Has anyone lowered their i3?

[Unsavedone]

ECS Tuning has H&R spring kits available for our cars. I was wondering if anyone has tried them. It says 1.2" drop up front and .8" in the rear. I think that sounds like a good stance for the car but I was hoping for feedback.

 

[alohart]

Several i3 owners in the i3 Facebook group have installed lowering springs from at least 2 different manufacturers. They all seem to like the result. No one has said that the ride has been negatively impacted significantly. Some have even installed wheel spacers as well as lowering springs.

 

[jadnashuanh]

BMW had recently indicated that they were not going to introduce the sport suspension on the i3 as a package where it was in the original press release. The reason stated was that the car would not meet the crash tests without some work...recertification was not worth the expense for the anticipated improvement.

 

[stumbledotcom]

The reason BMW USA can't sell the sport suspension option isn't crash tests or recertification. It's the lowered height of the bumpers. The US implemented bumper height requirements starting with the 1974 model year. Since then there have been multiple examples of cars that cannot be sold in the same form here as their home countries. The MGB notoriously had its suspension raised and handling severely compromised according to reports at the time in order to meet the standard. The regulation has also been cited as part of the reason Citroen withdrew the DS and SM from the US market. Even today BMW, Porsche, VW, etc. offer suspension options in other markets that are only available here as after market parts, often with the flimsy caveat that they're for track-use only. Right.

 

[imolazhp]

Yes

 

[imolazhp]

The reason BMW USA can't sell the sport suspension option isn't crash tests or recertification. It's the lowered height of the bumpers. The US implemented bumper height requirements starting with the 1974 model year. Since then there have been multiple examples of cars that cannot be sold in the same form here as their home countries. The MGB notoriously had its suspension raised and handling severely compromised according to reports at the time in order to meet the standard. The regulation has also been cited as part of the reason Citroen withdrew the DS and SM from the US market. Even today BMW, Porsche, VW, etc. offer suspension options in other markets that are only available here as after market parts, often with the flimsy caveat that they're for track-use only. Right.

False.

Somewhat.

Are you trying to say the bumper on the i8 is the same height as the i3? lmao Or a new corvette? ha! The i3's bumper is more than tall enough to meet safety requirements. The front of the car is almost a slab nearly up to the bottom of the windshield, nearly.

I don't know if we will ever know why the sport suspension was dropped from the shadow "sport" i3, but don't count out an option for sport suspension on the 2017 until details about the 2017 are released. The H&R springs I installed on my i3 brought the front down 1.25" and the rear about 1." It looks great

 

[Roadracer1977]

Hi there,

Looking at getting two sets of these:-
http://www.ebay.co.uk/itm/H-R-SPORT-SPRINGS-KIT-BMW-I3-RANGE-EXTENDER-I01-15-/291554061443
(I can't find anyone in the UK that imports these... any info on this would be welcome!)

My question is.... My girlfriend and I have purchased one of the 94Ah Rex versions (each), so with the denser batteries that this model brings and the slight extra weight, do you think this kit will still be suitable?

Thanks!

 

[jadnashuanh]

Depending on what and how you hit something, the height of the 'strong' point can make a really big difference in how well the structure responds. Changing the height of the bumper could mean that the i3 slides underneath things that it otherwise wouldn't. It's not all about what you can see, it's how things are made behind it.

 

[I33t]

Depending on what and how you hit something, the height of the 'strong' point can make a really big difference in how well the structure responds. Changing the height of the bumper could mean that the i3 slides underneath things that it otherwise wouldn't. It's not all about what you can see, it's how things are made behind it.

So you're claiming that the i8 is an accident disaster waiting to happen?

 

[jadnashuanh]

Depending on what and how you hit something, the height of the 'strong' point can make a really big difference in how well the structure responds. Changing the height of the bumper could mean that the i3 slides underneath things that it otherwise wouldn't. It's not all about what you can see, it's how things are made behind it.

So you're claiming that the i8 is an accident disaster waiting to happen?

No, that's not what I'm saying...what you see as the bumper and what structure that is behind it are not the same thing. The CG, the mandated height of the bumper, and the crashworthiness all depend on things being at a particular location. Change that, and without testing (you hope you don't become the test dummy and find out it doesn't work!), few people have the knowledge, computer power, and program to model it adequately, and I really doubt they have a few spare cars around that they can instrument and crash test. Course, if you never hit something, or nobody ever hits you, it's sort of a mute point.

 

[I33t]

I think you're over thinking it.

If you drop your i3 an INCH it isn't going to make a big difference. You would get the same result under heavy braking or a wheel dropping in a pothole at point of impact.

The height of the bumper (or the intrusion protection beam behind the bumper) on the i3 is a LOT higher than the i8. Here is what you said:

" Changing the height of the bumper could mean that the i3 slides underneath things that it otherwise wouldn't."

That would apply to an i8 even more than an i3 lowered an inch. An inch just isn't going to make much difference.

Driving into the back of a 4x4 would be an issue for just about every small to medium car.

 

[Unsavedone]

As much as I appreciate the feedback, when I started this thread I wasn't looking for the science of lowering a vehicle. I have had numerous lowered vehicles and the 1" - 2" drops have never maimed anyone due to tampering with the crash scenarios of height. I was only looking to know about ride degradation or pics.

 

[jadnashuanh]

As much as I appreciate the feedback, when I started this thread I wasn't looking for the science of lowering a vehicle. I have had numerous lowered vehicles and the 1" - 2" drops have never maimed anyone due to tampering with the crash scenarios of height. I was only looking to know about ride degradation or pics.

Depends on the spring rates you choose and damper settings. It's not nice to hit the bump stops if you make them too soft, and constantly jarring if the springs/shocks are too stiff. One person's cup of tea is another's poison...really hard to say. It really depends on what you're used to. With all of the battery weight down low, the i3 handles decent out of the factory.

 

[jadnashuanh]

If you drop your i3 an INCH it isn't going to make a big difference. You would get the same result under heavy braking or a wheel dropping in a pothole at point of impact.

And you don't think the car would drop even lower when braking if you had lowered the car? There are tradeoffs on everything...you don't get something for nothing. Only you can decide if it is worth it to you. The i3 has fairly decent road clearance, but putting the battery pack an inch or two closer to road debris would not be my preference, regardless of the look (which I can't see while driving!).

 

[I33t]

If you drop your i3 an INCH it isn't going to make a big difference. You would get the same result under heavy braking or a wheel dropping in a pothole at point of impact.

And you don't think the car would drop even lower when braking if you had lowered the car? There are tradeoffs on everything...you don't get something for nothing. Only you can decide if it is worth it to you. The i3 has fairly decent road clearance, but putting the battery pack an inch or two closer to road debris would not be my preference, regardless of the look (which I can't see while driving!).

Clearly, you haven't investigated spring rate effect on brake dive. Its entirely possible that you could lower the car by an inch with higher rate sport springs (they usually are) and have a car that is actually riding as high or higher (and more level) than a standard car with standard soft springs (and shocks) under braking.

I'm not planning to replace the suspension on my i3, but I have on other cars. I can tell you that the results definitely play out as described.

There are tradeoffs, but they are more likely to be NVH effects than increased nose dive.

 

[Unsavedone]

So I guess the answer is no, no one has lowered their i3. That's all I asked, not for a lesson on how suspension dynamics work.

 

[jadnashuanh]

again, missing the point...any car will have some brake dive. STart lower, it will drop still lower. Even if you put on a progressively wound spring or even just a stiffer spring, it's still going to dive some. Last thing I'd want to happen is to punch a hole in my battery pack that now sits lower because I think it looks better. Whether it works for you, only you'll find out. Whether it's as safe in a crash, if you test it, it may be too late to find out, at least with good end results! The manufacturer modeled it with some quite expensive software and then verified by crashing a bunch of chassis. None of the aftermarket kits have done that.

 

[I33t]

Clearly, you don't seem to have grasped the factors in suspension dynamics under braking.

For example, we had a vehicle that came from the factory with soft springs and underdamped suspension. After putting up with it for a year, we went to a local suspension supplier (Dobinsons) and they kitted the vehicle out with higher rate lowered springs and effective dampers with stronger compression damping. I'm absolutely positive that the vehicle did not dive as low at the front under heavy braking because it used to scrape on the ground under brakes if there was a minor bump on the road - it never did that after the upgrade.

Suspension matters, and an inch of drop does not have to mean the vehicle sits lower under braking. The i3 does not have stiff springs or strong damping but it is also not super soft.

I haven't replaced suspension on every car I've had, it depends on the suspension it came with. Of the last 6 cars 3 have needed upgrades. Not all were lowered but all of them rode flatter under brakes than standard. Time on the racetrack helps a lot rather than on the public roads, because it eliminates variables and I have done a lot of that but not in the i3

 

[I33t]

So I guess the answer is no, no one has lowered their i3. That's all I asked, not for a lesson on how suspension dynamics work.

Yes, some people have lowered their i3. Springs are available.

There is at least another thread on this forum about it: http://www.mybmwi3.com/forum/viewtopic.php?f=12&t=1563

Eg: H&R have BEV and REX versions:
http://www.hrsprings.com/application/search/results/4/1747/2015

http://insideevs.com/lowered-bmw-i3/

I'm sure there are others...

 

[Stancedi3]

Yes mine has been lowered with 20mm spacers since the day I bought it and I love it!