Theoretically you could replace just the shaft in the shock, the guts are probably OK. I have no idea if that's practical though.

--Ian

 

It looks like I can get 2 rear msm shocks for about $110 used, so I'll probably do that. But does anyone know how I can make it tighter to prevent this from happening again?

 

I used washers.

 

The shock shaft is supposed to have a shoulder on it that the top hat rests on, with the nut then clamping the two together. This locks the shaft's vertical position relative to the top hat & car body.

I'm guessing your shocks either didn't have that shoulder or it's located too far down on the shaft for the hat to rest on, and as a result you were simply tightening the nut against the spring pressure. If the shoulder is too far down then you need some kind of spacer between it and the top hat.

--Ian

 

You can also not use ISC top hats.

 

The shoulder sits against the bottom washer in the bushing stack, not the top hat.

The issue is excessive movement of the bushing, which is due to a) the fact that ISC hats do not locate the bushing as well as OEM and/or b) maybe you need some washers to preload the bushing more (for more friction) if you're bottoming out the nut.

But for realsies, @concealer404 has the good answer. Maruha hats keep the bushings centered like OEM, so the shaft can't walk into the sides of the hole. Alternatively, you could find bigger bushings that fit the ISC hats better.

 

I definitely do not want to use ISC top hats again. Maruha seems to be the go to and I'd like to order some. Can someone point me in the right direction of where to get them? In the meantime, I am running just stock nb top hats. My fronts were grounded just a little but just barely so I will be switching the top hats on those as well, but not the shocks. I have ordered a new pair of rear shocks.

 

Order Maruha top hats from Maruha.

 

Meh. My ISC tophats did fine for years. Maruha is prettier though. Either way, that was not working properly for you as assembled.

 

lol, I agree. It makes sense why I've always thought it rode like crap. Just running oem tophats in the rear it rides a million times better than I could have imagined. I can only imagine how it'll feel with new shocks and top hats installed correctly. They come in this Monday so if I have more issues I'll be sure to update.

 

...but you aren't still driving around on those shocks in your original picture, are you? Because that would a super bad idea.

 

I drilled out my ISC tophats, making the hole even bigger so that the "nipple" of the strut mount bushings fit into the hole and it centers itself. Works like a charm.

 

Change your shocks. The rod cross-sectional area is greatly compromised, and they will fail. When they do, best case you will damage many more expensive parts, worst case someone else is going to get hurt. Get new shocks and do not move the car until then.

 

Looks like I'll be ordering some Maruha's. Just installed my current set-up with ISC's but the above pictures have me kind of worried. I put a bushing and a few washers and torqued the shock nut down but can never seem to get it anywhere near the torque spec of ~23 - 34 ft-lbs. I just keep squishing the bushing further and further and then eventually bottom out on the shock's shaft threads. Is this normal?

 

Yes. That's how Mazda designed it.

 

Sounds good, thanks.

 

Just for reference and documentation, this is what my rear Bilsteins and Garage Star top hats looked like after a year/10,000 miles. I ran them with Integra Speedthanes cut down as bushings on top and bottom, so it was metal on metal contact. I had plenty of bushing, and they were torqued down pretty heavily. I drilled out the top hats and replaced them with OEM NB bushings yesterday to keep mine from looking like the ones above.

 

Looking for some preferences on B8 Bilstein shocks and spring rates. I've re-read through this thread again (after having made my own separate Bilsteins and posted about them about a year ago), but I'm having trouble finding what I'm looking for now.

I'm building up a track-dedicated champcar and I'm looking to use B8 Bilsteins for the suspension, mostly because I was able to pick some up cheaply. Now, even for performance, I'm seeing a lot of conflicting info where people are saying soft spring rates are more compliant and not necessarily slower than hard spring rates, and I've heard a range from 750lb fronts to 350lb fronts. I've also heard that stock-valved B8 shocks can only take around 550/350 front/rear before harder springs just make the ride harsher and unsettle the car when pushed to the limit.

What should I believe? What spring rates would you recommend and why? This is meant to be a track-dedicated NA used with extended top-hats. I'm looking for performance, the car doesn't have to be slammed low. FWIW I'm looking at racing at Road Atlanta, which has some fast turns and a low back stretch. Thanks so much for any advice or insight here!

 

Need more info.

-total comp weight
-tire model and size

Bilsteins are perfectly valved for about 300/200 springs and 205/50 250+ treadwear tires. The world runs twice those rates on race tires so the question is, how much are you willing to compromise grip (which come from compliance and softer springs) and responsiveness, which comes from stiffer springs.

I'm guessing a comp weight of less than 2350# and 205 RS4's. I would run 5.25" pinch weld heights and 450/300 rates. But what do I know :P

 

Ok that helps, that provides some context as to why I've been hearing different recommendations across the board. The car (95) will be stripped with a roll cage, so if starting around 2300, maybe 2200 final weight? Not totally sure how much is saved from stripping, but I understand the cage adds back around ~150 lbs.

I'm looking at running 15x9 wheels, probably 6ULs, but haven't committed to anything yet. Will probably try to run 245/40-15, but may resort to 205 RS4. Would that make a big difference in spring rates? Thanks a ton for the feedback!
Best,
Dylan