[57vette]

Here's a question for our good moderator David Pozzi. How big a difference in handling can be gained by a decent coil-Spring/leaf-Spring vs a 4-link? Many of us think a 4-link/coil-over is the Valhalla of suspensions but OTH, many don't have the budget for one. You've been racing and autocrossing Gen1's for long enough to perhaps give us some pointers and results.

I'm curious (sure others are too) about just how good a leaf suspension or 4-link can be tweaked to deliver the best possible street performance, and maybe the occasional autocross event.

This might be a redundant question, and if so I apologize.

 

[Larger Dave]

Leaf springs where used on horse drawn carriages and wagons. Just because it is older than dirt doesn't mean it won't work, it just means in the past couple of centuries a more flexible (adjustable) system wouldn't arise to meet the needs of racing.

I personally can not think of any competitive race car aside from one that was rule restricted that uses leaf springs due to it's lack of suspension tuning capability. NASCAR circle track cars uses coil overs on the end of truck arms unless they are road racing in which case they go to a four link and Watts linkage.

Drag racing (those that aren't solid mounted) use a three or a four link system with coil over shocks; because you can adjust it to match track conditions. The three link is a modified four link with the top control arms joined to form a wish bone structure to be able to run without a Panhard bar.

Unlike a traction bar that can not be used on the street due to the bars binding if the rear end articulates, the four link is able to follow any amount of wheel movement; which is why they are used in off road all wheel drive competition vehicles and rock crawlers.

Even the factory used a four link on their Chevelle and the full size Chevrolet that had a live axle with coil springs (IRS used A-arms on the Corvair and the Corvette). Leaf springs were used on the Camaro and the Nova because they were cheaper to produce (though the Chevette and Vega had trailing arms and coil springs similar to light trucks).

Big Dave

 

[57vette]

LOL... Dave, as noted above I'm with you 100% on progress, but I think you missed my point. If we followed the "outdated technology" point of view, then Hotchkis, Global West, Ride Tech, Eaton Detroit, and a number of other companies marketing leaf springs had better close down those operations. BTW, I wonder where the transverse corvette leaf spring fits? It was an "independent" suspension, yet it employed a horse and buggy leaf spring!

What I was asking, was there any gain from using (obviously less expensive) alternative rate leaf springs like the Hotchkis/Global West over stock spec leaf springs. And of course using those springs in concert with other suspension parts like sway bars, traction bars, slide-a-links, relocated rear shocks, adjustable shocks... assuming the front end was "improved" as well. There's all kinds of opinions about 3 or 4 link setups, and torque arm setups, ladder bar setups. But can the 1st Gen owner build a better handling car _without_ going the multi-link route. Not necessarily _better_ than a 4-link, but significantly better than any _stock_ 1st Gen.

I've been a believer all my life that almost anything mechanical can be improved if the time and energy is applied to research it and test it. My last ride was a Ford SVT Lightning. Ford's SVT engineers changed spring rates, ride height, shocks, and a bunch of other things to make the truck totally out-handle a standard F150 and in fact out handle many cars. In my own truck, I ran Hotchkis leafs, Strange adjustables, Ground Force coils, different sway bars, and with a 3" front and 4" rear drop over the stock SVT... my truck handled like it was on rails compared to a stock Lightning. Granted it wasn't a race car... but it was pretty amazing considering the weight and lack of any real aerodynamics.

 

[Larger Dave]

When you add a Slide-a-Link (or what was called a pipe inside a pipe back in the forties), or a traction bar (slapper) you are in effect converting your spring into a barely adjustable four link (Cal-Trac has only one other hole you can choose plus the preload adjustment). These issues are covered in most books on suspension with force diagrams and illustrations describing how the adjustments affect the instant center.

Will Eaton Detroit Spring, Moog or Eaton go out of business tomorrow? No. There are too many cars on the road today that need to have their old sagging springs replaced before they crack or break from metal fatigue.

Why would any one want to replace their leaf springs, move them inboard to clear a bigger tire, or in any other way modify their Hotchkiss style suspension? Simple: it is cheaper than back halving the car. Plus there are those pesky purists who think you should never attack a sacred Camaro with a torch (needless to say I am not one of them).

It is only because Camaro bodies became too expensive that I switched over to the "Stretch Limo" version of the Camaro body called a Nova. I have been just as fast (low nines) with both body styles, but the Nova was able to sucker in a lot more grudge matches than I ever got with a Camaro body.

The down side to a Nova is the rear quarters have fender skirt styling that restricts tire size unless you put everything well inside the rear quarter of the body which requires a back half for the room needed to install my ten bolt rear end (count them my Dana 60's all have ten bolts holding on the rear inspection cover). I used to run 14 inch wide slicks that fit easily on a 1967-'68 Camaro by taking a saber saw to the rear quarters to remove the outer lip (there is a bit of the tire that sticks out, but back then that was expected). This was impossible to do with leaf springs and a Nova body. Once again purists go rabid over sawing on a Camaro, but it is how I ran my '67 and '68 Camaros back when they were for sale on used car lots.

Big Dave

 

[DOUG G]

4-link give you a lot more adjustability.

I know this isn't a rode course or cone race car....but...Leafs can and do work. BUT, you need to put the time and effort into it, as with any suspension
Leaf Spring Tips and Tricks from X275 Racer Ron Rhodes - Hot Rod Network

Mid to low 4's in the 660' on leafs with a small block

 

[flat tire]

I clicked the above link and


Dangerous Web Page Blocked

You attempted to access:

Leaf Spring Tips and Tricks from X275 Racer Ron Rhodes - Hot Rod Network

This is a known dangerous web page. It

 

[DOUG G]

I got no flags when I went to it, more than a few times :scratchinghead:

 

[scblucam]

Works fine for me. Where you been hanging out?

 

[57vette]

Hmmm... I guess I didn't think straight when I wrote the original post. I did post it here in the "ProTouring" section where I thought nobody would interpret it as what works best for drag racing. My bad on that. I probably should've asked the question over in the ProTouring forum. But I was asking Dave Pozzi to perhaps comment on improving street handling with maybe the occasional autocross event, nothing else.

Aside from my mistake, the link Doug posted was pretty interesting from the drag racer's perspective. And while I get that "warning" on a few web pages on my iPad, I don't get them on my desktop iMac. It's something that has started with the last two iOS upgrades.

 

[3d cad]

Not too many here mention auto x and road courses. I dont think there is anything in that drag article that you can use. That setup has been around for decades. Only thing he's missing is a birdcage. One of my friends has the calvert split mono setup in his camaro and its no peach on the road. I hope to auto x my car when its done. Not seriously though just for fun. I would like to see if i can beat the time on the same course on the same day that i run with my mr2. I dont think that would be possible with leafs though.

 

[Larger Dave]

I tried Auto Crossing with my Camaro in the early seventies. We (the sports car club) held events in the parking lots of USF.

It is were I learned about under steer and over steer and how 95% of USCC members drive small light narrow European imports (back then it was MG, Triumphs, Fiat, Volvo, Morris Minors and VW Ghias). They set the turns up for their turning radius, not an American made behemoth like a 427 L-88 powered Camaro. All I could do was make tire smoke and eat cones. Still tons of fun and a good learning experience.

Big Dave

 

[DOUG G]

I was only pointing out... leafs "can work" with some tuning and the right supporting components regardless of your "sport".

Most guys here will never need anything more, but a lot can happen with just the right tires, shocks, sway-bars, and suspension tuning.

 

[57vette]

Not too many here mention auto x and road courses. I dont think there is anything in that drag article that you can use. That setup has been around for decades. Only thing he's missing is a birdcage. One of my friends has the calvert split mono setup in his camaro and its no peach on the road. I hope to auto x my car when its done. Not seriously though just for fun. I would like to see if i can beat the time on the same course on the same day that i run with my mr2. I dont think that would be possible with leafs though.

One of the reasons I posted it in the PT section. I agree with both you and Dave that drag racing and cornering are two different animals. I had an MR2 once, what a fun car to drive... my son was forever "borrowing" it LOL.

I tried Auto Crossing with my Camaro in the early seventies. We (the sports car club) held events in the parking lots of USF.

It is were I learned about under steer and over steer and how 95% of USCC members drive small light narrow European imports (back then it was MG, Triumphs, Fiat, Volvo, Morris Minors and VW Ghias). They set the turns up for their turning radius, not an American made behemoth like a 427 L-88 powered Camaro. All I could do was make tire smoke and eat cones. Still tons of fun and a good learning experience.

Big Dave

Dave... I've been to a few of the recent GoodGuys events here in MASS (2 miles away) where they had set up an autocross and ironically some of the fastest cars were Gen1 Camaros! Some had 4-link, a couple were Hotchkis leaf cars IIRC. I'd say if there were 15 real autocross vehicles, 6 or 7 were older Camaros. Unfortunately they gave up the venue here and moved over to New York. Also seen some nasty little "pickup" trucks run that course.

I was only pointing out... leafs "can work" with some tuning and the right supporting components regardless of your "sport".

Most guys here will never need anything more, but a lot can happen with just the right tires, shocks, sway-bars, and suspension tuning.

Agreed... 4-link is the cats-meow and the better leafs are an _improvement_ over stock but no match. But yes... most of us can get by just fine with a tweaked leaf suspension for more enjoyable cruising and the occasional twisty. My favorite is Route 2, the Mohawk Trail from Greenfield to North Adams.

 

[BPOS]

I know this wasn't about drag racing, but since it was brought up...

My brother's 69 Nova. Stock rear wheel wells (no tubs), Cal-Tracks and split monos, 10" slicks. Nuthin' fancy. 5.3 LS turbo and a TH-400