Leonel

Which bushing should be replaced while replacing the t-bars? What will be a good replacement,stock,Weltmeister or Racer's Edge?Keep in mind this car is driven mostly on the streets .

Skip

The inner and outer spring plate bushings are the ones that are normally replaced when doing T-bars. The factory rubber is molded to the parts, and cannot be replaced except by replacement of the whole unit.

Weltmeister (poly-graphite) deflects slightly more than the Delrin material used in the RE bushings. I prefer the Delrin because it *will not* squeak (to my knowledge and experience). The Poly-Graphite will squeak if not kept lubricated properly (funky moly stuff). Some folks have added a grease port to the outer, but there's really nothing you can do for the inners.

My vote is for RE Delrin, but you should wait for others to chime in.... since I'm:

924RACR

You mean the spring plate bushings, ja? Unless I'm mistaken (and perhaps someone here will know better than I) you cannot buy new replacement stock spring plate bushings (in rubber). Rather, the replacement of the stock parts involves completely new spring splates, as the bushing rubber is vulcanized onto them. Therefore, unless you want to buy new spring plates, you're stuck getting Weltmeister and/or delrin replacements.

I'm bummed, because though I have the delrin and Weltmeister bushings for the rear of the racecar, I'd like to get new stock rubber ones for my street turbo...

Skip

And, the reason some of us (like Vaughan and I and many others) have a mix of the Delrin and Welt bushings is because the inner bushings were not available in Delrin until recently.

Skip

M758

I have been using the weltmeister black poly bushings on my t-bars for the past 2 1/2 years of autocross, DE and Racing. Unlike the black front suspension bushings these have held-up very well. I reciently swapped 28mm tbars for 30mm tbars. In that process I inspected the bushings on the spring plate and also for the carrier mount to the chassis. They all looked fine. I really cannot say if they squeak or not since they are on a gutted race car, but I can say that they can stand-up to track duty in the rear.

Unfortuanlty I have not been happy with the Welts on the front either black or reds with my steel arms. Seem to be better than stock rubber, but not good enough for hard track work. Sphericals are not legal for my class so I am working with Skip and Jason on delrin in the front.

Leonel

So,if I replace them with the RE delrin inner and outer bushings ,i won't need to replace the whole spring plate,right?

924RACR

Wow, Skip really was all over that one! <img border="0" title="" alt="[Wink]" src="wink.gif" />

Skip, I don't suppose you guys sell the rear trailing arm inner bushing replacement in delrin now, do you? I need to upgrade, still have stock rubber there, but don't want the expense of a bearing really. M758 - you said you found the plastic a-arm bushings NFG for track use? I take it you're talking about compliance, yes, not wear? Can you elaborate? I have trouble comparing, since I went straight to spherical on the front. However, I'm thinking hard about doing the front of the next car in plastic of some sort, due to the expense and intent to see some street use. I'd like to hear more feedback...

Skip

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Leonel:
<strong>So,if I replace them with the RE delrin inner and outer bushings ,i won't need to replace the whole spring plate,right?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That is correct. However, wait till you get to remove the vulcanized rubber from the spring plate... heat, pliers, knives, good ventilation, and a lot of patience needed. It's not hard, just not much fun.... well worth it, though.

Skip

Skip

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 924RACR:
<strong>Skip, I don't suppose you guys sell the rear trailing arm inner bushing replacement in delrin now, do you? I need to upgrade, still have stock rubber there, but don't want the expense of a bearing really.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Yup - just checked to be sure it's on the site (MC-3001)

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>M758 - you said you found the plastic a-arm bushings NFG for track use? I take it you're talking about compliance, yes, not wear? Can you elaborate? I have trouble comparing, since I went straight to spherical on the front. However, I'm thinking hard about doing the front of the next car in plastic of some sort, due to the expense and intent to see some street use. I'd like to hear more feedback...</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I don't want to answer for Joe, but I do know some of the info you're asking for. We are working with Weltmeister and Racer's Edge to attack this problem on two fronts. First, the poly-impregnated rubber Weltmeister bushings (new, red) are not intended for *racing purposes*. We all know that line, and why it exists, but it seems in this case to be very true. We're hoping the issue can be fixed by slight modification to the design (like adding a metal collet to increase load and torque compliance). If Delrin is suitable for the front control arms as a bushing, then these should be considered the choice for racers that can't or don't use metal - I don't have a schedule for availability, but it is "in the works" (partially thanks to Joe - thanks, Joe!)

Skip

924RACR

No, Skip, what I mean is a delrin equivalent of MC-2550 - the bushing replacement for the rear trailing arm.

M758

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 924RACR:
<strong>M758 - you said you found the plastic a-arm bushings NFG for track use? I take it you're talking about compliance, yes, not wear? Can you elaborate? </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">As skip said for me it is wear think. Both ovalizing of the main hole and breaking of the outer ring due to braking loads. I will not say they won't work on a street or for light track duty, but I am starting to race my car pretty hard and seem to be able to bust through a set in a weekend or two. Remember this is with toyo race tires and race pads KFP magnum's that Paragon sells. Seems like the pads work too well <img border="0" title="" alt="[Wink]" src="wink.gif" /> .

But, the rears black welts seem to be a-ok.

Dave E

M758, Did you install the updated caster blocks Porshe recommends when 17" wheels are used? or are you using the stock ones? Maybe the amount of deflection in the rear mount is causing the accelerated wear. Let me know, I bought a set of those red bushings from Paragon and wasn't told they aren't good for the track and didn't find out until it was too late. I'm now looking for a solution that wont force the change to the expensive (not to say it's not worth it) monoball/casterblock setup from Racer's edge.

924RACR

Wow, and you're not even running Hoosiers! I am, with the KPF Magnums (love those pads!!!) and I guess I'm glad I went for the sphericals!

The rears, you're talking about the torsion bar housing mounting bushings, right? Or does Weltmeister in fact make trailing arm bushings? That's what I'd like to know. I might yet get the RE spherical inserts, but want to know the options. For the mounting bushings, we fabbed our own aluminum inserts (actually a copy of the 933/D-Prod parts).

M758

Dave E:
My car uses the steel control arms so upgrading to 968 rear blocks are not possible. The rear caster blocks on have never seem to give me a problem. If you look at the arrangement the car pushes on the control arm through the cross member. The pushes on the bush and effectively tries to shove it through the hole in the control arm. The caster block cannot resist this to any large degree. It is just physics. I also use 15x7 cookie cutters with 225/50 Toyo RA-1's.

On the steel arms the ring on the control arm is just that thin steel ring. The aluminum arms have cast hole and I think more wall thickness. It looks to me like the thin ring on the steel arm is such that bushing does cannot hold this back and cuts though the outer flange of the bushing. The aluminum arms may not have this problem since they distributre the load over a gearer bushing surface area.

Also remember that there is difference between racing and DE. I am driving the car VERY hard lap after lap after lap. Idealy I would get spherical's, but due to cost and mostly the rules my bushings must remain non-metallic.

Vaughan: I was just talking about the spring plate bushings that the non-moving t-bar carrier mount to the chassis. NOT the trailing arm mount to the t-bar tube. I do not know and have not found bushings for this area.

924RACR

OK, yeah, we're on the same page. Thanks. Dude, you should talk to Shine Racing Service in MA (www.srsvw.com). That's where I got my spherical front bearings, about $285 as I recall. They're honestly not as nice as the RE parts, they press in and weld in instead of screw in, and if you bend an a-arm your spare better already have the replacement bushings on it, but hey, they're cheaper. Though based on my experience in having to replace suspension arms at the track, I'd consider going with the RE parts next time around for replaceability.