JRZ Suspension

[nsx1]

I've been searching for a suspension for over a year. I did a lot of seat-of-the-pants testing from the passenger seat of a dozen or so NSX's. I determined my preference and made the decision to buy -- only to discover my choice was no longer in production. So the search continued.

After reading the acclaims of the JRZ suspension by Anil (serialNSXer) and talking to Jon Martin of Cerritos Acura, I ordered the JRZ coilovers. It's kind of a new setup, so I hadn't had the chance to "seat-dyno" it. I put a lot of trust in these guys, so only time will tell if they are worthy. (I'm not too worried.)

The dampers are 2-way adjustable and the springs that come with the setup are Eibach... 300 lb/in. in front and 350 lb/in. in the rear. That's approximately equivalent to 5.4kg/mm and 6.3kg/mm respectively.

I went to Darin of West End Alignment for install, corner balance, and alignment. Darin did a fantastic job! He balanced the car on the 3rd try and aligned the car the "old-school" way.

The car weighed in at 3029 lbs with about 16 gallons of gas in the fuel tank. So, based on 6.35 pounds per gallon of premium (API gravity of 54), I figure the car weights approximately 2927 lbs. without fuel.

I need to evaluate this suspension for a while before I can give a good assessment, but if my drive back home from West End is any indication of their performance, I can say that the car has never felt so razor-sharp in the steering department.

The ride is near stock, yet I could feel the imperfections in the road as the car just seemed to be sucked down to the pavement. I just didn't notice that "air-born" feeling like I noticed with the stock suspension when the undulations in the pavement oscillated the wheels. There was no pogo effect whatsoever.

Weigh distribution...

Final result...

 

[ediddynsx]

Well if you decide you don't want your JRZ's I would be more than happy to exhange my JIC's with some cash for them....

 

[nsx1]

Well if you decide you don't want your JRZ's I would be more than happy to exhange my JIC's with some cash for them....

LOL... Eddie, you're so funny. :biggrin:


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[Alittleboost]

Mind I ask you how much this suspension is?

 

[stuntman]

Probably $3,000-4,500

 

[da3dalus]

The P-Car boys have been raving about JRZ's for a couple months now. I'd like to know any further assesments of them you have as you get more seat time!

 

[NSXGeek!]

I noticed you are using the stock rubber bushed upper mounts. I'm surprised they didn't include mono ball upper mounts with the price of the damper. They will reduce the inconsistent response rubber bushings will give under compression of the damper. However, if you are not concerned that much about performance, the rubber will give you the best noise resistance. Those upper mounts are used even in TEIN's entry level Flex damper. Also, the tender spring is usually put on top of the main spring so that under large rebound moments (like what is shown in your photo of the front suspension) the main spring does not come unseated and gall into the top of the damper.

 

[stuntman]

I noticed you are using the stock rubber bushed upper mounts. I'm surprised they didn't include mono ball upper mounts with the price of the damper. They should be used in any performance application to reduce the inconsistent response rubber bushings will give under compression of the damper. Those upper mounts are used even in TEIN's entry level Flex damper.

Monoballs transmit EVERYTHING to the car, since this JRZ was the "RS" -street damper, they used rubber to isolate some unwanted vibrations. The thickness of the polyurethane/hard rubber that they use is most likely stiff enough to not cause 'inconsistant response' under the forces acted upon it.



JRZ/Moton = same thing. I run on them all the time, and we have them on the Factor X Black Unlimited car and the retired silver Modified car - driven to all those victories.

-Also use them in many different cars in Grand Am. They're great, what else do you wanna know? :biggrin:

 

[john@johnhudakracing]

My 0.2

Can't speak to the RS model. Likely similar to the Moton Club Sports or the Ohlins with the DFV.

Eibach ERS 300/350's. Maybe seems a little light on the rates out of box. Doesn't say on their web site, what does RS stand for if not Ridiculously Stiff? :biggrin:

With stock upper mounts and bushings, bigger street sport tires... I would guess that in a street car moving to those dampeners, proper corner balance/alignment what have you.... should feel pretty darn excellent. Sporty while still quite manageable over harsher grades. Unless their was a setup problem, I can't imagine you being unhappy or finding them to be too harsh like Tein or too numb like the T stockies. I'd speculate you'll be in the middle of the road so to speak.

All around that is some nice gear for the street and a significant step up. On the Cali highways I've been on with a low CPM / suspension frequency they should have no problem dampening those lower rates out of box. Quite nice from where you were.

I'm also running JRZ's now, but can't really add anything here... as our setup's are frankly not in anyway analogous.

I'm using their original dual adjustable pro motorsports shocks with remote reservoirs, rebuilt/setup to my spec, with 1000lb + staggered race springs matched to my aero with a fully non-compliant mono-ball suspension and upper mounts and solid everything. Ride comport was obviously not my main priority.:wink:

While mine are still settling in and have room for adjustment, so far I've been very pleased on track. I feel like I got what I paid for, and they should be a great learning tool.

Now street... well if street means a highway with brand new fresh pavement then quite good too. LOL. Of course that never lasts more than a mile. Rough roads ahead... hit a bridge seam or truck rut or changes with a high suspension frequency.... and it is kind of like being on a paint shaker provided your tire is even on the ground. My problem is if I don't put a dab of Loctite on every nut and bolt on my body it just falls off in an hour or two.

Still, if you are looking for re-assurance on your purchase, you have it. I'd love to try a set of the club sports on my other car. :smile:

 

[nsx1]

John,

Thanks for your comments.

I have not had a chance to drive the car much since the install (rain, etc.), but I feel the spring rates are a bit soft for my taste. Only time will tell.

Doesn't say on their web site, what does RS stand for if not Ridiculously Stiff? :biggrin:

The USA site does not say what the RS stands for, but the main site (Holland) says it means "Race Sport".

Steve

 

[john@johnhudakracing]

In that case I'll tell you what.

I have an extra set of Eibach ERS springs here from Danny that he had on mine before I over-hauled them. Wee bit stiffer. I'll double check the rates tonight. I have them in a box with the tender springs and everything you would need I could let go cheap.

 

[goldNSX]

I noticed you are using the stock rubber bushed upper mounts.

and there seems to be too much suspension travel.

 

[Todd McKelvie]

I commented on the JIC system in another thread, but might be ok to post again.

I had been driving around for 6 months on the JIC system on the softest setting. 2 weeks ago I set the dampening to 6 clicks (10 is the max) as a test. My NSX has been transformed. It is so "planted" now. Turns, bumps... everything seems to get soaked up without any harsh side effects.

Just my 2 cents worth on the suspension subject.

 

[nsx1]

I commented on the JIC system in another thread, but might be ok to post again.

I had been driving around for 6 months on the JIC system on the softest setting. 2 weeks ago I set the dampening to 6 clicks (10 is the max) as a test. My NSX has been transformed. It is so "planted" now. Turns, bumps... everything seems to get soaked up without any harsh side effects.

Just my 2 cents worth on the suspension subject.

Todd,

Your SOS Spec JIC's were one of the nicest suspensions I rode in... and that was before you fixed it. :wink:

Steve

 

[Up2Yu]

Steve,
Congrat on the new suspension. Sorry, we didn't have a chance to talk at the last meet! I sold my Zeal Function B6 and just got the DG5 installed yesterday. Scheduled with Darrin on 12/27 for the treatment. We have to compare at the next meet. I need your opinion on the DG5 since you rode on my Zeal!!!
Hoa

 

[da3dalus]

Are they able to be lowered past what you have them set at?

 

[nsx1]

Steve,
Congrat on the new suspension. Sorry, we didn't have a chance to talk at the last meet! I sold my Zeal Function B6 and just got the DG5 installed yesterday. Scheduled with Darrin on 12/27 for the treatment. We have to compare at the next meet. I need your opinion on the DG5 since you rode on my Zeal!!!
Hoa

Sure Hoa... I'd like to check-out your new DG5's. Though, it's going to be hard to beat those Zeal's you had... they were great. I didn't expect you to have much trouble finding a buyer. Whoever it was, will surely be pleased.

I have now taken two drives with the JRZ suspension. First, was coming home from the shop after the install. Second, was today, when I drive 60 miles down to Cars and Coffee. While I was there, I had the opportunity to drive some twisties.

So far, I have to say, I really like the JRZ's. They are a very nice setup. I still need some more seat-time to write a real review.

On the freeway, the ride is near stock... just more planted. In the curves though, the car seemed practically as flat is the higher spring-rate suspensions I experienced. It's counter intuitive, but they seem to be either soft or stiff when they need to be... I don't get it.

I was told that the JRZ's are special in the way they remain planted to the pavement when going over bumpy/bouncy roads. Now... I can attest to that. My car has never seemed so planted... all 4 corners just seem glued to the road surface no matter the dips, droops, divots, undulations, ripples, etc.

I'm not an expert with suspensions because I don't have long-term experience with different setups. But I can say... if you want a smooth ride that is near to stock, yet razor-sharp steering response with all 4 corners planted to the ground like mature oak trees, this is a great choice.

Jon Martin told me, "They out-perform all other suspensions in all categories except one... price."

More later,
Steve


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[nsx1]

Are they able to be lowered past what you have them set at?

Almost the entire body of the damper is threaded. So, I would imagine that you could lower the car to the bump-stops. I looked at mine and it seems there is another 1.5 to 2 inches of drop before bottoming out.

Here are a couple of photos from above...

 

[stuntman]

NSX1: I'll have to meet up with you at the next cars n' coffee!

-Very interested in riding in your car. I drove on triple adjustable Motons on the Factor X silver "modified" car on the street and loved them - with 1000 and 800lb springs!

Would be very interested in riding on your RS setup!

-billy

 

[Simons2k]

Congrats on the suspension Steve! Now it's time to test them out tomorrow :biggrin:

 

[CRJ Captain]

Not to dig up an old thread, but wanted to correct something.... looking at the picture your springs are not 300/350. Eibach labels their springs Rate/Inner Diameter/Length.

So your springs are 800 lbs / 2.25" ID / 3.5" Length and 700 / 2.25" ID / 3"

 

[iCEE]

Not to dig up an old thread, but wanted to correct something.... looking at the picture your springs are not 300/350. Eibach labels their springs Rate/Inner Diameter/Length.

So your springs are 800 lbs / 2.25" ID / 3.5" Length and 700 / 2.25" ID / 3"

actually, the eibach ers springs are marked length.ID.rate

haha. 3 inch springs. lol :biggrin:

 

[nsx1]

Not to dig up an old thread, but wanted to correct something.... looking at the picture your springs are not 300/350. Eibach labels their springs Rate/Inner Diameter/Length.

So your springs are 800 lbs / 2.25" ID / 3.5" Length and 700 / 2.25" ID / 3"

Thank you for correcting that... but you are incorrect!

1st # = Lo (length in inches)
2nd # = Di (Diameter in inches)
3rd # = C (Compression in lbs/inch)

You can reference this Eibach Catalog and refer to page 13 (for the fronts) and page 14 (for the rears.)

 

[CRJ Captain]

ya... my bad. I'm dyslectic.

 

[CRJ Captain]

OK, so is the JRZ worth it?

I've had my Comptech Pros for awhile and they are GREAT on the track and OK on the street. However, this weekend one of my students had a stock 05 NSX and it's the first time I have been back in a stock NSX in a long time and I forgot how nice the ride was.

So... got me thinking of either going backwards to the Type S (part of me is tired of tinkering and as long as it can be adjusted I will keep adjusting. ) or bucking it up and getting a set of JRZ.

On the Comptech Pros I had to jack up the car enough to get the tires to droop and then could reach above them and adjust the rebound. To adjust compression, I have to take the wheel off and undo the top mounting to rotate the shaft while pressing a button down. Too much trouble to do out at the track.

How do you adjust the comp/rebound on the JRZs?