[Gator328i]

I'm curious to know if there are any definitive ways to get rid of the understeer I experience in my 328i. Has anyone successfully gotten rid of it in their car? Currently, I have the stock set-up with Bridgestone run-flat tires. I'm wondering if perhaps I could use a stiffer sway bar in the rear to help alleviate some of it. Or, is the problem the tires? Any ideas or suggestions would be greatly appreciated.

[galahad05]

Are you running the sport package?
If so...you could reduce or remove your tire stagger.

[smack]

Do you have the sport package? Are you on all seasons or summers?

[Q4P]

To gain more oversteer - front and rear sway bars, rear LSD, the stiffest shocks and springs you can find or a set of nice coilovers. Certainly a set of wider wheels and tires would help as well.

[N6CRB]

Well. If your pushing' in the turns I'd go down on the track bar a couple a rounds.
Sorry, race rained out and I need my NASCAR fix.

[roadkillrob]

Wider front tires (or narrow rear tires) will do it - basically squaring up the setup, BMW runs the narrow front rubber for this purpose on the sport package. Stiffer sway bars will also help dial it out, I think Turner sells a kit or the M3 units will help. An LSD won't fix a chassis issue (if you have understeer off the throttle or on the brakes it is still understeer), but it will help rear traction in an on-throttle situation, which may actually make your understeer worse until you break traction and start to rotate the car on the throttle. Also, randomly firming up the springs can reduce understeer but will cause other issues as the sway bar is controlling that during cornering, if you stiffen up the shocks enough to reduce understeer, the sway-bar is no longer doing it's job properly and you will probably have introduced all kinds of other handling issues.
If you think you have issues - try my E93 top down which move the weight bias another 5% to the rear!

[Tom K.]

And for an inexpensive quick and dirty fix, try inflating your front tires about 4 psi above the recommended pressure. But be aware that the car will be more sensitive to crosswinds at freeway speeds.

Tom

[ZURICH]

Originally Posted by Gator328i

I'm curious to know if there are any definitive ways to get rid of the understeer I experience in my 328i. Has anyone successfully gotten rid of it in their car? Currently, I have the stock set-up with Bridgestone run-flat tires. I'm wondering if perhaps I could use a stiffer sway bar in the rear to help alleviate some of it. Or, is the problem the tires? Any ideas or suggestions would be greatly appreciated.

A Square setup will minimise any understeer, wide is beautiful

[JS82]

Looking at his picture, I think OP has the non-sport Coupe with a square setup

[ZURICH]

Originally Posted by JS82

Looking at his picture, I think OP has the non-sport Coupe with a square setup

Think you could be right, he never replied to the question! This is a sports package, including girlfriend wheel rash.

[Gator328i]

Originally Posted by JS82

Looking at his picture, I think OP has the non-sport Coupe with a square setup

You are correct, I do not have the sports package but on the option list it says I have the sports suspension. If memory serves that's standard on all the coupes, right? As for wheels, I'm running the standard 225/17s on all four corners. I'm really surprised with the level of understeer I'm experiencing. I can't help but wonder if the run-flats have something to do with it. I never had this kind of problem with my E46, which did have the sports package.

[smack]

Originally Posted by Gator328i

You are correct, I do not have the sports package but on the option list it says I have the sports suspension. If memory serves that's standard on all the coupes, right? As for wheels, I'm running the standard 225/17s on all four corners. I'm really surprised with the level of understeer I'm experiencing. I can't help but wonder if the run-flats have something to do with it. I never had this kind of problem with my E46, which did have the sports package.

Yes all the coupes have the sport suspension just not the rest of the package. I would put high performance summer tires on there and start from there. There is only so much grip an all weather tire can provide in the dry.

[edirtaynine]

Originally Posted by roadkillrob

Wider front tires (or narrow rear tires) will do it - basically squaring up the setup, BMW runs the narrow front rubber for this purpose on the sport package. Stiffer sway bars will also help dial it out, I think Turner sells a kit or the M3 units will help. An LSD won't fix a chassis issue (if you have understeer off the throttle or on the brakes it is still understeer), but it will help rear traction in an on-throttle situation, which may actually make your understeer worse until you break traction and start to rotate the car on the throttle. Also, randomly firming up the springs can reduce understeer but will cause other issues as the sway bar is controlling that during cornering, if you stiffen up the shocks enough to reduce understeer, the sway-bar is no longer doing it's job properly and you will probably have introduced all kinds of other handling issues.
If you think you have issues - try my E93 top down which move the weight bias another 5% to the rear!

what he said.

[335okc]

Originally Posted by roadkillrob

Wider front tires (or narrow rear tires) will do it - basically squaring up the setup, BMW runs the narrow front rubber for this purpose on the sport package. Stiffer sway bars will also help dial it out, I think Turner sells a kit or the M3 units will help. An LSD won't fix a chassis issue (if you have understeer off the throttle or on the brakes it is still understeer), but it will help rear traction in an on-throttle situation, which may actually make your understeer worse until you break traction and start to rotate the car on the throttle. Also, randomly firming up the springs can reduce understeer but will cause other issues as the sway bar is controlling that during cornering, if you stiffen up the shocks enough to reduce understeer, the sway-bar is no longer doing it's job properly and you will probably have introduced all kinds of other handling issues.
If you think you have issues - try my E93 top down which move the weight bias another 5% to the rear!

+1
I actually run wider tires up front for my auto-x set, since its more focused on turns. I run 245 front and 225 rear, oversteer nicely. Keep in mind, oversteer is more dangerous if you cant control your rear.

[wannabe]

All coupe's have the sport package standard, does this apply to convertibles also?

[LOLrance]

Tighten the nut behind the wheel.

[driverman]

If you like your RFT's (most people don't), you could experiment with different tire pressures in the rear. It looks like 32/35 is recommended for 328i coupes without Sports and normal driving. You could try 32/33.

Changing to non-RFT's will change the handling characteristics due to the softer sidewall. You could start there and if you still have too much understeer, lower the pressure in the rear tires a couple of PSI.

But some posts by experts to other threads have said that understeer varies depending on conditions. For example, it varies depending on where you are in a turn. Wet conditions also affect it. So I wouldn't adjust the rears by much because you might get the feel you want under normal conditions but set yourself up for a disastrous oversteer under wet or extreme conditions. BMW engineers spent lots of time trying to find the right balance for all conditions.

if none of that does it for you, you look aftermarket suspension kits like Dinan's Stage 1 or 2.

[fdriller9]

Originally Posted by Tom K.

And for an inexpensive quick and dirty fix, try inflating your front tires about 4 psi above the recommended pressure. But be aware that the car will be more sensitive to crosswinds at freeway speeds.

Tom

+1 This will prevent the side wall from rolling and help reduce understeer.

[mjollnir19]

no rft and get wider wheels and tires on the front

[Edward]

how about....scrub speed before the turn and focus on your exit.

There's only so much you can do to reduce understeer since inherent properties of the chassis are very difficult to change. Square tires will do the most. Once an understeering pig, always an understeering pig.

[captainaudio]

Originally Posted by wannabe

All coupe's have the sport package standard, does this apply to convertibles also?

The convertible only comes with the sport suspension if you order the sport (or M-Sport) package. This is one of the reasons the sport package is more expensive on the cabrio than on the coupe.

CA

[smack]

Originally Posted by Edward

how about....scrub speed before the turn and focus on your exit.

There's only so much you can do to reduce understeer since inherent properties of the chassis are very difficult to change. Square tires will do the most. Once an understeering pig, always an understeering pig.

+1. There is only so much a car can do. If you overcook your entrance will will undoubtedly understeer through the turn. Slow down a bit more and focus on your line through the turn and your exit.