Lowered guys - Do you cut your rear bumpstops?

[Shane361]

That's really weird. I've been running ultralites on my 08 for three years, and have never had a problem. In fact, looking at the stops while the car is on the ground, I have no idea how you would ever bottom out on the stops.

Difference between your body style and mine maybe? Went for a ride and so far no bumpstop bump

 

[GerRod]

I have the Steeda Ultra Lite springs. I widened my stock wheels to the inside 1 1/2" and I'm still not rubbing the bump stops.

 

[07VistaChicago]

Steeda ultras here and trimmed the tops off....

 

[Ssiptang]

K springs and I cut mine in half.

 

[Black_GT]

had to cut mine by half for my Tein's.

 

[AnotherS197GT]

I had kind of a rough ride on my car over bad bumps, so I did some searching and found out I should check my bump stops. I was about a 1/2 inch away from them, so I cut off two nubs. Did I cut too much off?

I also found that one of my bump stops was rotting away, so I need to replace them. The FRPP kit is about $5 more than a single bump stop, so I planned on getting that. Will I need to trim that as well? I've read its a little softer than factory.

I also reused my front bump stops. Should I consider replacing those with the FRPPs, or is it not worth the effort?

Here are my bump stops now.

 

[hamish]

That's where mine are cut with Eibach Prokits.
There is very little travel at the rear.

 

[908ssp]

I drilled mine from the top in a drill press with a huge step drill. I did not want them shorter and stiffer I wanted them softer so they come on more gradually. The shock load of the cut off bumper can really upset the adhesion of the tire causing snap oversteer.

 

[DiMora]

Cutting mine made a huge (positive) difference. It's one of those things where you don't really know you are hitting - until you aren't hitting anymore and the ride improves.

You could mark / chalk them, or clay them to verify hitting...but my ride difference was huge once I did cut them after starting this thread and getting advice on here to go ahead and do it.

Again, I am on Steeda Sport Springs and I cut off the top nub only.

I would like someone to make a progressive type bump-stop (Like 908SSP is describing) that comes at a lower height already.

Think of it this way, however: The bump-stops only adversely affect things if you are using up all your suspension travel and they are actually touching - and if you are touching...you want them, otherwise it would be metal-on-metal. the goal here is to have adequate travel WITHOUT them hitting...but if they do hit...they should not cause other issues such as what 908 is concerned about.

This would be a good aftermarket mod for some aspiring manufacturer to come out with. Whiteline, are you listening?

 

[PLee]

I drilled mine from the top in a drill press with a huge step drill. I did not want them shorter and stiffer I wanted them softer so they come on more gradually. The shock load of the cut off bumper can really upset the adhesion of the tire causing snap oversteer.

^^This. I've spoken to a number of suspension guys at Ford Racing... the bumpstops actually contribute to overall spring rate and handling. For a street car/straight line driver, probably not a big deal... but if you do any sort of performance corner carving, I'd definitely consider NOT cutting them, or switching to the FRPP stops. I have the K springs in my car which are pretty damn low, and the FRPP bumpstops in at full length. I'm pretty certain they are in contact almost constantly, considering some of the extra weight I have in the trunk.

 

[MGT2009]

I have K springs and checked mine yesterday. Found out my car was riding on the bumpstops at ride height. I promptly cut them in half. Rides 100x better now.

 

[Marc s]

I've spoken to a number of suspension guys at Ford Racing... the bumpstops actually contribute to overall spring rate and handling.

They should be fired.

I cut mine. Silly me for expecting my spring/sway bar rates to control the energy of the car in a corner.

Handling will be less than really bad if the car at rest, is on the bump stops. I can't imagine anyone saying that the bump stops are designed to help with corning. Put a car on the bump stops and then put the car into a fast rough corner. let me know how the car reacts. Using the bump stops to control the sway/energy of the car will make it very unpredictable.

 

[AnotherS197GT]

I ended up getting the FRPP bump stops. The FRPP kit ended up being $21 after tax, which was cheaper than one single bump stop at dealer cost lol. I cut the top nub off the new bump stops and the car feels great.

 

[TexasBlownV8]

Running the same setup (dspecs and steeda sports). I cut of the top section of the rear bumpstops, about 1/2".

 

[MELLOWYELLOW06]

cut them in half

 

[Wes06]

i still gotta trim mine down alitle, i havnt checked exactly how close i am at ride height, but its gotta be tight in there

 

[RocketcarX]

Mine is lowered 1.5 all the way around with the AM house springs. So far so good, at least I haven't hit any bumps that have made me think I needed to check them. Maybe I should, lol

 

[DiMora]

I have the Steeda Ultra Lite springs. I widened my stock wheels to the inside 1 1/2" and I'm still not rubbing the bump stops.

I'll bet you are. I didn't know I was until I cut them and noticed the ride improvement. They are quiet when they hit...when you cut them, you will notice a "smoother" ride in the rear over the same surface that was previously rough.

They should be fired.

I cut mine. Silly me for expecting my spring/sway bar rates to control the energy of the car in a corner.

Handling will be less than really bad if the car at rest, is on the bump stops. I can't imagine anyone saying that the bump stops are designed to help with corning. Put a car on the bump stops and then put the car into a fast rough corner. let me know how the car reacts. Using the bump stops to control the sway/energy of the car will make it very unpredictable.

I agree 100%. Although on a stock ride-height car with stock shocks and springs...the OEM bump-stop length is probably perfect. When we lower the car, the OEM bump-stops are now too long (thus the need to but them or replace with shorter ones).

Mine is lowered 1.5 all the way around with the AM house springs. So far so good, at least I haven't hit any bumps that have made me think I needed to check them. Maybe I should, lol

As I stated above with Gerrod - mark them with some chalk and go over a rough road with some cornering mixed in...I'll bet you are hitting. Or better yet, cut a nub (or drill using the 908SSP method) and I'll bet you get a ride improvement.

If any of you who are NOT cut presently end up cutting, please report back on what you notice after doing so.

I have zero doubt my ride was improved.

I am going to order some of the Eibachs, which are manufactured lower (and designed for lowered cars already). I want to do so to compare the compound to OEM and see if it is identical (or perhaps it has a different rate) - some have reported the Eibach compound is softer.

Like this:

Notice the hole in the middle on the Eibachs (Factory-molded 908SSP technique):

Eibach P/N is bs45001617 - Summit has them, and Pep boys *may* carry them.

 

[hamish]

Is that hole in the middle for a bolt?

 

[MGT2009]

In my case, since i was riding on the bumpstops at ride height, it was acting like a ghetto anti-roll bar. Rear end would come out around even the slightest corner. Also rode like a brick shit house.

Now, no more skating rear end, rides like a stock car and also fixed a "swaying" problem i was experiencing while changing lanes at highway speed.