New performance strurts

[Alphabettispaghetti]

Its funny how geometry affects everything. My 750kg kit car had 650lb front springs and had great ride quality.

 

[johnymd]

When I asked how much, he new an exact price and I can't remember to the penny but it was just short of £1100.

The guy was very helpfull but didn't like the idea of going much lower on front spring rates. Even suggesting that he used 650's on the front of his E30 and that was pretty similar to the 240 weight and ballance wise. I explained that it was used on the road a lot but also lots of track use and some drag racing. I said I understand that it would have to be a compromise to be suitable for all uses. My car is 1130kg with 53% on the front. The 1jz doesn't make much difference to the weight.

It's quite difficult to push a company into building something they don't fully agree with. I was hoping they would agree with my figures of 250/200 rates. I'll wait untill my top mounts arrive the pay them a visit to discuss the setup further. It's a company I would like to use as they have a good reputation and are right on my doorstep. In the meantime I'll get all the other bits for the suspention ordered which are:

Ground control top mounts.
Techno toys front/rear arms, tie rods, and bump stear spacers.

 

[Alphabettispaghetti]

£1100 would be for the all singing and dancing versions(fully adjustable) including vat.

I think illumina's are £120+vat per corner
Springs £175+vat

So about £780 for what is essentially an unmatched set+about £40 a corner for a threaded tube conversion and it makes going to GAZ a very viable option.

For less than the cost of the above you could have the none adjustable but bespoke spring/damper/coilover conversion done.

 

[SKiddell]

I run 225 fronts and 250 rears with an oversize ARB front and back (which may be too much for the front)
Its as stiff as a board with minimal roll, quiet nice mannered on the road

 

[datsun dave]

Its as stiff as a board

 

[datsfun]

When I asked how much, he new an exact price and I can't remember to the penny but it was just short of £1100.
I'll wait untill my top mounts arrive the pay them a visit to discuss the setup further. It's a company I would like to use as they have a good reputation and are right on my doorstep. In the meantime I'll get all the other bits for the suspention ordered which are:

Ground control top mounts.
Techno toys front/rear arms, tie rods, and bump stear spacers.

I would pop in and have a word with the Gaffer, He is a top bloke and you may be able to get a better deal on the prices. I found them very accomodating with bespoke requests. A common problem when using top mounts is that pillow ball collars sometimes dont match diameter of the shock absorber shaft etc and GAZ were happy to do necessary machining etc so that everything bolted in smoothly.

Once they develop the kit, they can offer it "off the shelf" to other s30/hs30 owners subject to spring rates desired? This may mean more competitive prices as they may be able to sell more pieces

 

[johnymd]

Thanks for the advice and yes I will go and see them once the top mounts arrive. They did say they would machine an adaptor to make a perfect fit for the shock. I'm pretty sure I'll go with them but a bit concerned about the spring rates they want to use. Price wise, they are about the same as others so not a problem there. I was sold on the AZ type but they don't seam to think preload is an issue and I also share that view. I don't have the time and fascilities now to do the work myself so getting someone to build a complete strutt is appealing too.

 

[tel240z]

http://www.technotoytuning.com/media/products/z_conversion_05.jpg

I like this, was just thinking about some sort of rear end suspension conversion lots of late strong diffs and drive shafts about, incorperated with new suspension units, nice

 

[GTR-240Z]

I will be interested to know what spring rates you go for John the ones in the rear of my car are too soft but I don't know what the rating on them is just that its 10" in length. I was thinking of buying a pair of 200, 220, and 240Ib springs and experimenting.

 

[GTR-240Z]

http://www.technotoytuning.com/media/products/z_conversion_05.jpg

I like this, was just thinking about some sort of rear end suspension conversion lots of late strong diffs and drive shafts about, incorperated with new suspension units, nice

Up till recently that was what I was going to get but it does mean switching to 5 lug wheels which if your building a new project or fancy a wheel change at the same time would be my choice. Gabriel at TTT is also very helpful in dealing with your questions etc but this conversion will probably set you back an easy 3k before you convert your front hubs and a set of new wheels.

 

[SKiddell]

but they don't seam to think preload is an issue and I also share that view.

Thats certainly an interesting take on things

 

[pmac]

Thats certainly an interesting take on things

Actually its not at all interesting... Its downright naive.

Linear springs are the same spring rate no matter how much they are compressed. Almost all coilover systems come with linear rate springs. Linear springs are much better for sport driving, b/c they are much mroe predictable, and make tuning your suspension much easier.

You can only preload springs with threaded shock body coilovers.

To preload a spring, you compress it b/w the upper and lower spring perches by adjusting the lower collar with the spanner wrench.

With linear springs:
When you put the weight of a corner of a car (probably around 700lbs) over your spring it compresses to absorb that weight. With 400lb spring, it will compress about 1 3/4". So, if you start with the lower collar so that it is just tight enough to hold the top of the spring against the upper perch this would be 0 preload. Raise the collar 1 3/4", and you now have 700lb's of preload. (arbitrary #'s for the sake of illustration.) Since you have preloaded the spring, the same weight as the car's corner, when you put the car on that spring, it will not compress at all, and will simply sit on top of the spring. If you were to hit a bump, the force would still compress the spring the same amount it normally would if you had set the spring to 0 preload. Now if you set the spring to say 900lbs of preload, when you hit the bump (say its a bump that generates around 250lbs of upward force), the spring will compress much less b/c the spring is already beyond the load specified to absorb the bump. Since there is only 50lbs beyond the preload, the spring will only compress about 1/8th inch, and the car will likely be launched over the bump.

You will likely never ever preload a spring beyond the weight of the corner of the car it is on for that exact reason. Springs are there to absorb bumps, if there are any bumps at all, this is a bad idea.

What good is preloading the spring then?

It can provide you with more suspension travel in certain situations. In the ideal world, having the spring at 0 preload would place the piston inside the shock exactly halfway through it's stroke (middle of shock) once the car's weight is resting on the spring. This is almost never the case. by preloading the spring, you can adjust the amount of rebound, or compression travel you have in the shock. If you preload like 200lbs, this will give you more compression travel, and will help keep yourcar from bottoming out when cornering. You have to be careful though, b/c you don't want to sacrifice too much rebound travel, or you could cause all sorts of other problems.

 

[tel240z]

Thanks for the advice and yes I will go and see them once the top mounts arrive. They did say they would machine an adaptor to make a perfect fit for the shock. I'm pretty sure I'll go with them but a bit concerned about the spring rates they want to use. Price wise, they are about the same as others so not a problem there. I was sold on the AZ type but they don't seam to think preload is an issue and I also share that view. I don't have the time and fascilities now to do the work myself so getting someone to build a complete strutt is appealing too.

Well with 650 rate springs i dont suppose you would really want any preload, first sight of a pebble in the road and the 240 would hop all over the show, thats not to suggest that i endorse no preload, in 30 years of fitting springs to all sorts of cars and suspension theres allways preload of course not to much as we dont want to be pulling piston rods out of there tubes on hump back bridges

 

[johnymd]

That quote is exactly my take on the matter. If you preload a spring with say 50lb then when you lower it off the jack you will be adding another 650lb of load onto it. The bit you preloaded it by only limits your rebound length and makes no difference to the way the car handles, unless you reduce its corner weight by in excess of 650lb(hard cornering or adverse camber for example), then the wheel will loose It's contact with the road.

Please correct me if I'm wrong as I'd like to grasp why a little preload is bad. I can fully understand why a lot of preload is a very bad thing but I don't (yet)see a problem with a small amount to reduce ride height.

 

[tel240z]

Thats why you need adjustable platforms for the springs and adjustable shock tubes so you can set the preload then adjust your ride height

 

[zbloke]

John,

For some more ideas on spring rates try searching Hybrid Z for "East Coast Vs West Coast Setup"

The general consensus seems to be that running springs over 300lbs, in a shell that has not been stiffened or strengthened in some way, can result in the car becoming one big spring

Personally I run 275F 300R, a bit of pre-load on the front, almost non on the rear and standard ARB's

Ride quality is good on the road but I still get a little body roll on track

 

[No Hands]

Up till recently that was what I was going to get but it does mean switching to 5 lug wheels which if your building a new project or fancy a wheel change at the same time would be my choice. Gabriel at TTT is also very helpful in dealing with your questions etc but this conversion will probably set you back an easy 3k before you convert your front hubs and a set of new wheels.

You can use s13 hubs, they are 4 lugs, or silvia k's, they are 4 lugs, 240sx have 4 lug.

 

[GTR-240Z]

You are correct you can use s13 hubs to retain 4 lug wheels but for me the whole reason to do the conversion would be to use stronger 300zx tt hubs and cv's which have a thicker and bigger splined shaft going into the hub I think from memory it was something like 31 splines where as the s13 had 27 splines. The 4 lug route with there conversion just seemed a compromise and a wasted opportunity to use the most strongest components. I felt there was more cost effective options if you had to use s13 hubs but thats just my opinion.

 

[MikeB]

Gents,

A bit of advice & comment would be welcomed. My standard weight 240 has very stiff suspension and I've been reading what's been posted above. I've now pulled the suspension out, the car has a coil over conversion with oil filled shocks. Haven't got the dampers out as yet, there is a special 4 lug nut on the top of each strut, but the dampers while being stiff are not overly so and compress when I lean on them, I'd say they are as stiff as a Spax on 2 clicks if you get my drift. The springs are 2.5" and are 10.5 inches long and 140 on the front which had very little preload and 160 at the rear with 1 3/4 " preload.

Given some of the figures above I would have thought this as soft, but with std sway bars I get little roll and the ride is fine on smooth roads but hit a pothole and Boy do you know about it.

I'm perplexed about how this is with these spring settings, what do you reckon?



Cheers

Mike

 

[CheZ]

Anyone tried these?

Have used them on Ferrari Daytona's and Classic Lambo's with good effect.
Was thinking of getting some for the Datsun rebuild but still a long way away so just looking at options.

Luke