Time to upgrade the suspension ...
 

Hello everybody,

I think it is about time to upgrade my suspension parts as I got more seat time at the track and hopefully will reach the limit of the car with next two events and my car is pretty high for what it should be thanks to 255/40 295/35 tires on 19 wheels :rolleyes:.

Currently the car has only Whiteline front and rear swaybars. They worked pretty well to reduce body roll, but I want more, Also I want to reduce the center of gravity slightly, at least reduce the gained 7mm in height, and to be able to have better alignment setting.

So my buy list for suspension is as follow:

- SPL Front Camber Arm
- SPL Rear Camber Link
- SPL Rear Traction Link
- SPL Lockout kit
- SPL Adjustment Wrench

aaaaaand coilovers.

Pretty sure of SPL parts, but I would like to know if I need any other parts from their lineup, or I covered the necessary parts and more.

Next thing, the famous coilover question :happydance: which is better.

I was pretty sure that I will go for Tein coilover coupled with their EDFC Active pro, however, looking at the race track that I participate at and the initial setup for the device and install costs, I preferred to invest the money on a better quality coilovers.

So, the Z currently is serving as a weekend car and a track warrior for my pleasure. The setup I want is Street\Track oriented but more biased toward track, I would prefer to retain stock height or near stock height as streets here is not very low car friendly. I shortlisted some coilovers depending on recommendation, price, brand name from cheaper to most expensive, and beware that I can get JDM parts cheaper as I am in Asia (Middle east exactly) and shipping prices will be a lot cheaper.

- Tein Monosport (still an option without edfc if it's a great set, would the rates be too high for an aero-less car? 14k front 12k rear)
- KW V3 - most popular here
- Bilstein PSS9/10 - Great quality and like the one on my srt, maybe different model
- Zeal Function X (Soft 10k F & R or Hard 12k F & R) can get it for around USD 1800 and pretty reputable company in Japan - but not sure of the drop range

and another option has been viable is to have a custom set by MCA, mostly X or red series as my original plan was going to cost over USD 2,200.

These what I believe the best options I can find under USD 2500

Researching through forum and google just made me more lost, KW - Bilstein pretty good quality with good prices (cheaper of the rest except tein) but they are more biased toward street as is, Tein is very popular here locally, I didn't find a signle negative review on Zeals but no z34 platform review, lastely, I found mca suggestion here first, searched on web, and got a lot of positive reviews.

I want to make one time investment, and some thing time will prove that I made the right choice.



Appreciate your inputs

You failed to list "Powertrix" Probably the second best coilovers for the 370z and at a good price ($1300)

SPL tie rod ends
comes with pillowball joint and also spacers for bumpsteer adjustment i believe

are you getting the SPL midlinks to retain the OEM spring setup, or traction rod to go to a true type coilover?

for coilovers on the track, Aragosta or AST

but on a budget basically everyone loves Charles @ Powertrix since he will build you whatever you want if you ask him. I went with Aragosta but he still helped me sort out some spring issues, very nice guy

Yeah I read about Charles but shipping will be the biggest issue, for addon spoiler I got shipping quotation around $680, and I think coilover shipping will be more expensive. So it will shoot the price to over $2k, where I can buy (including shipping) KW V3 for $1600 (from UK) Bilstein under $1900 (UK as well) Zeal @ $2k from Japan. I wouldn't say they are better or his, as I didn't see a direct comparison. Nevertheless, I admire his work and liked his customer service and helpfulness from the little conversation we went through for the addon spoiler.


As I understand getting the traction link will give me a little more adjustment for toe over OEM regardless of the rear suspension type, and as far as I know, all coilovers I listed are OEM type except Zeal and MCA where they offer both types. correct me if I am wrong. I think mid link will be obvious choice :)

I would like to stay within $3k for the coilovers. I am not getting into competitions as we don't have much, only trackdays and hopefully autox if we found a sponsor :shakes head: so going over that is not necessary and even what I allocated is a lot, but I like to get quality parts instead of going through multiple cheapo parts.


and thank guys for the quick replays.

You get what you pay for with dampers.
1st JRZ RS1 Coilovers $$$$
2nd KW V3
3rd Bilstein PSS9/10

And without a shock dyno results handy, adjustable settings are just a mystery box.

Except $3k won't get him into JRZ tho. Possible with AST if he just reuses stock upper mounts.

Zeal is only $2k nowadays? I recalled riding in my mechanic's personal car with Zeal coilovers. It was an eye opening experience for my young self at the time. It was over 10years ago. We had the same make & model car, and his car's behavior over bumpy corners left me a great impression.

One minor advice, you may want to consider the availability of rebuild/revalve locally. It's a PITA to have to send the set back overseas for potential service work needed. Small chance, but still should be considered.

Anything from SPL is the way to go. Voodoo 13 is also a brand that is up there with SPL.

I will say V3's aren't good enough for repeated track use from what I have seen. They need a stiffer linear spring rate to be good, and KW will no longer revalve the V3's for a linear spring since the release of their Clubsport line. However, they do not offer a Clubsport for the 370z.

JRZ's are out of this world good.

MCS would be a good option equal to JRZ, as well as Moton if they offer anything for the 370z.

MCA's look good, as well as Stance Pro Comp 2's.

Bilstein PSS9/10's are a very recommended coilover in the European car world.

The higher level BC Racing coils (DR, HR, ER, ZR) are also very good and may be an option for you to look at.

Of course, you get what you pay, for a competition car it is worth to just take the best parts without looking at the price, but for one who just want to enjoy his car, it is not worth it. I will check if I can find shock dyno locally, but I doubt that.


Yeah I was just amazed with the difference in price between buying Zeals from US or Japan, the function x model is going for JPY 204,000 which is around $1,900. I don't know about other models pricing. Your short experience with Zeals is encouraging and hope the JPY rate will be better if I decided to go this way.

And I am pretty sure we don't have any shops that will rebuild/revalve coilovers. So, which ever is my choice, it will be the same. :icon14:

Thanks for replay, I will look into the options you mentioned and hope I just don't end up spending more than what I am planning :rolleyes:

Yes, I remembered something.

What do you think about the spring rates for our cars, I found lot of different setup, like 12k front 11k or 10k rear, and 12k or 10k front and rear, also 14k front 12k rear.

Which will be ideal for dual use for a car with no aero parts.

Take a hard look at the Aragostas too, the S or the SS, since they're higher spec internals, aluminum bodies, etc...You can get them in true type or OEM spring location as well as either solid or rubber upper mount. As for ride height, it's one of the few options that'll allow you to go even slightly above stock ride height. The SS is double adjustable and most likely above your price point but I'd get a quote on them regardless. Might be worth it. If I remember correctly, the Z34 Type-S are 14K front, 10K rear and true type. If you do a lot of street driving, I wouldn't go with a spring rate that's any higher.

The KW's are tempting but a PITA to adjust and they don't come with upper mounts, forcing you to reuse the originals. Plus their springs, like the Bilsteins, are progressive.

type-S is OEM type. Thats what I have. I wasn't even aware they had an option to go true style (not that i would have).

Yep, I have the Type S as well. Basically all you need to convert is the upper and lower spring mount/collar unit and the spring. If you look at the Infinti HV37 application, it's a true type in the rear. Same basic dampers as the Z34/CKV37 (G37).

I agree that V3s are not your best option for a track purpose. Their main appeal is the daily driving ability as well as a good track setup. But it all depends on how much you're willing to spend overall. The best track coilovers are going to cost a ton at first, as well as in the long run as their internals are amazing, but not meant for daily road use and will wear out faster. Where as the ones made to be more daily driver friendly will last longer between rebuilds, but usually aren't valved as well and won't perform as well as a track shock obviously. Honestly if you want the best, I would save up just a bit more and get some JRZ RS1s. You will be VERY happy that you did.

Well, RS1 is just JRZ's entry level product. They are great indeed, but I wouldn't put that on a pedestal so high as "the best".

Zeal (by Endless) isn't covered much here, IMHO it's probably the best Japanese coilovers (exclude the Euro x Japan collaboration units like Aragostas, or euro coilovers revalved for specific Japanese tunning shops). If OP can get a set of NEW Zeal Function X for $2k, then there isn't really anything to think about IMHO.

As far as V3 and Pss10's progressive rear springs, you can always just substitute with a pair of linear units from Hyperco or Swift, you just have to get the right adapter, rate, inner diameter, and length. But extra costs will incur.

http://i1093.photobucket.com/albums/...e-thinking.jpg

Should I overspend? :rofl2::rofl2: I think overspending will become a hobby for me LOL


Ape Factory
Interesting thing about Aragostas is their height, found them under $3k mark, however, front 14k is something to think about, if it is bearable as a weekend car I wouldn't care, but does the difference between front and rear rates makes the car understeer more? as I understand harder front springs or softer rear springs will make car understeer, is that correct? Specially that the car stock rates are harder at rear and it is still understeering, maybe the stock alignment is the culprit, I dunno.


BuddyH
yeah, I was putting V3 and PSS10 to be final resort in my price range as they are reputable companies. As far as JRZ, if any vendor will have a great discount now or during Black Friday, I may consider, maybe if it is 50% discount :rolleyes: It is a quality part and I am sure I wouldn't be disappointed if I go for it, and I wouldn't be broke either, I want to stay within current budget as the z is driven one or two days a week :)


cv129
I am digging zeals for now with the seller, I am just trying to confirm the ride height range.
There is two options for Function X, Soft and Hard, Soft is 10k spring rate for front and rear, Hard is 12k front and rear. Which one you think will be better?
Also, I am trying to get an estimate of Function A coilover, as they are fully made of Aluminum, lighter is better of course :tup: but I won't go for A type unless the price turns to be irresistible.

You could always use the Aragosta version made for the G37 (Skyline Coupe, chassis CKV37) which has 12K front and 10K rear. I found understeer to be reduced vs. the stock suspension but I most definitely need more front tire and I prefer a square setup regardless. For the tight stuff, it'll understeer. On the faster sweepers, it's not noticeable. So you could tune with tires and/or swaybars. But your basic premise is correct. You can also alter it via damper settings and it does have an affect on balance.

Aluminum vs. steel...Al is lighter but steel is more durable. I'd also consider getting a set of those coil-over "socks" used by Stance and a few others to keep the sand and dust out of the seals. Debating doing that myself.

Also consider whether or not you have easy access to someone who can rebuild them if necessary. A good quality coilover with low stiction seals will need to be rebuilt every 12-20K of road use to keep them optimal.

As for price, I have a source that can get the Type E's for under $2K and the Type S for about $2300 USD.

Edit: I do find it interesting that Zeal chose to go with equal rates front and rear given how much more weight is up front vs. the rear. I'm sure they did a lot of testing but still...I notice I can run my front dampers at a much firmer setting than the rear, even with the disparate spring rates. FWIW, the stock rates are about the same ratio.

I think under steer with our car is with the OEM alignment. Track guys advise to use stiffest front bar on this car, which effectively raise spring rates anyway. Some even disconnect rear bar all together. And some extreme examples, check out (link below) what kind of front to rear rate split the really serious guys run. Within the thread, member Jhro and GSS have no afternarket aero so I think their setups relate to you the most. Also note rear spring location (true type or OEM, can't compare the two rates directly).

http://www.the370z.com/track-autocro...ing-rates.html

As for the Zeal 12k or 10k....I hesitate offering a blanket opinion. If you ever lower it, or decide to have race wheels and tires in smaller diameter (lower height), or have big wide sticky front tires (bigger braking power), or you become Lewis Hamilton, I think you will overwhelm 10k fronts. But if you are sure you will stick to stock height, tracking just for fun and not for chasing lap times, and you want maximize comfort for your lady friend/wife, then maybe 10k is fine. Below is a link to various spring rates for reference if you don't already know.

http://www.the370z.com/brakes-suspen...ing-rates.html

My guess is, for Zeal, 12k should still yield fine ride quality. My fronts are approx 11.6kg/mm (OEM Nismo 8.6kg/mm). At full stiff (JRZ RS1), my butt feel is the dampers still take high speed compression better, and have better control on rebounds.

Edit: Echo on Ape's response, I find it kinda weird on Zeal's spring rate decision...I assume the rears are OEM spring location. It would be really really weird if the rear rates are for true type.

Off topic: haha never seen coilover socks, love it lol. Seems like a good way to protect your investment especially against sand and salt.

The Zeals are OEM spring location. And yes, those socks are a great idea. I don't own a set myself and personally I'm not willing to pay $100 for four of them. So...going to make my own and put those home economics sewing classes from 20 years ago to good use. Neoprene and a zipper. Can't be that hard.

And great post too with lots of good info! Personally I wouldn't go below 12K up front myself, the stock IPL rate is almost 10K front and 8K rear. Then again the car is about 400 pounds heavier than the 370Z. I feel like I could go down in rear spring rate but I'm trying to lessen the amount of understeer with the stock setup. I have a 225 width up front and a 245 out back with the same diameter bars as the Nismo. And I too have exceptionally crappy roads with steep driveways. Hence the reason I'm lowered less than an inch. Plus it doesn't change the roll center for the worse. IMO, the higher spring rates negate changes in swaybar diameter. Car corners amazingly flat now.

225 and 245 on a G?! A car heavier than the Z? That . . . does not seem like enough tire.

I was running more than that on my 240sx which is even lighter.

I think that's the oem tire setup, even on IPL G coupes, kinda crazy. But then again, the last gen C63 AMG came with 245 rear tires and that car put down power amazingly well for skinny tires with a monster motor lol.

It definitely isn't enough tire :) Which is why I'm going to a square setup with 19x9.5" rims and 255's all around at the very least. I can go wider (not as wide as the Z) but then I'm looking at large increases in unsprung weight. I've had traction issues on acceleration from day one with the stock 348hp. I partly blame the Bridgestones and the asphalt they use here but some of it has to be suspension geometry and OEM alignment specs. Can't imagine having C63 power and 245's in the rear.

This is why I like the forum :) a lot of insightful posts.

After that, I will be looking into the harder spring option. As my next tire setup will be re71r or mpsc2 with most likely 275/35 front 285/35 rear, unless I found the suspension compeling the stagger, I will be going for an equal stagger to my current one but with wider and stickier tires, in any case, harder springs will benefit me.

And thanks for the socks suggestion, as we have dusty weather mostly.

Lol looks like we may end up with a similar setup. I currently run that same sizes in RE71R.

Beware of wear rate on Cup tires...a GT3 owner reportedly (tire rack review) burned through a set within a few thousand miles of street driving (fast highway driving on coarse pattern concrete).

Best of luck :driving:

Haha, my 370 would be the impostor in the other half of earth. Going through your build, both builds are slow :tup: thumb up for slow builds LOL, what is your opinion about the size and bridgestones?

and noted about cups, the appealing point about Michelins is their weight, I saved over 3 lbs from each corner when I switched stock wheels with dunlop stock size tires to ze40 and pss. Also the car get driven 6k miles yearly, so I can see them last for a whole season which isn't bad

and you too, good luck :)

I don't have any constructive words on the feel at this point. I have very limited experience with the tires right now.

I was on 265/285 RE11 until recently, switched to 275/285 RE71R. Unsure if it's a change in actual construction or due to the size, i felt the 71R's were ever so slightly squirmier than the RE11 during my "emergency lane change" test (done on empty tollway @ speed limit). But it was a breezy night, tire pressure was around 33psi cold, and I haven't driven it much since. Hope to dip my feet into some beginner track days next year.

New house and baby took a all of my time these 1.5 yr, the Z now sits for 2 weeks at a time on average, and get driven for weekend morning grocery.....can't throw the car around even a little without fish and avacados just flying everywhere :shakes head:

Hope you enjoy the new tire set and be as expected and wish you a happy life, I haven't been through all this until now but many of my friends are currently in the same situation, I can relate and feel how busy you could be, at least you have the z and can drive it and enjoy it from time to time, here in Qatar, they just ditch any other cars and spend the rest of their lives with Land Cruisers :mad:

Function A for $ 2,600

:yum:

http://i30.photobucket.com/albums/c3...AS_Endless.jpg

photo for GTR set


I may end with them if I got the right shipping cost

is there any benefit going to a "true coilover system"??? I would love to get rid of the spring midlinks on the rears.