About a year ago, we needed a replacement car for my wife. As we already have 2 other higher HP cars we wanted to pick up something to complement our other vehicles. After a bunch of test drives we settled on a low mileage CPO F30 328. We picked the 328 instead of the 335 because it***8217;s a few hundred pounds lighter, has a very quick steering rack, and is quick enough for its main role as a daily commuter.
I also knew going in that the suspension in any current BMW 3 series is severely under-sprung and has limited damping capabilities. It***8217;s why we deliberately bought a used BMW as I knew I was going to be throwing away bits of the car. On the positive side, the current F30 chassis is extremely ridge, the N20 engine is torquey and reliable, and the 8 speed auto complements the entire package. The core was there for very good momentum car.
Step 1 ***8211; Dump the run-flats and overweight BMW wheels
Since we live in CA, we***8217;ve gotten used to running extreme performance summer tires year ***8211;round. My wife thought the run-flat tires on the 328 were like a bad joke. The grip is horrible, the tire squirm was high, and the ride quality is worse than an extreme performance tire. Nothing wrong with the stock BMW wheels except they are very heavy. By replacing both wheels and tires, with a set of 9 X 18 APEX wheels and Sumitomo HTR Z III***8217;s, I calculated that I saved about 10 pounds a wheel in unsprung weight. That may not sound like much but it made a significant improvement in the overall grip, ride quality, and drivability of the 328. I picked the Sumitomo***8217;s because I needed something cheap to get my wife through the rainy season and if I wanted to make a change later I would not feel bad about tossing a set of $600 tires. To my surprise the Sumitomo***8217;s are one of the best budget performance tires you can buy and will stay with the car a while longer.
Step 2 ***8211; Suspension- Replace but with what?
When considering suspensions, the first thing to figure out is how you drive the car and what you want out of the suspension. That leads to a decision on what areas of ride vs comfort do you need to compromise and how much are you willing to spend to achieve your goals. All suspensions are compromises, it***8217;s just a matter of in which direction and how much. In my case a fun road trip on the weekend can encompass some excellent driving roads like, Calaveras, Mines, Skyline, LA Honda, and a few others like HWY 1 to Big Sur. Fun driving roads all , but they are full of broken pavement, pot holes and other things that overtax a wimpy suspension very quickly. I wanted something that would eat up the bad pavement and not have a punishing ride. Suspensions that can do those things reside in the high end of the performance street category and encompass companies such as Ohlin***8217;s, KW, Billstein, and others.
In my case I selected the Ohlin***8217;s DFV***8217;s. I chose the DFV***8217;s from feedback I recieved from friends that the DFV technology does work and when you hit that heaved up section of broken pavement or pothole, at speed, the suspension just deals with it. Attached is a link to the DVF tech information so read at your own leisure***8230;. http://www.roadandtrackbyohlins.com/ Along with the Ohlin***8217;s I also purchased Ground Control adjustable camber plates since the 328 was lowered about an inch front and rear and the front camber is now set a relatively mild -2 degrees with zero toe.
Results ***8211; Did I hit my Goals?
Handling ***8211; BMW does not publish the spring rates for the F30***8217;s but suffice it to say that the Ohlin***8217;s spring rates are double to triple the stock BMW rates. That translates to very little body roll and a very quick turn in capability that happens ***8220;now***8221;. Shock damping is as advertised. The Ohlin***8217;s just eat up bad pavement and the car is now an extremely stable and predictable platform. Big bump or broken pavement in the middle of a corner the Ohlin***8217;s just eat it up and that provides an amazing feeling of confidence. The 328 is now a very playful puppy that loves to be tossed into any type of corner. Overall the car is very neutral handling but can be made to predictably rotate with the throttle if you want. The key word here is predictable.
Braking- The stock braking system on an F30 is actually quite good for street use. What is not good is the basketball effect with tires leaving contact with the pavement. Loss of contact occurs when braking hard into corners with rough or broken pavement, the front tires momentarily lose contact with the pavement as the stock suspension can***8217;t keep up. The Ohlin***8217;s ability to keep the tires planted on the pavement allows the braking system to function in a much more predictable fashion. It***8217;s a difference you can feel and as a result one feels a lot more comfortable braking harder and deeper in to corners.
Overall Drivability
Have had a chance to drive 2 fun roads since the conversion-
Calaveras ***8211; ate up the big whoops leading up to the park. Once on the hill I could really attack the corners with confidence and found myself carrying a significant amount of extra speed between corners. Had to cut the ride short due to time constraints, but it was awesome while it lasted.
Skyline ***8211; My wife drove part and loved how her car handled. She was easily carrying 10+ MPH above her normal cautious pace. The new suspension just gave her a whole new feeling of confidence. Once I drove, I could keep her comfortable and still up my pace about 10 mph over what I could normally drive with her in the car, before I***8217;d get complaints of tossing her around too much. The Ohlin***8217;s just smoothed everything out and got rid of 90+% of the unwanted body motion.
Overall Impression
For about a $4500 investment in tires, wheels, and suspension I got the results I wanted. Both my wife and I are very pleased with the decision to move forward with the Ohlin***8217;s upgrade. My only complaint on the Ohlin***8217;s is they are a single adjustable shock and I wish I had a bit more control over compression vs rebound. I***8217;d like to reduce the compression a bit more over wavy pavement to reduce a bit of ***8220;jiggles***8217; that do come though at lower speeds. (This is a very small complaint in the overall performance of the system.) Overall the 328 is now a very easy and rewarding car to drive at any pace. When the opportunity presents itself the 328 can be driven near its limits with extreme confidence.
I also knew going in that the suspension in any current BMW 3 series is severely under-sprung and has limited damping capabilities. It***8217;s why we deliberately bought a used BMW as I knew I was going to be throwing away bits of the car. On the positive side, the current F30 chassis is extremely ridge, the N20 engine is torquey and reliable, and the 8 speed auto complements the entire package. The core was there for very good momentum car.
Step 1 ***8211; Dump the run-flats and overweight BMW wheels
Since we live in CA, we***8217;ve gotten used to running extreme performance summer tires year ***8211;round. My wife thought the run-flat tires on the 328 were like a bad joke. The grip is horrible, the tire squirm was high, and the ride quality is worse than an extreme performance tire. Nothing wrong with the stock BMW wheels except they are very heavy. By replacing both wheels and tires, with a set of 9 X 18 APEX wheels and Sumitomo HTR Z III***8217;s, I calculated that I saved about 10 pounds a wheel in unsprung weight. That may not sound like much but it made a significant improvement in the overall grip, ride quality, and drivability of the 328. I picked the Sumitomo***8217;s because I needed something cheap to get my wife through the rainy season and if I wanted to make a change later I would not feel bad about tossing a set of $600 tires. To my surprise the Sumitomo***8217;s are one of the best budget performance tires you can buy and will stay with the car a while longer.
Step 2 ***8211; Suspension- Replace but with what?
When considering suspensions, the first thing to figure out is how you drive the car and what you want out of the suspension. That leads to a decision on what areas of ride vs comfort do you need to compromise and how much are you willing to spend to achieve your goals. All suspensions are compromises, it***8217;s just a matter of in which direction and how much. In my case a fun road trip on the weekend can encompass some excellent driving roads like, Calaveras, Mines, Skyline, LA Honda, and a few others like HWY 1 to Big Sur. Fun driving roads all , but they are full of broken pavement, pot holes and other things that overtax a wimpy suspension very quickly. I wanted something that would eat up the bad pavement and not have a punishing ride. Suspensions that can do those things reside in the high end of the performance street category and encompass companies such as Ohlin***8217;s, KW, Billstein, and others.
In my case I selected the Ohlin***8217;s DFV***8217;s. I chose the DFV***8217;s from feedback I recieved from friends that the DFV technology does work and when you hit that heaved up section of broken pavement or pothole, at speed, the suspension just deals with it. Attached is a link to the DVF tech information so read at your own leisure***8230;. http://www.roadandtrackbyohlins.com/ Along with the Ohlin***8217;s I also purchased Ground Control adjustable camber plates since the 328 was lowered about an inch front and rear and the front camber is now set a relatively mild -2 degrees with zero toe.
Results ***8211; Did I hit my Goals?
Handling ***8211; BMW does not publish the spring rates for the F30***8217;s but suffice it to say that the Ohlin***8217;s spring rates are double to triple the stock BMW rates. That translates to very little body roll and a very quick turn in capability that happens ***8220;now***8221;. Shock damping is as advertised. The Ohlin***8217;s just eat up bad pavement and the car is now an extremely stable and predictable platform. Big bump or broken pavement in the middle of a corner the Ohlin***8217;s just eat it up and that provides an amazing feeling of confidence. The 328 is now a very playful puppy that loves to be tossed into any type of corner. Overall the car is very neutral handling but can be made to predictably rotate with the throttle if you want. The key word here is predictable.
Braking- The stock braking system on an F30 is actually quite good for street use. What is not good is the basketball effect with tires leaving contact with the pavement. Loss of contact occurs when braking hard into corners with rough or broken pavement, the front tires momentarily lose contact with the pavement as the stock suspension can***8217;t keep up. The Ohlin***8217;s ability to keep the tires planted on the pavement allows the braking system to function in a much more predictable fashion. It***8217;s a difference you can feel and as a result one feels a lot more comfortable braking harder and deeper in to corners.
Overall Drivability
Have had a chance to drive 2 fun roads since the conversion-
Calaveras ***8211; ate up the big whoops leading up to the park. Once on the hill I could really attack the corners with confidence and found myself carrying a significant amount of extra speed between corners. Had to cut the ride short due to time constraints, but it was awesome while it lasted.
Skyline ***8211; My wife drove part and loved how her car handled. She was easily carrying 10+ MPH above her normal cautious pace. The new suspension just gave her a whole new feeling of confidence. Once I drove, I could keep her comfortable and still up my pace about 10 mph over what I could normally drive with her in the car, before I***8217;d get complaints of tossing her around too much. The Ohlin***8217;s just smoothed everything out and got rid of 90+% of the unwanted body motion.
Overall Impression
For about a $4500 investment in tires, wheels, and suspension I got the results I wanted. Both my wife and I are very pleased with the decision to move forward with the Ohlin***8217;s upgrade. My only complaint on the Ohlin***8217;s is they are a single adjustable shock and I wish I had a bit more control over compression vs rebound. I***8217;d like to reduce the compression a bit more over wavy pavement to reduce a bit of ***8220;jiggles***8217; that do come though at lower speeds. (This is a very small complaint in the overall performance of the system.) Overall the 328 is now a very easy and rewarding car to drive at any pace. When the opportunity presents itself the 328 can be driven near its limits with extreme confidence.
