JSilverman Posted May 10, 2007 Share Posted May 10, 2007 The rules are very vague in this area, and only state that a non metal bushing may be used. I tried searching here but no luck. The ER bushings look to be poly (which is legal) with a metal sleeve, would they be legal for spec? Here is a pic of the bushing: Quote Link to comment Share on other sites More sharing options...
comatb Posted May 11, 2007 Share Posted May 11, 2007 I'm not a rules maker, but I consider them illegal as Bronze is a metal. Tim or Joe, what is your rulling? Quote Link to comment Share on other sites More sharing options...
JSilverman Posted May 11, 2007 Author Share Posted May 11, 2007 Thats why Im confused. Its part poly part metal. The way I read the rules they dont want spherical bearings which are all metal, but these are sort of hybrid so I thought Id ask first. Quote Link to comment Share on other sites More sharing options...
Cory M Posted May 11, 2007 Share Posted May 11, 2007 The poly helps it fit in place but the moving surfaces are metal - so I would say they aren't legal (just my opinion, nothing official) Quote Link to comment Share on other sites More sharing options...
JSilverman Posted May 12, 2007 Author Share Posted May 12, 2007 bump for an official ruling. Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted May 13, 2007 Share Posted May 13, 2007 I am looking into it. I have been on vaction since last week with limited internet and have not had time to think about it. Quote Link to comment Share on other sites More sharing options...
Spec-944#70 Posted May 13, 2007 Share Posted May 13, 2007 You're kidding right Joe? What about "intent" and the "purpose" of the new class rules. These were supposed to not leave any grey areas. This is a metalic bushing and is not specifically allowed in the current rules. But hey do as you want and just keep playing it by ear. Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted May 13, 2007 Share Posted May 13, 2007 Eric, I have known these bushings have been around for while, but never know of their construction in detail. The "bronze" part has always told me metal. However I need look into them a bit more closely to ensure that BOTH the intent and letter of rules are in sync with what we are after. Simply put I need to understand what they are (construction) in greater detail before I state anything either way. The last thing I want to do to say yeah or nay without understanding what the implications are. Simple answer is if in doubt, don't use them. Quote Link to comment Share on other sites More sharing options...
JSilverman Posted May 13, 2007 Author Share Posted May 13, 2007 Eric, Simple answer is if in doubt, don't use them. Im getting ready to do the torsion bars in my car (fun fun!) and if these bushings are legal Id like to use them. I really dont know how the bushings work, so I thought Id ask you guys before I buy them. I tried searching the forum archives and couldnt find any info either. They came recomended by the shop that does my alignments so I figure it cant hurt to ask! Thanks Joe! Quote Link to comment Share on other sites More sharing options...
mfoley Posted May 13, 2007 Share Posted May 13, 2007 I think the word I used before was "arbitrary". I think it still fits. Unbelievable! Quote Link to comment Share on other sites More sharing options...
Cory M Posted May 13, 2007 Share Posted May 13, 2007 If the polybronze are legal then basically any bearing or bushing is legal as long as it is wrapped in plastic. The moving parts are all metal. I don't think polybronze will give you any measurable advantage on track but I don't see how they could be legal with the current wording in the rulebook. If they are legal then in theory one could replace all of his bushings with spherical bearings as long as they have a plastic shim between the bearing and the mounting surface. I do think the polybronze is superior to the weltmeister alternative and should last longer but if they are made legal it should be clearly spelled out in the rulebook. Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted May 14, 2007 Share Posted May 14, 2007 They are NOT legal and here is why. (cory touched on some of it) Rule states that only Non-metallic bushings may be used. Now what does this mean. This means that where the factory used a non-metallic material for a bushing (ie rubber) then you can only replace the rubber with some other non-metallic material. For this location on the t-bar carrier the factory used rubber and 100% rubber over the metal spring plate assembly. When you remove the rubber you may replace it with a differnet rubber compound, ploygrahite, delrin or other non metallic material. These bushings replace a portion of the factory rubber with poly and some with metal. The is replacement of rubber with metal is not legal and would constituite a "metallic" bushing. Now before you go off too far with this let me explain a couple other bushings. Front control arm to crossmember. There are 3 styles in wide use that are legal. 1) Stock rubber 2) polygraphite - 100% 3) delrin with steel sleeve. Not the delrin ones have a steel sleeve. So why is this delrin/metal combo legal? Well the stock rubber bushings are actually rubber over a steel sleeve. The key here is that in the delrin replaces the rubber and both stock and delrin use a similar steel sleeve. Now I have never measured that steel sleeve on the delrins and compared to the stock sleeve, but the are very similar. The delrins are clearly replacing the rubber with delrin and keeping very close to the original metal content. There are two other issues to bring up as well. 968 caster blocks vs 944 caster blocks. The 968 caster blocks are a rubber/metal mix as the stock 944 ones are as well. However the 968 units have quite a bit more metal in them. In THIS case these are legal since the 968 units are standard replacements for the the 944/951 parts. I believe they have been offical superseeded and the older parts are NLA from the factory. So this is a special case where the factory has made the upgrade. This is the same as 951 water pumps where in many cases the only new water pumps you can get are factory parts. The last issue is one of sway bar bushings. The weltmeister sway bars are quite popular and very legal in the class. They have a different mounting and the best practice is to use the mounting hardware they supply. In many places metal is used for bushings supportting the bars to the body/suspension. I want to make it clear that these standard mounts are legal since they are part of the sway bar mounting. Since any sway bar is legal you are free to mount it as directed by the manufacture of the bar. I hope this all clear and I also hope you understand why I wanted to think about this before I came up with yes/no answer. Quote Link to comment Share on other sites More sharing options...
comatb Posted May 14, 2007 Share Posted May 14, 2007 Joe, thanks for the ruling and clarifications. I agree totally! Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted May 15, 2007 Share Posted May 15, 2007 Sounds good to me. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.