BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST - View Single Post

FaRKle! · 02-03-2019, 07:00 PM

Coil Spring Boosters/Spring Rubbers

One of the things I haven't completely been satisfied with after getting my Eibach springs is the amount of front drop I have. For street driving it's not bad, but it does hinder my off pavement driving and I've had to be a bit more careful than before. I was looking at solutions on how I could get just a tiny bit more front lift (~1/2") and came across coil spring boosters. It seems like a lot of people use these to "fix" old saggy springs, and wasn't really a performance product, but then I discovered Longacre Racing also makes them (called spring rubbers). Apparently they're commonly used in racing applications where they're used to test/create higher spring rates. This was a bit of a bonus since one of the ways I was thinking of increasing my ride height was getting some slightly stiffer springs. With the spring booster I could get the height I want, and see if I liked a higher spring rate.

I found out that Autozone carries rubber coil spring boosters for only $6. I went to my local store and bought a couple.

To install them you jack your car up so the spring is unloaded and the space between the coils opens up. Then slide them into place and then lower the car. For extra security I drilled 4 holes into the middle section of the boosters so I could secure it to the spring with zip ties. When you secure it with zip ties, make sure to loop the ties on the side of the spring that the booster will prevent coils from hitting each other, otherwise, if the coils ever go to full compression they'll cut the zip ties.

Coil Spring Booster Installed

After lowering the car I was pleased to see I gained about 5/8", right around the 1/2" I was looking for. One thing to be mindful of is the amount of raise you get will be dependent on how close together your spring coils are with the weight of the car on them. A spring with fewer coils and more space between them will have less raise than one with closer spaced coils.

After riding around on these boosters for a couple of weeks I think I'm going to spring for the slightly stiffer spring I was originally looking at. These are a good way of "trying before you buy" for springs.

02-03-2019, 07:00 PM	#42
FaRKle! Brigadier General 4017 Rep 3,540 Posts Drives: 328d Wagon, M2 Comp, i4 eD35 Join Date: Sep 2016 Location: Bay Area, CA iTrader: (4) Garage List 2023 BMW i4 eDrive 35 [0.00] 2017 BMW 328dx Wagon [0.00] 2021 BMW M2 Competi ... [0.00]	Coil Spring Boosters/Spring Rubbers One of the things I haven't completely been satisfied with after getting my Eibach springs is the amount of front drop I have. For street driving it's not bad, but it does hinder my off pavement driving and I've had to be a bit more careful than before. I was looking at solutions on how I could get just a tiny bit more front lift (~1/2") and came across coil spring boosters. It seems like a lot of people use these to "fix" old saggy springs, and wasn't really a performance product, but then I discovered Longacre Racing also makes them (called spring rubbers). Apparently they're commonly used in racing applications where they're used to test/create higher spring rates. This was a bit of a bonus since one of the ways I was thinking of increasing my ride height was getting some slightly stiffer springs. With the spring booster I could get the height I want, and see if I liked a higher spring rate. I found out that Autozone carries rubber coil spring boosters for only $6. I went to my local store and bought a couple. To install them you jack your car up so the spring is unloaded and the space between the coils opens up. Then slide them into place and then lower the car. For extra security I drilled 4 holes into the middle section of the boosters so I could secure it to the spring with zip ties. When you secure it with zip ties, make sure to loop the ties on the side of the spring that the booster will prevent coils from hitting each other, otherwise, if the coils ever go to full compression they'll cut the zip ties. Coil Spring Booster Installed After lowering the car I was pleased to see I gained about 5/8", right around the 1/2" I was looking for. One thing to be mindful of is the amount of raise you get will be dependent on how close together your spring coils are with the weight of the car on them. A spring with fewer coils and more space between them will have less raise than one with closer spaced coils. After riding around on these boosters for a couple of weeks I think I'm going to spring for the slightly stiffer spring I was originally looking at. These are a good way of "trying before you buy" for springs.
	Appreciate 0 Quote