[ant]

G'day all,

I'm posting this as a bit of an FYI for people really. When i came to the GS game i came from an S-series background (S13 Silvias, 180s).

In these Nissans i tended to run 'standard' Japanese coilover spring rates e.g. F: 8k/R: 6k. Due to the Nissan suspension design (McPherson strut) these rates were pretty solid. I really felt with the Lexus being a luxury vehicle i didnt want to make it 'too hard'.

What i didn't really consider though was that the Toyotas use a double wishbone suspension system, which changes the way the suspension reacts and i have found it tends to give/compress a lot more. What is hard for a Nissan is not necessarilly hard for a Toyota (this is of course ignoring also the weight differences etc that may be present).

A constant point that comes up here too is the front Upper Control Arms, which of course bang away on the strut tower if you lower beyond a certain point on GS's. As such stiffer suspension can prevent you hitting the arms as often as well.

When i first was coilover shopping i was worried about 'too hard', so i went for Insurance Group coilovers. they're damper adjustable but dont go super low and also only have F: 10k/R: 6k springs. However, driving with these i just found much too soft when riding low. To compensate, i turned the damping right up Hard, and increased the pre-load on the springs (wound the perches under the springs up). Despite having 'soft' springs, this resulted in a harsh, crashy ride. It would 'hit' bumps rather than compressing, and overall didnt feel right.

Next i decided to step up to F: 12k/R: 8k. Again, these proved too soft and i still had to add reasonable amounts of preload and damping to try to stiffen the ride. As such the car rode slightly better but about the same as before.

Heartened slightly, i thought i would stop messing about and went for F: 18k/R: 12k. I also proceeded to lower the car all around by around 1/4" more.

This resulted in a ride height on 19" rims w/ 35 series tyres, of ~62.5cm from top of guard to ground up front, and 61.5cm up back (camber around -2.5 to -3ish). Despite this lower ride height and basically twice as hard springs as the coilovers originally came with, the ride quality is greatly improved. The car is less crashy over bumps and generally feels more solid but smooth on the road. Of course the UCAs do still bang sometimes, but no more than they did before with 10/6 or 12/8, and im now a fair bit lower too.

I'll throw some pics of my new ride height up later tonight, but basically my moral is if you do intend to go low you really need to go hard on the spring rates. don't be afraid to go hard on the springs and play with the damping, because it is much better to do it that way than to try to overcompensate for soft springs with damping & preload (in my experience).

Kaydee

good write up! did not know or was aware of this...

looking forward for the pictures

PHML

iTrader: (33)

wow....thats pretty stiff.

Ay-nako

iTrader: (25)

+1 ^, id like to see some pics or a vid of you rolling to see how hard!

JeffTsai

iTrader: (1)

I run 16k/12k on my car and it's perfectly fine. It's the Tein FLEX standard spring rate for the JZS161. I'm due for a re-tuning of my suspension soon though. I doesn't feel so stable at high speeds of 150-160+mph right now (On a race track of course )

[ant], what coilovers did you switch to every time? Or did you keep the same shocks and just keep ordering different springs for them? I'm thinking about changing mine out to 20k/14k pretty soon because the current spring rate is still too soft for my tastes lol.

[ant]

^ I didnt think Tein were that hard? looking at Nengun is says they're 10k / 9k?

But companies like Megan, Stance, JIC etc tend to have about 14/10. I also have a habit of looking at japanese companies such as Final Konnexion, Tanabe, Buddy Club etc in VIP Car / VIP Style magazines and notice theyre all something like 10-14 Front and 8-12 rear.

I went a bit harder than any off-shelf coilovers, but i did this because if you read the specs on the low Japanese cars you will notice those guys pretty much run 20k+ front and rear.

Jeff - i did just keep the same Insurance Group dampers each time. I upgraded springs with HSD springs as theyre available locally for $100AUD/pair. I know what you mean, me on 18/12 now just feels "right". I wouldnt say it feels super hard by any stretch. I am looking to upgrade again toward the end of the year and probably go for something like K-Break coilovers which can be specc'ed to have very hard springs (i'd probably go a bit harder as you suggested, or maybe 20k /16k)

These are my quick pics from my mobile. Not aligned yet, but probably wont change that much. I was at -2.5 camber all round before, probably closer to -3 now. Front is sunken alot but unfortunately guards are just rolled and any more offset at this height would scrub like mad. I had to raise the front a bit over what i first set it to cause the UCAs banged about 20 times each way on my way to work! lol

sorry for the last one couldnt get the whole side of the car in as there was another car there so i couldtn back up anymore! haha

SYNSEI

Great info! Thank you for sharing.

SorrGwa

iTrader: (1)

tein ss, 14F/12R, and yeah i do find them a tad soft.

i had an eibach sportline/koni setup before in my honda. dont remember the spring rate on those, but that combo seemed much stiffer than the GS.

but then, the GS feels like a boat around corners. =/