How much to shorten 180b steering arms?

[col]

Hi , Does anyone know how much length to take off the steering arms of a datsun 180b .
I'm interested in finding the relationship between steering wheel rotation and the amount taken off the arms.
I was under the cars I have around, a 180b and a 280zx,the steering arms are about a half inch shorter on the 280zx and I was wondering if that would be enough to change the steering rotations much.

[Stewy]

S13 Silvia hubs have 20mm shorter armsthan standard 1600arms and the 1600 now has awesome steering with out any feer of cut and shut Cast arms breaking.

Other option is using the R31Turbo Arms and struts as they are the same length as the Silvia. I used them on the (Khana) Blue bird and made a huge difference.

[col]

Thanks stewy
How many turns are you lock to lock?

[JohnnoEH]

Originally Posted by col

Thanks stewy
How many turns are you lock to lock?

Should be the same amount of turns lock to lock as standard, but you'll have more angle on the wheels, unless the tyres hit something first - good because you can pull in bigger angle slides.

[1600dave]

I'm using a complete 200B front end in my 180B SSS project, and will be replacing the 200B steering arms with 280ZX ones for quicker steering. All the folowing is based on replacing the 200B arms with 280ZX - you'd have to measure some 180B arms to see how relevant this is to you.

200B arms are about 152mm between centres, 280Zx are only 128mm. This is for a 280ZX with power steering - I have been told that the power steering models had shorter steering arms than those without power steering. I haven't seen this for myself, so don't take it as gospel.

Anyway, my rough calculations show that for the same side-to-side movement of the tie rods (ie same amount of turns lock-to-lock), the 280ZX arms will give 21% greater angle at the wheels. I guess this would equate to 21% less turns lock-to-lock. Say 3.6 turns standard (I can't remember how many turns a 1600 has) would come back to 2.88 turns to get the same amount of lock.

Another thing to consider if you're thinking of using 280ZX ones - the hole for the ball joint is offset. You will end up with 5 or 10mm (can't remember exactly) less effective length in the lower control arm (ie you will lose around 0.5 - 1 degree of neg camber)

Disclaimer : When I went to school, we had log books not calculators. Its been a while since I had to use trigonometry, so I may have miscalculated

[col]

Thanks Johnno and Dave.
I will be making longer lower controll arms so the camber will get sorted.
I have purchased an r30 skyline power steering kit, and I hope to fit that as well, I have read on some posts that it should fit without too much trouble.
I am thinking with the power steer and shorter arms, it should be a good thing. Only time will tell.
Thanks Col

[Damo]

Originally Posted by 1600dave

Another thing to consider if you're thinking of using 280ZX ones - the hole for the ball joint is offset. You will end up with 5 or 10mm (can't remember exactly) less effective length in the lower control arm (ie you will lose around 0.5 - 1 degree of neg camber)

Hi Dave - Are you sure it isnt the other way around? I know that the 280ZX arms increase the neg camber when used on Bluebird struts?

[1600dave]

I'll have a look tonight.

[1600dave]

The 280ZX arms I've got have the hole for the ball joint stud offset towards the outside of the car - ie the base of the strut is offset the opposite direction (towards the centre of the car), which would effectively shorten the LCA ??

The ball joint stud is at an angle through the steering arm, just to make it harder to visualise exactly what effect it will have.

See bad drawing below.

[col]

Thanks for all the info guys.
Do you know if the 280zx and silvia are the same?

[1600dave]

The drawing was crap - here's a photo (280ZX on left, 200B on right, they are opposite side arms)

[daewoo]

Does anyone know the measurements of MR30 Skyline ones???

One of the jobs for the khanacross hack is to shorten the steering arms, because at the moment you need 5 arms to get it from lock to lock quickly... and lengthen the control arms because the NonSlipDifferential can cause a little bit of understeer if you haven't managed to get the rear of the car at 89% to the road yet...

Any info appreciated...

Cheers,
Daewoo

[Kaptainballistik]

I got the Mazda ones shortened by J Waterhouse, Add the power steering box and you get 2.5 turns lock to lock and a turning circle of a london taxi!

I think they took out about an inch.

[Mx5 nut]

Back when I was running the Lancer I Cut and Shut the streering arms.
Ended up with 2 turns Lock to Lock ( Was Gold )
Even Bogan had a set of My arms.
I hit and bent suspention with this set up and they never broke in 2 hard year of rally

[col]

Mx5 Nut , do you rally the mx, or is it just for bitumen?
I also have one , I do the rally and dirt motorkhanas with the datsun and the bitumen with the mx. Just asking because if you are set up for bitumen I would like to know your opinions on springs, ride heights and alignment settings.