Bumpstop cutting for neuspeed race and koni yellows.

[93_Accorn]

Before I assemble everything I'm not sure if I need to cut the bumpstops or not. From loads of searching I still haven't came up with a conclusion as some people say cut them and some say not to. Anyone with any experience with this setup to shed some light? I'm not looking for any other spring/shock combo answers just specifically neuspeed race springs and koni yellows on any perch settings that were used.

[Grumpys93]

I cut my bumpstops in half when I installed this combo as well as lowered the perch down one ring. The ride was very comfy and felt good in the corners. This however is going on my memory of driving it years ago. I will have my car running next month hopefully and I can give you an update.

[Corweena]

If you have the Koni instructions, I believe they recommend cutting them.

the Fronts, I cut in half, and the rears, I cut one third off. Haven't had any issues at all.

Or you can just order short Ground Control bumpstops.

[Domesticated]

You need to make sure your bump stops retain proper block height or you'll blow a rod nut through your base valve...

[93_Accorn]

My instructions neither say to cut or not cut. Theirs only a picture showing I'd assume if you use your factory bumpstop and if they split get new ones. That's what I'm afraid of is blowing a shock so what do you mean by block height?

[Domesticated]

Block height is the length of a fully compressed jounce bumper. I know eibach lists multiple bounce bumpers with multiple block heights. I'm sure other suppliers do to.

[93_Accorn]

Hmm alright. Never dealt with springs, shocks, coilovers, at all so this is my first time. I may just leave them full length and adjust accordingly....

[cp[mike]]

I just recently assembled this same setup, and struggled with the same question. Based on my digging, it appeared most people recommended cutting them - the people who didn't, complained about bottoming out.

See the first picture below, of the parts spread out. Along the center you can see the brownish colored KONI bumpstops - these are the ones they provide from the manufacturer. Considering how short they are, this confirmed to me that the shocks would be OK with a shorter bumpstop (at least compared to the super-long OEM ones). I ended up returning the Koni bumpstops because they were too expensive for what they were.

Since my original bumpstops weren't worth saving, I ended up buying OEM 5th gen / CD5 bumpstops, and cutting them by 1/3rd. You can see this in my second picture. The ride ended up being very nice and I did not notice any bottoming out, though I didnt not get to ride on them for very long.

The last question I had to figure out, was - which end of the bumpstop to remove??? The fat end, or the skinny end? I figured since the "progressive" nature of the bumpstop comes from the skinny end, that I should leave that in place, in order to avoid a hard impact. Also, by removing some of the fatter end, this removes the part of the bumpstop that has a tight/small diameter hole. The OEM shock has a 10mm rod and the KONI shocks have a 12mm rod, so the original bumpstops are a tight fit - removing the fat end helped remove the constricting part, so now the center hole is a little wider and it fits over the shock better.

I ended up going with the LOWEST perch for the front, and the MIDDLE perch for the rear. My third picture below is a little bit misleading because it shows the rear perches set to their lowest position. I found the rear of the car to be squatting too low like that. Fortunately it was easy to raise the perches without removing the assembly from the car. You can see the final ride height in my fourth picture below.

Just FYI, for the dust covers, the CD5 ones are the same overall size/shape, but are completely plastic and won't corrode. The CB7 ones are metal and are usually beat up and rusty.

[Jarrett]

Man, I wish you still had that car.

For what it's worth, I've cut my bump stops as well. Roughly the same length that Mike cut his.

[Domesticated]

So there's a difference between bottoming out and hitting the jounce bumpers.

Jounce bumpers are used to improve handling, but early engagement of a stiff bumper can cause non linearities in ride. Regardless of your jounce bumper engagement and rate curve, you need to have the correct block height.

[93_Accorn]

Perfect response mike. I seen your thread about this situation. Great to know about the dust covers beigng metal vs plastic since I'm going with all new top hats, rubber mounts, insulators and all. Rather have plastic over the metal. Thanks!!

[93_Accorn]

In the final assembly I notice the poly front coil insulator and the shock mount/tophat bushings (red). I figured out the insulator from energysuspension but I can't for the life of me comfirm if http://energysuspension.com/parts-search.html are what I'm wanting or if those go to the radius rod. I couldn't source any poly for the rears and from judging from your pictures you went OEM rear insulators, seats and bushings? Apologize for the continous questions. Lol
Part# 16.7103G

[93_Accorn]

I got the fronts on and thanks for everyones input. Unfortunately I'm haveing the rear shock mount bushing problem. Ahhh. I also put the front shocks on the lowest perch. HOLY SHIZ. This seems way too dumped and I bottom out at places. Plus my uca balljoints look like they are stressing like crazy which is scary when you can actually see the ball and no grease. Spc is definitely happening sooner than later. Maybe the front will raise some once I get the rears on? For now I raised the perch up which is much better.

[TheSnigg]

We're these for sale on eBay recently?

[owequitit]

Before I assemble everything I'm not sure if I need to cut the bumpstops or not. From loads of searching I still haven't came up with a conclusion as some people say cut them and some say not to. Anyone with any experience with this setup to shed some light? I'm not looking for any other spring/shock combo answers just specifically neuspeed race springs and koni yellows on any perch settings that were used.

Basically what Mike said.

I try to cut them as little as possible, but if you are dropping the car a little over 2", then you effectively are reducing the travel by the same amount if you don't cut the bumpstops. Great in theory, but with the progressive nature of the Neuspeed Sport and Race, you end up bouncing off the bumpstops all day and it really makes it ride shitty.

Just like Mike said, start at the top and you should only need to cut the largest section off. That should cure any ride issues with either the Sports or Races. My friend had a CB7 on Races and Konis and with that little bumpstop modification, it rode like a dream (even though the thing would spark its exhaust on big bumps).

The advantage to most aftermarket struts designed for lowering is that they will allow for this before they bottom out and wreck the strut.

I cut the bumpstops the same amount on my CB7 with Neuspeed Sports and have put around 100K miles on the suspension with literally zero issues.