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Rear springs.

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Android 360
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Post by Android 360 »

i definately have plans of chassis strengthening in the future, i haven't finished setting up my garage yet, but when that's complete i'll have a bit of fun there :)

I know springs aren't the be all and end all, but the ones im getting made will without question be much better than the super soft factory springs i currently have in place.

i'll be going from an unpredictable rear end that seems to have a mind of it's own, to a rear end that follows the car. It will be a nice change.
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Callumgw
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Post by Callumgw »

you may be going to a rear end that does have a mind of it's own....

from my experience, when the back was to stiff you get oversteer. Under brakes was the worst, but lift off oversteer is more dangerous 'because the speeds are higher.

Timmzy had fun with rear tyre pressures being too high, as well.

C
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tassuperkart
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Time For Some Cold Water Pouring.

Post by tassuperkart »

Android 360 wrote:.......... but the ones im getting made will without question be much better than the super soft factory springs i currently have in place.

i'll be going from an unpredictable rear end that seems to have a mind of it's own, to a rear end that follows the car. It will be a nice change.
You certain about that?

Just because springs seem "super soft" does not mean they dont work.

Whats your rear end alignment like?.................. had it done?
Those lightweight pressed steel lower arms awith a stub axle welded in are not particularly tough and bend easily after hard work.

If you have a funky wheel alignment on the rear then you car will handle like a turd.

Moving along, going to springs super hard for such a lightweight car might keep the car level and ride hard enough to remove your fillings over matchsticks but can and very often REDUCE grip generated.
The harder springs will augment the swaybars to buggery as well FURTHER reducing chassis grip.

Dont forget that the dampening rates of whatever shocks you are going to use will be so far away from correct for such a hard spring.
Furthermore, the heavier the spring, the LIGHTER the compression damping and heavier the extension damping to compensate.

Its a double edged sword and the combination of too hard spring, too hard compression damping and too light extension damping FURTHER reduces the ability of the suspension to keep the TYRES ON THE ROAD which is how grip is generated.

The issuse of varying grip over uneven road surfaces is still FURTHER magnified.

Dampening rates are matched to the SPRING, not the chassis. this is why spring and shock combinations are dynoed as a pair and the spring does NOT come off that shock.
Any dampening changes are incremental at best and anything substantial would require the shock/spring to be dynoed again.

Adjustable shocks for road cars are solely designed to make you feel good, have bragging rights and to be able to adjust the ride quality.


Youll possibly end up not generating any chassis grip, or very little at all and relying solely on tyre grip alone and you end up with a car that seems to grip well a bit beyond what it might usually begin to move around and then let go violently and unpredictably.

This is especially so on varying and uneven surfaces like PUBLIC ROADS!!!!!

Be very wary of making such major spring rate changes without supporting dampening/other major changes on a road car.

I can almost guarantee your car will sit like a rock but actually loose grip much earlier and much more violently than a stock ET.

Have fun

L8tr
E
Last edited by tassuperkart on Fri May 15, 2009 5:35 pm, edited 1 time in total.
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15exa
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Post by 15exa »

let me know when u get these in joel, wouldnt mind coming to have a look, wanna get something adjustable to put in my arse :shock:
boost_truck_racer
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Post by boost_truck_racer »

Ive increased my spring rate 55% from standard

i when to a sprint at QR and found it was nice under brakes the only corner the was crap was the hair pin (partly due to old semis on the rear that i couldnt gat enough heat into) I think my rear rate and rear swaybar is causing some of the oversteer issue

probaly 30% increase would get you a solid setup for street and track


so best would be to reduce the front rate to and increase the rear a bit track days are the best way to get a real feel for what is happening


brendan
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tassuperkart
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Post by tassuperkart »

Thing is it might feel nice and solid. There will be no dispute there. Harder the better often in a straight line.
But, all due respect, seat of the pants testing/impressions is unreliable at best and useless at worst case. They are impressions.

The only way to determine if such major changes to spring rates was positive is to log the car speeds around individual corners.
Or at very least a stopwatch for overall times.

And without actually changing the springs mid-test, youll never know if they made any difference to speed.

You can have a car that is sweet and stable to drive everywhere and its just not fast and vice versa, it can be an absolute pig to drive BUT BE BLINDINGLY FAST!
We wont touch further on being slow AND a pig!!!

Of course, the secret is to have it fast AND sweet to drive but that is the circuit racers holy grail. Rarely achieved.

None of my bikes, superkarts or Formula Vees were much fun to drive really quick. Well except for the current Vee. Which is a delight to drive fast....but its not really fast tho in comparison to others!!!!
The formula E superkart was frightening...................

Android is also behind the eight-ball wanting to punt a vert hard..........
Callum makes the point clearly about chassis flex and nothing short of fully caging the vert would tame the thing down when pushed hard.
N12's are enough of a horror (see Timmzy's post) let alone removing the only substantial bit of strengthening its ever had!!!!

Android, you are indeed a brave man! *tassuperkart salutes*!!!!!

Id suggest you upgrade to the latest Android 9000. Come stock with balls of steel!
Your going to need 'em!!!!
LMAO

L8tr
E
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Timmzy
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Post by Timmzy »

^^^ Brendan! Nice one.

I found THE SAME THING!! With king springs (whatever they are) a second rear swaybar, and koni reds in the back. If you went into a sharp corner too quickly it would oversteer like a RWD car. It was amazing.

I have got onto a group buy/purchase of some coilover tube/thread/platforms/nuts and spanners for $200 thru the toyota celica forums. My intention is to setup coilover in the rear spring position. THus getting rid of the standard shock so that I can utilise 7 inch wheels. 2 birds one stone......The only challenge at the moment is finding a motorbike shocker or similar that is the correct size.

Ill let you know how it goes.

THats the real solution for the rear. Plus stopping those trailing arms from flexing.

Darren.
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tassuperkart
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Post by tassuperkart »

That would make plenty of sense.
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Callumgw
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Post by Callumgw »

Timmzy wrote: I have got onto a group buy/purchase of some coilover tube/thread/platforms/nuts and spanners for $200 thru the toyota celica forums.
You bastard, didn't tell the rest of us did ya! :lol:

The rear has NO adjustment in it, so a wheel alignment might tell you that you have a problem, but you can't fix it, unless you do this:

http://forum.n12turbo.com/viewtopic.php?t=4627

(no haven't got further with this yet, get the front brakes done first, which is after I make the beds, and the tool board and the....)

Matching springs and shock is critical like E said.

Seat of the pants is a good start, but lap times count, not your arse!

C
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Timmzy
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Caboose

Post by Timmzy »

Haha Callum, nice one. Think of it like this "You have to be 100% behind someone to stab them in the back"

But seriously:

I had 4hours to give and answer, and a requested spring rate (no excuse) and the guy who organised them bought 3 sets to make up a total of 12 sets -- Thats how fast this order was filled. RRP was $359 + postage. Group buy of 12 sets was $200 (!) plus postage. I COULD NOT SAY NO!! :)

So if a certain N12 owner wanted a set I might be able to pry them out of my mates possesion. But bear in mind, I don't know whether this will actually work yet Disclaimer :twisted: but I have to try something with this rear end. The caboose is loose so to speak. And if it doesn't work ill use this kit to build myself some front coilovers, and that will be great.

Alternatively if I can get 10 people off this site to sign up and pay, I'd do it. But history says that this never works -- And I have been a culprit in the past :oops:

These toyota celica boys were keen as, because they - like us - don't have many alternatives for performance suspension. And the majority of their cars are track whores. Whereas the majority of our cars are traffic light racers - thus coilovers will take a back step to other things

So ill start another project when these things arrive in a week or so -- ill get some pics up when they do. And I PROMISE to do a proper documentation of this project, as my last efforts were so poor. But the aim will be to install an adjustable coilover/damper setup in the original spring position, thus negating the requirement for that pesky standard shocker. Resulting in being able to use some 15 by 7inch wheels that I have my eye on.

Catcha. sorry to highjack...again

darren.
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boost_truck_racer
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Post by boost_truck_racer »

Evan your right

i lapped 1.5 seconds faster with my rear tyre pressures down 4psi
but the car didnt feel good

next time i will be taking a single sway bar give that a go

it would be nice to get another set of rear springs to try
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Post by gopulsar »

well guys im just a yardy and all ya lingo (while not knockin it at all) just goes over my head.. but i aint gunna race me exa either.. mine was stock when i got it and was real scary, a few near misses and ripped the springs out cut 1 full coil off each spring fitted new shocks, bought 2nd hand 15in mags (cheap) with new rubber 215's, needed 3mm spacers on the back and im in love!!
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Post by tassuperkart »

boost_truck_racer wrote:Evan your right

i lapped 1.5 seconds faster with my rear tyre pressures down 4psi
but the car didnt feel good

next time i will be taking a single sway bar give that a go

it would be nice to get another set of rear springs to try
Dont you just luuuurve testing/R & D!!!!!!!!!!!
LOL
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Android 360
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Re: Caboose

Post by Android 360 »

Timmzy wrote:Haha Callum, nice one. Think of it like this "You have to be 100% behind someone to stab them in the back"

But seriously:

I had 4hours to give and answer, and a requested spring rate (no excuse) and the guy who organised them bought 3 sets to make up a total of 12 sets -- Thats how fast this order was filled. RRP was $359 + postage. Group buy of 12 sets was $200 (!) plus postage. I COULD NOT SAY NO!! :)

So if a certain N12 owner wanted a set I might be able to pry them out of my mates possesion. But bear in mind, I don't know whether this will actually work yet Disclaimer :twisted: but I have to try something with this rear end. The caboose is loose so to speak. And if it doesn't work ill use this kit to build myself some front coilovers, and that will be great.

Alternatively if I can get 10 people off this site to sign up and pay, I'd do it. But history says that this never works -- And I have been a culprit in the past :oops:

These toyota celica boys were keen as, because they - like us - don't have many alternatives for performance suspension. And the majority of their cars are track whores. Whereas the majority of our cars are traffic light racers - thus coilovers will take a back step to other things

So ill start another project when these things arrive in a week or so -- ill get some pics up when they do. And I PROMISE to do a proper documentation of this project, as my last efforts were so poor. But the aim will be to install an adjustable coilover/damper setup in the original spring position, thus negating the requirement for that pesky standard shocker. Resulting in being able to use some 15 by 7inch wheels that I have my eye on.

Catcha. sorry to highjack...again

darren.
i may wait until you've finished yours - ideally, i would like the rears to be adjustable too...

there isn't much room to install coilovers in the rear but i have noticed that there is about 50mm between the chassis rail and the inner guard....
if you could chop the inner guard out and weld some new steel in place closer to the chassis rail then there would be HEAPS of room...
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Android 360
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Post by Android 360 »

I'm curious, what spring rate would you guys actually recommend in order to match the front coilovers?
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