For the people who lowered
#7
Pole Position
iTrader: (2)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
honestly, there may not be a difference with the bumpstop trimmed. it depends on how much suspension travel is left. bascially the bumpstop is where the shock bottoms out. since the lowering springs reduce the amount of suspension travel trimming the bumpstop should compensate for the loss in suspension travel, at least thats what ive read. ive done this on every car ive lowered just to make sure. usually Eibach specifies how much the bumpstops need to be trimmed with their prokit and sportline kits.
Trending Topics
#9
Tech Info Resource
![](https://www.clublexus.com/forums/images/ranks/rank-smod2.gif)
iTrader: (2)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
The bumpstop is not where the shock bottoms out, it's there to prevent sudden coil bind in the spring. Most shocks have an internal device to dramatically increase compression damping in the last 15 or 20mm of travel to prevent damaging the shock, so the bumpstop just helps add spring rate to avoid an instantaneous spring rate rise to infinity.
Keep in mind, when the spring is fully compressed, it becomes essentially a solid piece of metal, and the spring rate goes infinite.
If you really want to do this and do it right, you need to fully compress the shock with the new spring and determine how much of the bump stop can be cut away relative to the spring fully compressing. You absolutely want at least 10mm of stop before the spring goes solid.
You would also be wise to install the shock with the trimmed bumpstop in place without the spring and fully compress the suspension to see if your tire is going to rub at full bump. 10mm clearance is minimum. Rubbing is always bad.
Keep in mind, when the spring is fully compressed, it becomes essentially a solid piece of metal, and the spring rate goes infinite.
If you really want to do this and do it right, you need to fully compress the shock with the new spring and determine how much of the bump stop can be cut away relative to the spring fully compressing. You absolutely want at least 10mm of stop before the spring goes solid.
You would also be wise to install the shock with the trimmed bumpstop in place without the spring and fully compress the suspension to see if your tire is going to rub at full bump. 10mm clearance is minimum. Rubbing is always bad.
#10
Pole Position
iTrader: (2)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
The bumpstop is not where the shock bottoms out, it's there to prevent sudden coil bind in the spring. Most shocks have an internal device to dramatically increase compression damping in the last 15 or 20mm of travel to prevent damaging the shock, so the bumpstop just helps add spring rate to avoid an instantaneous spring rate rise to infinity.
Keep in mind, when the spring is fully compressed, it becomes essentially a solid piece of metal, and the spring rate goes infinite.
If you really want to do this and do it right, you need to fully compress the shock with the new spring and determine how much of the bump stop can be cut away relative to the spring fully compressing. You absolutely want at least 10mm of stop before the spring goes solid.
You would also be wise to install the shock with the trimmed bumpstop in place without the spring and fully compress the suspension to see if your tire is going to rub at full bump. 10mm clearance is minimum. Rubbing is always bad.
Keep in mind, when the spring is fully compressed, it becomes essentially a solid piece of metal, and the spring rate goes infinite.
If you really want to do this and do it right, you need to fully compress the shock with the new spring and determine how much of the bump stop can be cut away relative to the spring fully compressing. You absolutely want at least 10mm of stop before the spring goes solid.
You would also be wise to install the shock with the trimmed bumpstop in place without the spring and fully compress the suspension to see if your tire is going to rub at full bump. 10mm clearance is minimum. Rubbing is always bad.
#12
Tech Info Resource
![](https://www.clublexus.com/forums/images/ranks/rank-smod2.gif)
iTrader: (2)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
It's the same idea, but you have to hit the bumpstop before coil bind or there's no point to having the bumpstop. Bumpstops are rubber to add spring rate and slow compression before going into full coil bind.
Leaf springs can't coil bind (but they can still have some bad things happen), so in that regard it's a lot different.
Leaf springs can't coil bind (but they can still have some bad things happen), so in that regard it's a lot different.
Thread
Thread Starter
Forum
Replies
Last Post
sonbum1
2Gen IS250 / IS350 / IS-F Classifieds (06-13)
2
05-31-08 03:00 PM