Tein Flex Z Spring Rates - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

slacker221 · 05-03-2018, 05:57 PM

Hello all!

A question for the suspension guru's...

Can you change the spring rate on the Tein Flex Z's?
If you do change the spring rates, how badly will it affect the ride quality?
Im not trying to go with 16K spring rates, more along the lines of 8k spring
rates, since the Flex Z comes with 6K spring rate.

I have tried searching and googling for an answer about this, but was unable to find and answer, or any info about changing the spring rates on the Tein Flex Z coilovers.

I recently purchased the Tein Flex Z because my factory shocks with RS-R lowering springs were shot and felt bouncy all over the place. I went with the Flex Z because I have always had great experiences with Tein products, and I got a killer deal on the Flex Z's brand new. I had read that they are a little softer than others, and that they dont go as low as other coilovers on the market. Unfortunately I have to have the coilovers in the front almost maxed out as low as they can go without changing preload in order to get the ride height im looking for, not slammed but also not much wheel gap. The problem is that the coilovers are too soft for my liking, and since they are soft, the tires will rub under hard cornering over small bumps. The car will also rub sometimes while very slowly pulling into parking lots, driveways, ect. I have already cut and clearanced alot of the car to make the wheels fit as I am widebody and running 255/50R16 tires, but still have some rubbing issues so I want to go with a higher spring rate.

I understand that Tein matched the shocks for the spring rate, but is it so accurate that changing the spring rate slightly will have some adverse affects?

I know people change out the spring rates on coil overs like BC Racing without too much adverse affect, is that because BC does not build the shock to match the spring rates like Tein does?

TIA

CSG Mike · 05-03-2018, 07:39 PM

You need monosport, not flex z. Best price =/= best for your application.

slacker221 · 05-04-2018, 11:07 AM

Quote:

Originally Posted by CSG Mike

You need monosport, not flex z. Best price =/= best for your application.

Mike, yes I know the Monosport would have been a better option, but unfortunately that was not in my budget at the time and I could no longer wait as the factory shocks were getting so bad that the car felt unsafe to drive as it would bounce around all over the road. The factory shocks had leaked a lot of fluid out and you can hear the air pockets inside of the shock when going over bumps or pulling into parking lots / driveways. I also will not have the budget anytime soon to upgrade to a set of Monosports, or the CSG spec coilovers.

Mike, I know you have alot of knowledge around the Tein coilovers, could you please shed some light on what affects changing the spring rates to 8K would have?

CSG Mike · 05-06-2018, 06:00 PM

I wouldn't recommend it. It'll ride like crap. Save up, and buy coilovers that are designed for the spring rates you wish to run.

Kaotic Lazagna · 05-06-2018, 08:10 PM

I think the Flex Z does a good job of eliminating wheel gap. I did have to adjust the rear pre-load to get as low as the front tho.

I'll only rub if I corner really hard, but then again, I'm running 245/40/17 tires on 17x9 wheels. I used to daily drive it just like that and only ever had issues driving on gravel (actually got stuck and had to be pulled out on 3 separate occasions).

Submarinesonce · 05-09-2018, 02:57 PM

raise the ride height some and use the flex z as they come?

slacker221 · 05-10-2018, 06:00 PM

Maybe my point is not being conveyed correctly.... I want to try and make the tein's a little stiffer. Not crazy stiff, something along the lines of a 8-10K spring.

I understand that I did not buy the best coilover for my purposes at the time.
I understand that I can raise the ride height to combat the rubbing issue.
I understand that Tein designed the damper to work best with that spring rate.
I understand that changing the spring rate on the Flex Z's is not the best option in the world.
I'm not trying to slam my car, just get wheel gap that I can only fit one or two fingers in.

I asked these questions on this forum and not facebook hoping to get some actual insight, not just "It'll ride like shit", or "raise your ride height". I was hoping to start a discussion so that myself, and others can learn more about setting up, or modifying an existing setup.

I know people change out the spring rates on the Flex Z's on other platforms like WRX, Miata, S2000 ect. After market companies sell springs for the Flex Z in different rates for other model cars, so I figured maybe we can change the spring rate on the Flex Z for the 86 as well. Maybe Tein valved the dampers on the Flex Z so precise for the 86 platform that other springs rates will perform very negatively on those dampers?

Most other coilovers for the 86 platform have options to change out the spring rates, Swift makes alot of spring rates for different coilovers. But I have not seen any for the Tein Flex Z.

I do plan on getting a more track oriented coilover in the future, but that is not going to be anytime soon. (Sorry im not a baller like some of you guys

) So I would like to try and make the Flex Z work better for my setup, instead of just living with the issues.

Also one other thing if anyone has some insight on, if I have the damper adjustment set to the stiffest setting, will it damage the damper over time, or will it be fine running them 24/7 on the stiffest setting? Im currently 2 clicks away from the stiffest setting because im worried I may damage the damper by daily driving them on the stiffest setting.

CSG Mike · 05-10-2018, 06:22 PM

Quote:

Originally Posted by slacker221

Maybe my point is not being conveyed correctly.... I want to try and make the tein's a little stiffer. Not crazy stiff, something along the lines of a 8-10K spring.

I understand that I did not buy the best coilover for my purposes at the time.
I understand that I can raise the ride height to combat the rubbing issue.
I understand that Tein designed the damper to work best with that spring rate.
I understand that changing the spring rate on the Flex Z's is not the best option in the world.
I'm not trying to slam my car, just get wheel gap that I can only fit one or two fingers in.

I asked these questions on this forum and not facebook hoping to get some actual insight, not just "It'll ride like shit", or "raise your ride height". I was hoping to start a discussion so that myself, and others can learn more about setting up, or modifying an existing setup.

I know people change out the spring rates on the Flex Z's on other platforms like WRX, Miata, S2000 ect. After market companies sell springs for the Flex Z in different rates for other model cars, so I figured maybe we can change the spring rate on the Flex Z for the 86 as well. Maybe Tein valved the dampers on the Flex Z so precise for the 86 platform that other springs rates will perform very negatively on those dampers?

Most other coilovers for the 86 platform have options to change out the spring rates, Swift makes alot of spring rates for different coilovers. But I have not seen any for the Tein Flex Z.

I do plan on getting a more track oriented coilover in the future, but that is not going to be anytime soon. (Sorry im not a baller like some of you guys

) So I would like to try and make the Flex Z work better for my setup, instead of just living with the issues.

Also one other thing if anyone has some insight on, if I have the damper adjustment set to the stiffest setting, will it damage the damper over time, or will it be fine running them 24/7 on the stiffest setting? Im currently 2 clicks away from the stiffest setting because im worried I may damage the damper by daily driving them on the stiffest setting.

You *can* put stiffer springs on your Flex Z.

It *will* make your car ride like crap.

You really should consider the opinions and feedback from those more experienced than you. Isn't that why you made this post?

Why do you want to street drive on the stiffest setting? Do you know what the damper adjustment actually does?

x808drifter · 05-10-2018, 06:27 PM

You have your answers.
1: Change the spring rate to reduce compression. (It will ride like shit)

2:Raise the car.

Or even better what you should have done from the beginning...

Buy right not twice.

What more do you want?
Your too low on too wide a tire.

There are only so many things that can be done.
If you can't even afford decent coils maybe you should have not gone wide body huh?

VIP BRZ · 05-10-2018, 06:44 PM

slacker221, adjust the preload and give it a shot, see how you think it feels

"rides like shit" is subjective

these guys are like Hyper track oriented...

Student Driver · 05-10-2018, 07:38 PM

Quote:

Originally Posted by VIP BRZ

slacker221, adjust the preload and give it a shot, see how you think it feels

"rides like shit" is subjective

these guys are like Hyper track oriented...

agreed, i had 10k springs on coilovers valved for 8k just cranked up the stiffness and, in my own opinion, they drove fine, i didnt have any major issues, drove on them like that for 2 years and never damaged my coilovers.. i have since bagged my car but i dont think you are really going to hurt anything by increasing the spring rate a little bit and stiffening the dampening up. you could try to find a shop that can revalve the flex's you have to be setup proper for the increased spring rate as well. (not sure if you can do that with these coilovers or not, i just know it was an option for mine)

*by no means am i a professional, just my two cents from my own personal experience

churchx · 05-10-2018, 08:30 PM

Student Driver: Flex A can be revalved. Z was designed with unrevalveable/unserviseable damper inserts to get costs down.

As for OP ..
My first choice would be not drop stupid low
Second choice would be (if that gap THAT much bothers) to reduce it via other means, eg. fender extensions like this, this, this or this for suspension to still be functional as intended instead of sacrificing function for sake of arguable form
My third choice would be sell off Zs and buy instead something that was designed for what OP wants, with that low drop and that stiff spring rates.

CSG Mike · 05-10-2018, 09:29 PM

You know, OP could also just get better offset wheels... he is widebody after all.

Kinda funny cuz he runs 255 on a widebody, and I run 265 on a stock body, and I have zero rubbing issues. And I run 6k springs on my CSG Flex A.

churchx · 05-11-2018, 02:44 AM

CSG Mike: maybe alignment/camber (which i doubt you running stock) plays role in clearance? Also width aside, his wheels are also of high sidewall and R16. +5.7%/1.4" diameter. You probably have more reasonable sidewall profile to go along the wider width.
So it looks like "meaty tires" in addition to flushness/stance (who knows, possibly also stretch, depending on wheel width) from "looks trends" are prioritized .. i wonder why performance/comfort matters at all for him.

05-03-2018, 05:57 PM	#1
slacker221 Member Join Date: Dec 2015 Drives: 2013 BRZ Premium Location: Thousand Oaks, CA Posts: 26 Thanks: 16 Thanked 17 Times in 9 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	Tein Flex Z Spring Rates Hello all! A question for the suspension guru's... Can you change the spring rate on the Tein Flex Z's? If you do change the spring rates, how badly will it affect the ride quality? Im not trying to go with 16K spring rates, more along the lines of 8k spring rates, since the Flex Z comes with 6K spring rate. I have tried searching and googling for an answer about this, but was unable to find and answer, or any info about changing the spring rates on the Tein Flex Z coilovers. I recently purchased the Tein Flex Z because my factory shocks with RS-R lowering springs were shot and felt bouncy all over the place. I went with the Flex Z because I have always had great experiences with Tein products, and I got a killer deal on the Flex Z's brand new. I had read that they are a little softer than others, and that they dont go as low as other coilovers on the market. Unfortunately I have to have the coilovers in the front almost maxed out as low as they can go without changing preload in order to get the ride height im looking for, not slammed but also not much wheel gap. The problem is that the coilovers are too soft for my liking, and since they are soft, the tires will rub under hard cornering over small bumps. The car will also rub sometimes while very slowly pulling into parking lots, driveways, ect. I have already cut and clearanced alot of the car to make the wheels fit as I am widebody and running 255/50R16 tires, but still have some rubbing issues so I want to go with a higher spring rate. I understand that Tein matched the shocks for the spring rate, but is it so accurate that changing the spring rate slightly will have some adverse affects? I know people change out the spring rates on coil overs like BC Racing without too much adverse affect, is that because BC does not build the shock to match the spring rates like Tein does? TIA

05-09-2018, 02:57 PM	#6
Submarinesonce Senior Member Join Date: Mar 2017 Drives: Frs Location: Florida Posts: 130 Thanks: 21 Thanked 81 Times in 43 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	raise the ride height some and use the flex z as they come? __________________ JDL UEL Turbo GT2860RS, AP Racing BBK, Verus Splitter/diffuser/canards, Sard rep carbon wing, TFF bash bar, HKS hi power, Tein Flex A, Hotchkiss FSB, Radium MCB, Konig Hypergram 17x8, FS Indy 500, 6k HID, Whiteline trans bushing insert, Verus AOS, grimmspeed strut brace, Racerx oil cooler w/ setrab 619, ES steering rack bushings, Whiteline subframe bushings, Toms tails, STi mirror caps, IRP shifter, TRD Steering wheel

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05-03-2018, 07:39 PM	#2
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,918 Thanked 14,175 Times in 6,834 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	You need monosport, not flex z. Best price =/= best for your application.

05-06-2018, 06:00 PM	#4
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,918 Thanked 14,175 Times in 6,834 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	I wouldn't recommend it. It'll ride like crap. Save up, and buy coilovers that are designed for the spring rates you wish to run.

05-06-2018, 08:10 PM	#5
Kaotic Lazagna Senior Member Join Date: Apr 2014 Drives: GR Corolla Location: Lathrop, CA Posts: 4,919 Thanks: 3,082 Thanked 3,014 Times in 1,856 Posts Mentioned: 40 Post(s) Tagged: 2 Thread(s)	I think the Flex Z does a good job of eliminating wheel gap. I did have to adjust the rear pre-load to get as low as the front tho. I'll only rub if I corner really hard, but then again, I'm running 245/40/17 tires on 17x9 wheels. I used to daily drive it just like that and only ever had issues driving on gravel (actually got stuck and had to be pulled out on 3 separate occasions).

05-10-2018, 06:00 PM	#7
slacker221 Member Join Date: Dec 2015 Drives: 2013 BRZ Premium Location: Thousand Oaks, CA Posts: 26 Thanks: 16 Thanked 17 Times in 9 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	Maybe my point is not being conveyed correctly.... I want to try and make the tein's a little stiffer. Not crazy stiff, something along the lines of a 8-10K spring. I understand that I did not buy the best coilover for my purposes at the time. I understand that I can raise the ride height to combat the rubbing issue. I understand that Tein designed the damper to work best with that spring rate. I understand that changing the spring rate on the Flex Z's is not the best option in the world. I'm not trying to slam my car, just get wheel gap that I can only fit one or two fingers in. I asked these questions on this forum and not facebook hoping to get some actual insight, not just "It'll ride like shit", or "raise your ride height". I was hoping to start a discussion so that myself, and others can learn more about setting up, or modifying an existing setup. I know people change out the spring rates on the Flex Z's on other platforms like WRX, Miata, S2000 ect. After market companies sell springs for the Flex Z in different rates for other model cars, so I figured maybe we can change the spring rate on the Flex Z for the 86 as well. Maybe Tein valved the dampers on the Flex Z so precise for the 86 platform that other springs rates will perform very negatively on those dampers? Most other coilovers for the 86 platform have options to change out the spring rates, Swift makes alot of spring rates for different coilovers. But I have not seen any for the Tein Flex Z. I do plan on getting a more track oriented coilover in the future, but that is not going to be anytime soon. (Sorry im not a baller like some of you guys ) So I would like to try and make the Flex Z work better for my setup, instead of just living with the issues. Also one other thing if anyone has some insight on, if I have the damper adjustment set to the stiffest setting, will it damage the damper over time, or will it be fine running them 24/7 on the stiffest setting? Im currently 2 clicks away from the stiffest setting because im worried I may damage the damper by daily driving them on the stiffest setting.

05-10-2018, 06:27 PM	#9
x808drifter LMGTFY Join Date: Mar 2016 Drives: 13 FRS, 91 Miata Location: Lava Town, HI Posts: 2,776 Thanks: 5,561 Thanked 3,646 Times in 1,625 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	You have your answers. 1: Change the spring rate to reduce compression. (It will ride like shit) 2:Raise the car. Or even better what you should have done from the beginning... Buy right not twice. What more do you want? Your too low on too wide a tire. There are only so many things that can be done. If you can't even afford decent coils maybe you should have not gone wide body huh?

05-10-2018, 06:44 PM	#10
VIP BRZ Senior Member Join Date: Mar 2016 Drives: 2014 Subaru BRZ Location: CA - San Fernando Valley Posts: 492 Thanks: 242 Thanked 333 Times in 179 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	slacker221, adjust the preload and give it a shot, see how you think it feels "rides like shit" is subjective these guys are like Hyper track oriented...

05-10-2018, 08:30 PM	#12
churchx Senior Member Join Date: Mar 2015 Drives: 2014 GT86 Location: Latvia, Riga Posts: 4,333 Thanks: 696 Thanked 2,085 Times in 1,436 Posts Mentioned: 53 Post(s) Tagged: 1 Thread(s)	Student Driver: Flex A can be revalved. Z was designed with unrevalveable/unserviseable damper inserts to get costs down. As for OP .. My first choice would be not drop stupid low Second choice would be (if that gap THAT much bothers) to reduce it via other means, eg. fender extensions like this, this, this or this for suspension to still be functional as intended instead of sacrificing function for sake of arguable form My third choice would be sell off Zs and buy instead something that was designed for what OP wants, with that low drop and that stiff spring rates.

05-10-2018, 09:29 PM	#13
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,918 Thanked 14,175 Times in 6,834 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	You know, OP could also just get better offset wheels... he is widebody after all. Kinda funny cuz he runs 255 on a widebody, and I run 265 on a stock body, and I have zero rubbing issues. And I run 6k springs on my CSG Flex A.

05-11-2018, 02:44 AM	#14
churchx Senior Member Join Date: Mar 2015 Drives: 2014 GT86 Location: Latvia, Riga Posts: 4,333 Thanks: 696 Thanked 2,085 Times in 1,436 Posts Mentioned: 53 Post(s) Tagged: 1 Thread(s)	CSG Mike: maybe alignment/camber (which i doubt you running stock) plays role in clearance? Also width aside, his wheels are also of high sidewall and R16. +5.7%/1.4" diameter. You probably have more reasonable sidewall profile to go along the wider width. So it looks like "meaty tires" in addition to flushness/stance (who knows, possibly also stretch, depending on wheel width) from "looks trends" are prioritized .. i wonder why performance/comfort matters at all for him.

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