guessing what I'm picking up on isn't that much to do with the tires.

I need to get the alignment done and was thinking I may throw on springs prior since they're also cheap. I see a lot of people are changing out their "S" springs, is that because they leave a lot to be desired or because they want the lower ride height. If I can get a set cheap and it'd be worth it, I'd do those as well.

Thanks again,
Steve

I'm glad you're (mostly) enjoying the car so far! It's a great car, but you're right; there are a few things that I personally think BMW should have changed about it from the get-go.

The suspension is very soft, mostly to compensate for the harshness of run flat tires in general. It's not really a matter of how new they are, all run flats are pretty stiff in comparison to regular tires. Since BMW began making RFTs standard, they have accordingly softened the suspension to compensate and not make the ride too harsh. Great for 95% of BMW buyers in the US... not so great for you and me. This is what Matt (BrokenVert) was saying about the suspension and tires being the culprits to your issues.

There are a few solutions.. the most obvious is to switch out your springs and shocks/struts. A lot of people on here like the drop in height as you mentioned, but I think most of us do this as a handling upgrade. If you want to keep the same shocks, you can go with a less aggressive set of springs like H&R OE sport springs (they call it OE, but they're not the OEM springs) or BMW performance springs. These two are pretty mild compared to other solutions. Otherwise, I'd suggest getting a matched set of shocks and springs, or coilovers, so that you don't blow your shocks from overly aggressive springs. I'm sure you know the pros and cons of more aggressive springs and dampers, so I won't bore you with that.

There are also basically three very popular M3 mods that I tend to see on the forum, and each has a different effect on the handling. You can get any of these at your local dealership, but you can probably find them cheaper online. I would check United BMW (PM Dan@UnitedBMW here on the forum or check UnitedBMWonline.com) or HP Autowerks for these parts, because while the dealership will charge MSRP, these guys won't.

M3 Front Sway Bar will keep you flatter in the corners. It's a cheap mod, very easy to install. You'll want the E93 convertible version because it doesn't have the same kink in the middle that the E90/E92 version has. It's thicker, will keep you flatter in turns, and won't compromise the ride in any other way like springs/dampers would.

M3 Rear Subframe bushings are also cheap, but the installation is pretty involved if you're doing it yourself, and expensive if you're having someone else do it. To install anything back there (including rear sway bars or a new differential) you have to drop the rear subframe, which takes a while. However, the bushings themselves are cheap. They will eliminate the loose/squirrely feel of the car while accelerating. Basically, if you punch the gas right now, the rear of the car feels kind of loose like you don't know what it's going to do. The bushings help eliminate that.

M3 front control arms (which are composed of wishbones and tension struts) will give you some extra negative camber up front, widen the track, and improve steering feedback/feel. The car will go into turns much more nicely and you'll feel the road and communicate with the car through the steering wheel just a little better. Also, it'll just tighten up the suspension in the front of the car in general, almost as if you cranked a set of adjustable coilovers to be slightly stiffer. The parts are more expensive than the sway bars and bushings, but the labor isn't bad.

Those are what I usually think of as the "big three". Of course there are many other M3 parts which can be used on the car, but these have the greatest impact. The springs/shocks of the M3 suspension aren't compatible because they use different perches, and neither is the M3 differential. Other than that, most parts transfer over pretty well. But, as I said, the big three offer the greatest gains.

Finally, the last part of the equation is the tires. Run flats are expensive, and they don't grip THAT well compared to non RFT's. If you're upgrading your suspension to be stiffer and more aggressive (aka more fun!), then keeping the run flat tires might make everything a little TOO rough for you. Remember, BMW softened everything up so it works with the stiff RFTs. If you find this happening, the wheels/tire section is here. Everyone has their own favorites, but the general forum favorites tend to be Michelin PSS, Dunlop Star Spec, Bridgestone S-04, and Hankook RS-3 for the super high performing summer tires, and Hankook V12, Yokohama S.Drive, Kuhmo ecsta for the more budget conscious yet still very awesome tier.

Anyway, sorry for any misspellings, grammatical errors, or whatever. Hope this helps, and I hope you enjoy your car! When I first bought mine I wasn't really a "car guy" and was very happy with it. It took 4 years of slow upgrades to realize the potential that this beast has! Especially when less than $500 can net you 80 extra HP, and less than a thousand dollars in suspension upgrades can turn it from mild to sporty. It seems tame, but can kick that G37 right out of the water without spending much extra Welcome aboard!

[Greenkirby21]

^ post of the year

[SteveAZ]

Wow, what a great post...thanks so much! I've read a ton on this forum and a lot of it becomes information overload trying to decipher it all and sort out what's valid and whats validation. You've certainly made that a lot easier!

You've hit a lot of the points right on with the biggest being the amount of roll...it's not confidence inspiring at all and my other two cars are pretty flat through the corners. Kind of funny given my experience on sport bikes..I'll back it in, slam it into the corner, hit the apex, and pin it...in a car if the body starts shifting/rolling on me...my confidence goes to shit!

My reference to the tires wasn't so much about wear but in regards to my original comment....I thought there may have been sidewall flex contributing to the handling and that it wasn't the case since they're RFTs. We have them on our mini as well in 30/35s and sport suspension...talk about a rough ride! But hands down, that is the only car I've gotten in to and almost immediately felt comfortable with it...lots of feedback....something this car definitely lacks. But given that the tires are new, no rush on that end but could probably get a few bucks out of em when I choose to get rid of them.

It seems like a great car and my wife loves it...it's only got 24k miles on it so plenty of life left in it. I'm going to order the sway bar and do as suggested...drive it for a bit..and if it's all good then I'll pull the trigger and go all in....HP4, down pipe, finish the suspension, and wheels and tires. Much point in going with the M3 rear sway bar?

Once again thanks...that was a great post and much appreciated!

[froop]

Originally Posted by 135Pats

Im quite happy with how my vert handles, it has the m package and performance suspension...but if you want to improve it drastically, coils and sway bars are the way to go. It will be much stiffer through the twisty stuff.

Do you mean you have the BMW Performance Suspension Kit? Everywhere I've looked it says that kit is only compatible with the E82.

[froop]

Originally Posted by 1speedbike

I'm glad you're (mostly) enjoying the car so far! It's a great car, but you're right; there are a few things that I personally think BMW should have changed about it from the get-go.

The suspension is very soft, mostly to compensate for the harshness of run flat tires in general. It's not really a matter of how new they are, all run flats are pretty stiff in comparison to regular tires. Since BMW began making RFTs standard, they have accordingly softened the suspension to compensate and not make the ride too harsh. Great for 95% of BMW buyers in the US... not so great for you and me. This is what Matt (BrokenVert) was saying about the suspension and tires being the culprits to your issues.

There are a few solutions.. the most obvious is to switch out your springs and shocks/struts. A lot of people on here like the drop in height as you mentioned, but I think most of us do this as a handling upgrade. If you want to keep the same shocks, you can go with a less aggressive set of springs like H&R OE sport springs (they call it OE, but they're not the OEM springs) or BMW performance springs. These two are pretty mild compared to other solutions. Otherwise, I'd suggest getting a matched set of shocks and springs, or coilovers, so that you don't blow your shocks from overly aggressive springs. I'm sure you know the pros and cons of more aggressive springs and dampers, so I won't bore you with that.

There are also basically three very popular M3 mods that I tend to see on the forum, and each has a different effect on the handling. You can get any of these at your local dealership, but you can probably find them cheaper online. I would check United BMW (PM Dan@UnitedBMW here on the forum or check UnitedBMWonline.com) or HP Autowerks for these parts, because while the dealership will charge MSRP, these guys won't.

M3 Front Sway Bar will keep you flatter in the corners. It's a cheap mod, very easy to install. You'll want the E93 convertible version because it doesn't have the same kink in the middle that the E90/E92 version has. It's thicker, will keep you flatter in turns, and won't compromise the ride in any other way like springs/dampers would.

M3 Rear Subframe bushings are also cheap, but the installation is pretty involved if you're doing it yourself, and expensive if you're having someone else do it. To install anything back there (including rear sway bars or a new differential) you have to drop the rear subframe, which takes a while. However, the bushings themselves are cheap. They will eliminate the loose/squirrely feel of the car while accelerating. Basically, if you punch the gas right now, the rear of the car feels kind of loose like you don't know what it's going to do. The bushings help eliminate that.

M3 front control arms (which are composed of wishbones and tension struts) will give you some extra negative camber up front, widen the track, and improve steering feedback/feel. The car will go into turns much more nicely and you'll feel the road and communicate with the car through the steering wheel just a little better. Also, it'll just tighten up the suspension in the front of the car in general, almost as if you cranked a set of adjustable coilovers to be slightly stiffer. The parts are more expensive than the sway bars and bushings, but the labor isn't bad.

Those are what I usually think of as the "big three". Of course there are many other M3 parts which can be used on the car, but these have the greatest impact. The springs/shocks of the M3 suspension aren't compatible because they use different perches, and neither is the M3 differential. Other than that, most parts transfer over pretty well. But, as I said, the big three offer the greatest gains.

Finally, the last part of the equation is the tires. Run flats are expensive, and they don't grip THAT well compared to non RFT's. If you're upgrading your suspension to be stiffer and more aggressive (aka more fun!), then keeping the run flat tires might make everything a little TOO rough for you. Remember, BMW softened everything up so it works with the stiff RFTs. If you find this happening, the wheels/tire section is here. Everyone has their own favorites, but the general forum favorites tend to be Michelin PSS, Dunlop Star Spec, Bridgestone S-04, and Hankook RS-3 for the super high performing summer tires, and Hankook V12, Yokohama S.Drive, Kuhmo ecsta for the more budget conscious yet still very awesome tier.

Anyway, sorry for any misspellings, grammatical errors, or whatever. Hope this helps, and I hope you enjoy your car! When I first bought mine I wasn't really a "car guy" and was very happy with it. It took 4 years of slow upgrades to realize the potential that this beast has! Especially when less than $500 can net you 80 extra HP, and less than a thousand dollars in suspension upgrades can turn it from mild to sporty. It seems tame, but can kick that G37 right out of the water without spending much extra Welcome aboard!

Great post 1speedbike.

Btw, what do you think of the M3 rear sway bar? I was talking to a local performance shop in my part of the world about installing the M3 rear subframe bushings and he advised me to get the rear sway bar as it would "greatly improve handling" and wouldn't cost anything extra in labour since I would already have the subframe dropped for the bushings install.

[SteveAZ]

Boy am I running the risk of putting my foot in my mouth...but here goes.

So I'm reading about sway bars and the dynamics of suspension components and here's what I've gleened thus far...maybe somebody can set me straight.

This is all based on previous experience and what I'm perceiving in retrospect...feel free to tell me if I'm interpreting this wrong (I'm sure I am to some extent). and bare with me as in the past I just wanted to drive the cars, didn't want to wrench on them so I never got into trying to fine tune them. If I wanted to really canyon carve...I rode a bike.

When I had my S2000 it had quite a bit of body roll, going in to corners the front end tracked great...the back end...not so much and was unpredictable but that may have been due to tire choice and the VTEC definitely contributed to it. I'm guessing this car was engineered this way to be more track oriented. Problem was, if I loaded and unloaded the suspension abrupty...guaranteed 360...got better at it but wouldn't let anybody else drive that car and consequently ended up getting rid of it. These cars prone to neutral or oversteer?

G37s...this car is setup pretty stiff all the way around and thus is quite flat going in to and through the corners, however this seems to cause understeer as this car feels as though it will push in the corners but not to bad and is pretty predictable so I feel a bit more comfortable with rear wheel tire spin to compensate and help steer. It feels more predictable than the S2K did.

Mini...this car is very stiff and the front definitely pushes on it..but the front wheel drive helps with that...no problem...let off the gas....problem...it feels very predictable and of course wheel spin isn't an issue as I don't have to worry about it coming around on me nearly as much. Also prone to understeer?

So, what I'm getting at...it seems as though these cars (135i) stock may have a fair amount of understeer, won't just putting a 28mm ARB on it increase this and actually cause the front end to push more? Given it's the vert and I have to go with the 28mm bar and not the 26.5 is it too much? Throw in the soft suspension and won't this cause even more weight transfer to the front outside tire and cause the car to push even more?

If you actually read this, thanks...and if you have some insight...even more so.

I need to go drive this car harder this week and see how it responds, thus far it's just been semi-spirited corners that I noticed the body roll but no understeer, thus far I have yet to push it hard and see how well it'll track through the corners. The body roll kind of put me off on it initially and brought back memories of the S.

[BrokenVert]

The 135 has a different front suspension geometry than any of those other cars. It actually has a slight handling benefit - as less roll means less postive moment on the tires. Effectively limiting the amount of positive camber put onto the tire.

By chance was your S2000 and AP1? I've experienced exactly what you have while driving a 2002 car. They changed the rear suspension geometry entirely in 2004 I think to eliminate the tendency of the car to snap oversteer like that.

The car pushes heavily in stock form - all modern cars do. But it's easily remedied. I don't know how far you're willing to push it, but my solution thus far has been E93 front sway, lighter 17" OZ wheels, 245 square Dunlop star specs, and the PSS9 coil overs that I bought 3 days ago.

There aren't that many people that performance mod verts - only me, Mike, and a user long since gone named Nordic are the people that actually mod our verts to handle.


I can't wait to see what you end up doing with it.

Ohh also you'll have to remove two pieces of underbody bracing to get the swaybar in. It's no big deal - the bars are obvious and they're held on with 4 bolts each. They are sizes 15mm, 16, 17, and 18mm in defending order from the front of the car.

Just make sure the car is square on a lift - or jackstands - and removed the bolts.

That's the only complication of the vert install. And most importantly have fun with it!

[MikeinAlexandria]

Glad you like the 135i. I love my 128i convertible. That said, mine came with the M Sport package, and I believed that meant it had a tight, stiff, suspension. In reality, M Sportmhas become ///Ms plus nicer seats, cool steering wheel and a smattering of other stuff. (The multi spoke 17inch wheels are actually great)

I decided to go all in, and do a coil over suspension. For cost reasons, I chose the KW V1. I did not do sway bars for several reasons. One, my car already had M sport sway bars, and they work well. And two, stiffer sway bars can cause lots of handling issues if they aren't set up correctly. There is no substitute for a high end, well engineered suspension. My other complaint was ride height. Its a convertible, not an SUV! I did not want a slammed car, but just a nice lowering. KW coilovers are adjustable, and you can tune the height to the exact look you want, from a little slammed to factory clearances. The only thing I would consider doing differently would be to go with V2 coilovers vs. V1. The dampening is also adjustable, and I wouldn't mind the ride being a tiny bit stuffer. Further 135i, because of the extra weight, slightly stiffer coilovers make sense. The body has no flex at all, and you will have an amazingly well handling ride! Hold off on sway bars till you do the suspension. Since you live in Arizona, you could also go with 17 or 18" wheels with high end tires, like Micheline Pilot Super Sports. Don't skimp on tires, the run flats are fine for daily use on the East Coast, but they give up grip and ride quality for the run flat convenience.

Whatever you decide, a suspension will be the best investment you can do from a daily smile per mile value! My car feels SO nice, and is much more composed than it was with the stock M Sport suspension that was, of course, tuned to run flats. One other thing... The BMW performance Exhaust is fabulous. Great build quality, reasonable (online shopping!) and it sounds amazing when you wind up the engine. The version for the 135i is even cooler than mine and sounds better, no drone at all on the highway, just that nice Euro, inline six cylinder wail at high rpm. Makes the car sound like a proper sport sedan instead of a Lexoyta! I wish BMW would try to keep in mind that their customers are still enthusiasts, not just trying to get from point A to point B (that is what feet are for...). But sadly, that is not the case anymore, so our cars need a little tweaking to get them where we really want them. Good luck, enjoy the car!

[ken1137]

+1 for Speedbike...your complaints are the same everyone has once they move into a 1'er. As mentioned start with:

1) non-RFT's.
2) coilovers and front sway bar.

Then, if you need a bit more:
3) M3 front control arm kit.
4) M3 rear subframe bushings, especially if you add the rear sway bar.
5) upgrade rear toe arm.

[MikeinAlexandria]

Originally Posted by BrokenVert

There aren't that many people that performance mod verts - only me and a user long since gone named Nordic are the people that actually mod our verts to handle.

Umm, me! I planned on modding my car from the moment I bought it! I always wanted an M Technik convertible and the 128i M sport with a few tweaks is as close as one can get.

I may try the M3 front sway bar, it is a reasonably priced option and I know someone who can install it. Lots of great info in this thread, thanks guys!

[BrokenVert]

Originally Posted by MikeinAlexandria

Umm, me! I planned on modding my car from the moment I bought it! I always wanted an M Technik convertible and the 128i M sport with a few tweaks is as close as one can get.

I may try the M3 front sway bar, it is a reasonably priced option and I know someone who can install it. Lots of great info in this thread, thanks guys!

added to the list.

Sorry!

[SteveAZ]

Thanks for the input Mike...the KWs definitely sound appealing for the height adjustability and overall tunability. 2k is a little hard to swallow though.

Took the car out last night and did some fairly aggressive driving with it. Could definitely feel the front end pushing, pretty good amount of sway but at no time did I feel the rear end was going to come around on me. I do see what people are talking about with the rear bushings and the rear end shifting around a bit. Kinda felt like I was driving grandmas caddy the way it was bouncing around (top was down too) I'm guessing the bushings are gonna have to go as well and after changing out the springs and shocks/struts it's gonna be even more noticable.

The wife pretty much told me yesterday either way she wants to keep the car and if I wanted to get rid of it..."would you consider taking the G and modding that instead?"....uh....NO..."will you mod it for me then?"

So looks like I'm all in and have a budget of about 4 grand and looking at a few options.

Suspension:

BMW performance kit complete front and rears with sways. Am I reading that right that the rear sway is included for $1560 at ubmwo?

BMW performance springs and Koni sport adjustables all the way around with sways...looking like about $1900?

KW stage 2 with sways at about $2400.

Option 2 seems the most appealing as I can probably shop around and get the price down a bit and have a lot of adjustability...just no ride height adjustability.

Other goodies:

Of course the JB4..recommendations for best pricing option appreciated.

May do the catless downpipe if/when money allows.

Wheels and tires are still a bit up in the air but narrowing it down. Definitely 18s and under 23#s but hoping between 21 and 22 if money allows and will probably go with a square setup.

Rear bushings will likely wait a bit...gonna have to research who can do it around here, my level of comfort with them, and how much. M3 wish bones will be based on results and when money allows if.

Keeping my eye out for used options to make the most of my budget as well should anybody have any offerings.

Thanks again for the input and help.

[BrokenVert]

Steve - keep an eye out on the forums for used options.

I just picked up $2500 worth of suspension components for about $1300.

There was also that time a few years back where I got a set of PS2s with 2000 miles on them for the cost of shipping and nothing else


The forum is a hot bed of great deals. And of course there are always friendly people like us who are willing to help you out if you have questions.

[Dackelone]

This thread is quite interesting and informative.

[BrokenVert]

Dack correct me if im wrong - but I thought that BMW perf suspension components arent valved properly for the vert.