[finn335]

Hi,

tried to search about the subject but couldn't find anything, but sorry if this has been discussed earlier. I'm going to do a tune, dp:s and intake so should I upgrade the suspension? Something I found was that maybe I should change the backstruts to M3 struts? I have the m-sport suspension (I'm not sure if this is the sports suspension in NA?). I really wouldn't want to lower the ride/make it uncomfortable, since the roads are in very poor shape here + we have 2-3 feet of snow for 5 months of the year. I'm not gonna track the car, just basic street driving with maybe some spirited driving sometimes, but mainly I don't care if it doesn't become a race car since I think it handles pretty well now already. Just wondering if the suspension can handle the extra horses? Thanks for all the answers and every comment is welcome!

[cvc 22349a]

Depends more on if you're staying with run flat tires or not.
When you add torque and grip, the suspension bushings become inadequate.

[finn335]

Originally Posted by cvc 22349a

Depends more on if you're staying with run flat tires or not.
When you add torque and grip, the suspension bushings become inadequate.

Okay, thank you. That answers a lot. No runflats, just good ol' regular tires for me, please. At what power level you think that an LSD becomes a necessity or atleast something to seriously think about?

[cdgatti]

Sounds like you should keep your suspension stock. It is already very good.

[turugara]

LSD isn't really necessary unless your tracking your car or trying for low times on a drag strip. DDing, no matter how spirited, doesn't really justify getting an LSD imo.

[cvc 22349a]

Originally Posted by finn335

Okay, thank you. That answers a lot. No runflats, just good ol' regular tires for me, please. At what power level you think that an LSD becomes a necessity or atleast something to seriously think about?

Depends who you ask I guess. I think a LSD should be standard equipment on the 335i. It was my first and most important mechanical modification. As previously stated, when you add torque and grip to the 335i, modifying the 335i in attempt to tighten the chassis becomes a slippery slope and a money flush. Your original question was about your car's suspension; it was a vague question. this sub forum. People have been modifying their suspensions for over 4 years now.

[CALWATERBOY]

Originally Posted by turugara

LSD isn't really necessary unless your tracking your car or trying for low times on a drag strip. DDing, no matter how spirited, doesn't really justify getting an LSD imo.

Not so! W/LSD, very noticeable improvement in everyday driving's to be had - can be felt immediately after install, motoring down a driveway. Apply power - good things happen not possible before.

BMW's 'sport' suspension, a macabre joke in Munich I'm sure, is barely adequate. Even with stock power, suspension improvements make a major diff in quality of life.

[CALWATERBOY]

Originally Posted by finn335

Hi,

tried to search about the subject but couldn't find anything, but sorry if this has been discussed earlier. I'm going to do a tune, dp:s and intake so should I upgrade the suspension? Something I found was that maybe I should change the backstruts to M3 struts? I have the m-sport suspension (I'm not sure if this is the sports suspension in NA?). I really wouldn't want to lower the ride/make it uncomfortable, since the roads are in very poor shape here + we have 2-3 feet of snow for 5 months of the year. I'm not gonna track the car, just basic street driving with maybe some spirited driving sometimes, but mainly I don't care if it doesn't become a race car since I think it handles pretty well now already. Just wondering if the suspension can handle the extra horses? Thanks for all the answers and every comment is welcome!

(1) Yes, yes, and YES. You'll be shocked at the improvement, and how limited BMW's sport suspension really is. You'll be annoyed at the cost - figure $6-7k USD for M3 parts, Quaife or Wavetrac LSD; matched shocks & springs. Plus labor.... BUT....whatta diff!

(2) Dude! Sport suspension has 5" clearance at the doors; not optimal for snow. 4wd SUV, please.

[CALWATERBOY]

Originally Posted by finn335

Hi,

tried to search about the subject but couldn't find anything, but sorry if this has been discussed earlier. I'm going to do a tune, dp:s and intake so should I upgrade the suspension? Something I found was that maybe I should change the backstruts to M3 struts? I have the m-sport suspension (I'm not sure if this is the sports suspension in NA?). I really wouldn't want to lower the ride/make it uncomfortable, since the roads are in very poor shape here + we have 2-3 feet of snow for 5 months of the year. I'm not gonna track the car, just basic street driving with maybe some spirited driving sometimes, but mainly I don't care if it doesn't become a race car since I think it handles pretty well now already. Just wondering if the suspension can handle the extra horses? Thanks for all the answers and every comment is welcome!

The cheap date to cure that problem is a set o'Koni FSD shocks. Designed for stock springs, you'll be much happier with what you have. But you will not have the capability you can have w/other mods. [Click here] for perspective!

You drive a 2007 - well known for pothole 'explosions' due to BMW's suspension design. Yow! FSD's solve that problem, specifically.

[finn335]

Thanks a lot for all the answers! I really appreciate them Sorry if I ask some obvious questions, but I'm new to all this car-modding-business and want to get things right the first time. Really learning all the time and I do want to learn. About the snow question, I really didn't mean that I would be driving in it But there can be some heavy snow and since I DD the car, it should cope with atleast some amount of snow (and I believe it does when it's in stock height, been browsing the finnish forums). I'm happy being stock, but the KONI FSDs seem like a good compromise. Thank you for your suggestion! Also thanks for everyone commenting, they all really do help

[CALWATERBOY]

Originally Posted by finn335

Thanks a lot for all the answers! I really appreciate them Sorry if I ask some obvious questions, but I'm new to all this car-modding-business and want to get things right the first time. Really learning all the time and I do want to learn. About the snow question, I really didn't mean that I would be driving in it But there can be some heavy snow and since I DD the car, it should cope with atleast some amount of snow (and I believe it does when it's in stock height, been browsing the finnish forums). I'm happy being stock, but the KONI FSDs seem like a good compromise. Thank you for your suggestion! Also thanks for everyone commenting, they all really do help

In wet conditions, or particularly where there's snow, a limited slip differential will save your bacon - much better than BMW's e-diff. That & FSD's will flat put a smile on your mug!

Recommend: Do the suspension/LSD before power upgrades -- more power highlights deficiencies.

You'll want more. Are you aware of rear subframe bushing flex?

[GaryS]

Originally Posted by turugara

LSD isn't really necessary unless your tracking your car or trying for low times on a drag strip. DDing, no matter how spirited, doesn't really justify getting an LSD imo.

+1 I have a Wavetrac, but for track. IMO it's way too expensive to justify for the small difference it makes for street.

But I definitely recommend FSDs.

[finn335]

woops, doublepost

[finn335]

Originally Posted by CALWATERBOY

Recommend: Do the suspension/LSD before power upgrades -- more power highlights deficiencies.

You'll want more. Are you aware of rear subframe bushing flex?

I've heard about it, but not much. That is what I was referring to in my OP with the M3 stuff, but really didn't know what I was saying I think it has something to do with the stock bushings being so soft and causing the rear wheels to not be able to put down all the power (wheel hop?)? I'm sure I'm wrong, so please correct I looked to polyurethane bushings, but read about them being of poor quality? Could you point me to a direction with these and also thanks for the recommendation about the upgrade being done before the performance updates!

[CALWATERBOY]

Originally Posted by CALWATERBOY

....rear subframe bushing flex?

Originally Posted by finn335

I think it has something to do with the stock bushings being so soft and causing the rear wheels to not be able to put down all the power (wheel hop?)?

With stock bushings the rear's somewhat disconnected and vague. Problem's worse with more power and/or you'll be very aware of it after LSD install - cure that w/M3 bushings.

These bushings are not a trivial install - typical labor $500+, twice parts cost [USA]. As a DIY, it's an inexpensive cure for irritating behavior. Stability and precision's the name of the game.

[finn335]

Originally Posted by CALWATERBOY

With stock bushings the rear's somewhat disconnected and vague. Problem's worse with more power and/or you'll be very aware of it after LSD install - cure that w/M3 bushings.

http://www.turnermotorsport.com/p-14...e82-non-m.aspx

do you mean these? I want to really thank you for all the advice you've given, it's been very helpful

[tunachris]

Good coil-overs are a start. They will improve handling, and flatten the car in turns. Get rid of the RFT's and do shocks/springs to be able to use the power.

A good LSD will help to get the power to the ground both coming off the line, and powering out of the turns. I still think it is a crime that BMW doesn't offer this at least as on option for us lowly NON-M people. For most of us it is going to be the most expensive mod we do, but it is a must to use all the power that the car can make.

I haven't done M3 bits or sway bars myself, but this seem to be the next step. Bushings and control arms as well as anti-roll bars from the M cars should be the next step. I am not sure if I want or need this, but time will tell.

[CALWATERBOY]

Originally Posted by finn335

http://www.turnermotorsport.com/p-14...e82-non-m.aspx

do you mean these? I want to really thank you for all the advice you've given, it's been very helpful

No, those will give you a buckboard ride.

Try these M3 parts. HP Autowerks is a gold standard in the USA, as is Ground Control.

[finn335]

Can't thank you guys enough for all the info and help! Thanks CALWATERBOY for the links, I think I'm gonna order those subframe bushings asap! Planning to do some driving on lake ice this winter, should be fun with these upgrades! Can't even imagine how fun it would be with the whole shabang though... Maybe some day