Time to upgrade the suspension ...

Ape Factory · 11-12-2016, 12:06 AM

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.

cv129 · 11-12-2016, 12:20 AM

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).

Dedicated AutoX/Track Spring Rates

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.

Spring Rates

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.

cv129 · 11-12-2016, 12:33 AM

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

Ape Factory · 11-12-2016, 12:46 AM

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.

OptionZero · 11-12-2016, 01:05 AM

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.

cv129 · 11-12-2016, 01:15 AM

Quote:

Originally Posted by OptionZero

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.

Ape Factory · 11-12-2016, 09:36 AM

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.

AlWakRa · 11-12-2016, 02:44 PM

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.

cv129 · 11-12-2016, 03:49 PM

Quote:

Originally Posted by AlWakRa

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

AlWakRa · 11-12-2016, 05:58 PM

Haha, my 370 would be the impostor in the other half of earth. Going through your build, both builds are slow

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

cv129 · 11-12-2016, 09:47 PM

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

AlWakRa · 11-13-2016, 04:16 PM

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

AlWakRa · 11-14-2016, 04:24 AM

Function A for $ 2,600

photo for GTR set

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

tonythetiger · 12-12-2016, 02:59 PM

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

11-12-2016, 12:06 AM	#16 (permalink)
Ape Factory Base Member Join Date: Apr 2016 Location: San Antonio Posts: 210 Drives: Audi RS5/QX70S Rep Power: 9	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. AlWakRa likes this. __________________ '13 Audi RS5 Misano w/mods-The Red Mist '13 G37 IPL-SOLD Last edited by Ape Factory; 11-12-2016 at 12:08 AM.

11-12-2016, 12:20 AM	#17 (permalink)
cv129 A True Z Fanatic Join Date: Jul 2011 Location: Dallas, TX Posts: 3,223 Drives: 09 Nismo, 16 Nismo Rep Power: 163995	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). Dedicated AutoX/Track Spring Rates 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. Spring Rates 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. AlWakRa likes this. __________________ Setrab \| RE-71 \| SPL \| JRZ \| Nismo \| ARK \| Whiteline \| RacingBrake \| CJM Oil Pan \| Ti shield Last edited by cv129; 11-12-2016 at 12:27 AM.

11-12-2016, 12:33 AM	#18 (permalink)
cv129 A True Z Fanatic Join Date: Jul 2011 Location: Dallas, TX Posts: 3,223 Drives: 09 Nismo, 16 Nismo Rep Power: 163995	Off topic: haha never seen coilover socks, love it lol. Seems like a good way to protect your investment especially against sand and salt. AlWakRa likes this. __________________ Setrab \| RE-71 \| SPL \| JRZ \| Nismo \| ARK \| Whiteline \| RacingBrake \| CJM Oil Pan \| Ti shield

11-12-2016, 12:46 AM	#19 (permalink)
Ape Factory Base Member Join Date: Apr 2016 Location: San Antonio Posts: 210 Drives: Audi RS5/QX70S Rep Power: 9	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. AlWakRa and cv129 like this. __________________ '13 Audi RS5 Misano w/mods-The Red Mist '13 G37 IPL-SOLD

11-12-2016, 01:05 AM	#20 (permalink)
OptionZero A True Z Fanatic Join Date: Apr 2011 Location: Sacramento Posts: 3,228 Drives: 15 370Z Nismo 6MT Rep Power: 214100	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. AlWakRa likes this.

11-12-2016, 09:36 AM	#22 (permalink)
Ape Factory Base Member Join Date: Apr 2016 Location: San Antonio Posts: 210 Drives: Audi RS5/QX70S Rep Power: 9	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. AlWakRa likes this. __________________ '13 Audi RS5 Misano w/mods-The Red Mist '13 G37 IPL-SOLD

11-12-2016, 02:44 PM	#23 (permalink)
AlWakRa Track Member Join Date: Oct 2010 Location: Qatar Posts: 600 Drives: 10 370Z PW 6MT Rep Power: 13450	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. __________________ 2010 370Z Touring Sport Pearl White 6MT Powered by: Fast Intentions - Motordyne - Stillen - OS Giken - CJ Motorsports - Mishimoto - MCA Suspension - SPL - SuperPRO - RJM - Z1 Motorsport - Zspeed - Volk My Humble Journals

11-12-2016, 05:58 PM	#25 (permalink)
AlWakRa Track Member Join Date: Oct 2010 Location: Qatar Posts: 600 Drives: 10 370Z PW 6MT Rep Power: 13450	Haha, my 370 would be the impostor in the other half of earth. Going through your build, both builds are slow 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 __________________ 2010 370Z Touring Sport Pearl White 6MT Powered by: Fast Intentions - Motordyne - Stillen - OS Giken - CJ Motorsports - Mishimoto - MCA Suspension - SPL - SuperPRO - RJM - Z1 Motorsport - Zspeed - Volk My Humble Journals

11-12-2016, 09:47 PM	#26 (permalink)
cv129 A True Z Fanatic Join Date: Jul 2011 Location: Dallas, TX Posts: 3,223 Drives: 09 Nismo, 16 Nismo Rep Power: 163995	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 AlWakRa likes this. __________________ Setrab \| RE-71 \| SPL \| JRZ \| Nismo \| ARK \| Whiteline \| RacingBrake \| CJM Oil Pan \| Ti shield

11-13-2016, 04:16 PM	#27 (permalink)
AlWakRa Track Member Join Date: Oct 2010 Location: Qatar Posts: 600 Drives: 10 370Z PW 6MT Rep Power: 13450	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 __________________ 2010 370Z Touring Sport Pearl White 6MT Powered by: Fast Intentions - Motordyne - Stillen - OS Giken - CJ Motorsports - Mishimoto - MCA Suspension - SPL - SuperPRO - RJM - Z1 Motorsport - Zspeed - Volk My Humble Journals

11-14-2016, 04:24 AM	#28 (permalink)
AlWakRa Track Member Join Date: Oct 2010 Location: Qatar Posts: 600 Drives: 10 370Z PW 6MT Rep Power: 13450	Function A for $ 2,600 photo for GTR set I may end with them if I got the right shipping cost __________________ 2010 370Z Touring Sport Pearl White 6MT Powered by: Fast Intentions - Motordyne - Stillen - OS Giken - CJ Motorsports - Mishimoto - MCA Suspension - SPL - SuperPRO - RJM - Z1 Motorsport - Zspeed - Volk My Humble Journals

12-12-2016, 02:59 PM	#29 (permalink)
tonythetiger A True Z Fanatic Join Date: Oct 2010 Location: SA, TX Posts: 1,035 Drives: 10 Nissan 370z PG MT Rep Power: 193	is there any benefit going to a "true coilover system"??? I would love to get rid of the spring midlinks on the rears. __________________ KWV3/Eibach/StillenG3/FI CBE+LTH+34Row/Uprev/SPL/SouthBendSS/QuaifeLSD/4.08/TommyKaira/Status/VolkZE40/AP Radical BBK/Seibon/Amuse/VIS/Sparco/WorksBellGTC/RJM/Nismo

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