Thermos2003

I can't for the life of me figure out why it would be needed to cut the bump stops when lowering a tC. My old Ford ZX2 was lowered and no one ever cut any bump stops and I never had any problems with the shock compressing and hitting the bump stop... and why cut only the front?

If anyone can really explain this please go for it. I am confused.

PghtC

Think of it this way. Say your strut has 3" of travel to absorb bumps in stock form with the bumpstop installed. Without it installed it would have 5 or 6" to travel, but you would be bottoming out your strut on severe bumps.

So not you lower the car 2".

The springs are shorter so the strut loses ~2" of travel...so now with the bumpstop in stock form, you have 1" of travel in your strut to absorb bumps. You will hit the bumpstops much more frequently. Say you cut off an inch of the bumpstop. You now have 2" of travel which is much better than 1". This is why you cut the bumpstops.

Some manufacturer's recommend cutting the front and not the rear, because the front needs the extra travel as it takes the brunt of the force when hitting potholes, etc. Usually the rear wheels don't hit as hard and there is much more range of motion required in the front suspension as it is what controls the car. The front also has the weight of the engine to support, so the front struts need more travel as this extra weight will cause the car to compress the springs and struts more when going over a bump.

basically

I would trim the rears a little anyway. It wont hurt to trim 1/2" off of them, and rather be safe than have to take it apart later because of hitting them all the time...

But I would, without a doubt, cut the front ones.

Thermos2003

one more question. When people get the TRD springs installed at the dealership, do they cut the bumb stops? I would think that they probably wouldn't . If anyone knows let me know. Because I'm assuming that the dealership probably wouldn't "cut" any factory part. If they don't then it must be OK to run it without trimming the stops. Just a dumb question.

Thermos2003

Anyone out there had TRD springs installed by a dealer? Please let me know if they cut your bump stops.