shiners780

Karl Poeltl from Racer's Edge listed some time ago the weights of various LCAs. I have no way to verify these figures, but I trust he had done his homework:

Stock 5#
Charlie arms 7#
Racer's Edge 8#

When I received the Blaszak's, I weighed them myself on two different scales and they came in at 7#. I weighed the Blaszak's WITH the spherical bearings attached. I am not sure if the other LCA weights included bearings.

I'm not trying to be argumentative, but if these figures are indeed correct, then the point presented in your first paragraph is mute.

ENGINEERMAN

I checked this morning and indeed they are installed with the vanes rotating properly. I must have a set of rotors that, as you stated, goes against conventional wisdom. However with that said I have no issues with cracking or warping going on. One thing that I have noticed though is that my sons 87 951 requires much less pedal pressure to stop at any given speed using the standard 951 brakes vs mine with the Lindsey Racing Big Reds. Mind you they stop the car all day long with NO fade at all but you just have to push quite hard especially when slowing from high speed for a tight turn (modulation is very good though). It is a little disconcerting at first but they do get the job done admirably. I have switched from Pagid Oranges to Hawk HP Plus pads which eliminated the squeel of the Pagids and the Hawks seem to bit a lot harder too.

I have the stock master cylinder and assume that there is some mismatch going on or something like that. Any ideas?

Re the Control arm failure and the 19mm Geometry Correction ball joint issue, I spoke with Travis at Rennbay again today and he confirmed that they have over 400 sets of the 19mm GC ball joint kits ALL installed in aluminum 944 track car applications that have been lowered. There have been zero failures reported and he has never seen that failure mode due solely to stress failures. He says that the only failure mode of aluminum 944 Control arms has been either in instances where fracture occurs in the ball joint area of the control Aarm resulting from lowering and the consequential ball joint binding using stock ball joints or of ball joint pin failure in instances where the customer forgot to tighten the pinch joint. With that said I feel pretty comfortable that my set up is going to be ok based on my level of usage.

Best regards!

Tom

Skip Wolfe

I give up - you guys win.

2bridges

Just from [pictures my gut says your weights are off. I suppose you used a people scale??? very innacurate in the <20lbs range

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I also did a substancial amount of research and consultations about control arm and pin failures. I have yet to see or read any first hand experience of a arm failure that did not have a bind impact. I even got pics from one person claiming a true arm failure without bind...... pics say different - without a doubt impact from bind.

All pin shear events were with a bind event.

shiners780

Not "my" weights, those figures are from Karl at Racer's Edge. I don't know what type of scale he used. His reputation being what it is, I don't think he would throw false numbers around. Again, I have no way to verify. Maybe someone with an accurate scale and a control arm will chime in.

I weighed the Blaszak's on two different 'people' scales. I obtained the weight by holding the CA and weighing myself, then setting the CA down and weighing myself without it, twice on two different scales. So it's more in the 165# range, not the <20# range. Sure, the scales could be off a # or 2, point is the CAs aren't boat anchors as was implied.
Hey, I'm just trying to keep the facts straight is all. It's all for fun and in the name of science......love ya man!

shiners780

I just remembered I had my old stock control arms in the basement. Same scales I used to measure the Blaszak's previously, measured twice on both scales with me on the scale as well, 6#.

Here's a side by side comparison pic just for kicks:

Skip Wolfe

Out of curiosity, how much did you pay for you Blaszack arms?

shiners780

I'm not tellin'.

Because you're just going to tell me that for an additional $xxxxx I coulda bought some Charlie arms, or Racer's Edge arms, or...

Alright...$1175, includes the spherical bushings and the nifty 'made in Canada' decal.

Skip Wolfe

Hah - you could see that one come from a mile away couldn't you. Well not to disappoint...

For $425 you could go from this:



to this:



That equates to only a half a set of track tires, or one weekend at Watkins, or...

You may very well have gotten me on the weight issue - I was assuming on the weight - my bad. However, while I argue that the Blaszak arms have some fundamental design flaws - improper use of rod ends, and putting the ball joint end of one member and the caster mount end of another member under bending forces, all of which are subject to failure due to cyclic fatigue, you argue that to your knowledge none have failed therefore they are fine. That logic (it hasn't failed yet therefore it is fine) cost my company close to $1M in warranty related expenses this year so it just doesn't sit with me well.

OK - I'll stop picking on your arms - just hate to see anything happen to a fellow track junkie.

Oddjob

Either that pic is distorted, or those arms are different length - early & late offsets?

FYI, Fabcar arms are approx 7 lbs each - including the balljoint pin, but not including the front mounting bushing or the rear castor block and eccentric.

Chris Prack

Except you cannot buy Charlie arms right now. He has been out of production for some time. Supposedly he has someone else working on them but until they meet Charlie's approval you can't get them for any amount of money......

shiners780

Using that same logic, just because boring out a spindle to accept the 19mm ball joint pin hasn't yet caused a spindle failure doesn't mean it won't eventually either ....

It's all good Skip, I'm just toying with you now. I completely understand your logic and reasoning and you have made some excellent points. Thanks for that.

Oddjob, the arms are the same length. I must have had the camera at an angle when I snapped the pic.

Skip Wolfe

Hah - that's were I got you. I talked to Charlie and he actually calculated (real engineering not anecdotal failure rates) the strength of the bored out knuckle vs the strength of the pin and said it did not significanly weaken the knuckle. He actually got mad at me when I asked about using a 17mm pin, and told me I was an idiot if I considered using a 17 mm pin - classic engineer - brilliant guy with zero people skills.

Chris Prack

That's Charlie!

ENGINEERMAN

Hi Reno808:

Do you mean on the front sway bars where the project through the factory drop link? No one ever mentioned that to me before. There is no groove for a C-Clip and I reaaaaly don't want to take that assembly apart again (it's a bitch getting the drop links connected to the control arms)! In my case the sway bars project all the way through the rubber bushings by more than 1 inch. Things would really have to move a lot for them to come out if that's what you are referring to. Can you please clarify that that is what you are talking about.

Thanks!