[DaFish]

Well, after more than a year of research, pricing and putting my dealer through hell.... I have made the decision to keep my 335i E92 Black Sapphire Dinan S2 engine upgraded car. I will upgrade to Dinan Stage 3 suspension (ordered - Springs, shocks, camber plates, front (only) sway) and the M3 front control arms/tension struts. The ultimate reason on not upgrading to my dream M3 is cost - just money.

Here is my story for those that want to read.

What I want:
1) I won't necessarily track the car, but I won't rule it out
2) I want my car to accellerate nicely - the Dinan Stage 2 is a good start and sold through a dealer and covered under warranty - nice. Once I get past my 80kms warrantee, I will consider the Procede V4.
3) I am happy with the 335 braking, if I track, maybe not.
4) I NEED this to handle like a flippin champ.
- I want ultra crisp turn in
- no slop, no understeer - I want ultra grip on the front end to pull it into the corner
- no spinning of rubber - I had 4 mustangs - I am done with that
- I want to feel the car carve the turn, not plow like a bag of hammers. If I wanted safe (understeer), I'd buy some Trojans...
- I want the car to rotate on turn in and have me drive the car on balance around the corner. I want to feel the car carve ! BALANCE
- I want feel in the steering
5) I can't be "dropped". I have curbs, I have snow. I drive it with snows in the winter.
6) I have to have a decent ride quality or my wife won't get in it.
7) I don't want the tramlining
8) I want high speed at-the-limit cornering to be confidence inspiring. It is not currently.

Decision process:
I am in Canada: Dealer Quote: I priced out a 2011 M3 Comp and would trade in a 08 335i with 67,000 kms. New car: $89K my car: $33k. I would have to give them my perfectly good 335 and $63k to get into the M3. Too much.

Pros for the 335i decision:
1) 08 car's power, features, looks, seats, quality and stereo are all very nice and acceptable.
2) 08 - drives really well as a daily driver - what I do 90 % of the time
3) 08 rides very nice now with the non RFT new tires (I upgraded to 235/265 19" non RFT Bridgestone Potenza Pole Position tires) I did loose steering response on the non RFTs... and it seems to roll more....
4) With the Stage 3 suspension, I am hoping that this will fix the handling on the car to my satisfaction. It won't be an M, but from what I read, this fixes my complaints of sloppy turn in, too much understeer and way to soft on spritited driving - I won't be tracking the car.
5) Dinan Stage 3 is designed for this car and proven on many 335i cars.
6) It is all sold and warranteed through the dealer and Dinan. I have some confidence in that, more than a build from scratch option which has none.
7) This keeps my snows (that cost me 3600 at the dealer (yes I am an idiot)) - I wouldn't need to sell them and get new ones on for the M3 (additional big cost on top of the M3).
8) Keeps my warranty in tact on the 08 or at least covered by Dinan
9) keeps my service inclusive that I paid for until 80k - this is not transferrable to the M3
10) keeps my tire warranty insurance for flats (5 years) - not transferrable

The idea is I will then hold on to the car for a few more years

Cons
1) 08 - I am not happy with the handling on my car. It f'n sucks actually. I want more. Dinan Stage 3 will ideally fix this.
2) It takes 5k away from the savings on the M3
3) This also addresses any issue with modifying my 08 and me messing the car up with an unproven solution. Although there are KW/V3's and sway options that I was almost ready to pull the trigger on, ride height became an issue. I have researched this for ever. When I put on the non RFTs, I lost steering response and I realized how a small thing can afffect the car negatively. I want to get results that I want from spending 5k.

I think that is all the cons I have for it.... I would always want more power, and I could down the road once I am out of warranty with Procede V4, but that is something that I could live without - it is handling and feel that I am not satisfied with.

BMW's are designed top down for a reason. Dinan does the research I can't do. I trust them, and I trust my dealer. They sold a lot of Dinan upgrades and I don't want to guess on coil overs, or get too much drop, or too harsh of handling, or too low for the winter... Maybe I am too old.

I want the feel I thought I was buying. I hope this will do it.

Here is the Canadian price for Dinan Stage 3 Suspension - installed:
http://www.dinancars.com/store/produ...cat=321&page=1

Parts $2,466 (15% off at Dinan now)
Installation $1,377
Sub total $3,843 ($4,343 including tax)

(Dealer)
---------------
As we have promised you we will pay for the shipping so I omitted that price. The total includes the discount already. the M3 components that you were looking for. The thrust rods are $279 * 2 and the control arms are $204 * 2. Total for the Dinan M3 control arm components are $966 + tax ($1,092 including tax). The air filter is $100 + tax ($113 including tax)

the strut brace is only available for the front:

parts $823
installation $169
sub total $992 + tax ($1,121 including tax)

To sum it up the suspension is $4,343 including taxes. The M3 suspension pieces that you were inquiring about are $1,092, the air filter is $113 and the front strut brace is $1,121. Total for all would be $6,669.
----------------------------

I purchased the Stage 3 suspension from them for $4,343 including tax, then went to Tichler and got the M3 control arms/tension rods, black kidney grills, digital tire guage, and the BMW mobity kit for the non RFTs for $690 shipped.

I got the Dinan refill for the filter, not their $1000 air box, and I didn't get the Dinan strut brace for $1100... I can add that later if needed.

All in.. ~$5k Canadian.

So in short, this could be a really good compromise. Not spending $63k on the M3, additional insurance, gas....

It maybe the best 5k I ever spend. I will post some pics before the upgrade on ride height and post my detailed thoughts on ride/handling before and after. T

Stay tuned.

[e90pilot]

Your car will still have a touch of understeer on the track. It understeers to much for canyon carving but great for the track. The front sway bar is adjustable too so you can fine tune it. If the turns you take are long duration, you'll have time to settle car the into the turn.

[Yankees 2010]

wow... Before I say anything. How often do you take your car to the track and what club are you apart of.

[DaFish]

Originally Posted by Yankees 2010

wow... Before I say anything. How often do you take your car to the track and what club are you apart of.

I am not part of a club, but I would consider one in Ontario... not sure what the options are - suggestions?

If this car understeers after this, I am going to be pissed. I guess a tiny, tiny, TINY bit at the absolute limit - I mean at the point the car flips over - is ok. This would instill some confidence I guess....

I will track this a bit after I get this done, but it is my daily driver and I have been reluctant to go to the track in case I wreck it. I also find the brakes weak - after really spirited/hard braking... so that worries me on the track. They are really nice on the street.... acceptable.

I want complete balance and feel.

Just off now to clean the car and take measurements of the front/rear before the mods go in.

[DJKhan85]

You should also get the dinan LSD or a LSD in general. There is a tremendous difference in cornering when I give it power now. Before it used to just understeer like crazy when giving it gas near the limit of traction. Now it pulls into line and just carves up the turn like it's never done before.

Oh and on the ride height. The KW's can have a minimum drop of roughly .5 inches at their recommended max height. Combine that with 235/265 tires and you get a nice look with minimal drop. I measured with my buddies 335i sport to get that .5 measurement. Since I also have to deal with winter and curbs I did not want any drop at all.

Hope you enjoy it! Post up a review when it's all installed.

[Yankees 2010]

Originally Posted by DaFish

I am not part of a club, but I would consider one in Ontario... not sure what the options are - suggestions?

If this car understeers after this, I am going to be pissed. I guess a tiny, tiny, TINY bit at the absolute limit - I mean at the point the car flips over - is ok. This would instill some confidence I guess....

I will track this a bit after I get this done, but it is my daily driver and I have been reluctant to go to the track in case I wreck it. I also find the brakes weak - after really spirited/hard braking... so that worries me on the track. They are really nice on the street.... acceptable.

I want complete balance and feel.

Just off now to clean the car and take measurements of the front/rear before the mods go in.

I asked that question because I used to think just like you. I was scared about the brakes and spinning out at medium to high speeds. Trust me these cars are very capable even with the stock setup. The car just understeers when u push it to its turning limits, which was surprisingly calming since it was my first time at the track. It allowed me to take turns a little later and keep my foot on the gas

Here is a vid showing how fast im going around these turns. Hopefully it should give you some confidence when you take your car to the track.

[DaFish]

ok, pics before the upgrade. They aren't the greatest, I had nobody to hold the tape. Let me know of these are no good.

[e90pilot]

Originally Posted by Yankees 2010

I asked that question because I used to think just like you. I was scared about the brakes and spinning out at medium to high speeds. Trust me these cars are very capable even with the stock setup. The car just understeers when u push it to its turning limits, which was surprisingly calming since it was my first time at the track. It allowed me to take turns a little later and keep my foot on the gas

Here is a vid showing how fast im going around these turns. Hopefully it should give you some confidence when you take your car to the track.

Very good point. On the track understeer is desireable and faster. The important part is what conditions the understeer occurs. They way I have my car set up, I have slight oversteer in turnin while trail braking or off throttle. Adding throttle will cause it to understeer. It's really easy to control the racing line with throttle. It all depends on your driving style. If you have a 335 you can induce power on oversteer with power. I really can't do that with a 325.

OP, when you say you don't want understeer it's kind of vague. Stock ZSP I could make the car oversteer but I had to be drastic. With my setup now, I don't have to be as drastic.

[Gen_E92]

Good start, but I think this set up will still have alot of understeer for you if you think stock handling sucks THAT bad. If you really want it to handle CLOSE to an M3, you really need to add M3 rear sway bar and LSD to your list.

No offense, but the Stage 3 suspension is WAAAYYY overpriced. It's basically some modified Koni Yellows made to Dinan spec, stock style springs that's 20% stiffer IIRC, and Eibach sway bars. For roughly the same price you can have a set of AST 4100s or TCK Koni SA coilovers with Swift springs and M3 rear camber link conversion. For that, you get waayy better springs, height adjustablity and M3 rear camber link. Swift springs are custom so you can specify your desired spring rate or go with recommended rate, and you can specify longer springs if you want to retain stock ride height. You can pick your own sway bars and camber plates if you go that route.

From what you said in the OP, I think you're reading into Dinan's words too much. I would not pay more than $1600 for Dinan Stage 3 suspension.

[e90pilot]

When you buy shocks I would highly recommend having them revalved. From the manufacturer, the shocks have too much variance in the valving. I've driven 2 identical m3s with bilstien PSS10 suspension with the same spring rates and same tires. The balance was different between the cars.
That's why I liked the Dinan setup. They already have the revalved and they had done the R&D on matching springs rates. Yes, I drank the Dinan Koolaid and yes, Dinan is really expensive but there is a reason other than the fact it's Dinan.

[DaFish]

Originally Posted by DJKhan85

You should also get the dinan LSD or a LSD in general. There is a tremendous difference in cornering when I give it power now. Before it used to just understeer like crazy when giving it gas near the limit of traction. Now it pulls into line and just carves up the turn like it's never done before.

Oh and on the ride height. The KW's can have a minimum drop of roughly .5 inches at their recommended max height. Combine that with 235/265 tires and you get a nice look with minimal drop. I measured with my buddies 335i sport to get that .5 measurement. Since I also have to deal with winter and curbs I did not want any drop at all.

Hope you enjoy it! Post up a review when it's all installed.

Thanks. I will post the review.

What did the dinan LSD cost? Was your diff welded?

Cost on parts, and cost on labour if you would please.

[DJKhan85]

Originally Posted by DaFish

Thanks. I will post the review.

What did the dinan LSD cost? Was your diff welded?

Cost on parts, and cost on labour if you would please.

You got a PM.

[DaFish]

Originally Posted by Gen_E92

Good start, but I think this set up will still have alot of understeer for you if you think stock handling sucks THAT bad. If you really want it to handle CLOSE to an M3, you really need to add M3 rear sway bar and LSD to your list.

No offense, but the Stage 3 suspension is WAAAYYY overpriced. It's basically some modified Koni Yellows made to Dinan spec, stock style springs that's 20% stiffer IIRC, and Eibach sway bars. For roughly the same price you can have a set of AST 4100s or TCK Koni SA coilovers with Swift springs and M3 rear camber link conversion. For that, you get waayy better springs, height adjustablity and M3 rear camber link. Swift springs are custom so you can specify your desired spring rate or go with recommended rate, and you can specify longer springs if you want to retain stock ride height. You can pick your own sway bars and camber plates if you go that route.

From what you said in the OP, I think you're reading into Dinan's words too much. I would not pay more than $1600 for Dinan Stage 3 suspension.

Yes it is over priced, but by how much?

1) I keep my Stock ride quality or better
2) I keep my ride shock travel
3) It is proven to be designed for the car. This is a major one for me. You know as well as anyone on this forum of the myriad of choices and results on this forum. Some people have taken out their mods because they don't like them, or get bad results.
4) Adjustable shocks of decent quality
5) I have heard that the winters/snow/salt are not good for coilovers. And they require maintenance. This setup doesn't.
6) Turn in and steering feel is vastly improved.
7) I don't care about tire wear. I'll get new ones every year if this gives me the handling I want.

I was all set to follow FourPointDrift's setup. KWV3's, MORR rims (wider), M3 bits, H&R sways front and rear. This was more money, lower, and more of a track setup. I drive to work 90% of the time on the highway.

I changed my tires and it really affected the handling. I got nervous and worried that I was going to spend a ton and bugger the car up. This is not my line of work... So I pay. I pay for Dinan engineering, and I pay for the dealer to put it in. Ya. I am paying more... BUT I will have recourse if things are not correct (I believe).

$5k to me is ok. (that is labour, and tax). The parts are $2,400. Coilovers were 2k min with no sways, so I felt this was a CHEAPER option.... assuming it gives the performance I want.

I may pay another 5k next year when I do the rear end subframe bushings, control arms and maybe LSD - and take out the Dinan S2 and put the Procede in - when I am out of warranty.

PS: the M3 sways are designed to understeer as per FourPointDrift. The H&Rs are better for a more balanced feel than the M3 Sways.

Comments?

[Gen_E92]

Originally Posted by DaFish

Yes it is over priced, but by how much?

1) I keep my Stock ride quality or better
2) I keep my ride shock travel
3) It is proven to be designed for the car. This is a major one for me. You know as well as anyone on this forum of the myriad of choices and results on this forum. Some people have taken out their mods because they don't like them, or get bad results.
4) Adjustable shocks of decent quality
5) I have heard that the winters/snow/salt are not good for coilovers. And they require maintenance. This setup doesn't.
6) Turn in and steering feel is vastly improved.
7) I don't care about tire wear. I'll get new ones every year if this gives me the handling I want.

I was all set to follow FourPointDrift's setup. KWV3's, MORR rims (wider), M3 bits, H&R sways front and rear. This was more money, lower, and more of a track setup. I drive to work 90% of the time on the highway.

I changed my tires and it really affected the handling. I got nervous and worried that I was going to spend a ton and bugger the car up. This is not my line of work... So I pay. I pay for Dinan engineering, and I pay for the dealer to put it in. Ya. I am paying more... BUT I will have recourse if things are not correct (I believe).

$5k to me is ok. (that is labour, and tax). The parts are $2,400. Coilovers were 2k min with no sways, so I felt this was a CHEAPER option.... assuming it gives the performance I want.

I may pay another 5k next year when I do the rear end subframe bushings, control arms and maybe LSD - and take out the Dinan S2 and put the Procede in - when I am out of warranty.

PS: the M3 sways are designed to understeer as per FourPointDrift. The H&Rs are better for a more balanced feel than the M3 Sways.

Comments?

Lets compare Dinan S3 to TCK Koni SA coilovers with Swift springs since they both use Koni SA dampers ...TCK setup cost ~$1900, add ~$400 for F&R M3 sway bars. You also have the option to add M3 rear camber link conversion for ~$300. There are also other good choices out there, but I feel this set up is best for what you're looking for.

1) TCK setup will ride better even at reasonably higher spring rate due to superior springs.
2) You have the option of stock ride height/moderate lower or moderate lower/significant lower.
3) Dinan and TCK dampers are both re-valved by Koni according to their spec AFAIK.
4) Same
5) Winter is only a factor if the coilover is not made from stainless steel.
6) TCK wins hands down on performance. Dinan set up is really limited by the use of stock style springs. Stock style springs are alot heavier which is not ideal for both ride and handling.

Please elaborate how M3 sway bars are designed to be understeer??? That's kinda vague because understeer is a result of many things such as driving style, tire size, camber, damper setting etc.

I'm not sure how you pay $5k even with tax and labor when the parts are only $2.4k? Does installation have to be done by Dinan dealer? If so, and you really have to pay $5k, I'm sorry you're getting ripped off so bad I don't know what to say...

Harold@HPA is really the person to talk to, I'm just offering what I learned from him

[DaFish]

Originally Posted by Gen_E92

I'm not sure how you pay $5k even with tax and labor when the parts are only $2.4k? Does installation have to be done by Dinan dealer? If so, and you really have to pay $5k, I'm sorry you're getting ripped off so bad I don't know what to say...

Thanks for your feed back. The dealer is doing the work. I trust them, and trust the dealership - and I am still in warranty, and with service inclusive which I don't want to screw up. So that is why they are doing the work. Yes they are more.

COST:
Parts $2,466 - Only Stage 3
Installation $1,377
Sub total $3,843 ($4,343 including Canadian tax)

PLUS the M3 control arms/tension struts were another $500 shipped basically = ~$5k (dealer said he would install these for no labour cause he was in there).

I don't believe the total install of coilovers would be much cheaper than this with labour and Canadian tax, maybe 500 or so - certainly over 4k.

Originally Posted by Gen_E92

Please elaborate how M3 sway bars are designed to be understeer??? That's kinda vague because understeer is a result of many things such as driving style, tire size, camber, damper setting etc.

If you drive the M3, you will feel understeer on an onramp at the limit. Go see the mototrend comparo with the 2011 Mustang vs M3. The driver even says it. The BMWs are setup to understeer to be safe - the sways are part of that. For our car, FourPointDrift has found that the H&R sways are more neutral than the M3 sways.

Originally Posted by Gen_E92

Lets compare Dinan S3 to TCK Koni SA coilovers with Swift springs since they both use Koni SA dampers ...TCK setup cost ~$1900, add ~$400 for F&R M3 sway bars. You also have the option to add M3 rear camber link conversion for ~$300. There are also other good choices out there, but I feel this set up is best for what you're looking for.

6) TCK wins hands down on performance. Dinan set up is really limited by the use of stock style springs. Stock style springs are alot heavier which is not ideal for both ride and handling.

I am in no way saying that Dinan is the best. I am saying it was designed for the car, proven, tested, reliable, warrantied, and has quality.

You have read this thread - you commented on it.
http://www.e90post.com/forums/showthread.php?t=419998

Post #15:
"I did a full cycle. Stock sports suspension -> hr springs -> kw v2 -> ohlins

the sports were nice when the car was stock. Hr springs only, car was too low and harsh. The v2's were nice for the first year and half and then serious downhill. Very stiff ride even on soft settings and the car felt worse than a Kia in corners. Ohlins, very complient. Comfortable even when it's set to a stiffer setting. I'm running high spring rates as well and the ride quality is great. "

A lot of these guys are in California with mild or no winters. I don't want to be F'n around like this. Although I find this a lot of fun to mod my car, it is only fun if the mods work for a positive effect. badass335 seems like he knows a ton and he couldn't get his car right. Imagine how much he spent.... I worry I will mess it up and I have nowhere to go other than to pay to fix it again because I made the decision to do it.

Maybe I am putting too much faith in the Dinan Stage 3 with the M3 arms, we shall see, this is a done deal - it is ordered.

BTW, I do have a lot of faith in Harold, and he has a ton of experience modding these and racing them on the track. If I was to go outside of the Dinan choice, he would have gotten the business.

Anyway, this is the choice I made and why I made it. I will post my results up when I get it back and I will be brutally honest. I am already reading that it will have some understeer because of the staggered tires and that the camber won't take it all out. I may have rims and bigger tires in the future - so the modding continues....

Next year, LSD, Subframe bushings, M3 rear control arms/toe links.

When I come out of warranty, Procede with Meth, and some engine stuff.

[DaFish]

Originally Posted by Yankees 2010

I asked that question because I used to think just like you. I was scared about the brakes and spinning out at medium to high speeds. Trust me these cars are very capable even with the stock setup. The car just understeers when u push it to its turning limits, which was surprisingly calming since it was my first time at the track. It allowed me to take turns a little later and keep my foot on the gas

Here is a vid showing how fast im going around these turns. Hopefully it should give you some confidence when you take your car to the track.

Oh man that is fun !! I did see how you got on the gas earlier and powered out of the turn way sooner than you could without the LSD. You can see it.

The LSD is on the list....

[HP Autosport]

Better bang for your dollar, go for the Koni single adjustable coilover kit or doubles if your budget allows.

Add the M3 components - anti roll bars and front control arm kit.

You will still end up spending less and have better results.

The following is our Koni SA vs TCK DA and another photo of our SA kit.

[DaFish]

Does anybody know why Dinan only has the front bar now on their Stage 3? I thought this came with front and rear bars - it used to.

This has to affect the handling - you would think.

I am going to email Dinan.

[Pyrat 2]

Unless Dinan specifically dials in a lot of oversteer then you will continue to have understeer with your setup. The 235/265 combo combined with a virtually perfect 50/50 weight distribution will ensure that understeer is the rule at neutral throttle at the limit. As somebody posted though some understeer is actually nice. I have a 235/265 combo with LSD and when I am at the limit I can transition the car between understeer and oversteer simply by feathering the throttle. Note the LSD contributes to this control since mine is a clutch type. Under throttle there is some locking action that will induce limited understeer. During off throttle the same locking condition will tend to induce understeer.

I just spent the weekend at BMW CCA Octoberfest at Road America which has a very large carousel perfect for evaluating this. I was ultimately limited by the understeer from the staggered setup. I'm considering a 245/265 setup next time I swap tires. BTW I do have a slightly increased size rear sway bar overstock. This reduces understeer but not enough to offset the stagger.

[DaFish]

Originally Posted by HeelToe

Unless Dinan specifically dials in a lot of oversteer then you will continue to have understeer with your setup. The 235/265 combo combined with a virtually perfect 50/50 weight distribution will ensure that understeer is the rule at neutral throttle at the limit. As somebody posted though some understeer is actually nice. I have a 235/265 combo with LSD and when I am at the limit I can transition the car between understeer and oversteer simply by feathering the throttle. Note the LSD contributes to this control since mine is a clutch type. Under throttle there is some locking action that will induce limited understeer. During off throttle the same locking condition will tend to induce understeer.

I just spent the weekend at BMW CCA Octoberfest at Road America which has a very large carousel perfect for evaluating this. I was ultimately limited by the understeer from the staggered setup. I'm considering a 245/265 setup next time I swap tires. BTW I do have a slightly increased size rear sway bar overstock. This reduces understeer but not enough to offset the stagger.

Thanks. I am considering the Dinan rims too. They almost remove the stagger (only 10mm).

Recommended Tires: Michelin Pilot Sport II Front:265/30-19 Rear: 275/30-19.
Included Items (2) 19 x 9" Front Wheels, (2) 19 x 9.5" Rear Wheels
http://www.dinancars.com/store/produ...cat=321&page=1

Question: is there any other manufacture that creates a front/rear combo of 9" and 9.5" ? I think this could be a very good addition to the car. (if they weren't a ridiculous $5400). I just can't seem to get my head around 5400 + 1600 for tires = 7000.... plus tax.


What I have noticed is that when I had my winters snows on, same 8" rims, same size tires... the car felt MUCH more balanced and was more fun to drive. It actually felt better than my 19". Steering response wasn't as good as my summer perf tires, but the car would rotate and was balanced. Loved it.

I sent Dinan a note asking about the rear sway. Seems to me you just don't take a piece out without changing other things.

Apparently the H&R Proseries sways are more tuned for a true balance, the M3 sways are geared for understeer too... like the M3 does. M3 only has 20mm of stagger... and it understeers less.

[HP Autosport]

Originally Posted by DaFish

Thanks. I am considering the Dinan rims too. They almost remove the stagger (only 10mm).

Recommended Tires: Michelin Pilot Sport II Front:265/30-19 Rear: 275/30-19.
Included Items (2) 19 x 9" Front Wheels, (2) 19 x 9.5" Rear Wheels
http://www.dinancars.com/store/produ...cat=321&page=1

Question: is there any other manufacture that creates a front/rear combo of 9" and 9.5" ? I think this could be a very good addition to the car. (if they weren't a ridiculous $5400). I just can't seem to get my head around 5400 + 1600 for tires = 7000.... plus tax.


What I have noticed is that when I had my winters snows on, same 8" rims, same size tires... the car felt MUCH more balanced and was more fun to drive. It actually felt better than my 19". Steering response wasn't as good as my summer perf tires, but the car would rotate and was balanced. Loved it.

I sent Dinan a note asking about the rear sway. Seems to me you just don't take a piece out without changing other things.

Apparently the H&R Proseries sways are more tuned for a true balance, the M3 sways are geared for understeer too... like the M3 does. M3 only has 20mm of stagger... and it understeers less.

You can safely run a 18x9 or 18x9.5 at all four corners if you don't want the stagger. Forgeline makes some of the strongest wheels out there for about $1200 ea. at any offset and width.

There is a bit more to under and oversteer than just anti roll bars and tire/wheel stagger alone, plus the M3 has much different control arm bushing durometers and alignment settings than the 335i.

[e90pilot]

Removing or greatly reducing the stagger is a must if you want to get rid of the excessive understeer. My car still understeers with only 10mm of stagger but if I lift I can get the nose to point in again.