Bumpsteer spacer bolts?

[jefe de jefes]

Bumptsteer spacer bolt info required?

 

Anybody know what length/thread pitch is needed for a 1 inch spacer?

These are going to be used with 280zx struts.

[Docsis510]

I have a set. Ill check tomorrow and let you know the details

[Pacific coast Datsun]

""Bumptsteer spacer bolt info required?

 

Anybody know what length/thread pitch is needed for a 1 inch spacer?

These are going to be used with 280zx struts""

 

Jefe. I went with a grade 8 allen bolt for my bump steer spacers. Im running the same struts as you. I believe they are 2 inches long. I can dbl. check for you tomorrow if need be.

[jefe de jefes]

Cool, keep me posted guys.

All I need is these bolts and longer studs to complete my strut swap.

Thanks

[datzenmike]

Are the spacers just that, a spacer, or are they wedge shaped too? for camber??

[thisismatt]

Ideally you should get a class 10.9 bolt (Grade 8 is a reference to standard bolts, not metric. Metric 8.8 is more like Grade 5, 10.9 is more like Grade 8). You should get a measurement and get a bolt with a smooth shaft up through the spacer and only threads going into the strut. I want to say the bolt is a 10x1.25 but I can't remember for sure.

[jefe de jefes]

Are the spacers just that, a spacer, or are they wedge shaped too? for camber??

Just a spacer I guess. Mine aren't wedge shaped.

[dennis]

The smooth area between the head and the threads is called grip length. If you can wait a few days till my new set comes in I can run my caliper across it and let you know the size, grip length, and thread pitch along with any head markings.

[jefe de jefes]

The smooth area between the head and the threads is called grip length. If you can wait a few days till my new set comes in I can run my caliper across it and let you know the size, grip length, and thread pitch along with any head markings.

Perfect.

I plan on installing maybe this coming weekend.

[Pacific coast Datsun]

Are the spacers just that, a spacer, or are they wedge shaped too? for camber??

They are mainly used to correct the suspension geometry...

[thisismatt]

The smooth area between the head and the threads is called grip length. If you can wait a few days till my new set comes in I can run my caliper across it and let you know the size, grip length, and thread pitch along with any head markings.

* nods * Couldn't think of the name (I know it's not a shoulder like a lot of people like to call it).

[dennis]

* nods * Couldn't think of the name (I know it's not a shoulder like a lot of people like to call it).

 

The only reason why I know it was because I was a aircraft metal fabricator in the Navy and it was drilled into my head over and over again when I was in school.

[RadioLobo]

Can you drill out the middle? My ball joint hits it when i try to bolt it together with the strut, maybe something else wrong?

[Dime Dave]

Boy, I have no idea how these things got named "Bump Steer Spacers".

 

To adjust bump steer you need to change the spatial relationship of the inner and outer tie rod ends to the lower control arm's pivot and ball joint locations. This is all left unchanged when you use these spacers. What they will do is put the tie rod/LCA in a closer to stock position where bump steer is likely less dramatic, but they do not alter the bump steer amount that is inherent in a suspension’s design.

 

What these spacers do is change the location of the spindle to the ball joint. What this does is change the camber gain on the front suspension.

 

In stock design the ball joint is lower than the inner pivot point. When the strut is loaded in a turn, it compresses and gains negative camber. This was done to help keep the tire squarer to the ground in corners. The negative camber gain in the suspension counteracts the positive camber gain from body roll.

 

When you lower a strut suspension car, the ball joint often becomes higher that the inner pivot. In this condition, the strut actually gains positive camber when compressed. This increases the angle of the tire to the ground in cornering and adds to the angle caused by the body lean compounding it and greatly reduces the car’s cornering capacity.

 

So these spacers are important to maintain negative camber gain on lowered cars for better cornering and are at best a band-aid to correct the bump steer issues that exist.

 

Does anyone remember the “How to Hot Rod your Datsun” book. In the 2.5 TransAm build they raised the inner LCA pivot and bent the outer ends of the steering arms downward. The raised inner pivot point not only helped camber gain, but also removed bump steer. The lowered tie rod end on the steering arm was done to reduce bump steer as well. The severity of these changes give you an idea of how off the bump steer is on a stock 510 suspension.

[jefe de jefes]

"Boy, I have no idea how these things got named "Bump Steer Spacers".

 

 

Roll center adjusters? Everybody here calls them bumpsteer spacers......

[RoadRace]

12 x 1.25 x 55mm. i had a very hard time getting this capscrew in a 10.9 rating, in fact i had to buy 400 of them if i wanted them because they were special order. i regret to say i was not prepared to spend close to $1/bolt just for 4 of them. i went with standard 8.8 (from Aklands Supply, ~$18 for 10) and i check them every race and replace as necessary. do yourself a favor and get the tap to clean the threads out as well.

[RoadRace]

Does anyone remember the “How to Hot Rod your Datsun” book. In the 2.5 TransAm build they raised the inner LCA pivot and bent the outer ends of the steering arms downward. The raised inner pivot point not only helped camber gain, but also removed bump steer. The lowered tie rod end on the steering arm was done to reduce bump steer as well. The severity of these changes give you an idea of how off the bump steer is on a stock 510 suspension.

 

i like the datsport kit that addresses these issues. But at what point do you stop calling it a 'band-aid'?

[jefe de jefes]

12 x 1.25 x 55mm. i had a very hard time getting this capscrew in a 10.9 rating, in fact i had to buy 400 of them if i wanted them because they were special order. i regret to say i was not prepared to spend close to $1/bolt just for 4 of them. i went with standard 8.8 (from Aklands Supply, ~$18 for 10) and i check them every race and replace as necessary. do yourself a favor and get the tap to clean the threads out as well.

Thanks for the info. Got any extras you might be willing to sell?

[Pacific coast Datsun]

Good info DimeDave. Another reason to run these would be guys who have done the 280 ZX strut swap & discover the caliper very close to the tie rod ends. The spacers push the strut down & away from the tie rod ends.

[RoadRace]

Thanks for the info. Got any extras you might be willing to sell?

 

maybe - i'll take a look tonight. i should have checked back here sooner!!

[thisismatt]

There are places that will sell smaller quantities of 10.9 bolts. Metricmcc.com comes to mind, but it's been a while since I ordered from them. The minimum was 10 when I bought from them for my spacer bolts (mine were longer, though, using 1.5" spacers).

[dennis]

mcmaster-carr (mcmaster.com) has them.