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Posted

So I fitted the rears last night, hit a few road bumps. But all went pretty smoothly.

The rear springs have 79.5 220 7kg written on them. My understanding is that they are 79.5mm diameter x 220mm long @7kg (391lb)

Now is that a spring free length of 220mm? What length should they be compressed then? Will the spring rate be any different when it's compressed?

 

Simon, my guess would be that that is the free length of 220mm, but if you can measure them, then you will know for sure  ;D

 

The spring rate will be lineal for those springs, from the quick glance in the photos. Unless they are progressive rate which is easy to tell by the change in coil rate and also sometimes the diameter of the wire and sometimes a change in the overall coil diameter.

 

When you set everything up, forget what looks fully sick and low, get the car to someone who can corner weight it and properly set up preload on the springs as well as get the ride heights done correctly to work with the other suspension components. This will cost some dollars but will be better bang for your buck than more power. I have no idea who would be the suspension set up gurus down yor way, but talk to some of the guys who race at the front of the field in categories such as Prod Sports and IPRA at full racing meetings, not the sprint day guys as the racers will know who is who in terms of best service and dollars needed and what you will get in return for the outlay.

 

I was always taught, and yet to be disproven, if you want to go faster by seconds a lap spend your budget on suspension, if you want to go faster by tenths then spend it on the engine.

Posted

Cheers Matt. I thought they were Lineal, not progressive. Will look into getting it set once it's all done.

 

Have to aggree with your statement. 

I did initially spend money on suspension and brakes before engine. But now I have the PMC, I need to improve suspension more so.

Posted

Here are some pics of old vs new.

Note the length difference. I still dropped the coliovers another 25mm  :o

 

Took it for a quick spin up and down the road, but cant really feel a massive difference from that sort of testing.

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  • 3 weeks later...
Posted

I've been having issues with the air intake hose coming off the airbox inlet.

So i wind up just tightening the clamp tighter and tighter until it cracked.  :'(

I even tried to put a lip on the edge with some resin, but that didn't work either.

So back to what I know.......... STEEL!

I rolled up some sheet metal, much like an egg ring. And pushed it into the inlet of the airbox, making a snug fit. Now when I tighten the clamp, the forces are between the clamp and the egg ring. Fibreglass is clamped real tight now  ;D

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Posted

Was vibrating off. Tried to tighten it more. Cracked fibreglass  >:(

So thought it needed more support.

Coilovers are still being worked on when I get time.

2013 is going to be a busy year for me.

  • 2 weeks later...
Posted

I've been investigating adjustable lower control arms.

This will be necessary for performance reasons. But to also to clear my coilover conversion on the front if I want to keep the Watanabe mags.

One of the most import parts of this mod, is the rod ends to connect to the cross member. I've decided on brand, size and type.

I've gone for the Japanese made IKO POS20EC.

These are teflon lined outer race and are maintenance free. They have a static load capacity of 30kN. More importantly, they have a dynamic load capacity of 61.6kN.

I think these will be up to the task and are a bit more expensive than the next ones down.

They are ordered and shall pick them up this afternoon  ;D

Time to work on those front coilovers tonight!  8)

Posted

Well, I did some work on the front coilovers. Was going to remove the strut thats there, bolt in the new one. And measure the spring compression, to work out the height, to weld the threaded collar onto the shortened strut.

Only, when I removed the wheel. I found a problem.

the front brake upgrade is going to be too close and actually interfere with the new strut/coilover.  Meaning I won't have time to do the mod before the national!  :'(

 

So back to concentrating on camber and caster.

Also, need to get the new coil and CDI box installed. So I can finally have it tuned on a dyno!

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Posted

On a side note, I ordered these today.

Been wanting them for ages, but never actually did it.

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looking fowards to having them on the car  8)

 

I also have driven the car to work today, first time since installing the rear coilovers. I'm pretty happy with them.

The ride was a bit harsh initially, but I turned down the adjustable shocks, much more comfy in traffic.

The rear end doesn't bog down anywhere near as much as it did previously too!  8)

  • 2 weeks later...
Posted

I've been trying to squeeze in suspension work with a busy family life..........

First up - LCA's

As I've mention in previous posts. M20 x 1.5 teflon coated rod ends have been selected. But they need to connect to the cross member. So some bushes were turned up, plated and pressed in.

The stock dimensions of the LCA was measured and cut at a length allowing 20-40mm wider adjustment.

Blocks were machined to fit.

Welding to come.

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Posted

Steering arms are done. Well, one set are anyway.....

Dad got a set from the wreckers, off another Datsun. But doesn't know which model, said it was a big one. lol

So they got cut in half and turned to equal lengths. Steel rod was cut to length, bored for a tight fit 15mm deep and split up the guts with a slot drill. Then they were all trial fitted, careful to get left and right threads...... Welded together, then turned down to look pretty and painted.

Clamps were sandblasted, gal comes up nice with a blast. Fasteners were wire brushed. DONE!

They are now 35mm longer  ;D

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Posted

I've been trying to squeeze in suspension work with a busy family life..........

First up - LCA's

As I've mention in previous posts. M20 x 1.5 teflon coated rod ends have been selected. But they need to connect to the cross member. So some bushes were turned up, plated and pressed in.

The stock dimensions of the LCA was measured and cut at a length allowing 20-40mm wider adjustment.

Blocks were machined to fit.

Welding to come.

 

Wow, the man has skills! You should produce more of this stuff, maybe some for S30's too. I no I'd buy some for mine and probably my bro's 510  ;D

 

Are you going to do the rears too?

Posted

Cheers G unit.

I do plan on getting my own equipment in the future, so I can make some for other people.

Got a few major projects going on at the moment. Hopefully in the next few years.

  • 2 weeks later...
Posted

Slowly making progress on creating more corner speed via front suspension set up.

All the parts are made, just welding, grinding, painting and fitting it.

Got to give the mig welder I bought off Jamo its first real test........ And I love it!  8)

 

Front end was dismantled, parts welded, cleaned up and painted on Friday night. Fitting parts on Saturday.

Guys here would understand that while working on your car with new parts, you keep waiting to hit that brick wall and have problems........ Well......... It never happened!  :D

Everything went smoothly. Goes to show that good planning saves time and hassle!

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Posted

Here are some more pics.

From underneath you can really see the angle of the LCA towards the front. I ended up moving it forwards 15mm.

I also found the best way to turn the steering arm adjusters, is with a claw hammer in the slot.

 

Last pic is of the bump steer spacer I got from Iain, when he upgraded his suspension.

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Posted

Here are some more pics.

From underneath you can really see the angle of the LCA towards the front. I ended up moving it forwards 15mm.

I also found the best way to turn the steering arm adjusters, is with a claw hammer in the slot.

 

Last pic is of the bump steer spacer I got from Iain, when he upgraded his suspension.

 

thought they looked familiar :-)

Posted

Don't know why people call them bump steer spacers - when they don't actually fix any bump steer :( - sure the bump steer is better but the issue is still there just like the factory setup - however it is outside the normal range of movement from factory and with these spacers installed.

 

However these spacer alter Roll Center - and this could cause other issues - ie you have now changed the relationship between the front RC and rear RC - that is why they should be called Roll Center Adjusters - and bump steer relocators. If you want to eliminate bump steer you need adjustable tie rods, something to measure the actual bump steer for your given setup and then adjust the steering/tie rod height until you have an acceptable and manageable bump steer.

 

Then you fix the bump steer without altering the RC

 

ok my rant over :D

Posted

Don't know why people call them bump steer spacers - blah blah blahdity blah

I'm aware that they are called roll center adjusters. But they are just commonly known as bump steer, to leymans like me.

Even though its no issue on tracks, I'm hoping it will reduce the steering pulling while driving on crappy bumpy roads.

Posted

Roll center adjusters are now off, as they where wat to close to rotors and could actually touch  >:(

Removing the RCA's pushed the camber out even further.

 

After removing, changing, dropping and checking clearance many times............

I ended up with 2mm more on the caster rod! Not less at all.  ???

 

Given that the 280ZX has the caster rods towards the front and inwards. Whenever you push the camber out, the caster is already arcing towards the front of the car.

 

So if you put 3° of neg camber on, use std caster rods!

 

Posted

While under the car again last night, it was noticed that the cup washers (either sides of the rubbers) were actually on backwards  :-[

So off they came again............ then the wheels scrubbed the front spoiler........... again  :'(

So off they came....... again........ spaced them out and dropped it down. And was finally happy with the clearance! About 6mm longer than standard.

Alignment getting done this arvo, so will post up settings  ;)

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