Alternative to ISC top hats
#21
So it sounds like your idea is to get a top hat deeper than you need and then block off the part of the travel that would put the A-arm through the chassis? That's not what you want to do. In that case you've gained 1cm of bump travel at the cost of 4cm of droop.
It looks to me like you don't need deeper top hats at all. If you really wanted that last bit, ISC makes them in whatever size you'd like so you could get a 1-2cm deep top hat. I think you're set with what you've got, though.
You should probably measure the distance between those perches and make sure it's greater than your springs' block height while you've got the chance, that looks pretty close to me.
It looks to me like you don't need deeper top hats at all. If you really wanted that last bit, ISC makes them in whatever size you'd like so you could get a 1-2cm deep top hat. I think you're set with what you've got, though.
You should probably measure the distance between those perches and make sure it's greater than your springs' block height while you've got the chance, that looks pretty close to me.
#22
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In my case, it was a matter of the shock hitting the bumpstop before the spring (or upper arm) ran out of travel. This was with old style FM springs & NA tophats. Very jarring to hit those stops. Happened nearly every time I drove the car. Note that old FM springs were known to sag, and mine had, quite severely.
Therefore, by getting new springs and ISC tophats, I was able to get more travel before it bottomed out, keeping me off the bumpstops for most of the time. I can still hit the stops over severe bumps, but that is now pretty rare, so the ride is better.
Therefore, by getting new springs and ISC tophats, I was able to get more travel before it bottomed out, keeping me off the bumpstops for most of the time. I can still hit the stops over severe bumps, but that is now pretty rare, so the ride is better.
#23
Edit: ^^^ this harsh bottoming out is what I'm trying to avoid. I managed to fix that issue with my old Racelands, but the shocks themselves still sucked lol.
Yeah, once I started thinking about the 1.5"/4cm hats it seemed like overkill to have all that dead space above the top of the shock body. But, I pulled those thin bumpstops off and installed some random ones in the garage that are about 3cm thick to give it a little more cushion, which of course made the space between the arm and frame more like 4cm at initial contact with the shock body. So having a deeper hat would allow me to run a thicker, progressive bumpstop instead of that super thin bandaid of a bumpstop, yes?
I did have a close look at the springs and there are witness marks on two of the coils, but not on every one up the entire height of the spring, so I'm thinking it is not binding. I'm sure it'll be up in the air again soon, so I'll do some measuring then.
Yeah, once I started thinking about the 1.5"/4cm hats it seemed like overkill to have all that dead space above the top of the shock body. But, I pulled those thin bumpstops off and installed some random ones in the garage that are about 3cm thick to give it a little more cushion, which of course made the space between the arm and frame more like 4cm at initial contact with the shock body. So having a deeper hat would allow me to run a thicker, progressive bumpstop instead of that super thin bandaid of a bumpstop, yes?
I did have a close look at the springs and there are witness marks on two of the coils, but not on every one up the entire height of the spring, so I'm thinking it is not binding. I'm sure it'll be up in the air again soon, so I'll do some measuring then.
#24
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Longer coils, and having another inch or so of travel eliminated all but the worst of it, and I can live with that.
#25
I just went out and bombed my favorite local canyon, looks like the thicker bumpstops cured the hard hits, but it's a little firm out back The springs are 6" eBay specials and on the edge of binding. I can probably live with another inch of height, or half inch if I adjust a bit out out, by going with some 7" springs.
#26
Yeah, once I started thinking about the 1.5"/4cm hats it seemed like overkill to have all that dead space above the top of the shock body. But, I pulled those thin bumpstops off and installed some random ones in the garage that are about 3cm thick to give it a little more cushion, which of course made the space between the arm and frame more like 4cm at initial contact with the shock body. So having a deeper hat would allow me to run a thicker, progressive bumpstop instead of that super thin bandaid of a bumpstop, yes?
1" longer spring and 1" lower perch won't change the ride height as all.
#27
The bumpstop is 3cm-ish free length, maybe a touch longer. It is not engaged when at rest. That drive I took has some seriously deep bumps and I didn't have any hard hits despite my best try at pissing it off. I wonder though if some of the new firmness is due to the bumpstop being engaged quickly.
#31
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Also, you might want to come up that 1/2" with the longer springs. I just raised my car recently, and dear god it rides like a caddy compared to before and handles way better through the rough corners on some of the backroads around here.
I think i'm around 12.75f 13r or so if you do the hub/fender measurement. My pinch welds aren't the straightest so it's hard to measure there.
I think i'm around 12.75f 13r or so if you do the hub/fender measurement. My pinch welds aren't the straightest so it's hard to measure there.
#32
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In my case, it was a matter of the shock hitting the bumpstop before the spring (or upper arm) ran out of travel. This was with old style FM springs & NA tophats. Very jarring to hit those stops. Happened nearly every time I drove the car. Note that old FM springs were known to sag, and mine had, quite severely.
Therefore, by getting new springs and ISC tophats, I was able to get more travel before it bottomed out, keeping me off the bumpstops for most of the time. I can still hit the stops over severe bumps, but that is now pretty rare, so the ride is better.
Therefore, by getting new springs and ISC tophats, I was able to get more travel before it bottomed out, keeping me off the bumpstops for most of the time. I can still hit the stops over severe bumps, but that is now pretty rare, so the ride is better.
oh you got new springs, n/m.
#33
Also, you might want to come up that 1/2" with the longer springs. I just raised my car recently, and dear god it rides like a caddy compared to before and handles way better through the rough corners on some of the backroads around here.
I think i'm around 12.75f 13r or so if you do the hub/fender measurement. My pinch welds aren't the straightest so it's hard to measure there.
I think i'm around 12.75f 13r or so if you do the hub/fender measurement. My pinch welds aren't the straightest so it's hard to measure there.
#34
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Exact same situation here as you can imagine. I know there were a few turns I could never "hit" even quickly, as the roughness of the road would cause my rear end to lose traction mid corner and toss me into a slide.
Now with the higher ride height i can hit those same corners much faster with ease, and roll on the throttle to slide out of them if i so choose, which is much better
I basically adjusted the ride height so that with the car on the ground the front a arms are parallel to the ground, instead of having to slant slightly upward from the subframe to the hub. I think the suspension is working better at this geometry now.
Now with the higher ride height i can hit those same corners much faster with ease, and roll on the throttle to slide out of them if i so choose, which is much better
I basically adjusted the ride height so that with the car on the ground the front a arms are parallel to the ground, instead of having to slant slightly upward from the subframe to the hub. I think the suspension is working better at this geometry now.
#36
These seems like they would be terrible. The fact that they're aluminum means the bolt isn't tack welded to the bottom side, so tightening shock mounts will be a two-man job. **** that.
I don't have any complaints about my ISCs other than the fact that they used standard hardware instead of metric. If the garage stars use a tack-welded metric bolt, I think they're about as good as it's gonna get.
I don't have any complaints about my ISCs other than the fact that they used standard hardware instead of metric. If the garage stars use a tack-welded metric bolt, I think they're about as good as it's gonna get.
#39
I've played with different types of top hats, and one consideration is the width of the shock tube. There probably won't be any problems with thinner body shocks like Koni, but I've found that Bilstein's can top out on the top hat tube corner.
I HAVE NOT TRIED THESE UNITS OR THE ISC's. Checking for marks on the shock and top hat will confirm, but if the top hat tube is a smaller I.D. than the shock O.D., there could be issues.
I HAVE NOT TRIED THESE UNITS OR THE ISC's. Checking for marks on the shock and top hat will confirm, but if the top hat tube is a smaller I.D. than the shock O.D., there could be issues.
#40
I've played with different types of top hats, and one consideration is the width of the shock tube. There probably won't be any problems with thinner body shocks like Koni, but I've found that Bilstein's can top out on the top hat tube corner.
I HAVE NOT TRIED THESE UNITS OR THE ISC's. Checking for marks on the shock and top hat will confirm, but if the top hat tube is a smaller I.D. than the shock O.D., there could be issues.
I HAVE NOT TRIED THESE UNITS OR THE ISC's. Checking for marks on the shock and top hat will confirm, but if the top hat tube is a smaller I.D. than the shock O.D., there could be issues.