ISC tophat questions.

ChrisJuliano said:

Question, at my current ride height my "helper springs" I think they are called, cuz the racelands have 2 seperate springs, the smaller spring is COMPLETELY compressed, would it be beneficial to take it out completely. I am refering to tracking my car and handling, not juts going as low as possible. So from a functional stand point.

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If I recall the RL helper springs had so little rate to them that they essentially played no role. My understanding is that the helper/tender springs should have enough spring rate to them that when a shock is very extended (unloaded inside of the car during a turn?) and the main spring is nearly expanded at it's full length with the shock dropping down: the helper spring will come into play and continue the downward push keeping your "contact patch", so to speak, on that corner.

ChrisJuliano said:

I sorta understand what your saying. So with it gone car will drop lower, so I can raise up the coil adjustment which would benefit me with travel at lower heights eh?

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My understanding with the ISC's is that by moving the uppermost mounting point of the shock shaft higher (above and into shock tower etc.) you can combat suspension travel by either a. leaving your spring/perch at the previous height you had setup with OEM style mounts keep the top of the shaft in a normal location or b. even moving the spring and perch up higher on the shock body in turn gaining back even more travel yet perhaps still lowering the car a bit more (thanks to the ISC's) than your previous setup with OEM's.

Disclaimer: I've never seen an ISC in person. Everything above could be blatantly false.

Hope that helps Chris. Thanks for your pm's. Those pictures above are a great way to visualize how they are intended to work.

If you have an NA the ISC tophats will not add enough preload to be noticed. You will need to adjust your ride height anyways, so preload is the last thing to be worried about with these tophats. You will have more than enough room to make any adjustments. The NA tophats are pretty thick themselves. You will need to play around with your ride height a good bit after install.

If you are using NA hats these will lower you a good bit. Their mounting surface is very thin, the spring will be a lot closer to the subframe. Because you lose droop with these hats, I don't think it will matter if you use the helpers. Your suspension cannot droop enough for them to be uncompressed.

These top hats don't magically allow your coilovers to have more stroke, they just move the shock higher up into the car. Your bumpstop will be around 2" higher up then it is now. You lose droop(how far your suspension extends when in the air) in exchange to get off your bumpstops. This is great if your slammed, because you will actually be using the coilover and not riding the bumpstop all the time.

If you are slammed, the only thing that sucks with a 2" ISC hat is you probably will be using your tires as bump stops now. Your tire will hit something before your shock runs out of stroke.

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.

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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.