Custom springs

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GeminiCoupe
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Custom springs

Post by GeminiCoupe » Thu Sep 15, 2005 12:29 pm

For Melbourne blokes that want to fix the rotten handling of their Piazza...

Centreline Suspension in Thomastown custom make springs to suit in your required spring rate or height for just under the $200 mark, plus around $150 for fitting including alignment. Contact info@centrelinesuspension.com.au or call 03 94692914

Browns Springs [also in Thomastown] can modify and reset your standard springs to your desired ride height. These guys are responsible for the suspension work on some of the V8 Privateers, from memory cost was $90 for a set. If you can remove your standard Piazza springs in one piece then this is the place to go.

Nick-
project - 76 Gemini Coupe G200z EFI Turbo
daily - 02 S15 Nissan 200SX GTspecS Turbo
wet-weather fun toy - TX 75 Gemini Sedan G200z

faffled
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Post by faffled » Fri Nov 04, 2005 9:31 am

u can get lowered king springs from qld for $100 from the wholesaler... n get couriered to where u need for 20..not too bad..

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Rodeobob
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Post by Rodeobob » Fri Nov 04, 2005 3:39 pm

faffled wrote:u can get lowered king springs from qld for $100 from the wholesaler... n get couriered to where u need for 20..not too bad..
So what the contact number??? No point posting up shit like this to contradict/undercut whats been said if you cant provide better contact info.

Bob
Too many Piazzas to little money.

Currently unemployed. Watch this space.

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Post by faffled » Fri Nov 04, 2005 11:23 pm

just find out the number its king springs in qlds.. yellow pages or the telephone directory..

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Post by faffled » Sat Nov 05, 2005 7:53 am

thats at trade price though

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speedracerles
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Post by speedracerles » Fri Mar 27, 2009 5:12 pm

Does any one have any leads on springs for the Jr? i need both front a rear or if you know of someone that has a full coil-over kit, thats what I really want but if they dont make them then the springs will have to do....
Isuzu impulse turbo, my weapon of choice!

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speedracerles
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Post by speedracerles » Tue May 17, 2011 3:00 pm

Im still wanting to lower my car a bit, and I would like to know what would be a good set up for that... I already own a set of kyb gas shocks but I want it to sit a bit lower then it is now.. Let me know...
Isuzu impulse turbo, my weapon of choice!

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eyecon
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Post by eyecon » Thu May 19, 2011 12:04 pm

Hi speedracerles, are you looking for something in Oz because you haven't been able to find anything in your area? KYB and King Springs also come to mind for custom springs in Oz.

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speedracerles
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Post by speedracerles » Mon May 23, 2011 10:50 am

Im in the US... across the pond...lol
But Im wanting to run a nice tier on the back and lower the car a bit. Like stagerd or something.
IDK yet. I see some of the pics on here and the look like they sit real nice so Thats all...lol

I have KYB's on the now but Im looking for lowering springs now...lol
Isuzu impulse turbo, my weapon of choice!

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archangel62
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Post by archangel62 » Sun Oct 07, 2012 3:28 am

Just bumping this thread with some more recent info.

I emailed King Springs, and they've told me they have no base specifications for a Piazza at all, so they can't make a spring for the car as such. Of course, they can make a fully custom spring, but that comes with a fairly substantial risk of being not quite right, and they'd need very in-depth information to do it.

I called the other mob, Centreline Suspension, and they said they haven't done a Piazza for 5-10 years, and that they'd have to see the car. Definitely still seem like good blokes if you're local, but useless for me interstate.

I called Industrial Springs here in Adelaide and they can do a fully custom set of springs at $324 per pair. Not cheap (at all), but they said that if I put them in and they weren't how I wanted them, they'd take them out again and reset them for me. Not bad at all when you think of it like that.

- Based on this thread -

- And this page -

- I'm thinking the standard Piazza spring rates could be anywhere between 3.8 and 5.2kg/mm front, divided by a ratio based on their placement on the arm (Geminis are around 66% effective I believe, just as a yardstick)... and rears in the general vicinity of 2.0-4.8kg/mm progressive (roughly), I'm starting to get a very very rough idea of a spring rate I'd like. I don't suppose anyone's cornerweighted a Piazza?? Haha.

I'm thinking around 6.5, maybe 7.0kg/mm front and 3.5-5.0kg/mm progressive rears, but I'd like to get an idea of the weight distribution first and crunch some numbers properly.

EDIT:
Ahaha, youuu beauty!

- Kerb weights front and rear -

Based on that, if the rear springrate averaged maybe 4.7kg/mm, the *effective* front springrate should be about 5.94kg/mm to match... so if the front springs were offering 66% effectiveness like a Gemini setup... that'd be more like 8.9kg/mm to match! Yeesh! That's damn heavy. Might round it down to 7.5...
Indigo - '76 TX Gemini sedan, G180W+T project,
Abigail - '81 TE sedan, white, G180W ITB project,
New Hotness - TG Gemini drift car, orange, 4ZE1+T
Tardis - 1986 Piazza 4ZC1-T, black, forged, 136rwkw @13psi
Coupe - TX coupe grip car, "do it later", G180W+twin carbs
Trevor aka Jimmy's Gem - Grandpa-spec TD
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eyecon
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Post by eyecon » Sun Oct 07, 2012 11:40 am

For turbo models (from 84.5 to 89.12):
Front springs: 4.5kg/mm, unsprung height=390.5mm, coil dia= 14mm, outside dia= 101.1mm, active coils= 8.29, total coils= 10.04
Rear: progressive 2.05-4.79kg/mm, unsprung height= 300mm, coil dia= 9.3-12mm, outside dia= 119mm, active coils= 5.5, total coils= 7

Keep in mind this data is off a Japanese spec sheet referred to as 'normal' turbo, which I believe is the same as our XE models. the Japs also had the 'sports' turbo, which is the XS model that we never got in AU. Anyway the 'sports' had different spring configurations again, as did the HBL, Irmscher etc.

Hope this helps, and I hope this right for our AU spec cars.

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Post by Bugle » Sun Oct 07, 2012 7:21 pm

Is it possible to make stiffer & lower springs that are the same extended length as originals? I have lowered springs but at full droop they can fall out so i'm going to have to sort that out before I get mine rego'd.

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eyecon
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Post by eyecon » Sun Oct 07, 2012 10:18 pm

I'm in the same boat as you bugle. The king springs that are on the car now are doing the same thing at full droop. Will need to change for rego, beside the fact that its 10mm too low. I'm thinking if King springs can reset the ride height it might just fix the other problem at the same time. I'll be calling them soon.

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Post by archangel62 » Mon Oct 08, 2012 10:16 am

Cheers Eyecon, yeah I wasn't sure which one to look at, that definitely helps.

Bugle - you can to an extent using progressive rates, ie a long soft bit up the top which binds on itself once the car's weight is on it. Imagine if you had a slinky duct taped to the bottom of a normal car spring. It can be super long, but as soon as you put it down it'll compress the slinky and you'll be left with just the heavy car spring... But this only works to a limited degree, costs more, and is harder to get right.

Guys - my advice - short stroke shocks. I'd foresee the rear as being the main issue, I doubt the front would stop being captive, and it definitely wouldn't fall out (this is based on Gemini experience however), but after tinkering with rears on my mate's Piazza I can definitely confirm this is an issue. Due to the angle of the shock absorbers it may get a bit tricky, I've been meaning to cut a pair of Commodore King Springs I've got lying around as an experiment - get the ride height right, check out the spring rate, and see how short the shock absorber stroke will have to be to keep them captive.
Indigo - '76 TX Gemini sedan, G180W+T project,
Abigail - '81 TE sedan, white, G180W ITB project,
New Hotness - TG Gemini drift car, orange, 4ZE1+T
Tardis - 1986 Piazza 4ZC1-T, black, forged, 136rwkw @13psi
Coupe - TX coupe grip car, "do it later", G180W+twin carbs
Trevor aka Jimmy's Gem - Grandpa-spec TD
BA Falcon - Tow car

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eyecon
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Post by eyecon » Mon Oct 08, 2012 3:06 pm

Yeah I rang Koni re shorter stroke shocks but they can't rebuild the existing koni shocks I have in there ATM. The Koni shocks they have for the Piazzas are apparently shorter than the original set. I think it will be cheaper to get new springs or reset the existing ones than to muck around with shorter stroke shocks.

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