Tein flex coilovers too soft???

[BAT-man]

Like i mentioned, total length doesnt make much of a difference, the car being lowered, but the shock travel already being maximized...i too, however, did not like Teins suggested height settings, so i raised it approx. 1/2" from there. I would like to post a picture, but it doesn't seem my low post count will allow me to do so.

[Shagrington]

It isn't your post count, only club members can add photos directly to posts, as a guest you can link to photos hosted by a third party - there is a guide here https://www.rx8ownersclub.co.uk/forum/v ... =2&t=35968

[PeteH]

They are shorter (like all coilovers) because they have less total travel, but the spring rate is higher to compensate. Whether the ratio of total travel and spring rate is to your liking, that's up to you and the type of roads you drive.

You won't find any coilover with as long a travel, and as soft a spring, as the stock set up.

[DB2626983C]

Thanks for the info Pete. It's good to understand the physics involved in the design.

[BAT-man]

So I presume nobody has found the part numbers for replacing the rear TEIN Flex Z springs on the rx8? 7kg would be great.

[PeteH]

If anyone is serious about wanting to change their Tein springs for stiffer items, pm me. There's a lot to consider, but Tein make a huge range of stuff, and almost anything is possible.

Word of warning. Setting up suspension properly isn't cheap....

[Marda]

Hello,

it has been a while, but after driving for further 10 000 miles on "stock" tein flex z, i am still in decision to go for a stiffer spring rate on rear shocks as well as on front shocks(to compensate), cause I cannot stand that bottoming on rear any more.

I just send inquiry to TEIN UK and ask for the prices:
Rear 7kgf springs, and
Front 10kgf springs to fit my flex z shocks.

Still think that Tein miscalculated spring rates in flex z, especially for street use.

Any new thoughts about this issue, anyone...

[13Black]

10KG front & 7KG rear is Tein Mono Sport territory, just as a heads up. It's probably as stiff as I'd ever want on a road car.

[BAT-man]

Flex is 7 and 5. Why not go 9 and 7? Why go 10 up front?
Also please let us know the spring part numbers and pricing, i am really considering the same route here in the US, as well as a few others who have the same exact issue.

[Marda]

hi,
Tein uk send me specs and prices.
Im also thinking to go for 9/7kgf.

Here are part numbers for 9kgf front and 7kgf rear:

SL090-01200 STD SP 65-9.0-200 £84.00
ST070-01175 TP SP 70/90-7.0-175 £84.00

Rear spring is 20mm longer but we have that amount of space left for adjustment.

Now preload on my rear springs (5kgf) is 0,and I can rotate spring freely while in place but it is still "knocking". Before I make the final decision to buy stiffer springs I am thinking to try to do negative preload (to make a free gap of about 10-15 mm).
Dont know if this is wise / dangerous.

[13Black]

It shouldn't cause any positive effect that I can think of, the car will just droop down further on the damper stroke, before being supported by the spring... so you'll probably hit the bump stop earlier. There may be a risk of the spring unseating going over bumps as well. So probably not exactly ideal given no added benefit for your added troubles.

Where are you on the damping setting?

[PeteH]

It's a bad idea to have a gap at full rebound. It will make an awful noise, and the spring could end up anywhere. You shouldn't need a gap when you have height adjustable units.

Also, if you run stiff springs you will probably end up with quite a bouncy car, because the units won't have enough damping for those spring rates.

You'd be much better off buying better coil overs.

[warpc0il]

zero or negative preload is not the way to go.

I've worked on two 8s where people had done this, unintentionally, as they didn't understand the difference between pre-load and ride-height adjustments.

Anyway, the ride and handling were awful and they made noises like someone banging bin-lids together.

One of the cars was sitting at an angle because the spring wouldn't stay located in the seat, on one side.

Altogether bad news.

[ChrisHolmes]

Just for reference the Meister Coil Overs I have fitted have 6kg rear and 8kg front springs and Ranjan commented at Mallory that I need stiffer springs as the car was "wallowing" though the corners, not that my bum data logger could feel it!!!!

[13Black]

What do you have your dampers set to on the Meisters Chris when out on track out of interest?

[ChrisHolmes]

"Wallowing" could just mean that the rebound damping needs to be tweaked a touch


Sent from my SM-G800F using Tapatalk

[ChrisHolmes]

What do you have your dampers set to on the Meisters Chris when out on track out of interest?

I take a very technical approach to my damper settings Nick......full hard all round!

[Conan]

It’s not separate bump and rebound on Chris’s units
Which is a very good thing
I don’t know what this has to do with the Tein suspension though

[ChrisHolmes]

It certainly is Pete as that's one less thing to have to set!
It's comparative Spring rate information Pete.

[V8 Power]

See below some figures I compiled some time ago.
Maybe of use?

RX8 Suspesion Spring Rates
Lbs/Inch F/R N/mm F/R
156 113 OEM 27 20
200 148 Bilstein B12 35 26
257 137 Koni Sport 45 24
336 224 Tein Street Basis 60 40
392 280 Tein Flex 70 50
450 280 KW 80 50
456 285 Ohlins R&T 80 50
456 343 MeisterR ZetaCRD+ 80 60
560 392 Tein Mono Sport 98 69
571 400 BC ER 100 70
571 514 HSD MonoPro 100 90
732 457 Ohlins Full Race 130 80

Springs Only
Lbs Inch F/R N/mm F/R
187 136 Eibach 33 24
187 136 Racing Beat 33 24
207 145 Tein STech 36 25

[BAT-man]

Sir, you are the MAN! I was trying to get this exact info from a forum member who said to contact him directly, and got zilch. This is all we need to contact Tein with, and get the ball rolling. So it looks like the rear springs needs to be tapered from 70 to 90mm and be 175mm long, while the fronts are 65mm inside diameter and 200mm long. Sounds about right. Thanks again!

Also to an above poster - 0 preload will not cause any issues, as far as clunking goes. The spring is still in full contact with the perch at maximum rebound, albeit its not compressed, just snug. Its the best possible way to use the default Flex Z setup.

hi,
Tein uk send me specs and prices.
Im also thinking to go for 9/7kgf.

Here are part numbers for 9kgf front and 7kgf rear:

SL090-01200 STD SP 65-9.0-200 £84.00
ST070-01175 TP SP 70/90-7.0-175 £84.00

Rear spring is 20mm longer but we have that amount of space left for adjustment.

Now preload on my rear springs (5kgf) is 0,and I can rotate spring freely while in place but it is still "knocking". Before I make the final decision to buy stiffer springs I am thinking to try to do negative preload (to make a free gap of about 10-15 mm).
Dont know if this is wise / dangerous.

[warpc0il]

The spring lengths have to be matched to the design of the damper unit and it's seat mounts.

The correct length for one system may be totally incorrect for another.

For example, while the Mazda Sports Suspension on both the S1 and R3 provide an almost identical ride height, the actual spring lengths are very different.

Putting S1 "lowering springs" on an R3 gives a 4x4 stance.

Sent from my SM-G800F using Tapatalk

[Marda]

#13black
Im driving Teins with EDFC Pro so I have damping force from 16-0.
In all modes (even most softer or most stiffer) the rear coils slap at bumps.

#BAT-man
Im glad that I helped you with this info. What will you ask Tein? The same springs kgf F9/R7 or maybe other specs?

Im still in consider will the 2kgf higher spring be ok for that dampers...will they affect ride comfort, quality or handling too much.

[PeteH]

(Warpc0il)

And if you order a 5kg and a 10kg spring, both 200mm long, you will end up with radically different ride heights.

Spring design and specification is very involved, and there are no simple answers. If you don't know how to do it, take it to someone who does.

[BAT-man]

#13black
Im driving Teins with EDFC Pro so I have damping force from 16-0.
In all modes (even most softer or most stiffer) the rear coils slap at bumps.

#BAT-man
Im glad that I helped you with this info. What will you ask Tein? The same springs kgf F9/R7 or maybe other specs?

Im still in consider will the 2kgf higher spring be ok for that dampers...will they affect ride comfort, quality or handling too much.

Yes, I will be ordering 9/7, I think the may be ok for the dampers. The alternative would have bee 8/6, but if that were to bottom out as well, it would be money wasted, so I'm going with the maximum acceptable stiffness on the springs.

warpc0il - Yes, different spring length are required for different stiffnesses, but luckily we have height adjustment separate from preload, and can adjust accordingly.

FYI - confirming the spring choice, these are the exact same springs that the TEIN Flex used to be shipped with:
https://www.nolimitmotorsport.com/prod/DSM58-6USS4