5-Link Design Consideration





Camber gain is the whole reason for the SLA suspensions in most vehicles. (IIRC, old Volkswagens had zero camber gain setups in the front ends.)
You can add static negative camber back there, but you're just bandaiding a geometry shortfall.
So a static negative camber will make the tire correct when the terrific bending forces are trying to make the wheel go to positive camber
Last edited by gkull; Mar 13, 2019 at 12:56 AM.
To simplify it to the most extreme, I shoot for keeping my drive wheels as square to the ground as possible! Whether that is in a turn or going straight! One reason why I like all of those heims and spherical in the back, as they will attempt to self tune all of the different components, being that the tire is trying to stay flat, and likes flat the most! In my case, the more heims and spherical the better! The collective rotation customizes itself, as there is input from traction, road irregularities, suspension travel, etc etc etc. I kind of wish the human body had spherical and heims, as your knees, elbows, ankles, your spine are restricted way more límitedly in movement that something that will self swivel or rotate based on demand, feedback like a spherical or heim.
As I have said in threads in the past, operating on heims and sphericals can be hazardous on the street! I think there are only two cars brands that use them in production- some Porsches and some Ferrari’s! They can cause your tires to be grabbing every road irregularity that exists! The car can wander, track dangerously, etc. If you operate these on the street, then you better stay on top of your driving! These fancy vintage rear suspensions I have are full of heims and sphericals! So why I bring this up!
The front!!!! Camber gain is complicated and actually limited by Steering, potential bump, Ackerman, etc! A lot going on up there! You can bump tune, for your sweat spot! Yet again, I look for having the front suspension self tune! But you have ball joints and tie rods, you can have spherical in your shocks, the arms are an equation where you want steady and sure, and free movement! Why rigid solid bushings were good on our cars!
I personally think the front is what you have to work with in dialing in the balance and front to rear characteristics, but after the setup up of the back, which can net the most competition advantage, if you can get that working great, then I balance out the front afterwards with things like tire pressures, camber, caster, toe, bump, shock settings, tire size stagger or four corner square, cross weighting, spring rates, sway bar size to dial it as best as possible to compliment your rear suspension set up! If you can’t get an advantage! Then just tune and align the front to not cause you to lose.
Last edited by TCracingCA; Mar 13, 2019 at 01:43 AM.
But, changing the discussion parameters a little, since it is not so easy to change the camber gain in the front, how can the mismatch of reducing the rear camber gain vs. the front not make the car a bit tail happy in corners? i.e. "for those who like to oversteer".
Evidently they are thinking you use the lower setting on the street and the upper setting for racing.
Interesting to note that the '63 through '67 Vettes were set up with a higher roll center and more camber gain. Then in '68 they lowered the inner pivot of the strut rods which lowered the roll center and reduced camber gain.The Smart Struts lower the pivot point even more. I plotted out camber gain a while back at the various settings.
I used Greenwood lower Arm arrangement as a reference in my 80. I use a heim joints and run a rod from the front of the rear spindle to a point on the frame close to the front diff mount. Distance from car center for my front mount is the same as the rear link on the diff. This creates the triangle.
My biggest question is what I should do with the pick up points to optimize roll center. Make the lower link parallel then adjust the top a arm inner point down to set camber gain?
Camber gain is 1.5 on car now
Evidently they are thinking you use the lower setting on the street and the upper setting for racing.
Interesting to note that the '63 through '67 Vettes were set up with a higher roll center and more camber gain. Then in '68 they lowered the inner pivot of the strut rods which lowered the roll center and reduced camber gain.The Smart Struts lower the pivot point even more. I plotted out camber gain a while back at the various settings.
One instant mod for a better C2 rear suspension set up, is change to a latter 68 and up camber bracket! As the reduced roll center is a good thing!
I actually should not knock this particular product, as I actually have never bought this setup, used it, worked with it, or even really studied it!
There have been different brackets, with a change of geometry and even what they call a camber plate or block to drop the bracket location! And then I run good old fashion heim end rods! I guess I am in the school to pursue a suspension geometry that is set up right, and this product gives one depending on what you have, a way to dial that in for a wide range from stock components heading toward race! Locking these in would be my concern! In my suspension, I have cotter pinned things, safety wired things, etc to not ever loosen or move!
I am not a fan of stock components under the car, but for the majority that have stock component based suspensions, it fills a niche! Seems like a product that heads a Corvette suspension into the right direction!
Most of of these components should be scaled much like the Guldstrand catalog components were! 1 being pure street, 5 being performance, and a 10 being full race! Such would help an individual marry the components together to a certain planned level of performance! So where do we score the smart links, maybe for usage from a scale from 1-6, or 1-7?
Last edited by TCracingCA; Mar 13, 2019 at 11:28 AM.





The Best of Corvette for Corvette Enthusiasts
The Pacific Coast Championship Race and the Guldstrand car he raced was very old school with like truck springs cut, and beefier shocks! The Penske 1966 was actually pretty stock! The real Corvette handling improvements really started hitting their stride with Delorenzo and the Owning Corning Team (there is a small almost pocket sized book that details there mods) and Greenwood (if you can find a Briggs Chevrolet catalog, you will see the HD parts, as that was the earliest catalog where I have seen the stuff- and pre-Guldstrand catalog), Greenwood who started out more of a truck spring, beefier shock guy himself too, but evolved! Guldstrand basically did assemble the truly first performance and race Corvette suspension catalog! I have most of them! In an article in 1971, he authored the suspension mods to race a Corvette! Even though many around the Country were doing these mods, he I think was the first to share what everyone was doing with an article! I can go get that mag and month year, article! I have the actual article too, but would have to find it!
Last edited by TCracingCA; Mar 13, 2019 at 12:26 PM.





Last edited by TCracingCA; Mar 13, 2019 at 11:55 AM.
I used Greenwood lower Arm arrangement as a reference in my 80. I use a heim joints and run a rod from the front of the rear spindle to a point on the frame close to the front diff mount. Distance from car center for my front mount is the same as the rear link on the diff. This creates the triangle.
My biggest question is what I should do with the pick up points to optimize roll center. Make the lower link parallel then adjust the top a arm inner point down to set camber gain?
Camber gain is 1.5 on car now
The best I have seen was the guy who was working up a Stainless boxed upright in the Greenwood style in a thread awhile ago! He seemed to have designed in the most advantageous geometry that would fit under our cars! If I get into work, I can load a picture of that beautiful piece!
Uestions to you, would be how much suspension travel are you looking to have? How much body roll do you think is permissible? With fitted larger back spaced clearances tires, some using larger than stock Diameter rims, etc many more variables!
My use of a program was more trying to design something to fit rear coil overs! My Guldstrand aluminum uprights have a lower and some clearance, but I think that wasn’t by design, but by accident! A good accident!
The things that gets me, is independent individual side camber gain. I just think body roll kills the best attempts at engineering a reasonable and needed camber progression! Yes street cars need more, to deal with real World wide ranging suspension challenges, but to put it simply—- I just like the car to handle flat, and mainly from four corner springs, not sway bars, and then keeping those tires square, with tracking tire footprint swivel!
My biggest enemy is bad potholed, or dips and holes! Basically have to slow way down, if even a simple short stretch is all tore up. If I hit this stuff at speed, the cars just kind of violently hits and skips over, maybe the tire doesn’t even drop into a hole, but whacks it! Overall if driving on the street, I am just doing my damnest to just get it there! Or where I go play, the roads are better maintained!
When I have found myself driving the cars on the street, I have changed the springs and shocks, and might even throw on some thicker sway bars to compensate, just in case I what to race a Lamborghini still!
But if I am going anywhere at all, where I will be out playing with lethal handling cars, or have a chance encounter, I will leave the Corvettes in full lethal mode and just bare and grind my teeth in the street commute, to get someplace! The last thing I want, is to be embarrassed by like a Nissan GTR or similar!
Last edited by TCracingCA; Mar 13, 2019 at 12:56 PM.





The Pacific Coast Championship Race and the Guldstrand car he raced was very old school with like truck springs cut, and beefier shocks! The Penske 1966 was actually pretty stock! The real Corvette handling improvements really started hitting their stride with Delorenzo and the Owning Corning Team (there is a small almost pocket sized book that details there mods) and Greenwood (if you can find a Briggs Chevrolet catalog, you will see the HD parts, as that was the earliest catalog where I have seen the stuff- and pre-Guldstrand catalog), Greenwood who started out more of a truck spring, beefier shock guy himself too, but evolved! Guldstrand basically did assemble the truly first performance and race Corvette suspension catalog! I have most of them! In an article in 1971, he authored the suspension mods to race a Corvette! Even though many around the Country were doing these mods, he I think was the first to share what everyone was doing with an article! I can go get that mag and month year, article! I have the actual article too, but would have to find it!
Naturally Chevrolet wasn’t putting forth factory efforts, as the parts support network, as geared more for amateur Racing!
I like the vintage racing, because sometimes you have such a variety of different class cars, it is educational! I was watching the Tommy Bahamas yellow Trans Am Corvette going against some dated NASCAR racers and dusting them off! But then they had an IMSA GTO Nissan just blow off that Corvette, as they were leaving peak day Can Am cars behind!
Last edited by ignatz; Mar 13, 2019 at 09:04 PM.













