Suspension: stock vs. aftermarket

[symphony-step]

2004 6 speed manual coupe w/ 85K miles. 20 years later and I'm still smitten with this car. Others have come and gone, but this one is a keeper. Not a daily. Weekend back roads with the occasional track day. Everything is stock/OEM except for fortifying the VANOS and subframe. Rod bearings are next and it's about time for suspension as well.

It's lost some responsiveness and shows more oscillation with bigger bumps. Worn and a little less precise, but not terrible. I appreciate the car for its overall experience, good and bad. No major performance complaints on the streets, and my HPDEs are for safely enjoying the car at its limits, not chasing lap times.

I find myself going around in circles on stock vs. aftermarket. Ohlins are my top pick from reading other threads. Not just for getting the most out of this brilliant machine, but also because they might do a better job protecting the car on rough roads and bumps vs. stock. Although part of me wants to try something new, I've never been a big modder and have this romanticized notion of growing old with this car largely as it was from the factory. However, it seems like everyone goes aftermarket (Koni yellows + Eibachs at the very least) instead of staying stock.

Looking for opinions and suggestions to help me make up my mind. Thanks for entertaining another suspension thread!

[ethan]

If you end up wanting to stay with stock, get Sachs instead of Bilstein's "stock replacement" B4. In my experience, the latter are harsher without appreciable benefit. Other than maybe RTABs, solid subframe bushings, and camber arms when you have the B-team-designed rear end out, I wouldn't change a thing given your description of how you enjoy the car. In my opinion, only go for camber plates if you must have camber control or you have shortened shock bodies. Only go for aftermarket shocks and springs if you must have them for track performance. Only go for monotubes if you're willing to spend a lot on FCM or Ohlins (and even then consider TC Kline,) and don't buy MCS for a street car (I just sold mine.) Do use the FCM spreadsheet. Don't spend money on mods unless you're sure it's the right thing - I've gotten it wrong a lot, but they say you pay for your education.

[Advorsor]

Given your situation, I'd probably just do: 1) Yellow Tag (712) rack upgrade (plug-and-play) and 2) Front/Rear sway bars. Not too expensive and should make a noticeable different for you.

[ethan]

Given your situation, I'd probably just do: 1) Yellow Tag (712) rack upgrade (plug-and-play) and 2) Front/Rear sway bars. Not too expensive and should make a noticeable different for you.

Yellow tag's great, but sway bars only if you know why you need them. In my case, I couldn't achieve appropriate front roll couple with both upgraded front and rear sways, so I've gone back to stock in the rear. YMMV with different wheel setups, corner weights, and spring rates.

[Chas3n]

B4's, (fresh mounts) Eibach pro kit springs, f/r sways and get an alignment.


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[Altaran]

First I would get all suspension and subframe bushings replaced. Worn out and dried rubber will ruin handling. After 20 years the rubber will not perform like new. If you want better than new stock handling, consider monoball and solid subframe.
Öhlins R&T is a great choice for a street and track combined usage. Get camber plates for better adjustment range when lowered.

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[symphony-step]

...RTABs, solid subframe bushings, and camber arms...

If you want better than new stock handling, consider monoball and solid subframe.

RTAB - SPL (monoball)
Subframe - CMP (solid)

Those seem like to go to picks for bushing upgrades, but it's unclear how much NVH impact they will have. The FCP guide notes a firmer and sharper ride with monoballs and solid bushings. However, many others on here report very little or no difference. If they protect the car and improve reliability while still feeling close to factory, I'm open to going aftermarket. Thoughts?

[Altaran]

RTAB - SPL (monoball)
Subframe - CMP (solid)

Those seem like to go to picks for bushing upgrades, but it's unclear how much NVH impact they will have. The FCP guide notes a firmer and sharper ride with monoballs and solid bushings. However, many others on here report very little or no difference. If they protect the car and improve reliability while still feeling close to factory, I'm open to going aftermarket. Thoughts?

The other thing you should consider is reinforcing the rear subframe mounting points if you have not already done so. It's necessary at some point either way as they tend to crack over time, but with solid subframe bushings you will have more direct impacts being transferred to the chassis.
Bottom side reinforcement plates and a top side reinforcement: best solution is an x-brace, but the Vincebar also does the trick if you want to retain full trunk availability.

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[symphony-step]

The other thing you should consider is reinforcing the rear subframe mounting points if you have not already done so. It's necessary at some point either way as they tend to crack over time, but with solid subframe bushings you will have more direct impacts being transferred to the chassis. Bottom side reinforcement plates and a top side reinforcement: best solution is an x-brace, but the Vincebar also does the trick if you want to retain full trunk availability.

I had the Turner subframe reinforcement kit installed in 2013. Considered the x-brace, but didn't want to lose trunk space even if it's removable. The Vincebar looks bulletproof, but maybe too hadrcore for a mostly street car.

[oceansize]

RTAB - SPL (monoball)
Subframe - CMP (solid)

Those seem like to go to picks for bushing upgrades, but it's unclear how much NVH impact they will have. The FCP guide notes a firmer and sharper ride with monoballs and solid bushings. However, many others on here report very little or no difference. If they protect the car and improve reliability while still feeling close to factory, I'm open to going aftermarket. Thoughts?

Subjective opinion, RTABS and solid subframe enhance sharpness will little to no penalty. I went CMP subframe and CMP RTAB plus GC ARCAs (monoball). However, there are some dudes here who are in their thirtys or forties and about to turn ninety so their backsides hurt on the bumpys.... lol. I'm 53 and have no such issues . Those guys are the best though and they know who they are

If you're super sensitive just stay stock.

[symphony-step]

...there are some dudes here who are in their thirtys or forties and about to turn ninety so their backsides hurt on the bumpys.... lol.

I like to think I'm aging with this car...old but still good 😁

[Zajce46m3]

First I would get all suspension and subframe bushings replaced. Worn out and dried rubber will ruin handling. After 20 years the rubber will not perform like new. If you want better than new stock handling, consider monoball and solid subframe.
Öhlins R&T is a great choice for a street and track combined usage. Get camber plates for better adjustment range when lowered.

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I agree. Replaced Trail Arm and rear diff bushings. Powerflex Black series for the street. KW V3 Coilovers on mine but don't recommend because you clearance issues on aftermarket wheels is tight.

[ethan]

I had the Turner subframe reinforcement kit installed in 2013. Considered the x-brace, but didn't want to lose trunk space even if it's removable. The Vincebar looks bulletproof, but maybe too hadrcore for a mostly street car.

Unfortunately, plates alone aren't considered a long-term RACP solution anymore. In 2013, we mostly thought they were. A Vincebar doesn't change anything about your suspension or NVH - it just improves the chassis structurally - and it doesn't interfere with the interior. It's one of the best mods for this car IMO. And done with epoxy and rivets, it's not that invasive.

RTAB - SPL (monoball)
Subframe - CMP (solid)

Those seem like to go to picks for bushing upgrades, but it's unclear how much NVH impact they will have. The FCP guide notes a firmer and sharper ride with monoballs and solid bushings. However, many others on here report very little or no difference. If they protect the car and improve reliability while still feeling close to factory, I'm open to going aftermarket. Thoughts?

If you don't want to add any NVH, go with fresh OE across the board. In theory, solid subframe bushings help protect the RACP subframe mounts by reducing motion in that interface, but if you do go for a Vincebar, you're probably fine with new OE. Because there's still rubber in the diff, RTAB, and LCA bushings, solid subframe bushings are generally considered to be a low NVH mod (you still have isolation everywhere,) but if you're sensitive to NVH, then in my experience you will notice. Personally, I like them.

On the other hand, I find monoball RTABs to add significant NVH. Great for track or if you drive on good pavement all the time, but consider OE or Z4 bushings with a single limiter in a street car. See Bry5on's build thread:

https://nam3forum.com/forums/forum/main-forum/member-build-journals/195928-black-tan-332it?p=217643#post217643

[symphony-step]

Vincebar doesn't change anything about your suspension or NVH - it just improves the chassis structurally - and it doesn't interfere with the interior. It's one of the best mods for this car IMO. And done with epoxy and rivets, it's not that invasive.

Appreciate you elaborating on this, because it made me realize I confused it with the older CMP option that was visible in the trunk. The Vincebar style is right in line with what I prefer on my car. Thanks!

If you don't want to add any NVH, go with fresh OE across the board. In theory, solid subframe bushings help protect the RACP subframe mounts by reducing motion in that interface, but if you do go for a Vincebar, you're probably fine with new OE. Because there's still rubber in the diff, RTAB, and LCA bushings, solid subframe bushings are generally considered to be a low NVH mod (you still have isolation everywhere,) but if you're sensitive to NVH, then in my experience you will notice. Personally, I like them.

The CMP solid subframe bushings recommend topside chassis reinforcement to counter the increased chassis stress. Would the Vincebar + my older Turner reinforcement plates be sufficient to prevent damage from solid bushings?

[ethan]

Appreciate you elaborating on this, because it made me realize I confused it with the older CMP option that was visible in the trunk. The Vincebar style is right in line with what I prefer on my car. Thanks!



The CMP solid subframe bushings recommend topside chassis reinforcement to counter the increased chassis stress. Would the Vincebar + my older Turner reinforcement plates be sufficient to prevent damage from solid bushings?

Yup, Vincebar the top and run whichever subframe bushings you want.