Guys, my '82 S10 drag truck still has the stock, multi-leaf spring pack in it yet.

Would there really be a marked advantage in installing Calvert Mono-Leaf rear springs?

My objective is better, more consistent traction and maybe even a better vehicle reaction time.

I may elect to lower the rear end some at the same time then.
And maybe install sliders, but I don't want to fool with welding.

Thanks!

I made that change about 20 years ago. I still run the Calvert springs, but I don’t remember the change from stock multileafs being noticeable at all, really.

My two cents for what it is worth. I would not buy the Calvert springs.

Save your money and then someday go to Fourlink or Ladder bars.

Got a friend who had a nice 56 Chevy and he kept asking us back half it or Calvert springs. he asked about a dozen of us racers and we all said back half it. Finally he found someone who said Calvert springs. So he gets the Calvert springs and can only run like a 9 inch tire. He was constantly complaining "Track is Junk" or tires are are only lasting 56 runs, Blah, Blah, Blah. We all told him to save his money and do it right.

Yes, when track is prepped like a National event (Rare) and the weather is good and the car is set up right it will work with Calvert system.

But if you go with a four link or ladder bar especially if you can go with bigger rear tires then you have much wider margin of error and will go more rounds. The chassis will work better and be able to tune it better.

Unless you are running an NHRA class where you are REQUIRED to run stock type suspension I would not even consider the Calverts.

Do you have the Cal-Trac bars on it?

quote:

Yes, when track is prepped like a National event (Rare) and the weather is good and the car is set up right it will work with Calvert system.

But if you go with a four link or ladder bar especially if you can go with bigger rear tires then you have much wider margin of error and will go more rounds. The chassis will work better and be able to tune it better.

Unless you are running an NHRA class where you are REQUIRED to run stock type suspension I would not even consider the Calverts.

Sorry Curly, have to respectfully call that horrible advise.

Having run Caltracs for over 25 yrs on multiple cars, I've had better luck than many friends who went the backhalf route. Caltracs flat out work and have a large tuning window.
Two cars stick out in my mind as "shouldnt" work but continually win on a weekly basis are Kevin Mendenhalls 66 Nova running 6.0's on a 28x9" PBR and Kyle Kohr's 68 Dart also on a 28x9 PBR running 6.20's with 100' wheelies. Sometimes I think on a crap track Caltracs are even better .

I think the rear springs are definitely worth the investment. With them and having your front end set up right, your truck should never spin.

When we built our truck I purposely went out of my way to narrow the original frame and run Caltracs with a big tire. Trucks been 1.300 60' @ 3400lbs and zeroxes 60' numbers like I expected.

Its a spring that supports the load of the truck there's not a ton you can do with a leaf spring in the first place.

As spring tech goes for traction bar (calvert/CE slide a link, regular traction bar) applications go, split monos are at the top of the list of options. It allows more separation on the back half of the spring (towards the rear of the truck) which enables the traction bar to push the rear end even further down IE more separation b/t rear end and chassis provides more down force if needed. Lower HP cars likely won't need this or won't be able to use this but its there if you ever need it. They are built very nicely and are likely the highest quality springs you'll buy. There aren't many other options i'm aware of.

The second thing they do is locate the rear end front to back and left to right in the truck and resist the "twist" of the Pinion/rear end. Because they are race designed they do a good job of this as the front half of the springs looks pretty thick and they should be able to resist pinion wrap pretty well. When you start putting serious power on them and put tons of laps on them they may develop an S shape in the front half of the spring, ALL leaf springs do this over time in high hp drag race applications. It's pretty rare that they break and IMO they are the best option out there to resist this. In a multi leaf application the only part of the spring responsible for this is the top layer, the others are there to re-enforce the top layer and provide additional spring rate. So in this regard i think calvert monos are best choice.

Multi leafs can be setup to provide plenty of body separation if you know how (remove all rear clamps, clamp the front half of the spring in multiple locations). Make sure the rear leafspring shackle is functioning properly or replace them with a slider. At a minimum all rear bushings must be in good shape, lubricated well, and bolts not tightened so much as to lock the rear part of the spring, use self locking nuts, plenty of bushing lube and only snug the rear shackles. Best option is to replace with a slider. Front bushings should be treated with the same care as the rears, usually swapped to aluminum bushings, but must rotate freely, at a minium i'd think swapping to polyurethane hard front spring bushings and using lube and follow tightening instructions from bushing mfgr would be best.

In short will you see a performance advantage by swapping to split monos, the answer to that is "IT DEPENDS" on the condition of your existing springs and the particulars of your setup.

As far as swapping the leaf springs out for a different technology (4 link or ladder bar) if you are looking for additional tire clearance and would like to lose some weight, have the $$$$$ and time for a back half job, then yes, swap to a ladder bar or 4 link. In my experience 4 links and ladder bars are not light years better than leaf springs and Calvert style bars assuming you have the same shocks, wheels, tires etc. in place when you make the swap. The reason most folks say they put ladder bars or 4 link under their car and went away from a leafspring/calvert setup the car was 100% better is because they add so much more tire (taller and wider) that it has to be better.

I've done AB testing leafsprings vs. ladder bars (5.50's, BBC, 3200lb nova, Bracket Racing). Raced it for years on split monos and CE slide a links, swapped to ladder bars, same shocks, same tires, same rims, same engine/trans, same driver. The end result was exactly the same. Some days it would be great, other days it would struggle. This car was on radials so it was either dead hooked or spinning like a fuel funny car. The ladder bar was a 36" long, fully adjustable upper bar, i tried all the settings i had to no avail. It acted the same. It was a function of the tire selection and the car setup.

I wouldn't back half a car and use leaf springs for a pure drag race application if i were starting from scratch. If I already had the Calvert bars and split mono's in place and needed additional tire clearance, I'd do it in a heartbeat.

If it's a scratch build and you don't already have split monos and calvert style bars, a 4 link/ladder bar is best option IMO. they are about the same price as far as suspension systems go when you add everything up (calvert bars, split mono, GOOD shocks, anti-roll bar) vs Ladder Bars/4Link.

This message has been edited. Last edited by: Triple Nickel,

100% agree with the Professor. I run the 28 x 9 Hoosier DBR and I wouldn’t accept a free backhalf job.

I don’t want my original comment to come off as if I don’t like the Calvert springs. I do. I answered the question as if a person could only afford one modification. In that case, I’d focus on the front end first. The leaf springs alone aren’t going to give you a monumental improvement.

The only advanage the splits over the stock springs is they would be new and a little lighter. If you made big power(1000+) and still wanted to run leafs you would need them.
Assuming you already have some type of rear traction device i think I would spend most of my time and money on getting weight out of the front end and improving front suspension.

To lower the rear you can take out the overload spring if you haven't already. It's normally the bottom leaf.

Way more value in getting the front end sorted out before you do the back end as Lenny has pointed out.

Travis is going to want truck weight and bias. We went one step lighter spring and it’s still too much but works great.. like Lenny about twenty ago and never looked back.
Car then was consistently 1.40 and after the change it was mid to high 1.30’s. Now it’s best of 1.29 and on a good hit it’s 1.30-131. All front shock, travel and rear shock adjustments .
Cars friggen heavy!
Good luck.

I’ve watched Chuck Rayburn 1964 426 Hemi at 3700# with cal tracs in SS/BA with a 9” tire go 9 teens and 1.20 60 foots. He wants to go high 8’s on the 9” inch tire. Pretty cool!

This message has been edited. Last edited by: BP758,

Tracy at Sunset had a pic in the entry to his shop of his red first gen Camaro pointing the headlights at the sky with Cal Tracs, pic was in the 90's IIRC but I don't know if he ran their springs, the guys at the RaceShop at SDPC would probably know.