Second gen Trans am LCA question

[Takid455]

I did a search in this forum hoping to find an answer but found a bunch of dead ends. I am looking for a set of Tubular lower control arms. I understand that geometrey will remain the same which is good. I am running coil over's, so a little more strength wouldn't hurt. I have gw's UCA. other than stock or GW's , I can't find any that will be able to take stock diameter bushings (i am a fan of intercahangability should you need to replace something in a hurry). looking to fit Del a lum bushings into the LCA. I have look at the following companies and this is what I have found:



GW's - seem like the best choice, costly
BMR - seem just as good as GW but have their own size diameter bushings (no interchangeability)
Heidts - seem good, but when you have to add the cost of del a lums, you are better off going with the gw's
Stock - well , its stock, simply put. strength??

wondering if anybody has any input on this subject.

[BonzoHansen]

To add to the issue, didn't the LCA bushing change over the years?

[Takid455]

I believe 70-74 and 75-81 are the dates that interchange. i am concerned w/ the later . car is 1978

[JoshStratton]

I am not so sure you would need tubular lower control arms. The 2nd gen stock lower arms should be perfectly fine with a little bit of work...even with coil-overs.

Hopefully David, Matt or one of the other suspension guru's will chime in here...

[zbugger]

If you're worried about strength with the stock lower control arm, you might just think about boxing it. Being that you're running coil overs, I'd recommend adding a little plate to the mounting on the arm for better strength. Also keep an eye on the ball joint area as it's the usual weak spot. You can also pop the Del-A-Lum's in them. Otherwise, just go with the GW arms.

[Mean 69]

It is not our policy to hype up future products, but we are well into the development of stock frame type, tubular upper and lower control arms. It so happens that the first iteration is teh second gen F body platform, mostly because the customer car we are working on will be getting the first set. They should be very nice, there's not a whole lot you can do to a control arm that hasn't been done already, but we have a few things that will find their way onto the designs that don't seem to be out currently. In addition, they WILL be coil-over compatible, and that's all I am going to say on that at this point.

There's a huge amount of differences in the lower bushings over the years, as well as differences from Camaro to Firebird in certain years too. It's a mess. We are likely going to standardize to the earliest Camaro (1970) design, because it is the same as the 67-69 F body design, so for us at least, it'll help us in terms of inventory, etc. This is not completely set in stone. Bushings will be the slick nylon type deals invented long ago for the race cars, and developed by folks like Global, DSE, etc, for the street cars. They work. Engineering design will be completed this week with a bit of luck (already mostly completed), prototype arms will happen quickly thereafter. We'll be doing an announcement on this and other forums when we have some pictures of the actual products. They may, or may not be what you are looking for, but it's probably worth your time to wait and see how they come out unless you need something right away.

Thanks,
Mark

[Takid455]

matt
I don;t need then right this moment, so I will wait and see what your's look like. the nylon inserts, are they anything like the greaseable del's? do you have an estimated cost. i assume they will come complete with ball joints and bushings, correct? any differences in weight (hopefully lighter).

[Bandit]

I was looking at doing the same thing, but later changed my mind. Most of what I read seemed to indicate that my $600-1000 could be better spent in terms of handling. First, the stock arms are strong, probably stronger than most aftermarket ones. So you save 5-10 lbs of weight with tubular arms, but is it worth it? In my case, I threw a full set of PST Polygraphite bushings into the stock arms and called it a day.
Save the money and put it towards a killer tranny!!

[Mean 69]

I'll agree, there is only so much an aftermarket control arm can do functionally, but there can, without question, be significant benefits.

From a geometry standpoint, the control arms can (and ours will) be made to induce additional static caster that is not possible to get with the stock arms due to clearance issues with the frame. Caster is important from two different standpoints, one, it aids in straight line stability due to the additional king pin/caster "trail," helps keep the wheels in a self correcting straight orientation. Gives a bit of steering feedback in turns, too, which is a good thing. Second, all things being equal, additional caster has benfits to the dynamic geometry, in particular when going around turns. It will actually help negative camber gain a bit, and also helps load the inside tire a bit (as well as the rear outside tire), which can benefit overall cornering "grip" by taking a bit of the load off of the laden front tire (which sees the majority of the weight transfer in the general case).

From a strength standpoint, the stock arms in general seem to be just fine, I've never seen a broken one. If engineered correctly, it is possible to get equivalent, or greater strength while reducing weight by a fair amount. Strength by itself shouldn't be THE compelling argument to go with a tubular arm, though I have seen some scary aftermarket arms that I would never put on my own car.

Bushing choice is highly subjective, but the fact of the matter is, that unless you can keep a poly bushing well lubricated at all times, they will bind, period. Even the impregnated materials suffer from this, the squeaking that is typically heard is evidence. I have never had good luck with them, but they are clearly very popular. Do a search on this topic and I'm sure you'll get a ton of info. The nylon and synthetic derivitives (Delrin, Nylatron, Acetal, etc) are pretty darned good for a bushing design, they work really well. Delrin is used a lot because it is very effective, machines really well, and it is affordable. We are looking at some of the more recently developed alternatives, but so far it is not apparent that the better material properties outweigh the cost. Friction coefficients are the main benefits, but since the bushings in general are lubricated as a service procedure, it might not (or it might) be a compelling argument to go with something more exotic.

The last big benefit from our standpoint with going to a tubular arm is clearance for a coil-over conversion (a "true" coil-over, not like the helical units on the market, but rather the type used in racing). This is important because it allows relatively easy adjustment and tunability, as well as the ability to swap out springs without having to worry about ride height and corner weighting, you can easily tune the setup.

Anyone that has ever spoken to me knows that I am a function first type of person, but let's face it, a nice tubular arm looks a heck of a lot better than the stamped pieces.....

Mark