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What to do with overly hard springs???


JXL
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Steve,

Yeah thats cool i'll see what happens.

Guys i got the new Eibach Race Kit on there 450 pound at the front and 300 at the back and damn what a difference 1/3 reduction makes. Its still a bit hard but more than bareable. I'm pretty damn happy with the change.

I can't go down any softer the guys said because it won't be in harmony with the Zeal shocks cause the shocks will be doing too much work with softer springs and get worn out.

jlnewton,

how is your change going. I'm thinking if I had any harder than what i've changed to it will be still a bumpy bumpy ride.

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I think it is about 200 pound for Aussie streets Japan is harder from what WA Suspension told me.

But I can assure you that 300 pound is ok for most Perth roads but if you come across potholes good bye skirts and bumper.

But then look at your shocks if you got damper adjustment that makes a big difference too.

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I can't go down any softer the guys said because it won't be in harmony with the Zeal shocks cause the shocks will be doing too much work with softer springs and get worn out.

Sorry JXl, but that simply isn't true, the rebound on the shock is there to dampen the recoil of the springs after they have been compressed (by a bump, pot hole, body roll etc). So if you use a softer spring then the shock has to "work easier" to control the springs rebound. So it is in fact the reverse, softer spring = less wear on the rebound valving of the shock.

There is an argument that says the compression valving on the shock may work a little harder since the spring is not holding the car up at such a high rate. But the effect is minimal noting that there are stabiliser bars and bump stops involved in also controlling the compression of the suspension.

Rebound damping is by far the most wearing part of the shock and is most often the part that fails first. Plus rebound damping is 60% to 70% stronger than bump valving in the first instantance, so it's work is a lot harder.

Hope that makes sense

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Thanks for the info gary. dp u know much about the dampner controls in the Tien HA series coilovers. Would it be worth the play around in it. Obviously i dont expect anythin special out of them...

Dean, I adjusted mine by taking the backs as hard as they would go, then going for a sprited drive, reducing a little, and repeat.

Once the rear seemed to be around the best spot (where oversteer seemed to settle to an acceptable level), I then adjusted the fronts - same process as above.

I have since tried adjusting the rears again, but ended up in about the same spot.

You can feel when you have gone too far, the damping adjustment (on mine anyways) does make an appreciable difference.

Pretty easy to do, I am not sure exactly how its done on a circuit car, but I would imagine apart from corner weights, the rest would be a similar process - to suit the car to the driver.

Perhaps SK can add???? SK?

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I dont think it will make alot of difference. I started from hardest, as I knew softest was way too soft, and I had 30 odd adjustment points, so didnt want to spend the whole day/weekend doing it, so I thought it would be quicker to start at the top and work down.

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SK - What spring rates do you recommend for a full time street car/part time track car? I've got the Whiteline Works kit (Handling kit, Subframe lock kit, bilsteins & whiteline springs) in my car, but because it's got progressive rate springs, it's got too much initial lean, and the car tends to push into the corners and makes the car feel a little unsettled...

The other thing is with regards to disabling the HICAS - How do you do it in the 33's?

Thanks for the info btw!

Cheers,

matt

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Hi Matt, we run 450 lbs in the front and 200 lbs in the rear on the GTST. We have Ohlins quad adjustable dampers, (hi and low speed bump and rebound). We use a 27 mm front stabiliser bar and 24 mm rear, both adjustable. Around the street we run the bars on soft, and on the track we add some anti roll, how much depends on the balance. Ditto the dampers, we run very little high speed bump on the road, medium low speed bump, and not much high speed rebound and lots of low speed rebound.

The understeer on corner entry may be caused by a lack of caster, how much caster have you got on it? What is the camber. front and rear?

The HICAS can also adds to the initial understeer, you will find when it is gone the car is much more settled. The cornering attitude will be more easily adjusted using the throttle as well.

To remove the HICAS on an R33, we just replace the rear rack with a billet alloy rack like this one

http://www.stillen.com/product_images/308550_t.jpg

I have seen others use a fabricated tube, threaded for the tie rods in the ends. But you have to make sure the threads are of good quality. When you unplug the HICAS wiring harness at the rear, the dash warning light will stay on, we simply remove the bulb.

Hope that helps

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Hi Steve, that site is Stillen USA and they only do the 300 ZX version. I saw one on a Targa Tas car, I liked the style so I took some photos. I then copied the basic design but with R32 dimensions and had our race team fabricator make one up. I tested it, works like a charm, fairly light and durable so now we fit them to the race team R32's, GTR and GTST.

I can only suggest that you print out the Stillen design and take an R33 rear rack to your local aluminium fabricator, they should be able to give you a quote.

Hope that helps

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im basically trying to find someone in melb to do this for me... my JICS are way too hard and road holdinh is pretty poor when going over bums on the road... my rear is perfect, so ill try get the rear bsprings from the coilovers put to the front and new rear ones... my only concern is can i get a spring from an aussie supplier like king, whitline, eibach or do i have to go to JIC...

doesanyone know who could set this up for me in melb?

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jlnewton,  

how is your change going. I'm thinking if I had any harder than what i've changed to it will be still a bumpy bumpy ride.

Mine will be going in Tuesday week, after the long weekend to get them fitted. Was going to do it myself but the first nut I came to undo ripped my socket apart so I propmtly gave up. I had to get the cusco Rear camber arm off my other car and had to wait for the cusco caster arm and whiteline front camber kit and pineapples to turn up, which they have now. Its going to Ron and Bruce of LEDA suspenson. Can't wait to see how it feels, I still have my reservations about the coilovers, but I am hoping they will be ok after getting them rebuilt and adding the new springs, but there seems to be sooo many negative comments about them I will have to wait and see. Next will be some decent sway bars, I will probably get the whiteline adj. ones.

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I think you may find that a spring that is perfect for the rear, may be very lacking on the front of a car, as the weight distribution of a car is not even.

Have you tried playing with the damper rates?

yeah i understand that the front and back is differnt....

now my JIC's are not damper adjustable only height thats my problem!!! there is nothing on the coilovers that can be adjusted other then height!

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Hi guys, Skyline springs are the same dimension front and rear so you can interchange them. I have swapped the rear springs to the front many times, it is particularly effective in a large number of brand name Japanese coil over kits. Many come with front spring rates like 12 kgs/mm (670 lbs/inch) and rears at 8 kgs/mm (450 lbs/inch).

In order to get decent traction we have found around 4/5 kgs/mm (220/280 lbs/inch) in the rear to be a good starting point. So swapping the 8 kgs/mm springs (450 lbs/inch) to the front maintains a reasonable balance. This means I only have to buy one pair of springs not 2, the money saved is better spent elsewhere. With adjustable radius rod bushes (for caster) and upper front suspension arm bushes (for camber) being the most favoured.

Hope that helps some more

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SK, thanks for the reply... The 450 & 200lb springs aren't progressive rate obviously? Any recommendations for who to get to make up a set?

As per the whiteline pack - I've got a 24mm front bar, and 22mm rear - which are both adjustable - but in the neutral positions atm.

Regarding castor/camber/toe, the car's due for a suspension re-alignment, so at the moment - it's all a little bit out of whack. What settings would you recommend? I believe with the whiteline kit, I'm able to dial in about 1.5deg of castor. I guess it's a case of as much castor as you can get yes?

With the HICAS - as a temporary solution, is it as simple as just disconnecting it, or does that have other side effects?

PS - What do you do for a strut brace in your RB30DET motored cars? I've had to take mine off because of the extra height.

Thanks for all the info - it's greatly appreciated!

Cheers,

matt

Hi Matt, we run 450 lbs in the front and 200 lbs in the rear on the GTST. We have Ohlins quad adjustable dampers, (hi and low speed bump and rebound). We use a 27 mm front stabiliser bar and 24 mm rear, both adjustable. Around the street we run the bars on soft, and on the track we add some anti roll, how much depends on the balance. Ditto the dampers, we run very little high speed bump on the road, medium low speed bump, and not much high speed rebound and lots of low speed rebound.

The understeer on corner entry may be caused by a lack of caster, how much caster have you got on it? What is the camber. front and rear?

The HICAS can also adds to the initial understeer, you will find when it is gone the car is much more settled. The cornering attitude will be more easily adjusted using the throttle as well.

To remove the HICAS on an R33, we just replace the rear rack with a billet alloy rack like this one

http://www.stillen.com/product_images/308550_t.jpg

I have seen others use a fabricated tube, threaded for the tie rods in the ends. But you have to make sure the threads are of good quality. When you unplug the HICAS wiring harness at the rear, the dash warning light will stay on, we simply remove the bulb.

Hope that helps

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