Suspension tuning - dampers, spring rates, etc.

[coolhandluke]

The front lower compliance are the only sphericals Chris (and now I) will recommend for a heavy street car. I am considering Kingpin's front lower arms due to how rarely I drive my car. It's only received a few hundred miles since Expo, that will change shortly (thread to come.)

[DC2Iggy]

Just wanted to get a general opinion here regarding caster. Since we can't adjust caster without either doing the washer mod or swapping the upper control arms, i'm trying to figure out what would cause my R to have caster in the 1.70 range. There is quite a bit of range allowed (min: 0.16, preferred: 1.16, max: 2.16) in the helms manual but without being able to change the caster with stock components what could be cause a higher than stock number?

[coolhandluke]

Just wanted to get a general opinion here regarding caster. Since we can't adjust caster without either doing the washer mod or swapping the upper control arms, i'm trying to figure out what would cause my R to have caster in the 1.70 range. There is quite a bit of range allowed (min: 0.16, preferred: 1.16, max: 2.16) in the helms manual but without being able to change the caster with stock components what could be cause a higher than stock number?

Are the upper control arms OEM? Is the 1.7 a recent change? Are both sides 1.7 or just one?

[DC2Iggy]

Just wanted to get a general opinion here regarding caster. Since we can't adjust caster without either doing the washer mod or swapping the upper control arms, i'm trying to figure out what would cause my R to have caster in the 1.70 range. There is quite a bit of range allowed (min: 0.16, preferred: 1.16, max: 2.16) in the helms manual but without being able to change the caster with stock components what could be cause a higher than stock number?

Are the upper control arms OEM? Is the 1.7 a recent change? Are both sides 1.7 or just one?

Upper arms are OEM and I'm not sure if it's a recent change as this is the first alignment I received since I got the car. Exact measurements are left: 1.75 and right: 1.60 with -1.5 degrees of camber on either side and 0 toe up front.

From what I've read online, increased caster is supposed to increase straight line stability, however, this past weekend I completed a time attack event and found that the steering got fairly light and unsteady at high speeds and over bumps. Ball joints are good, tie rods are good, wheel bearings are good. I can see one lower control arm bushing looks a bit worn and i think the rear trailing arms could use a refresh. I've done the steering rack adjustment as well and it did not help.

[coolhandluke]

Upper arms are OEM and I'm not sure if it's a recent change as this is the first alignment I received since I got the car. Exact measurements are left: 1.75 and right: 1.60 with -1.5 degrees of camber on either side and 0 toe up front.

From what I've read online, increased caster is supposed to increase straight line stability, however, this past weekend I completed a time attack event and found that the steering got fairly light and unsteady at high speeds and over bumps. Ball joints are good, tie rods are good, wheel bearings are good. I can see one lower control arm bushing looks a bit worn and i think the rear trailing arms could use a refresh. I've done the steering rack adjustment as well and it did not help.

I would start with the Rear Trailing Arms. These impact straight line, braking, and high speed turn stability.

The rear lower arms are easiest to buy new OEM. Prices continue to rise, the Rear LCA's are now $72 per (used to be $38.)
-RR: 52350-ST7-R00
-LR: 52360-ST7-R00

I would also inspect the rear upper arms. If aftermarket, common to fail prematurely.

[DC2Iggy]

Upper arms are OEM and I'm not sure if it's a recent change as this is the first alignment I received since I got the car. Exact measurements are left: 1.75 and right: 1.60 with -1.5 degrees of camber on either side and 0 toe up front.

From what I've read online, increased caster is supposed to increase straight line stability, however, this past weekend I completed a time attack event and found that the steering got fairly light and unsteady at high speeds and over bumps. Ball joints are good, tie rods are good, wheel bearings are good. I can see one lower control arm bushing looks a bit worn and i think the rear trailing arms could use a refresh. I've done the steering rack adjustment as well and it did not help.

I would start with the Rear Trailing Arms. These impact straight line, braking, and high speed turn stability.

The rear lower arms are easiest to buy new OEM. Prices continue to rise, the Rear LCA's are now $72 per (used to be $38.)
-RR: 52350-ST7-R00
-LR: 52360-ST7-R00

I would also inspect the rear upper arms. If aftermarket, common to fail prematurely.

Thank you for the recommendation. I'll definitely start replacing bushings to get them all refreshed. Been meaning to do this over the winter but I don't think it can wait. I'll be taking inventory tonight of all the worn bushings and go from there.

[coolhandluke]

Feel free to post up here. Many (including) myself have replaced the entire suspension setups. Your use-case and budget will drive recommendations:
1.) OEM rubber
2.) Mugen/Spoon/other "hardened" rubber options
3.) Spherical


1.) OEM rubber is my general recommendation for a balance of cost (used to be 50-100% cheaper), performance, and ride quality. Here is a previous conversation (for context) for rubber:

Interesting. Maybe I'll be making a stop to the dealership to buy OEM bushings before they disappear. Spoon also makes a bushing set, and it's only $170, I've never been a fan of most of the things available on the aftermarket. Spoon is one of the manufacturers I would trust when it comes to something like that.

Age definitely plays a factor though, my doors are already starting to sag a bit and the windows are rattling when rolled down. Definitely on my to-do list this winter.

Ping Cris @ Acura Parts Express or Chris @ Kingpin Machine. Both support ITR Expo and can do two options:
1.) Buy OEM bushings or complete arms for self-install (Acura Parts Express)
2.) Buy arms with already installed spherical or OEM bushings (Kingpin Machine)

I'm not skilled at pressing bushings other than RTA's, so I went with a combo of new OEM arms (Rear LCA's, Rear Sway Bar, Rear Compliance / Toe) and new OEM via Kingpin (Front LCA's.)

2.) Hardened rubber options
-Mugen
-Spoon
-HardRace

My personal experience was HR held up for Rear Trailing Arm and Front LCA's. Note, the RTA's were a PITA to install due to being oversized. HR's other bits decomposed in under 10k. Mugen RTA's are what I recently ran on my 97 for more street-level comfort. Mugen bits are expensive but offer higher quality than HR. I can't speak for price or quality comparisons to Spoon.


3.) Spherical
Kingpin Machine should be your go-to for sphericals. Their build quality is top-notch and unmatched. Kingpin is also an Expo sponsor and a Type R Community member. RTA's are an exception, where PCI is a go-to.

For cars that see street time, I recommend limiting sphericals to:
-Front Lower Compliance (Kingpin)
-Rear Trailing Arm (PCI)

Kingping Review: The No-Flex, No-Nonsense Advantage of Spherical Bearings

[aw614]

I tend to go with Spoon/mugen if the price of OEM gets really close to a spoon/mugen set. That has been the case with the OEM compliance bushing vs the Mugen/Spoon pieces and also buying new engine mounts. There might be a few others where the prices are similar. I do wonder how much stiffer they really are as not many people seem to buy them or just go with aftermarket pieces.

Hardrace front lca bushing disintegrated on my friends eg hatch after 4 years or so of daily driving and frequent trips from Tampa to the east coast of Florida. I don't think an OEM bushing would have disintegrated the way the hardrace bushing did. I need to see if I can find the pics from the fb convo, but it looked worse than the 190k bushings that my ek civic beater has. After seeing that, made me wary of buying hardrace. Some people have had better luck, but my friend was one of those people who would make sure the bushings were clocked exactly at ride height and use a torque wrench for the most obscure part that people wouldnt bother to use a torque wrench

[DC2Iggy]

I was actually looking at ordering a few of the Hardrace bushings but have seen threads pop up saying they were just re-branded megan racing or vice versa. I don't think any locals have use Hardrace bushings in their cars so I'm not sure how well they would hold up with our terrible streets.

Can someone confirm the correct OEM part number for the RTA bushings? I am seeing 52385-SR3-000 and 52385-S21-003 and they appear to be about $44 plus shipping each. Spoon is $110 plus shipping and Mugen is $155 plus shipping (jhpusa.com).

[coolhandluke]

Questions
1.) What DC2 sway bars am I missing?
viewtopic.php?f=8&t=696
2.) What are the top CTR rear sway bars?