Cuban Missle Crisis!!!

[okayfine]

To test this I put a ratcheting strap around the rear tires just to see how much force was required to deflect the rear control arm and / or the LCA bushings. Holy cow! They will move in 3/4" with very little pressure.

Some of that may be in the compliance of the rear crossmember bushings. They're much bigger than the a-arm bushings and can yield more movement. Search here for "savage washers" and see what you think. I've run them on my sedans with no real drawbacks.

[Byron510]

I plucked this off a previous post of mine- it's come up so many times!!

...But to stay on topic, you don’t even need to make a Savage washer to do the trick of making the rear X member more solid. Switching the stock washers around to a different combination will do the same trick.
First drop each side the X-member enough to remove the upper washer all together.
Then mount X member against the body on the bottom side by first using the thick, small diameter washer, then invert the large cup washer, so that it presses against the X-member directly, then install the lock washer and self locking nut (preferably a new one, which can be had at most motor cycle shops – Honda uses this size and pitch on many of their products). Make it all gootintite! And you have a sold rear X-member and a 510 that won’t “rear steer”....

If you are driving your 510 hard, this is a must, and either the Savage Washer or the above method both net the same results; you want to eliminate the rear steer when backing off the throttle when in a corner. You'll find that there is very little compliance inthe rear LCA bushings, just enough to take care of the miss alignment of the adjustable brackets. Or you can do as I have done and spherical bush the rear LCA's, but in retrospect, I really don't think it's all that necessary - better yes, but not really necessary.

Byron

[okayfine]

Byron, do you figure the NVH potential is about the same of the Savage washer vs. the method you outlined above? I imagine there is an increase in NVH even with the Savage washer mod, but in a 510 it's probably not noticable.

[Byron510]

I just googled Savage washer and came up with this…

http://datsun510.com/photopost/showphot ... imit=views

What a great comparison shot – gotta love a Google search!
The method I explained above give the exact same results as the Savage washer, with the same NVH characteristics I would expect. Both systems simply help the inner bush (connected to the body) and the outer bush (connected to the subframe, diff and the rest of the rear suspension) be less connected, almost to the point where they are one! I guess there can be a very slight amount of movement considering the leverage that is applied, but it has to be extremely small I would think. I’ve know guys (like myself) that even removed the rubber washer at the top to eliminate that “squish” as well. That get s a bit hard core, and you will feel the lack of the washer when hitting a sharp edge on the road like a concrete joint or even a X walk raised painet line on low profile tires!

Yes, this will add road noise that the Nissan engineers tried so hard to reduce back in the day. I’m not so sure that the polyurethane set ups would be much less, I guess that would depend on the durometer of the polyurethane used. I don’t consider the Savage washer type mod to be that bad, but I’m also willing to put up with a lot for a gain in performance!

Byron

[okayfine]

You're right. I had to look at it again, but the Savage washer bottoms out against the crossmember mount just like your method. I'd thought it just squished the rubber bushing to limit movement.

[S15DET]

Why did you have to send in the Racelogic unit?

[batfastard]

To test this I put a ratcheting strap around the rear tires just to see how much force was required to deflect the rear control arm and / or the LCA bushings. Holy cow! They will move in 3/4" with very little pressure.

Some of that may be in the compliance of the rear crossmember bushings. They're much bigger than the a-arm bushings and can yield more movement. Search here for "savage washers" and see what you think. I've run them on my sedans with no real drawbacks.

The compliance I'm talking about doesn't involve the rear X-member. What I'm saying is that if someone had arms that were long enough to go to the back of the car and grab the rear of the rear tires and pull inward, it doesn't take much pressure to change the rear toe. As for the "savage washer", I made a 3/8" alumnium spacer to put in place of the cone washer on the bottom of the X-member a while back. I'll post a pic tomorrow when I'm at the shop. Thanks for the suggestions BTW and keep them coming.

BF

[batfastard]

Why did you have to send in the Racelogic unit?

The digital adjuster wasn't working properly. Wrong software or something like that..... Works great now!

[S15DET]

Darn, you have the digital screen too, that's an expensive set-up. Do you have an inside line on them?

[rnorrish]

I'd have to say then that the adjuster isn't quite tight...
Make sure the top swing bolt is tight, not just the small lock bolts.
there's nothing else that allows movement.
(were the outer ears previously slotted?)

except rusty parts.

[batfastard]

Darn, you have the digital screen too, that's an expensive set-up. Do you have an inside line on them?

No, not really, my brother ordered it, maybe he worked out some kind of deal because when mine came back there was a whole 'nother set up for his RB powered Z in the box as well. I was the guinea pig, it works great, and I'm not asking questions if you know what I mean. I guess the worst part is that I have to install it into his car. Like I said, "I ain't complaning". I just wish someone would chime in here and say "I have a perfect ring and pinion for your R-200 that is a 3.54 ratio.". That would be the icing on the cake.

On a side note, I think I'm going to go by the local 4X4 custom fab shop tomorrow and see if they can make new RCA's for the car while I'm on vacation next week. Custom tubular LCA's, spherical bearings and a slight mod to my sub frame spacers should tighten the rear end up for some real abuse. Like Byron said, I'm willing to increase some noise to get the increase in performance. I'll just use a lot more dynamat when time comes.

BTW, does anyone run front sway bars (or rears for that matter) on their 510's with an SR swap? Or do you just use stiffer springs? I'm thinking of making one for the front and keeping the same spring rate ('cause it has such a nice ride quality).

BF

[batfastard]

temp pic.JPG

I'd have to say then that the adjuster isn't quite tight...
Make sure the top swing bolt is tight, not just the small lock bolts.
there's nothing else that allows movement.
(were the outer ears previously slotted?)

except rusty parts.

EVERYTHING is tight..... I think. (99% sure) And no, nothing was previously slotted. Since you brought it up, I'll put it on the lift and double check everything tomorrow. I suspect that the control has some deflection to it as well as the LCA bushings. I bought the LCA bushings NOS from a guy here on the realm (I cant remember his name) and they looked, well....NEW. Maybe they are the cause of the movement. Either way, new rear LCA's and spherical bearings should eliminate the problem and give an increase in rear suspension geometry under hard cornering. I would also like to run wider rear tires.

BF

[rnorrish]

I'm just thinking, if you can move it by hand, something is loose.
Deflection under a heavy load, fine. Blame the squishy 40 year old parts...

But things are new and replaced and being worked on.
It's gotta be something simple.

[S15DET]

I'm making a front bar now out of two S14 hollow front bars. Because I moved my motor back towards the firewall, I can't use the bars that Dan sells here, but maybe you can.

http://www.dgrfabrication.com/

[hang_510]

BTW, does anyone run front sway bars (or rears for that matter) on their 510's with an ...

not for an SR, but out of the way for anything

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