Was wondering how many people were cutting their bump stops on the IX's during the installation of the GF210's? I was told I may not need to but just wanted to confirm.

 

I cut my bumpstops just like the instructions stated to.

Have my GF210's now for about 2K miles, no problems

 

Does cutting bump stops affect ride quality?

 

No, only when you hit big holes or are hard cornering will your bump stops come into effect. They are there so your shocks don't bottom out, or when they do it is a softer hit. I just cut the fronts one hump and left the rears whole. Just don't cut off too much. Peace.

 

Got the GF210s too. How much did you guys cut? Instructions states to cut from 15mm to 25mm.

 

Cut what the instructions tell you, If you don't cut enough then you will bounce off the bump stops too often and could upset the car in a turn. Cut too much and you will destroy your strut over time.

 

Most people will more than likely be ok not cutting the bump stops due to the aggressive damping rates of the EVO stock suspension.

Cutting the bump stops is to regain some suspension stroke.

Suspension stroke is the amount of travel the suspension is allowed before hitting the bump stops.

When you lower the car, the suspension stroke is reduced. We use a higher spring rate with our GF210's, so the spring + damper assembly compresses less than factory, but still exhibits a full range of motion. Trimming the bump stops allows slightly more stroke, but you must take caution not to over cut the bump stop, as the shock piston can bottom out into the shock casing, damaging the delicate valving inside.

Putting some chalk on the bottom of the bump stop is a good way of indicating if you are hitting the bump stops if you are not sensitive to the jumpiness or harshness indicative of hitting the bump stops. Only trim the minimum and trim in small increments.

Most users will not need to trim their bump stops for their driving application. The GF210 spring does not drastically lower or "slam" the car in such a way to eliminate all stroke (this is bad). Our engineering staff designed the GF210 to allow enough stroke for proper traction over various surfaces. Hope this information helps!

Tanabe Racing Development USA