Datto_610's 180B - Street Legal!

[Datto_610]

I'm about ready to pack it in.... na I would never do that but still no where near closer to finishing! So went to the Chamberlains spring shop on my lunch break and talked to one of the guys there and said I basically wanted an 800lb version spring of what I already had but he mentioned that I could encounter more problems with handling and traction if I went that stiff.... he measured what mine are currently rated at which is around the 575lb mark also the ones I have are actually rally spec datsun springs that have been compressed to achieve my current ride height. If I want to go 800lb they will make them but will cost a pretty penny and reckons It won't corner as well as it does currently. His suggestion was basically longer bump stops so it doesn't bottom out on the body... I am so over this and just want it done!

[broke]

That would get to anyone. Do they not want to make money selling their product?

Here's an idea if it's just the CV rubbing stopping you passing:

1. Fit standard UJ halfshafts
2. Pass cert
3. Refit CV axles and sort out the rubbing later (or not)
4. Profit

I have 510 axles and companion flanges + R200 stubs if you want to try this....

[gman]

Fitting uj's wont fix any thing uj's hate angel more than cv's. just find some original springs. or I will go and get some made for you. and 800lb is far to heavy 650/ 700 which will give you an actual spring rate of 210 /230lb .

[broke]

It could work as a solution to the rubbing. Obviously CV's are a better long term idea.

[gman]

It could work as a solution to the rubbing. Obviously CV's are a better long term idea.

Yes but it wont fix the camber problem by going up 50mm and 25 to 30% heavier springs every thing will be fixed .

[85_Z31]

the 800lb spring doesn't actually sound too far from the mark.

the spring rate itself is only 1/2 of the puzzle. Its the spring location in a 510/610 that needs to be considered. because the spring is so close to the cross member pivot it doesn't have a very long trailing arm to activate it.

This can be explained with Motion Ratio and wheel rate but In Practical terms, the current spring are too soft, that's a known piece of information, so going another 20-30% stiffer would put you right in a ballpark of 800lb.

I can understand the guy behind the counter saying you could run into traction problems because it sounds like a really high spring rate. Its all just opinions until the numbers are done.

Once the calculation is performed you are looking for a number around the same as the front springs or maybe a tiny bit more to prevent squat. People can say a lot about what works and what does not but it could still not be the right thing for your particular car.

This is a great link to calculate motion ratio and wheel rate
http://alison.hine.net/cobra/tweaks/motionratio2.htm" onclick="window.open(this.href);return false;

http://www.nzdatsun.com/forums/viewtopi ... =17&t=2730" onclick="window.open(this.href);return false;

This method worked great on my z, its no accident it handles as good as it does while having a softer ride and still cornering like a demon.

[gman]

the 800lb spring doesn't actually sound too far from the mark.

the spring rate itself is only 1/2 of the puzzle. Its the spring location in a 510/610 that needs to be considered. because the spring is so close to the cross member pivot it doesn't have a very long trailing arm to activate it.

This can be explained with Motion Ratio and wheel rate but In Practical terms, the current spring are too soft, that's a known piece of information, so going another 20-30% stiffer would put you right in a ballpark of 800lb.

I can understand the guy behind the counter saying you could run into traction problems because it sounds like a really high spring rate. Its all just opinions until the numbers are done.

Once the calculation is performed you are looking for a number around the same as the front springs or maybe a tiny bit more to prevent squat. People can say a lot about what works and what does not but it could still not be the right thing for your particular car.

This is a great link to calculate motion ratio and wheel rate
http://alison.hine.net/cobra/tweaks/motionratio2.htm" onclick="window.open(this.href);return false;

http://www.nzdatsun.com/forums/viewtopi ... =17&t=2730" onclick="window.open(this.href);return false;

This method worked great on my z, its no accident it handles as good as it does while having a softer ride and still cornering like a demon.

Sorry spring rate can never be grater in the back off a rear wheel drive car.

[85_Z31]

Sorry spring rate can never be grater in the back off a rear wheel drive car.

Its coming back to me now, i started out with 400lb springs on my rear arms, and then i moved up to 450lb to reduce the squat a wee bit. I can't remember all my maths but it must have worked out a bit softer in the rear but not a huge amount. My mistake its been a couple of years since i set up all my spring rates.

With too much rear spring rate would it just over steer massively and be a pig to drive ?

[gman]

Sorry spring rate can never be grater in the back off a rear wheel drive car.

Its coming back to me now, i started out with 400lb springs on my rear arms, and then i moved up to 450lb to reduce the squat a wee bit. I can't remember all my maths but it must have worked out a bit softer in the rear but not a huge amount. My mistake its been a couple of years since i set up all my spring rates.

With too much rear spring rate would it just over steer massively and be a pig to drive ?

yes it would over steer and spin up all the time wouldn't allow the car to squat under power.

[Datto_610]

I've re-read the Rectification Sheet, and it doesn't actually mention specifically to reduce camber... It says:

*Rear wheels rubbing on inner body(which I know now they are not). Reducing negative camber may help.

*Confirm wheel alignment specs for rear suspension

*Supply new copy of wheel alignment.

I have been looking at these on the Datsport website but they are quite a bit shorter than what I have currently
http://www.datsport.com/suspension-rear ... S1601.html" onclick="window.open(this.href);return false;

I also jacked the arm up again to see if the bump stop hits the body first, it doesn't... The guys at Chamberlains put shorter ones in that don't seem to serve there purpose would it be better to put longer ones than whats in there or try track down some standard ones?

So I may not need to raise it up and may get away with just stiffening up the rear springs