I recently saw an ad for National Parts Depot advertising new repro knuckles for early Camaros. I starting thinking that if they could do this then they could make them slightly taller for improved geometry.

So I called to find out who was making them. I was informed that they aren't available yet but that the company making them was a subsidiary of Classic Industries. I called Classic Industries and got the name and extension of their "head tech guy", Bob Brennan at extension 309.

I called Bob and tried to explain that stock spindles modified to be slightly taller would be marketable. He replied that they only create stock reproduction parts for restorers and leave performance improvements to someone else. I tried to explain that many "restorers" would accept a part that looked that close to stock but offered an improvement. He said he would follow up but that he didn't expect anything to happen. I'm not sure he intends to do anything, he didn't seem very interested in the prospect.

Maybe if enough of us call or maybe if someone with more time (and more detailed knowledge) could pursuade or find the right person to talk to we could convince them there is a demand for a knuckle with a slightly taller height.

I really didn't and still don't expect this to happen, but it is a slight possibility.

I know we are finally getting close to having options from Wayne Due (Mark's spindle) and Kyle, but still think an option for stock brakes would be good for many of us. (And there are already bigger brake kits that work on the stock spindles, including David's CBB.)

68SSConvt

[This message has been edited by 68SSConvt (edited 01-30-2001).]

Thanks for the info.
You know GM made taller spindles for the road racers back in 69!
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

I have also spoken to companies about a taller stock-type spindle with the same results. It's frustrating seeing ads offering dropped spindles that "will not affect factory suspension geometry" when the original geometry is the biggest weakness of the first gen. It's a shame that these companies will spend the time to re-engineer a spindle for a 2" dropped ride height but don't make the spindle slightly taller while they're at it.
I am also one of those who would prefer a stock type spindle, as I have recently purchased a 12" disc brake kit that bolts to the original type spindle, and I'm not sure if the taller ones being developed now will be compatible.

David, I didn't know about GM offering taller spindles. Where did you get this information? I assume there was special tooling for this? I think the new spindles were going to be made using GM tooling, or at least that's what the first guy (at NPD) said. If tooling exists for the tall ones and we can show Classic Industries that the part was available from GM, then maybe they will consider making them. Did the tall spindles have any other differences from stock?

I'd also like to talk to them again about this from a marketing standpoint. I don't think they realize that they will only sell stock ones to people without them, but could sell upgraded ones to many more people.

Ray

If I read Global West's literature right, their "negative roll" system is based on a taller spindle. They claim that dropping the upper control arm pivot 1 inch is still not enough! How tall is their spindle? They say that when they made it tall enough to get "negative roll" they had to redo the brakes, upper control arms etc. because stock parts would no longer work. Of course this means lots more $$. Again it sure would be great to see some track testing of Gulstrand vs. spindle extenders vs.Global West etc. to see how much improvement you could expect from each .

cls, yes the Guildstrand mod isn't enough alone. That is why Mark Steilow and Kyle tucker combined new taller spindles with relocated mounting points.

Global West's system uses a stock spindle off of some other vehicle that had the right height difference. But this spindle wouldn't work with the stock brakes and the steering arm location required making a new center link to avoid excessive bump steer. They created a new upper control arm because increasing the spindle height results in needing a shorter arm or having excessive shims to align the car. (Kyle and Mark also created shorter upper arms.) All of these arms also have more caster built. So most of GW changes were done to make the spindle they found with the correct height work on our cars, with the added plus of claimed zero bump steer.

Global West's system seems great, but not cheap or close to stock. I might be interested, but it is designed for stock mounting points and I've already lowered mine and can't go back.

I asked them and they said that there system would have too much neg. camber if used with lowered mounting points. I also asked their opinion on using the Guildstrand mod with the Pro Motorsport extenders and gave them the specs. They said that would be too much. I assume there spindles are between 1.25 and 1.75 inches taller than stock. (Just a guess.)

My question is, exactly what is the optimum hieght increase?

I think the spindle extenders (1 15/16") used alone might be a very good and economical option, but not with my lowered mounting points. Some have an issue with the strength of just a bolt through the tapered ball joint hole. Couldn't a bushing be created to fill the void area, similar to the bushings used to adapt different taper ball joints and holes?

Hurry up Kyle and Wayne!


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Ray

68 SS Convertible
Corvette(77) Yellow
383 DFI Fuel Injection
on MiniRamII intake
700R4, 3.31 12bolt Posi
Guildstrand Mod
AGR 12:1 power steering

[This message has been edited by 68SSConvt (edited 01-31-2001).]

So it would appear that the spindle extender actually gets you higher than the GW spindle. You are right--what is the optimum height? Does the Gulstrand lower mounting point give you some advantage that the increased spindle height does not?

The GM taller spindle is pictured in the "Camaro Untold Secrets" book. It was a racing option as SCCA didn't allow moving frame mount locations.

The Pro Motorsports extenders give almost 2" taller upper ball joint mounting. This looks to be too much if you look at what it does to the roll centers. The way it's made, I believe you cant do it any shorter. It is an improvement over stock but goes to an excess the other way.

It does give a lot of negative camber gain, but that is not all a car's suspension should be designed around.

the Guldstrand mod (about 3/4" lowering and a small reduction in anti-dive) was designed for Penske's Trans Am Camaro in the late 60's, probably for racing ride height and for the Goodyear Blue streak sports car special tires that were used.

The ideal amount of camber gain and roll center height should ideally come from an engineer like Kyle Tucker based on todays radial tires. I would suspect that slightly more neg camber gain (and resulting higher roll center) than the Guldstrand mod would be best, But that's just a guess.

I feel the Guldstrand mod is so close to ideal that it's the best thing we can do for now.
If you wanted to be a little brave you could go another 1/4" lower.

I think when you are this close to optimum, there would be little gain from lowering the inner mount more, maybe 1mph through a slalom.

The global west spindle takes second gen rotors and components, I suspect it's a second gen spindle with steering arm mods to make it work on a first gen.
The first gen ball joint tapers are different too.
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

cls, that was just a guess on the GW height. It may be a little more than this. GW didn't tell me the measurement on their spindle or what it came off of. Anyone here have one they can measure, just for curiousity's sake?

The goal is to move the upper ball joint higher in relation to the upper mounting points. Since the stock ball joint is lower than the mounting point, when it moves up the arm swings outward, causing positive camber gain on suspension compression. This is opposite of what you want.

I don't think it really matters how you accomplish it. You can change one or the other, or both.

I think the biggest advantage of moving the mounting point is that it is free and can be done at home with simple tools. The disadvantage is that it isn't just a bolt on and can't be undone, and there is a chance you may do it wrong and screw things up.

And yes, what is the optimum height??
Any of the experts out there?

I read a post here (I think from David?) that said Guldstrand tried lowering it more but decided it didn't help. The same post mentioned that maybe with the tire technology changes that now more would be better. I'm curious as to what the original reason was that going more was decided against.

Supposedly, suspension modeling shows that more would improve the camber curve, that the current mod doesn't actually create a negative camber curve, just reduces the positive curve. I just don't know the correct number. (I haven't done this myself.)




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Ray

68 SS Convertible
Corvette(77) Yellow
383 DFI Fuel Injection
on MiniRamII intake
700R4, 3.31 12bolt Posi
Guildstrand Mod
AGR 12:1 power steering

David, we must have been typing at the same time. You answered some of my questions in the above post in your post above it, that wasn't there when I started typing.

What was the reasoning behind removing some anti dive, is there some performance benefit, or was it just because it was hard to lower the rear point as much as the front?

And yes, I agree the optimum measurement should come from an engineer. That's why I'm patiently awaiting the supposed future offerings from Kyle and Wayne(Mark's design).

Ray

I e-mailed Kyle somemore questions on superbowl sunday. You can tell what I think of football, Eh.

I asked him about using Stock Car Products, Inc. semi-finished custom forged spindles and bolt on steering arm with the lower balljoint mounting hole. To create a custom spindle that is about 9.060" tal vs our cars stock spindle height of 7.125". Making one this tall will also raise the wheel spud, and so will drop the front, too.

The down side of this conversion is MONEY, and lots of it, right, David!! By the time you buy the spindles and arms and machine them, look out.

I will post Kyle's reply's.

Please read the last few posts at this long winded thread that Teetoe started for Kyles answers to some of my earlier questions, "Gauging intrest in custom frame for Kyle Tucker suspension!!!". It's just 5 or 10 days old. pdq67