[ashmostro]

(Finally)

Wow.

ZOMFG.

Coming from AST 4100's with DDP's which in their own right are very good prosumer shocks, the JRZ's are noticeably better. By "better" I mean the following:

- Follows imperfections at low and high speeds with less drama (chassis doesn't get unsettled as much)
- Harder bumps are masked more than they were even with the stock ZSP suspension
- Low speed driving feels a bit stiffer as I feel the overall suspension frequency is tuned for a higher speed now- the ride settles down considerably above 40 mph.
- Compression is highly controlled while rebound at +5 is not too intense. Haven't tried higher settings yet as this is just Day 2.

Setup is 450 lb 7" Hyperco springs in front with 800# 8" Hyperco's in back. I am not running any helper springs at all as I just don't feel they are needed at my taller ride height (slack at full droop is minimal). If I were to add them later I'd probably go with Hyperco as their fully compressed heights are only .25" (I will have some NIB Swift helper springs for sale soon)

I am running Vorshlag camber plates up front and HPA adjusters in rear. All M3 arms and bushings, with the exception of Megan camber, trailing, and toe arms which are wonderful.

Camber settings are -2.7 in front and -1.5 in rear. Ride height looks about an inch lower than ZSP. Corner balanced to 49.97% cross weight!

Pics of the product:



Pics of the car before the JRZ's (ride height is about .5" higher now):



Track Wheels setup:




Happy to answer any product questions y'all might have.
-Ash

[ajsalida]

Nice!

[Techevo]

Excellent choice my friend, superb suspension, and nice to see someone investing in decent chassis upgrades! Have fun!

[ashmostro]

Originally Posted by Techevo

Excellent choice my friend, superb suspension, and nice to see someone investing in decent chassis upgrades! Have fun!

Thanks man! Appreciate such comments from a fellow handling junkie!

[justpete]

Originally Posted by ashmostro

(Finally)

Wow.

ZOMFG.

Coming from AST 4100's with DDP's which in their own right are very good prosumer shocks, the JRZ's are noticeably better. By "better" I mean the following:

- Follows imperfections at low and high speeds with less drama (chassis doesn't get unsettled as much)
- Harder bumps are masked more than they were even with the stock ZSP suspension
- Low speed driving feels a bit stiffer as I feel the overall suspension frequency is tuned for a higher speed now- the ride settles down considerably above 40 mph.
- Compression is highly controlled while rebound at +5 is not too intense. Haven't tried higher settings yet as this is just Day 2.

Setup is 450 lb 7" Hyperco springs in front with 800# 8" Hyperco's in back. I am not running any helper springs at all as I just don't feel they are needed at my taller ride height (slack at full droop is minimal). If I were to add them later I'd probably go with Hyperco as their fully compressed heights are only .25" (I will have some NIB Swift helper springs for sale soon)

I am running Vorshlag camber plates up front and HPA adjusters in rear. All M3 arms and bushings, with the exception of Megan camber, trailing, and toe arms which are wonderful.

Camber settings are -2.7 in front and -1.5 in rear. Ride height looks about an inch lower than ZSP. Corner balanced to 49.97% cross weight!

Happy to answer any product questions y'all might have.
-Ash

Sounds really great! Have you had a chance to track them yet? On a track would be best, but ya' know what I mean I think.

Did you change ride height and/or corner balance with the new suspension? Any changes to bump steer, toe front and rear, etc.? Curious if the JRZ are more readily optimized within the limitations of the chassis, if that makes any sense. Or does it not make sense to try and separate the dampers' contribution from the sprung setup? Quantum mechanics? Piece of cake. Chassis dynamics? Friggin' black magic.

[11SEC]

Sick suspension. I'd love to have a set of JRZ. Congrats. This post has got me itching on upgrading my setup lol.

[CJ421]

Great concise write-up of the RS1's. And excellent upgrade from the AST's.

The RS1 is a no-brainer if you have the $. Only advice I can give is have them installed by a shop very familiar with consulting on JRZ's as much more goes into the setup - picking spring configurations, rates, ride height, alignment - than your typical off-the-shelf suspension. Experience doing that counts for a lot. VAC is my go-to; others would be Bimmerworld, Turner, Fall Line.

[chris82]

I had my RS1s installed 2 weeks ago. They are incredible like you say

[ashmostro]

Originally Posted by justpete

Sounds really great! Have you had a chance to track them yet? On a track would be best, but ya' know what I mean I think.

Only had them on the car for 3.5 days so far so no track work yet
But as I have tracked with the ASTs extensively I will have a lot of baseline data to compare against... quite excited!

Did you change ride height and/or corner balance with the new suspension? Any changes to bump steer, toe front and rear, etc.? Curious if the JRZ are more readily optimized within the limitations of the chassis, if that makes any sense. Or does it not make sense to try and separate the dampers' contribution from the sprung setup? Quantum mechanics? Piece of cake. Chassis dynamics? Friggin' black magic.

lol. Well, as I mentioned I did raise the car slightly over where the ASTs were sitting - generally speaking, AST is known for liking really low ride heights. It's a philosophy that comes over from making race shocks for so long but not adjusting that approach when building out their prosumer line, and I think it was a mistake.

Kept toe the same as before. Camber I already mentioned. Bump steer you can't easily alter on these cars other than minimizing roll and more importantly, matching front and rear motion frequencies to compress and rebound more naturally. I'm running essentially the same spring setup as I had on the ASTs (I tried various combinations) so these performance changes are definitely attributed to the dampers alone.

[ashmostro]

Originally Posted by CJ421

Great concise write-up of the RS1's. And excellent upgrade from the AST's.

The RS1 is a no-brainer if you have the $. Only advice I can give is have them installed by a shop very familiar with consulting on JRZ's as much more goes into the setup - picking spring configurations, rates, ride height, alignment - than your typical off-the-shelf suspension. Experience doing that counts for a lot. VAC is my go-to; others would be Bimmerworld, Turner, Fall Line.

Definite no-brainer. As you have mentioned separately, the work JRZ put into tuning the compression and rebound "connectivity" is part of the magic. Can't wait to try more settings as I get a feel for the front and rear independently (I'm starting to form hypotheses to this effect already).

As for setup help, I generally agree. In my case, I'd tweaked and tuned the spring rates, lengths, ratios and alignment so much in my garage that I felt comfortable just ordering the dampers instead of the full kit and piecing it together myself. Proud to say it's worked out pretty well so far!

That said, I bought these from VAC and they are my guys too, as you know. Just a great outfit.

I'd like to ride in your car one day to A/B the different philosophies around front to rear rate ratios. Would be really interesting.

-Ash

[CJ421]

Also Ash I think with your setup, you did a great job isolating the difference the damper makes. It's the most important piece of the suspension behind the tire which is not widely understood. The JRZ RS1 (and RS) really shines in race classes where the are limitations on the spring rate but not the damper (other than specifying no external reservoirs, typically). The damper makes all the difference there and the RS1 is unmatched vs. all other monotube dampers I know of. High gas pressure (which can be tuned via schraeder valve), large 16-22mm piston rod, simultaneous rebound/comp adjustment and beautifully valved comp/rebound stroke. These also have a very long life cycle before needing revalving (30,000+ mi on normal roads). World class tech.

-Charles

[cvc 22349a]

[Eat.Sleep.Race]

Nice review, i can only imagine having those at the track!!

[ashmostro]

Originally Posted by Eat.Sleep.Race

Nice review, i can only imagine having those at the track!!

So far, I can only imagine too! Haha... soon...

[ashmostro]

Originally Posted by CJ421

Also Ash I think with your setup, you did a great job isolating the difference the damper makes. It's the most important piece of the suspension behind the tire which is not widely understood. The JRZ RS1 (and RS) really shines in race classes where the are limitations on the spring rate but not the damper (other than specifying no external reservoirs, typically). The damper makes all the difference there and the RS1 is unmatched vs. all other monotube dampers I know of. High gas pressure (which can be tuned via schraeder valve), large 16-22mm piston rod, simultaneous rebound/comp adjustment and beautifully valved comp/rebound stroke. These also have a very long life cycle before needing revalving (30,000+ mi on normal roads). World class tech.

-Charles

Egg sackly! I wanted something that hit on all the right points for both street and track, and didn't require frequent rebuilds like so many other "race" dampers. Viewed from that perspective, I'd say that RS1's are underpriced if anything! IMO, it's the additional kit contents that make the setup seem pricey. Source your own springs, rear adjusters, top plates and mounts and you can save some good dough. But yes, you do need to know what you're doing and be willing to iterate a bit. Personally, I find that to be half the fun.

[tres]

nice setup maybe we will meet up at the track one day at summit.

[ashmostro]

I'll be there in September, Oct, Nov!

[ashmostro]

AMUSING UPDATE.....

So, I had been intent on locating some low-profile top nuts for my front struts as the vorshlag stack is a little tall for the RS1's, which prevented the front adjuster knobs from being able to be mounted on the adjuster shaft. The supplied Nylok nut is too tall in this combination, which was a bit of a surprise to me. I did not have this problem with my ASTs.

Simple fix, but it took a while to find a grade 8 M14x1.5 jamnut... ended up going through mcmaster.

So here's the funny part... as I finally had the opportunity to install the adjusters on the front, I of course needed to ensure they were on securely and wouldn't spin, so I turned the knobs to reindex them. The JRZ literature recommends an initial setting of +5 from full soft for the street and +10 for track. I'd asked the installer to make the +5 adjustment after install which he did. Except that when I turned those front adjusters towards full soft, it goes 1-2-3-4-5----6-7-8...WTH??

They were +5 from FULL STIFF!!! This whole time! All four corners!! You see, JRZ's full soft is fully clockwise, which is the opposite of most needle adjuster type coilovers. The guy didn't bother looking at the '+/-' signs on the knob I guess, or my explicit instructions.

And yet, they have been supremely comfortable, other than that slight juddering at low speeds that I reported up top (which is now completely gone). Of course I immediately took the car for a spin and was cracking up at how cloudlike the ride now felt- maybe a touch too soft but I'm going to let my butt recalibrate before tweaking. I was running a setting stiffer than the recommended race setup on the street and both me and my wife were comfortable enough!

I'm just continually amazed at these dampers. I'm running ~3x the spring rate over stock and somehow the ride is *more* compliant?? Hamazing.

I'm still at this whole thing.

[TSM330i]

Most people just don't understand how good coil-overs are vs. a spring/shock combo. Not only do they handle MUCH better, but the ride is so much more controlled and better as well.

[ashmostro]

Absolutely... most folks that see coils as a too-extreme solution for the street are either not adjusting them correctly, or using them for stizzance and running low-quality stuff designed for moar low rather than appropriate damping.

As for my damping settings, I bumped front and rear up to +7 as I found +5 a little floaty for my tastes. I might raise the rear another click to bring more rebound front-rear balance.

[EJ_3]

I was just looking at getting a set of Ohlins instead of getting my PSS9 rebuilt when its time. Going to look more into JRZ after reading this review.

[ashmostro]

Wise choice

Highly recommend you call VAC in Philly to figure out the right setup for your needs. They are great guys.