Aluminum suspension tubes-- 88 Rear Suspension with Rod Ends

Starlite528 · Post by **Starlite528** » Sun Mar 18, 2007 4:38 pm

Series8217 wrote:Lots of racers use NMB bearings if they arent using Aurora
Here's a source:
http://www.bakerprecision.com/rodend.htm

I think they make NMB bearings where I used to live in Chatsworth, CA. At least, there's a big building with "NMB" on it, and I know they do bearings.

The Dark Side of Will · Sun Mar 18, 2007 4:50 pm

Series8217 wrote:I have all the parts now, just no time to install them. Probably will get it done around the beginning of summer.
WCF is selling a setup for 88 Fieros now.

I'm thinking I could have mine installed next week.

I didn't see it on the WCF website.

The Dark Side of Will · Sun Mar 18, 2007 5:00 pm

The '88 bushing sleeves are 1.580 long, so a 3/4" thick rod-end would require 0.415 thick spacers on each side. I don't know the thickness of a 5/8" rod-end boot right off, but that will take up some of the space.

Series8217 · Post by **Series8217** » Sun Mar 18, 2007 7:05 pm

The Dark Side of Will wrote:
Series8217 wrote:I have all the parts now, just no time to install them. Probably will get it done around the beginning of summer.
WCF is selling a setup for 88 Fieros now.
I'm thinking I could have mine installed next week.

I didn't see it on the WCF website.

It's under tubular A-arms.. they've been up there for awhile. No pic yet but I'll try to get one.
We put extended length ones on a wide track kit car.

The Dark Side of Will · Mon Mar 19, 2007 8:07 pm

Ordered 4 RH rod-ends, 4 LH rod-ends, RH nuts, LH nuts, two 10" tubes and two 8" tubes. The Chassis Shop does not seem to have a *secure* online order form, so I'll order from them by phone tomorrow.

The Dark Side of Will · Sat Mar 24, 2007 11:33 am

I didn't get the rod-end boots ordered until yesterday. I'm starting my annual two weeks for the Navy on Monday, so I won't get to install things until the weekend of April 7/8.

The wrench flats on the tubes aren't anything to write home about, but otherwise the tubes are ok.

I'm not very happy with the rod ends. They're looser than I think they should be, but I'll use them anyway just to see how they work out. The RH threaded ones are almost tight enough. The LH thread ones are all looser than the RH threaded ones. On both I can turn the balls sideways and see machine marks on the races. Maybe they'll be ok if I use a *really* stiff grease.

Further proof that you get what you pay for.

The Dark Side of Will · Sat Apr 07, 2007 1:32 pm

I've been away for two weeks and haven't gotten anything done.

The Racecar Engineering stickers were applied to the tubes overtop of stickers for http://www.allstarperformance.com

I haven't been able to find the tubes on their website yet.

The Dark Side of Will · Sat Apr 07, 2007 9:06 pm

Chassis Shop rod end boots are made by a company called Pro-Werks ( www.pro-werks.com ). They are supposedly 0.063 thick for all sizes, which led me to a-priori design spacers 0.350" long.

I made the spacers tonight. Now that I put together a pair of spacers, a pair of boots and a rod end, the assembly is 1.555" thick, which is 0.025 short of what it should be. Hypothesis: the boots are actually 0.050 thick.

Confirmed. I had to whip out the mic to measure them because the shape isn't conducive to using calipers, but they are 0.050 thick, despite the Chassis Shop catalog specifying that they are 0.063 thick. Grrr...

The Dark Side of Will · Sun Apr 08, 2007 2:54 pm

Weights:

Stock Lateral: 2#4
Stock Toe: 1#13

New Lateral: 1#2
New Toe: 1#2

The toe & lateral links differ in weight by less than an oz. Overall I save 1#13 per side, with approximately half being unsprung. That's not quite 1% of the rear unsprung weight.

I have one side together, but I have to go back to the shop to skim about .001 off one bushing because it's just a smidge too big. I guess the rod end I took with me to test was on the high side of the tolerance.

According to this: http://www.dansmc.com/torque_chart.htm
A 12 mm class 10.9 bolt can take 83 ftlbs dry.

http://dodgeram.org/tech/specs/bolts/M_bolts.html says that lubed threads can take 115 Nm... which is 85 ftlbs.

Yet a third ( http://www.idraprince.com/teched/Preven ... ueSpec.pdf ) says 75 ftlbs for anti-seize, 98 for "blue" (presumably loctite) and 116 dry. This specifies socket cap screws. Are they always 12.9?

And a 4th ( https://www.misumiusa.com/CategoryImage ... 7-1848.pdf ) a value equivalent to 71 ftlbs lubed.

I think I'll got with 75-85.

Once this is tightened, I shouldn't have to worry about the outer pivot bolt again. It only works loose with the stock bushings because the bushing inner sleeves aren't rigid in compression and experience torsional forces because of the bushings. Neither is true in the case of rod ends.

The Dark Side of Will · Sun Apr 08, 2007 6:09 pm

Thus concludes my experiment with cheap rod ends.

Of the 8 grease fittings, 5 either broke off, pulled out or almost pulled out... the very FIRST time I was greasing them.

They are press-in grease fittings with 1/8" shanks that can't have more than 1/32" of wall thickness. They're not good steel either. I'm not even sure they ARE steel.

I did not have high expectations of $8 rod ends, but these consistently failed to meet even my modest expectations. They are loose. The races show machine marks. The grease fittings break off. They are un-mitigated shit. Do not buy them. I will be calling McMaster tomorrow to see what they have to say about it.

cactus bastard · Post by **cactus bastard** » Sun Apr 08, 2007 6:14 pm

Holy crap. Why would they even bother to sell shit like that?

The Dark Side of Will · Fri Apr 20, 2007 10:45 pm

Probably because nobody tested it.

Here's a potential cure for the cheap rod end blues:

http://www.currieenterprises.com/cestor ... oints.aspx

I'd have to upgrade to the 3/4 tubes, however, so I'd have to replace my WHOLE setup. They're only $40 each, too.

Series8217 · Post by **Series8217** » Sat Apr 21, 2007 3:47 am

Not solid though..

The Dark Side of Will · Sat Apr 21, 2007 11:06 am

I know, but they have a larger diameter at the friction surface than most poly bushings, so the contact pressure (thus deflection & wear) are lower.

Nemesis · Post by **Nemesis** » Wed May 23, 2007 8:37 pm

So where did you end up ordering from, Will?

You used aluminum tubes with welded on steel tube adapters?

The Dark Side of Will · Wed May 23, 2007 9:41 pm

The tubes in the link Steven posted are tapped. I used those tubes but didn't spend enough on rod ends.

Series8217 · Post by **Series8217** » Fri May 25, 2007 1:08 pm

Get a replacement rod end set yet? I'd like to hear how well these perform. I haven't had a chance to do mine yet (busy quarter at school).

cactus bastard · Post by **cactus bastard** » Sat May 26, 2007 4:05 pm

I've noticed that finding greasable rod ends for racing applications is rather tough. If you're having a hard time finding any, rod ends used on hydraulic equipment usually have a grease fitting on them. Maybe you could be looking down that alley too. I've no idea what sort of engineering data is available, but just thought I'd mention it.

The Dark Side of Will · Sat May 26, 2007 7:24 pm

I'm still using the cheap ones. I might as well get my money's worth out of them.

Are there any suppliers I should check out for equipment rod ends vice automotive rod ends?

Nemesis · Post by **Nemesis** » Sun May 27, 2007 2:18 am

Has anyone investigated the rear camber gain on an 88? Looking at pics of me autocrossing, the rear has a noticeable amount going on.

With adjustable rear links (I have a line on premade units with poly bushings) to widen the rear, this can be fixed, right? My custom made cradle already has the toe link mounts moved in to line up with the lateral link mount to get rid of roll steer.

Am I thinking correctly here?

How far can the rear be widened before the axles pop out? I have an IMSA with huge rear fenders, so I don't really have to worry about the tires sticking out. But how much longer would the links need to be to be effective?