The truth about caltracs

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chad67gtdart

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I have read every post on this site about CALTRACS, and have come to the conclusion that no two cars are the same,even if set up nearly identical! I have a 1974 DART sport,360 stroked to 410c.i. making 600hp @ the flywheel on the dyno,727w/5500stall,4:30 gears & weighs 3300lbs with me in it running M/T et street radials. With the 40year old stock springs & slapper bars my 60ft. times were from 1.47 - 1.50. I went like a fool & bought caltracs,monoleafs & thier rear shocks . I have tried every possible combo of settings, up & down on launch rpm,0 preload to a 1/2 turn,every shock setting, as low as 13psi tire pressure, even top hole with no improvment. The best 60ft. I can get is 1.54. I have talked to John Calvert himself several times & all he can say is its not his product! Its the track, my tires, transmission, converter, carb. , even the driver(me). I have the full travel on the front he suggested +(5.5inches) everything free & not binding. I have concluded that caltracs are for fords & chevys & are useless on a mopar! If anyone can supply a solution on settings, other than whats on this site, please do so. Otherwise I will be removeing this crap & returning to my stock suspension! As a side note I have several other mopar racers i've spoken with who are also unsatisfied with thier caltracs! :banghead:
 
It's your fault Chad.....Just kidding!

I'm no longer a racer, and have never used a Caltrac setup. I've just been watching to learn, and as you have seen, the results are mixed at best.

My original thoughts were the Rancho style shock just wasn't adjustable enough and that a high dollar QAL or some similar type could cure the problem. But now I wonder if the "split mono" spring just isn't gettin' it on Mopars with the shorter front vs rear bias.

I'll be watching to see what others may have come up with. I know several here have had the same issue.
 
cal tracs, splits, ranchos, 275dr, SB 560ish hp, 3300#, 1.41-1.43 60's 10.60, 124

DougsCuda.jpg


Just one car that proves otherwise. With Afco rear shocks it's gone 1.37's 60's and 10.53 - 125+.

I would stop talking to guys that don't and can't make them work and find guys that can and do make them work on A body mopars.
 
That car looks to have a ton of separation compared to the vids i've seen of some other cars with that setup that have less then optimal 60's. I know there's a secret to it, I just need to figure it out.....

Spring mounting mods? Shocks? Weight bias?.........A low gear 5spd & 5.38's...:D.
 
All stock rear mount locations, non tubbed, 904, 4.56's IIRC. A good working chassis that takes work to get sorted out. People can make tuning suggestions, like Calvert. Unfortunately, it's a bit different for every car and cal tracs likely don't want the same set up that SS springs do.

What rear suspension is on almost every good running competitive stock eliminator A body... not SS springs!

I'll stop now as not be arrogant according to another member that can't get them to work either. :)
 
crackedback said:
cal tracs, splits, ranchos, 275dr, SB 560ish hp, 3300#, 1.41-1.43 60's 10.60, 124

DougsCuda.jpg


Just one car that proves otherwise. With Afco rear shocks it's gone 1.37's 60's and 10.53 - 125+.

I would stop talking to guys that don't and can't make them work and find guys that can and do make them work on A body mopars.
Click to expand...

:eek:ops:
wow and just think how much faster he would be if he went to a real rear suspension set up.
 
What? Like the SS springs that came off it when it went 1.46-1.48 hanging the drivers front tire 12" higher than the pass side? :)

It's the chassis tuning and it likely not the rear end of the car that's the problem.

BTW, what's a good 60' for a 10.50 car, at least according to most calculators? :)

I don't give a crap about what anybody runs for suspension, tuned them all. Any of them can get a car to run hard 60's. There are no magic beans, it takes work. And that's reality!
 
The biggest problem that the CalTracs don't address is instant center. On any leaf spring car the IC is the front spring eye. Mopar A bodies have the shortest front spring segment (20") of any car out there, resulting in the IC being too short and high. This makes the car hit the tires too hard, creating the classic Mopar bounce/porpoise problem. The Chevy and Ford cars have 25" front segments that put the IC in a favorable position. Some racers I've talked to have been told by Calvert that if they want to make the car work properly that they would need to run Chevy springs in their car, but most just don't want to do that. A lot of guys in the Drag Radial classes move their spring mounting points just for this reason. Some guys have great results because their track is run by guys that know how to do excellent prep, thus virtually anything will hook well even if the suspension sucks. One of the biggest culprits is VP LC7 lane choice track prep compound. This stuff is ruining tracks left and right. It does not work in the heat period. At the start of the season I was cutting 1.50 60' times in cool over cast weather, now the 60' in the heat are 1.6-?. At the end of the season they will come back down to 1.5 again. Used to never have this problem when the track used PJ1 VHT.

2012-10-27223349_zps88a494b2.png
 
If that car is a auto, it has to be hitting it extremely hard like a underpowered stock class car would do. Meaning a giant converter? Those 60' times would support a low 10 and maybe even a very high 9 with a 1.41/1.37.

I agree with Bob. Once you need to move up from a stock setup, unless mandated by rules, i'd go right to a ladder deal. I understand why Chris White didn't want to do that, because he wanted the option of putting his car back on the street without a bunch of mods & $$$ being spent. And yes, he has to work with what he has for now, but I do understand his point of view to get the most consistent times with his current setup.
 
Wow. That car actually runs the numbers the HP equates to. Imagine that.

crackedback said:
cal tracs, splits, ranchos, 275dr, SB 560ish hp, 3300#, 1.41-1.43 60's 10.60, 124



Just one car that proves otherwise. With Afco rear shocks it's gone 1.37's 60's and 10.53 - 125+.

I would stop talking to guys that don't and can't make them work and find guys that can and do make them work on A body mopars.
Click to expand...
 
crackedback said:
All stock rear mount locations, non tubbed, 904, 4.56's IIRC. A good working chassis that takes work to get sorted out. People can make tuning suggestions, like Calvert. Unfortunately, it's a bit different for every car and cal tracs likely don't want the same set up that SS springs do.

What rear suspension is on almost every good running competitive stock eliminator A body... not SS springs!

I'll stop now as not be arrogant according to another member that can't get them to work either. :)
Click to expand...

From what I understand there is more than one Mopar guy at Spokane County Raceway that is having troubles with the Caltracs....I don't have an iron in this fire so that is all I am going to say....
 
OldmanRick said:
If that car is a auto, it has to be hitting it extremely hard like a underpowered stock class car would do. Meaning a giant converter? Those 60' times would support a low 10 and maybe even a very high 9 with a 1.41/1.37.

I agree with Bob. Once you need to move up from a stock setup, unless mandated by rules, i'd go right to a ladder deal. I understand why Chris White didn't want to do that, because he wanted the option of putting his car back on the street without a bunch of mods & $$$ being spent. And yes, he has to work with what he has for now, but I do understand his point of view to get the most consistent times with his current setup.
Click to expand...

Chris is pretty frustrated. To compound the problem one lane up here is a bit different than the other....have heard more than one racer complaining about the right lane. Like most things in life, there is always more than one way to skin a cat....
 
Your not alone. modified stock springs 1.38 60fts with j heads and mostly junk parts in the heat of the south. Caltracs are ok, but if you understand whats required to make a good hook they are not required. Assassins or a real race suspension would work well. Depends on the combo and how hard you want to work.
 
crackedback said:
What? Like the SS springs that came off it when it went 1.46-1.48 hanging the drivers front tire 12" higher than the pass side? :)

It's the chassis tuning and it likely not the rear end of the car that's the problem.

BTW, what's a good 60' for a 10.50 car, at least according to most calculators? :)

I don't give a crap about what anybody runs for suspension, tuned them all. Any of them can get a car to run hard 60's. There are no magic beans, it takes work. And that's reality!
Click to expand...
I agree with this,there's nothing for free.
 
there are extensive threads over on moparts about the caltracs.
I read through because I was more interested about what was posted here. some of the old leathery racers say that when people do see a marked improvement when switching to caltracs, it's because there chassis wasn't set up correctly in the first place.

apparently the front shocks have a lot to do with it. your weights on all 4 wheels are important. just throwing parts on the rear wont solve everything. the know how is more important than the wallet.

to the thread starter: i'd highly recommend checking out some of the threads over there, just immerse yourself in the tech. you will get it all straightened out
 
The problem as I see it is that some people put a new rear suspension in their car and think that the car will magically go faster. The rear suspension is just one piece of the puzzle. Also, once you change your rear suspension you could very possibly need to retune your front suspension for maximum performance. It is kind a like replacing your carb and thinking that it will work perfectly with no tuning. Best thing to do is to go to the track and try different changes ( one at a time) to see what your car does and does not like. It can sometimes takes a while but will be worth it in the end. JMO
 
Thanks for all the feedback! BUT , like I said i'm looking for real answers, lets offer up some of these chassis tuning secrets. If I have to keep spending money,I will return the caltracs & go ladder bars. Crackedback , you have a very impressive car, but if I had 4.56 gears I would cross the stripe in the 7000-7200rpm range. Shouldn't have to turn it that hard! My car has been a best of 10.74 @ 123mph crossing @ 6600-6800rpm on the 40 year old STOCK springs with slapper bars,leaveing @2500rpm! I have been looking for nearly three months to find someone who knows Mopar suspension , but all I get are the same generic chevy & ford guys. Heck, I cant even find a frontend shop that knows Mopars! I live in south central Va.,where Mopars are the blacksheep @ nearly every track around! I have three different tracks I frequent within a 90 mile radius, two Ihra & one Nhra & on any given race day there will be no more than 8 Mopars out of a field of 150-200 cars. Most are big blocks. I'm not the enemy, just looking for real advice on setup. I was not thinking caltrcs were magic beans, only that they would be an improvement over 40yearold stock parts. Just looking for Mopar setup advice in a sea of chevys & fords!
 
I had the SS 002/003, comp 3ways set to 50/50, qa1 drags up frt on the loosest ,race torsion bars and about 3in travel. I would 60ft 1.49-1.51 all day long anytime of year even with a 9.5 or a 8in convert. Everybody told me to get the caltracs so I did. I bought the springs,bars and stepped up to strange shocks. I did lower hole no pre to 1 full turn preload and tried upper hole as well and could only get 1.55 all day long. I redid the frt end got almost 6in travel and loosey goosey still the same. So far my best is 1.53 in upper hole zero pre shocks on 7. I have also messed with the carb to the point I went and bought a new one set up from Prosystems no change at all. Right now I think I should have stuck it out with the SS set up and did more tuning. The only thing I can think of is with the SS I might of had a little wheel spin to get the rpm up quicker and the caltracs it just a dead hook but I don't know .
 
hi, If you dead hook , its a bog, car will loose 60' times. been there many times, a little wheel spin will not pull motor down. car will be faster. can be frustrating. I noticed on steve wann's 69 cuda, C/SA, car, the rear doesn't drop very much. also, they can't move front hanger. that car is fast and consistent.
 
It's not my car, the guys that own it are very sharp and worked hard to get it where it is now. Not bad for a pump gas street car that gets driven a lot! I made an error, it's got 4.30 gears and a 10" ATI converter. I thought they had 4.56's and an 8" ATI in it.

My experience, 123mph at 3300# is not 600hp unless you have something chewing up a lot of HP in your driveline/chassis. I'd expect the car to run in the 126-127+ range if the wt/hp is true. Converters are the #1 spot that chew up hp.

The front end is where a TON of 60' time is hiding in these cars. Shocks, torsion bars, ride height, alignment, how you bolt stuff on/together, ease of movement, etc. It's the little details that add up. If the front of your car looks like an elephant sat on the hood at full extension, you have problems. That alone will help unload the rear tires. I've heard it all, you don't want to do big wheelies, it's wasted motion, etc. To a point that's correct, it's yin yang deal, there's a healthy balance depending on hp driving the vehicle. When someone tells me that the Cuda looks goofy or shouldn't be doing a wheelie because someone else said so, the proof is in the number compared to their bigger tire stuff running 1.5+ 60's, is it not? Two words.... Pitch Rotation! If you don't have it, you're behind the 8 ball.

The rear rancho/calvert shocks are decent, BUT, they wear out kind of fast especially on cars that 60' well. Shock control on these rear suspensions is paramount. Porpoising is usually a shock control issue. We all get to fight some design issues with these A body cars. Ranchos/calverts cost 200/pr, afco about 400/pr. If you want to run the leafs/bars, not cut it up for ladders/link, are serious, then spend 2 extra bills on Afco's. Otherwise you'll be buying Ranchos every couple years depending on number of hits you put down.

Sometimes more weight is a good thing, sounds crazy, but it often works. Strap 75-100# in the trunk and see what happens, preferably as far back in the the trunk as possible. I've welded LOTS of thick flat steel plate in behind the rear bumper on cars.

I didn't see what size tire you had. Most guys I see using 275/60 DR's run the pressures way too low. The cuda and some others I've dealt with all run at least 20psi. Run the most tire pressure you can that provides best 60's. There's a tipping point. More air will also usually help your MPH too.

Find a copy of Doorslammers by Morgan. IMO, It's boring as all get out to read. You could read the summary or last 3 pages of each chapter to likely get the gist of what's going on/suggested.

Yes, it sucks being the minority folks at every track... :)

I hope you guys get your cars sorted out.
 
Im curious, in this conversation are we talking foot brake cars or Trans brake. I see that most of the complaints come from foot brake cars. I fall into this catagory and Im still tuning. Just wondering.
 
68 hemi dart, 528 race hemi puts 773hp and 676Tq. best on the foot brake was a 1.54, on the brake is a 1.42. we never really had a good track or enough time to tune it out but should go 9.80's if not into the 9.70's.

P.S. this pic is foot braking it, dont have a wheelie pic on the brake but its about 2ft high at Vegas with a cold track.
 

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Do you know if your ride height, alignment specs or pinion angle changed with the Calvert setup? Did you know where it was at before you made the changes? Maybe you need to re-align the car. Perhaps check pinion angle too. Just a thought.

Ride height first, then align.
 
rmchrgr said:
Do you know if your ride height, alignment specs or pinion angle changed with the Calvert setup? Did you know where it was at before you made the changes? Maybe you need to re-align the car. Perhaps check pinion angle too. Just a thought.

Ride height first, then align.
Click to expand...

right the old shops set height first, new guys dont. when running calverts we run the disc bumpers on the bottom and the car sits about 1/4- 1/2" off those. with the top stop out we get about 4.5-5" travel usually.

other thing we do is i watch the car at the top end and see how high the front end is, and jack the car up to that height and align it there.
 
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