I know there have been a few threads concerning this topic but I'm not really finding the details I'm looking for. I want to go with all spherical/pillow ball bushings in the rear of my race car. If I were to change out the rear lower control arm, rear upper adjustable control arm, and rear compensator arm to all pillow bushings, would you still "need" a upgraded rear trailing arm bushing? I've heard of race teams like Realtime using "stock" trailing arm bushings so I'm not sure how necessary it is to change/upgrade.

I think my problem is that I'm not really understanding how much this bushing really affects the suspension movement, could someone clue me in?

This is what I'm looking to get:







Also, has anyone had any experience using one of these? and will these work to install a spherical/pillow ball trailing arm bushing?

 

I have all of the hardrace rear suspension pieces and I've been very happy with them so far.

For the trailing arm bushing, they need to be pressed in, they cannot be pounded or hammered in. A machine shop can do this for a small fee.

 

Where can these hardrace parts be bought? They are sick. Thanks!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eficker &raquo;</TD></TR><TR><TD CLASS="quote">Where can these hardrace parts be bought? They are sick. Thanks!</TD></TR></TABLE>

http://www.hardrace.com

 

RJ, how is the movement on the spherical trailing arm bushing from Hard Race? It looks as if it has a fixed shaft, wouldn't you want a sliding one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 6ghatch &raquo;</TD></TR><TR><TD CLASS="quote">RJ, how is the movement on the spherical trailing arm bushing from Hard Race? </TD></TR></TABLE>

Its not fixed Movement is pretty free as far as I could tell.

 

here is a quote from RR98ITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">If the trailing arm bushing is replaced by a spherical bearing the suspension design is transformed into something more akin to a wide based semi-trailing arm with an undesirably acute angle. The toe link then does nothing - nothing, aside from try to rip the nose off the trailing arm. Only if the spherical bearing is free to move laterally on the pivot shaft is such an application sensible at all - but the shaft and bearing will wear quickly.

</TD></TR></TABLE>

 

I cant really comment on them "wearing quickly" although I see no reason for them to. I have only had them on the car one year, and to be honest if they last 2 years I'll be happy - I figure thats pretty good life for track only bits.

 

Those guys are in TW, do you just email them or call them? Their site is not setup for e-commerce. Thanks!

 

Email........

 

JHP.com also sells a trailing arm bushings. i have about 10 to 15 track days on them, with a fair share of offs and they still work fine.

 

It looks like there are several acceptable approaches to this.

The old DC cars ran/run the sphericals directly on pivot shafts. The two lessons appear to be that appropriately lubed they don't wear out super fast, and the higher shock loads into the pivot shaft mountings don't cause rapid fatigue failure of the mounting.

The current Tripoint Mazda's do the same thing. Lubing the assembly occurs every weekend. Their shafts "may" be 7075 Alum.

I've got a friend with an old GT car with a strange rules driven "Macpherson Strut" interpretation that is very similar to our application. He went to the trouble to run the "strut" shaft thru a replaceable bronze bushing with a zerk captivated within the Heim bore. He gets a long service life out of his setup.

Another possibility is to use a precision linear bearing insert assuming you can match one to a spherical of suitable dimension, and then grind a shaft to what you need.

Without decently structured first hand experience it's hard to say what's worth what. Scott Zellner has in the past said that there's no need for anything more rigid than the Mugen TA bushings, and he's expressed concern about the higher radial shock loading of the spherical setup.

But many of us can't help our attraction to the idea of minimizing dynamic toe in of the outside rear.

Scott, who in 2006 is going to un-screw-up his kaa and try to confirm that Zellner is right before switching from Mugen to Heim...

 

scott what do they "lube" it with. I have just been running my dry, but would like to add some lube..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">scott what do they "lube" it with. I have just been running my dry, but would like to add some lube..</TD></TR></TABLE>

I don't know...probably some tenacious snot with Molybdenum Disulfide - that's what you always seem to see in a high pressure application. Sounds like one more unpleasant recurrent service job...definitely prefer a bushing with a zerk ... or a Mugen rubber unit!

Scott, who doesn't like nasty routine service jobs...

 

The hardrace bushings have a dust boot to keep the grease in very convenient

 

Those Hardrace rear trailing arm bushings look very good. I installed the Mugen ones a few years back, but they are barely stiffer than the stock ones. I actually measured the deflection of a stock one and a Mugen one by hanging weights off the end and checking deflections of the bushing in a couple of directions. At first it was hard to see any difference, and then I think I convinced myself there was about 25% more stiffness in the Mugen, which I assumed might be due to them being new. Rubber bushing stiffness is a little tricky to measure. It was a lot of trouble to change those bushings and I thought the effort was hardly worth it. Bushings in the front suspension are much more important, and I have some of the sphericals there. But I might start again in the rear if others like RJ like the Hardrace ones, since at least those might keep things more in line.

So how much do they cost?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote">
So how much do they cost?</TD></TR></TABLE>

I think they were $250 for the pair. I try to forget such things

 

wow Hardrace has a ton of really nice looking stuff. I may have to look into a few things from them when it comes time to replace.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Erik95LS &raquo;</TD></TR><TR><TD CLASS="quote">wow Hardrace has a ton of really nice looking stuff. I may have to look into a few things from them when it comes time to replace. </TD></TR></TABLE>

Yeah, Just checked out the site ... nice stuff. Will have to give them a call.

 

Looks nice. Anyone in the states we can buy from?

Edo

 

Guys, I was in contact with the owner of hardrace for awhile.

The only way to get his stuff is to order straight from him and get it from behind on the shipping.

He told me he was looking for a US distributor, but I think the buy-in is pretty high.

 

the hardrace design will still have deflection, the bearing sits inside a rubber bushing, looks cool though better than stock.

As for the type of lube used, use the extreme pressure greese sold by McMaster Carr part# 1392k31

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg6vtec1 &raquo;</TD></TR><TR><TD CLASS="quote">

As for the type of lube used, use the extreme pressure greese sold by McMaster Carr part# 1392k31</TD></TR></TABLE>

thanks!