ISC tophat questions.

ChrisJuliano said:

Okay, so I have ricelands and 2" ISC tophats, a friend brought it to my attention that I need new bumpstops apparantly if I want more spring travel?

I bought theses so I could lower my car to around moderatly slammed height, and still remain some spring travel so when I track my car it dosnt handle like crap. So I am wondering if I just throw the tophats on as of now, is it just compressing my sprigns more which would be counter productive? Or what?

Sorry for the noobness, but I am willing to learn, I dont understand the tophats completely so all the info is appreciated and I couldnt find anything with info that helped.

Click to expand...

It's really not that hard.

Imagine your car's suspension at whatever ride height.

What limits travel up?

Well upward, you want to top of the shock to contact the bumpstop and stop all further upward motion just before the tire hits the body or the control arms hit the frame. But on a Miata with stock suspension, the rear shocks would fully contact the bumpstops before you run out of travel upward. You could change that by installing a shock with a shorter body, but you have to remember that the travel of the suspension downward depends on the piston inside the shock not reaching the top of the shock, too.

So it's better to give a longer shock body more room to move upward by installing an extended top hat. The only thing there is that if you extend it too much, now the tire will hit the body or worse, the control arm will hit the frame. If you were only needing to add 1.5" of travel and you installed top hats that extend your upward travel by 2", then your bumpstops would need to be 0.5" longer.