Leaf Springs and the Anti Squat Line Explained

Leaf Springs and the Anti Squat Line Explained!! I cover how the Anti Squat line relates to the leaf springs on a drag car. This is absolutely a great tuning aid for understanding your leaf spring car's ability to plant the tire on the hit and during the run!
While not the only thing you must take into account, this video shows you exactly what to do and how the Caltracs and Smith Assassin bars impact the hit and Instant Center of Leaf Springs!
Samson Performance of Sam's Alignment in North Charleston, SC:
Get with us at our shop to let us help you scale your car and do a complete plot of your car as it is today and then we can discuss what changes, if any, we would recommend. We do drag car chassis tuning, chassis setup and ensure the suspension is setup for the best drag racing launches possible! We also offer online remote services from our website here below:
samsonperformance.com/service...
Facebook:
/ kevinwilsonsbc
Instagram:
/ kevinwilsonsbc
Leaf Spring videos:
• Leaf Springs for Drag ...
• Leaf Springs for Drag ...
Nitrogen Shock Digital Pressure Gauge:
amzn.to/3oyXfXI
Finding Center of Gravity Height:
bit.ly/2Y2IikU
#suspension #dragracing #noprep #streetrace #samsonperformance #kevinwilsonsbc #antisquat #smalltire #bigtires #chassistuning #4link

[@user-ps3uc5me8y]

Thank you. Its Christmas Day, 2023. The first Kevin S video I listened to today was you describing your faith, health and fitness journey. I salute your courage and faith! I am learning about suspensions from your are your videos and illustrations.

[@HorsepowerDepot]

After watching this video I will be calling Calvert, getting a stiffer front half spring, and taking the lowering blocks out! Thank you!

[@mikegonzalez4469]

Love your channel brother .... you guys haul ass in those old classic chevy's I love

[@KevinWilsonSBC]

I agree!!! Go fast, go straight! Be SAFE!!

[@KevinWilsonSBC]

Please keep me posted!!! I think you find the stiffer front half will make a good improvement, if the current spring is too weak for your power levels! Go fast, go straight! Be SAFE!!

[@ronaldlockhart8657]

Love your videos. It is great to see someone who cares enough to help racers

[@KevinWilsonSBC]

Thanks, Ronald! That means a lot to me as I want to give back. Thanks! Go fast, go straight! Be SAFE!!

[@nealesmith1873]

Great video! I'm pretty sure my lifted leaf spring Jeep has a high enough front spring mount to have antisquat!

[@sellis330]

Thanks for the explanation. I’ve been struggling to get my S10 to hook on the street, this gave me a bunch of ideas. Side note: it’s funny how people are willing to drop all their money into motor/trans/etc, but get tight fisted when it comes to suspension parts and tuning.

[@markwise9868]

People don't even want to spend money on transmissions! LOL!

[@KevinWilsonSBC]

Sean, it is so crazy how many racers I try to help and they want to control all this new power that we have today with 12 year old 90/10's and some single adjustable shocks a friend gave them 7 years ago... crazy man. Go fast, go straight! Be SAFE!!

[@KevinWilsonSBC]

So true... Thanks guys for commenting!!! Go fast, go straight! Be SAFE!!

[@hackjobgarage9289]

I put cal-tracs on my LS-S10 and it was like night and day. I do struggle with traction as well to be honest, even with 200 lbs welded to the tailgate. about to install sliders as well

[@lokedragracing]

Thank you for a great video 😊🙏🏻 building a split leave spring slider Caltracks 1932 Studebaker 120 wheelbase and this video was very helpful becouse there is no kit out there, so I had to modify both length of rear spring and the lenght of the lower bar of the Caltracks (shorter/longer) so Thanks from Norway 🇳🇴

[@alanm7312]

Kevin, I have only just come across your channel today and want to say it is amazing! So many things explained and you take the time to explain them well! Thank you so much for your work and shared knowledge. If you haven't already, could you please do a video talking about wheels and tires? Effect on having a narrower wheel that tire section width? Same width and wider? Drag radial viruses slicks? More sidewall verses lower profile. Tall tire verses small tire? No beadlock, single beadlock, double beadlock? Coming more from a street/no prep perspective. Cheers from down under 🇦🇺 👍

[@mikeymac9]

Thanks for the leaf spring videos. I’ve watched them all a few times. I’m still trying to figure it out lol. My main issue is bogging out of the hole. 350whp 3300lbs stick car. 1.65 60’ but I think it it should be 1.59 capable. Traps 113mph.

[@KevinWilsonSBC]

Thanks for commenting!!! Definitely get the bogging fixed and I am sure the 60' will impress you more than that! Go fast, go straight! Be SAFE!!

[@jonathanmoore5929]

Wow this cleared up a few things. I’m not racing your usual car or truck. I have a 05 Chevy Colorado awd that i’m trying to no prep race with. Working on trying to get the suspension to work.

[@mickhipwell7012]

Thankyou for all the info! I wish you threw in 30 seconds about wedges to add or remove pinion angle if that can help or not. LOVE the videos! Sending love from Australia

[@KevinWilsonSBC]

I meant to add that in.. sorry... with leaf springs to get pinion angle you will need to use wedges for sure... I will get that added soon. Go fast, go straight! Be SAFE!!

[@Mo--Dad]

Another thing I'm in the same boat as u with my Dad he has learned me so much over the last 45 years...I just know it would be hard to go to the track without him he is my best friend I don't never want that day to ever happen I fell like your the same

[@KevinWilsonSBC]

O man... I understand we all must face those days, but that day will I will need some serious support. I try to focus on capturing as much as he will let me... he hates being on video, but sometimes as we talk I just turn on my voice recorder and let him talk. He let's me do that more than video him. I think my son is beginning to take interest in "going fast" but I am trying to keep him focused on finishing at the University and then we can add some boost to his Ram 1500 Hemi 5.7... he wants a whipple supercharger on it bad!!! Thanks, Jimmy! Go fast, go straight! Be SAFE!!

[@knowbull5hit590]

This was such great info thank you man

[@lukesimeon5756]

Awesome explanation thanks

[@stuartwall8212]

very informative. Thank you.

[@victordahn2150]

awsome! I needed this lecture in my life you answered so many of my questions.

[@mrk20z3]

Great video

[@KevinWilsonSBC]

Thanks, Kendric!!! Go fast, go straight! Be SAFE!!

[@dgil4810]

Awesome info once again!

[@KevinWilsonSBC]

Thanks so much!!! Appreciate you leaving a comment! Go fast, go straight! Be SAFE!!

[@NilesJStJohn]

Great info and excellent explanation!! Really helping me and I am sure many others with leafs. Thank you Kevin.

[@maktvmidamericakustoms8837]

Great video!

[@KevinWilsonSBC]

Thanks, Adam Hodson MAK!! Go fast, go straight! Be SAFE!!

[@ajaychapman2276]

Another awesome video thanks kevin

[@KevinWilsonSBC]

Thanks so much, Ajay! Appreciate you! Go fast, go straight! Be SAFE!!

[@chriscarson5696]

Great information, well presented!

[@KevinWilsonSBC]

Thanks, Chris!! Appreciate you man! Go fast, go straight! Be SAFE!!

[@laynelommen9460]

Great video. Thx bro.

[@KevinWilsonSBC]

Glad you enjoyed it! Go fast, go straight! Be SAFE!

[@jodysmith3662]

Great Video Kevin as usual.

[@KevinWilsonSBC]

Thanks 👍 I appreciate you leaving this comment! Go fast, go straight! Be SAFE!!

[@markmincey7330]

Thanks!

[@prestonedmonds4128]

Great explanation Kevin!

[@KevinWilsonSBC]

Thank-you for posting a comment! I appreciate you supporting the channel! Go fast, go straight! Be SAFE!!

[@nitrousnov]

great video kevin , i needed a refresh on setting my car up and getting it to hook like it used to, thanks , leaf spring cars to the front !!

[@billmorton6977]

I've been working with Kim over at Smith's with the wife's leaf spring nova. Very happy and grateful for all of his help. Thank you for your videos

[@KevinWilsonSBC]

Good stuff Thanks for commenting!! Go fast, go straight! Be SAFE!!

[@billmorton6977]

@@KevinWilsonSBC thanks Kevin. I just got introduced to your channel and I'm definitely going back through your videos and checking them out.

[@johncjessome1]

Very awesome advice very well explained

[@KevinWilsonSBC]

Glad it was helpful! Go fast, go straight! Be SAFE!!

[@bigbuck610891]

Man what a great video 👍

[@KevinWilsonSBC]

Thanks, Cody!! Appreciate the compliment! Go fast, go straight! Be SAFE!!

[@fitzeesfabrications]

Waiting on this one. Well done. I'm building a leaf setup from scratch and this is a great help. Clears up some qustions I had.

[@KevinWilsonSBC]

Glad it was helpful! Thanks so much for dropping a comment!! Go fast, go straight! Be SAFE!!

[@heatherrigby7371]

WOW Brilliant and thank you. Donnie

[@KevinWilsonSBC]

Glad you liked it!! Go fast, go straight! Be SAFE!!

[@patfleischman3096]

Thanks for taking the time to explain all that. Very useful information and very easy to understand drawings.

[@KevinWilsonSBC]

Thanks so much, Pat!! Go fast, go straight! Be SAFE!!

[@fast38ca]

Nice video Kevin!! Leaf springs FTW!!!

[@KevinWilsonSBC]

You know it! My first experience around 5 years old was dad kicking the butt off a 1970 vette with a BBC and dad running his 6 Coronet with 440, 4 speed and dana 60 with 3.90s and leaf springs with homemade slapper bars. That freaking Coronet would hook on a dirt road!!! The vette ran him 3 times that night... on the first 2 runs dad would not stay in it all the way, so the vette thought he was close... kept taking his cash.. on the third run dad kept it floored and put 2 cars on him and the vette knew he had been had. Paid up and we went home. OMG.. it is in my blood from an early age! Go fast, go straight! Be SAFE!!

[@craigbilyeu4051]

Great video Kevin! Can't wait for test n tune so i can put all of the stuff I've learned from your vids to use.

[@KevinWilsonSBC]

Definitely keep me posted!!! Thanks, Craig! Go fast, go straight! Be SAFE!!

[@gerardorubio3612]

I have a stock leafspring mazda rx3 that I'm mini tubing 26×1150×15 tires and put in a 2×3 inch frame for the street and strip. Thanks for the videos on pinion angle and this one since it's a trial and error for me. Hope me being an import car doesn't make me an outcast or something. Thanks again.

[@RegularGuyGarage]

I’m new to a leaf spring setup so these videos are priceless. Thanks Kevin 👍

[@KevinWilsonSBC]

Glad you like them! Thanks for commenting!! Go fast, go straight! Be SAFE!!

[@waynegriffin8327]

Nice doing set up on 2006 Colorado

[@boostedgringo5885]

Nice video. I made my own “farm tracs” (mainly from tractor supply and John Deere) and I now get over 4” of separation on my little 4 cylinder truck. Went from 1.6s to 1.35 so far on a radial. Interesting that on mine the bar isn’t really running uphill either. I think it’s that the front spring is so short. Now I need to install some dbl adj shocks to control it. I’m betting I can get a 1.2x. Which is crazy bc it’s almost as good as my 4link 2500lb car and this one is a 3100lb truck. Thanks for explaining

[@KevinWilsonSBC]

That is awesome!!! keep me posted please! Go fast, go straight! Be SAFE!!

[@flynntaggart1023]

Your videos are coming along well Kev. Really owning the presentation, it takes a grounded understanding to present things in a simple manner without too much jargon and it really comes through.

[@KevinWilsonSBC]

Thanks so much, John! Go fast, go straight! Be SAFE!!

[@oldschoolbudgetracing1458]

Back around the 2007/ 2008 area I had a 78 camaro with slapper bars. I cut the back of the springs off so it was monoleaf in the rear then I clamped the 2 longest onto the front to stiffen the front of the spring. Cut my snubbers and put wedges in (not getting into detail but I am sure you know why) but that car separated and would hook on a dirt road. Yes it was a street race/ no prep setup. But it's funny knowing now that they created the split mono leaf spring to do just that. I just did it for free.

[@shanestewartfat416]

Awesome ,im heading in the tight direction for separation

[@Ryanz80]

Been having some traction issues in our leaf spring falcon ute. My mate sent me to your videos and has opened my understanding. Just bought a traction bar kit and new shocks and fitting asap. Will try again at the track soon. Thanks

[@frankdeon6539]

You actually have me rethinking the suspension in my lowered B2. Was going triangulated 4 link. Now I am going to try this first. Thanks.

[@KevinWilsonSBC]

Not sure of you use case, but leaf springs setup properly absolutely work!! Go fast, go straight! Be SAFE!!

[@kevinoneill560]

Thanks Kevin, I am trying to understand how my car works. Some say I could lift the front wheels in the snow. It has factory 65 year old multi leaf springs with Cal Tracs. Your videos are helping me understand how the car is getting traction. Keep up the good work. Could you please do a video on the pre load science / procedure. Regards Big Kev from down under.

[@KevinWilsonSBC]

Thanks so much, Kevin!! Great to have you here and dropping comments! I will definitely do a video on pre-load. I will use the 53 Studebaker for a real world video of setting pre load and showing the scales at the same time. That video will be simple, clear and easy to understand on moving weight with the upper left 4 link bar!! Stay tuned! One of these days I will get to down under and do some visiting!!! Go fast, go straight! Be SAFE!!

[@highboostedcivic]

You answered every question I had 😅 super awesome. Thanks a ton. I can wait until my track opens in March. 2 miles from my house I'll be their every opening day testing

[@KevinWilsonSBC]

That is awesome!!! Please keep me posted when you are able to go test!! Go fast, go straight! Be SAFE!!

[@tracykouns4903]

Tin solider leaf spring brackets for the win guys great video

[@KevinWilsonSBC]

Yes, they make some very good leaf spring brackets! Go fast, go straight! Be SAFE!!

[@christopherpearce7011]

Love the spring videos. I have a leaf spring wheel standing pinto. Currently with slapper bars. I'm upgrading to calvert split springs and probably the assassin bars. I'm hoping for the same but better results. Hopefully it's not too much of a learning curve. Keep the videos coming, and check out our team, TeamChinto. It will help you understand what we do with leaf springs. Thank you brother

[@RatifiedCamaro]

Thanks to your videos, my program has been going much better! Even though I still run slapper bars! Love your content

[@KevinWilsonSBC]

Love to hear that and the slapper bars do work when you put it all together with the entire combination!!! Go fast, go straight! Be SAFE!!

[@tylermoore121]

YOU ARE THE MAN!!!!!!!!!! thank you so much for actually reply to my one comment. Thank you for the great information.!!!!!!!!

[@KevinWilsonSBC]

You got it!! I really try to respond to every comment, but at times I do fall behind.. Thanks again, Tyler, for watching and supporting the channel! Go fast, go straight! Be SAFE!!

[@tylermoore121]

Biggest answer for me was anti squat line doesn’t change thru out all suspensions I always thought it did. Calculating my anti squat now

[@whysohigh]

I've been waiting for this topic. I run Caltracs and now I understand the solid front bushing. They made a huge improvement but my launch is my weak point right now. I've been watching your videos on dual adjustable shocks and that might be where I go next.

[@KevinWilsonSBC]

With today's power levels having the proper dbl adjustable shocks on the rear is so critical to keep control of rear movements, especially if the shock is extending too quickly. Go fast, go straight! Be SAFE!!

[@JohnnyBAwesome]

Good explanation on how leaf’s work. I’m a hardcore leaf guy. Been 1.14 to the 60’ and 4.40’s@168. Could go quicker, but I’m heavy at 3400lbs.

[@rustyhook8637]

Comment for the rhythm. Great explanation 👌

[@KevinWilsonSBC]

Thanks again, Rusty Hook!! Go fast, go straight! Be SAFE!!

[@Mo--Dad]

Thanks Kevin I've got a A body Mopar with the split mono leafs slider's and caltracks it's a bad mother car got sub frame conecters roll Gage but I'm learning more and more from you thanks for sharing your knowledge most wouldn't share like u r Kevin thatnks

[@KevinWilsonSBC]

You are welcome, Jimmy! Thanks for taking the time to leave a comment and for the compliment! I appreciate that more than you know. Go fast, go straight! Be SAFE!!

[@oldandboosted]

We have been running the split monoleafs and caltracs for years. It really straightened out the Dart. I know they work, I just didn't know why. Now I do. Thanks for the explanation

[@KevinWilsonSBC]

Love it!!! They absolutely work.. hands down! Thanks again! Go fast, go straight! Be SAFE!!

[@stevelangworthy9553]

Fantastic! Thanks. I really enjoyed your explanation for 4-link and was wondering how it relates to my leaf spring f-body car. This info is really timely. Installed a 9" and caltracs last weekend. This really has me thinking...if I get this to hook really well, the front spring pockets are really going to be taking a beating. Your comments about the sway bar really got my attention with how this all works together. If the car hooks it already tends to pull the driver side up...even further beating up on the passenger side pockets and tries to twist the body. This is GREAT. Thanks!.

[@KevinWilsonSBC]

Glad it was helpful! Thanks, Steve, for leaving a comment and the compliment! Go fast, go straight! Be SAFE!!

[@scoop440]

Good video, I'm working on a 64 Chevy II, installing a 6.0 vortec with a 5 speed manual trans and was wondering about it hooking. Thanks for the info.

[@jasonjohnson3133]

Hi Kevin, great explanation mate! Since installing cal type bars with the bar front mount only about a bit over an inch lower than the spring mount I have been battling with extreme separation on the hit, it just smashes the tyre into the track before it starts to move at all. I don’t have the shock to control it so will now start to lower the bar and monitor the changes. Thanks again for the video, awesome 👏

[@KevinWilsonSBC]

If you do not have the right valved shocks then you will chase this forever. I cannot emphasis enough the proper valved shocks on leaf springs and caltracs. This suspension absolutely separates as it is designed to do and have shocks with the right extension valving is absolutely critical. See: kzbin.info/www/bejne/aKnGgmaDat2moa8 and kzbin.info/www/bejne/ioipeaimbLCJpas and kzbin.info/www/bejne/roiTZah-m7l-adE as must watch videos from my channel on Shock valving. Go fast, go straight! Be SAFE!

[@michalyoung410]

Great info I wish your channel the best and that people can use the info you produce! You mention in a lot of segments about lowering a leaf spring car and how it affects chassis reaction and my question is , how would a reverse front eye leaf affect chassis dynamics compared to a standard front eye ? The front eye is in the same location or pivot point but the the chassis typically drops 1 1/2”-2”

[@KevinWilsonSBC]

Thanks so much! It is more about the location of where the mount point is on the frame in relation to the Anti Squat line when I encounter reverse front eye... which I don't encounter them very often. The chassis doesn't know nor care if it is a standard eye or reverse eye, but it does care about the height of that push point in relation to the AS line as a reference. Go fast, go straight! Be SAFE!!

[@drivinwithdrew7676]

Love these videos, I have a NA 383 stroker c1500 extended cab, Ive been working on the 60 ft I have stock leaf springs with air shocks and the helper spring removed and cheap traction bars, I may upgrade those. I get a little separation before it breaks the tire loose. I’m thinking my rear hangers must not be free, but I know I need to get a anti roll bar, in it and get the front sway bar off too

[@KevinWilsonSBC]

Thanks for commenting... Keep going on the c1500 as it sounds like you are heading in the right direction! Go fast, go straight! Be SAFE!!

[@shorty808100]

The way we tuned our suspension was with a Camcorder and watching the VCR tape back wasn’t no computers back then and I still wouldn’t run that crap on my car today

[@KevinWilsonSBC]

Using video and slowing it down is still in use today... I wish more people did that actually! Go fast, go straight! Be SAFE!!

[@fredcooke5570]

Hey Kevin your videos are awesome. Do you have a video that explains exactly how to find the center of gravity. I remember doing this with my dad when I was as a kid on our dirt cars but it’s been 45+ years ago.

[@KevinWilsonSBC]

Checkout these: kzbin.info/www/bejne/lafXk5KrqdaGgK8 and kzbin.info/www/bejne/pIaXgYuNnJd3nZo Go fast, go straight! Be SAFE!

[@DNRAuto]

“That’s what’s happening” stares into the camera. My favorite part

[@KevinWilsonSBC]

Appreciate your support of my channel, brother!!! Have a Merry Christmas!! Go fast, go straight! Be SAFE!

[@Rizziegyatler]

Great videos!! Could you do a video about leaf spring and stick shift cars with Cal-tracs or bar of choice? I get same principles apply. Leaf springs fo LIFE!! lol

[@KevinWilsonSBC]

I will add that to the list. Go fast, go straight! Be SAFE!!

[@Plumber1339]

So right know I have stock springs with two lowering blocks. I want to purchase spilt mono spring do I get stock height or -2 springs then remove my lowering blocks. Great info love the leaf spring videos

[@KevinWilsonSBC]

Definitely work with Calvert or your split mono leaf vendor with those measurements and they will get you in the right springs. I just need a bunch more info than that to even begin getting that specific and really the spring vendor can get you there faster than I can. Hope you understand. Thanks for being a subscriber and supporting the channel. Go fast, go straight! Be SAFE!!

[@DHUMPTXTX]

In a high horsepower radial leaf setup with an adjustable front bracket, what height in relation to the axle centerline would be best to set the middle of the bracket in the car. I know there’s a lot of variables involved. Just want and idea of what to look for

[@KevinWilsonSBC]

LIke you said there are so many variables that will impact this location, especially tire diameter and the relationship of the axle centerline to your car's anti squat line. I would really want a better idea of the car's AS line in relation to the axle centerline . If you could mock it up with the middle in line with the axle centerline, I would think you would have plenty of adjustment for more rear separation. Sorry for not a direct answer, but I would need a bunch more info to give you a direct answer. Go fast, go straight! Be SAFE!!

[@randyrutledge62]

Good stuff, easy to understand. How about addressing our home made slapper bars that you mentioned. I modified a Summit racing slapper bar to fit my 71 F100 and am looking for more traction. They are great for controlling wheel hop, not so great for traction. Also my snubber is 1/4' from the front spring eye. This truck has the weird 2 piece rear hanger, what affect is that having ? Thanks

[@KevinWilsonSBC]

I would need a bunch more info about your car to even begin helping more. Sorry. Go fast, go straight! Be SAFE!

[@chrisbergeron5399]

You killed it Kevin. I have watched many video's and await more info daily as I build my truck. I have cal-trax and waiting to order my 2" drop split mono. I bought a build in progress, had the cal's and stock springs minus the overload spring. I was doing a SRC rear suspension, but decided I wanted the split mono. With that being said and your video, would it not be better to get a factor ride height spring and use billet lowering blocks to get the lowered height I want? (Gen 2 reg cab S-10 max 5" rear lowering). That way I'm maximizing bite or anit-squat with the blocks lowering my angle. I will be using bolt-on sliders for adjustability of blocks, added weight I.E. turbos, intercooler. (Daddy Dave's s-10 set-up). About to watch the linked video's because obviously I missed some and I just checked 2 day's ago. Thank you for your help man getting us new guys up to speed. I was going to do a 4 link after a season or so but I might be able to get a stock location/stock suspension, all metal/all glass, stock firewall/stock floor to compete with this Forged 408 on twins in the no-prep world pushing 1400ish.

[@KevinWilsonSBC]

I like where you are thinking for sure! Maximize bite for sure! I am glad you found the channel and definitely watch the linked videos. Keep me posted! Go fast, go straight! Be SAFE!!

[@Plumber1339]

Is the minus -2 spilt mono springs stiffer is that why the stock spring with blocks is better

[@Dunecoones]

The 38 is set EXACTLY as said in this video. Only difference is some serious Tom Fullery of angles!! Lol This stock appearing ( raised front mount) has sent people home early.😁 Thanks Kevin!

[@KevinWilsonSBC]

Thanks for dropping your comment!! Love to hear people are getting sent home early.. LOL. Go fast, go straight! Be SAFE!!

[@Dunecoones]

@@KevinWilsonSBC Brother it's all you, and I appreciate every video!

[@zero2583]

How exactly do you get an inverted hanger to angle backwards? My truck from the factory has the leaf above the hanger and it sits slightly forward of vertical. I tried to adjust it to make it lean back but it just won't do it. Sliders is out of the question until I can get someone to fab up a pair of mounts.

[@frankkoppen7281]

Bin watching a lot of your video's lately. I've never heard of "anti-squat line" . When did this term start to be used ? I'm used to "percentage of rise" . I went back and re-read my Chris Alston Drag Racing Chassis Manual , and it's not in there. I got the book in 1990 . yes I'm that old 64 just retired. Back in the 80's 90's went racing every weeked for 20 years. But since than only go about once every two years. But now that I'm retired, plan to go alot more again. Of course back then we measured and layed it out on the floor.

[@KevinWilsonSBC]

Been around mainly since the 90's. Checkout my video on the Percentage of Rise at kzbin.info/www/bejne/o57NmpibiNSparM and I remember dad drawing it on the floor with welding chalk. He still does actually just to confirm that there computer of mine is right! Thanks for commenting and being a subscriber!!! Go fast, go straight! Be SAFE!!

[@terrellhubert5753]

Kevin have you seen the mak TV lower cal trac brackets. What is your thought on those.

[@KevinWilsonSBC]

O yes... They work! Go fast, go straight! Be SAFE!!

[@keysautorepair6038]

Great video would love to see one just explaining moving the leaf spring mount front and rear explaining a little better pretty pretty please.

[@KevinWilsonSBC]

Thanks for the idea! Will add that to the list. Go fast, go straight! Be SAFE!!

[@firstrespondergarage]

👍👍 🚒🚨 thank you

[@YerkitRacingChannel]

Explains why I cant get any traction in 2wd on my Cummins. Have the caltracs in the bottom hole on a lifted truck. Going to move it up to the top hole and see if that helps. Thanks again Kevin!

[@KevinWilsonSBC]

Keep me posted!! Go fast, go straight! Be SAFE!!

[@YerkitRacingChannel]

@@KevinWilsonSBC will do!

[@micahcarroll8788]

I have been watching your videos and in your part 1 leaf spring video you did, you talked about making a hole above the calvert factory hole in the spring plate under the rearend housing. Just curious if you could elaborate more on what that might accomplish. So top hole in the front and let's say top hole in the back plate if I drilled one. Would it allow more separation? Thanks in advance

[@KevinWilsonSBC]

Generally the more uphile the caltrac bar is from the rear end going toward the chassis, the more you will help with separation of the chassis and pushing the rear end toward the track. If you flatten the bar getting it closer to level, the less upward tq being applied to push the chassis up and the more you are helping drive the chassis forward. However, the big factor is the location of the front spring mount and if you are allowing enough motion on the rear leaf spring mount. So if you are really wanting more separation, make sure the rear leaf spring mount is free to move and there is enough movement in the rear to allow for more separation. If the rear spring mount cannot move forward or forward and down more, then you are effectively done separating. This is really key hence all the focus on sliders or hangers that are canted back at ride height so you have more movement to allow the rear end and spring to continue down toward the track more. Go fast, go straight! Be SAFE!!

[@dougvanbuskirk1369]

Kevin very informative thanks. would a stick shift Nova 540ci 3.73 gear 9" slicks caltracs be setup the same ?

[@KevinWilsonSBC]

With just that info, I would say yes... you can run a little less aggressive caltrac angle with the stick shift if you are hitting it real hard. These days the converter technology and automatics hit pretty dang hard... power management is still key though on the hit. Go fast, go straight! Be SAFE!!

[@dougvanbuskirk1369]

@@KevinWilsonSBC Thanks for response . That is what I thought . We hope to get it to hook and not break parts. What do you think of the clutch tamer?

[@jessebragg1202]

Within this discussion is the use of weight relocation and ballist to effect center of gravity fore/aft and height. Combining use of CG location and ride height gives the leaf spring car options for separation tuning . It is upon the leaf spring racing community to video and explain practical application of these concepts.

[@KevinWilsonSBC]

Yes!!!! Thanks! Go fast, go straight! Be SAFE!!

[@leewedding1807]

Do you have any videos on the fox body rear suspension suggestions need a little knowledge on it I'm used to leaf spring and Cal tracks but I'm doing a car for my wife and it's a Mustang I need a little more knowledge on the factory triangular for at length stock suspension Mustang

[@KevinWilsonSBC]

I will be publishing a Fox Body suspension video soon. For now stick with my 4 Link Videos as the parallel and triangulated follow the same principles. Go fast, go straight! Be SAFE!

[@joedozier3422]

Great video. now it's time to go to work on my 65 dodge dart with ss springs and pinion stubber old school i just can't get to to hook 2.02 60ft I'm just over powering my tires there are 28/10.5

[@KevinWilsonSBC]

Joe, speaking of darts, checkout my community post of the 63 Dart GT with leaf springs... kzbin.infoUgkxJK6reXNNHnQjk-WfCx6444vmDgP5F0YT Go fast, go straight! Be SAFE!!

[@fitzeesfabrications]

Now my next qustion. I see alot of guys having trouble with wheelies in a leaf spring car. What causes this? Seems to see it in leaf cars alot.

[@KevinWilsonSBC]

For one the leaf springs seriously dead hook the rear, which certainly begins to apply the HP/TQ to rotate the front. This is where front end control, front limiters and power management are key. With the ECU's today, implementing wheelie control is almost a must do for the radials for sure. I have had leaf spring cars on radials fight wheelies with the front tied down nearly completely. At that point, it is add weight to the nose or implement an aggressive power management control on the ECU... Go fast, go straight! Be SAFE!!

[@fitzeesfabrications]

@@KevinWilsonSBC would lowering the front spring mount help combat this too? Or would raising it up help. Most cars I seen doing it still have leafs in stock locations. So by changing this would it help combat the problem

[@KevinWilsonSBC]

@@fitzeesfabrications for a slick, not a radial, it would help take some rear separation away and not dead hook the slick. For a Radial, you have to be careful taking away AS, but if you have adjustable front mounts, then you can make some small changes, reset pinion angle and test. If the front end is properly slowed down or even limited with a radial, then I would use the ECU to help control this. If no ECU, then I would add 15 lbs on the nose as low as possible and test, before relocating a front mount without an adjustable front mount. It doesn't take a bunch of weight to make a change. Hope this makes sense... Go fast, go straight! Be SAFE!!

[@cathygambill1554]

I used the stock spring and slid the second leaf all the way forward and re-drilled the center bolt hole. this made the rear of the spring a mono and the front way stiffer and worked like a charm. This was 20 years ago, before I ever heard of split springs. My question is if a block is added between the spring and differential does this add leverage to the rotational force applied to the cal trac set up ? I also made 1" billet spacer blocks to lower the Cal trac bracket between the spring and the bracket to lower the rear of the bar for more of an upward angle.

[@KevinWilsonSBC]

Very cool info cathy gamtbill! The further distance from the axle housing generally acts on the suspension for longer during the run. Go fast, go straight! Be SAFE!!

[@hooligans_garage7465]

Will the traction bars that mount to the front spring perch without the cantilever give u the same advantage? Or do they just control spring wrap? Really new to suspension tuning, I’ve used your 4link videos to setup my no prep mustang but the leaf springs confuse me. Thanks for the awesome videos!

[@KevinWilsonSBC]

They are better than nothing, mainly controlling wrap and wheel hop. Go fast, go straight! Be SAFE!

[@hooligans_garage7465]

@@KevinWilsonSBCthanks for the reply man appreciated it!

[@ChevyMustang1]

Great video I have a 68 camaro street/strip car 355sbc 538hp at the crank turbo 350 with a 4.56 rear gear stock multi leafs and old comp engineering slapper bars and a 28x10.5 slick. Car runs great but I'm hitting the tire to hard and crushing the sidewall no matter the air presure. Does the length of the slapper bar and and height of the snubber determine how much seperation/bite I'm getting. My slapper bars are a bit short and not quite to the front spring eye would lengthening the bar so the snubber contacts the spring eye help

[@KevinWilsonSBC]

I wouldn't spend too much time trying to lengthen the slapper bars, I would definitely focus on the rear shocks and their Extension (R) valving. Thanks for dropping a comment! Go fast, go straight! Be SAFE!!

[@ChevyMustang1]

@@KevinWilsonSBC thanks for the reply I really appreciate it. Even though I've been racing for quite a few years I've learned alot in the last few weeks I came across you'd channel. I'm walking a fine line with this 68 camaro it's way to nice to be beating on it at the track that's mainly why I'm trying to stay away from the cal tracs if I get it working to good I'll race it even more lol. As it sits now its a 11.20 @125mph pump gas street car. From your videos I have already realized that a good adjustable shock will help slow the separation I just wasn't sure 8f lengthening the slapper bar to reach the spring eye would be an advantage. Thanks again for the great videos keep them comeing

[@misterbutterfinger]

ChevyMustang1, years ago I used 1"thick pieces of flat bar a little wider than the traction bar bolted to slapper bar In place of the snubber. Made them long enough to go under the spring eye. Used a 3/4" bolt in the spring eye end and adjusted my air gap there. It was simple but effective. Originally I was hitting the spring so hard it was bending the leaf so this put the pressure under the spring eye. I later switched to Southside bars. Those worked great. This was on a 70 Nova.

[@oneiam1533]

Any specific thoughts on 69 or 70 mustang chassis set up. Stock shock location seems to be way wrong.

[@KevinWilsonSBC]

That is a very broad question so shoot me an email with more specifics and why you are concerned. [e-mail] and Go fast, go straight! Be SAFE!!

[@FilmProductions380]

I want to know how to get traction on a full size 5300 lb (64/36) 144” WB truck with leaf springs

[@tjhanson992]

Kevin, I have had good luck with my leaf spring setup in my truck. I have cut a 1.32 @4650#, but my question is im wanting to introduce even more seperation, I already have my caltrac bar in top hole and i cant relocate my bolt holes higher for the front leaf spring hole, but what im wondering is if i can add more holes in the bracket on rear end where the bars bolt up... If i could get the back of the bars a couple inches lower in the rear would it help more with seperation? Truck has a radial and double adjustables on all 4 corners.

[@KevinWilsonSBC]

Great question... increasing the angle will help apply more upward force on the chassis and help, but you need to make sure you have adequate travel on the rear mounting point of the leaf spring. Checkout my part 2 video here to get a better visual of this one: kzbin.info/www/bejne/jZSkZquHfLyjq7s Without more travel and without more shock travel the combination will be limited. Go fast, go straight! Be SAFE!!

[@tjhanson992]

@@KevinWilsonSBC 10-4 yes I have plenty of travel. Thanks for the response 👍

[@chevy2adam850]

Hey Kevin. I have a question about the rear bar placement. Adjustable rear leaf spring perches are becoming common like what come with the assassin bars but I can't seem to find much info on how the rear bar placement would affect the tire. Obviously the front holes will adjust the instant center but how does the rear affect it? I've been mostly just shooting for level at ride height depending on what hole I'm using on the FWD bar.

[@KevinWilsonSBC]

Are you talking about the rear leaf spring mount height or something different. My apologies, but not sure I am following you exactly on which "bar". Go fast, go straight! Be SAFE!

[@chevy2adam850]

@Kevin Wilson I'm referring to the lower leaf spring plate that the AFT heim joint attaches to. On the cal tracs it only has one option to mount to but lately I have seen the Smith assassin and MAK "gap brackets" and other company's give you multiple holes at various heights to attach to allowing to change both the front and rear bar height instead of just the front like the cal tracs. Just wondering what effect changing the rear would have on the tire. Thank you for your time Kevin!

[@KevinWilsonSBC]

@@chevy2adam850 checkout my other videos on leaf springs for sure: kzbin.info/www/bejne/e6TRdYiHn9V8pLc and kzbin.info/www/bejne/jZSkZquHfLyjq7s then let me know if that helps. Go fast, go straight! Be SAFE!

[@chevy2adam850]

@@KevinWilsonSBC Hey Kevin. Me again. Just realized my old comments might of been confusing. I have watched all your Leaf spring videos and become much faster over the years because of it but I still have this question. Let me try again. Some of the kits have multiple holes at the rear mount where the bar connects directly below the axle to allow more adjustability. We always talk about how the front hole affects the car but what would adjusting the rear do? I have around 4 holes of adjustability in the rear and the standard 2 in the front that calvert supplies. Google "MAK Gap Brackets" for a example of what im talking about. Thanks again Kevin and have a awesome week.

[@donk2859]

Thinking this question has more to do with the front end working correctly than the the Cal Tracs, but what to do when you are dead hooking and doing 3' wheelies for 60'? Yes, i know, I have Dbl Adj shocks ordered,lol

[@KevinWilsonSBC]

Yep, the first thought is slowing down the front end a good bit and you may even apply more power on the hit to try to get some wheel speed. Do you have any caltrac options on your setup to raise or lower the front or rear of the caltrac bar? Go fast, go straight! Be SAFE!!

[@donk2859]

@@KevinWilsonSBC I have the bar in the lower hole of the front bracket. Split monos in stock location. Still using old school 90/10 Shocks. Car is on 8.5 x 26 Hoosiers.

[@KevinWilsonSBC]

​@@donk2859 I hate to say it, but the 90/10 is likely really letting the front end come up way too fast... The shock technology today will absolutely change your launch by slowing the front end down but letting it still come up slowly to transfer weight to the rear. Did you see my video on the Suspension review from the SRC channel? If not, watch this one: kzbin.info/www/bejne/oWPJZ5yjh7Khqbc Go fast, go straight! Be SAFE!!

[@donk2859]

@@KevinWilsonSBC my plan is to slow/tie the front down and see if I can get wheel speed, then come off the break higher (3000 now).

[@donk2859]

Thank you, really enjoy your videos, i was wondering where the ic was with Cal Tracs. Going to start with front Vikings, probably rears too.

[@smilsmff]

How do you fix the Bunny hop With Cal trac on A-Body Mopars, , I see them launch ,tire smashes and front engoes up but suddenly stops and car then goes, their sixty foots are off by tenths?

[@KevinWilsonSBC]

There are many pieces to that recipe... Most of the time I see this issue, the shocks on all 4 corners are the most neglected and understood part of the recipe based on the power levels, starting line ratio and weight transfer control. Go fast, go straight! Be SAFE!

[@RTRacing87]

Kevin on a foot brake car is having the assassin bar angle steeper in the front more or less critical leaving with a trans brake. Shock settings differ? No prep/street stuff. M/T street r radial 275/60 tire.

[@KevinWilsonSBC]

Depends on converter... when foot braking, if you load up the converter having more uphill angle can help. Transbrake leaves with the right shocks you can leave the angle alone and make some Rebound changes on your shocks to tighten up a tad. Definitely with a radial, you WANT uphill angle and use your shocks to tune. Make sense? Go fast, go straight! Be SAFE!!

[@RTRacing87]

@@KevinWilsonSBC thank you sir. Thanks for sharing your knowledge.

[@RTRacing87]

@@KevinWilsonSBC if I run ladder bar/floater setup, is running a slider still a good idea? I’m going to that setup on my mud drag truck.

[@KevinWilsonSBC]

@@RTRacing87 Yes, the rear sliders will help allow the separation to continue more than not... the ladder bars with floaters is a must, the sliders on the rear are optional, but will only help in my opinion. Go fast, go straight! Be SAFE!!

[@melissamcallister2867]

I like the video but just installing a caltrac kit well help but the biggest issue here is the plnion angles like being positive numbers is a nogo

[@KevinWilsonSBC]

Not too sure I am following your line of thought on this comment. Pinion angle is critical to a properly setup rear suspension and the goal is getting the static offset angle correct based on the amount of movement on the rear suspension so that during the hit and through the run, the pinion centerline is parallel to the engine/trans centerline. Go fast, go straight! Be SAFE!

[@Dave_9547]

There is a white S10 with stock leaf springs and CalTracs that hooks extremely well. Probably more than one.

[@KevinWilsonSBC]

O yes, David! Thanks for commenting! Go fast, go straight! Be SAFE!!

[@donbenson2099]

How would the bars work on a 69 Camaro road race car?

[@2000r0283]

How do calculate the AS value?

[@michaelgray7125]

I have a 72 f100 and having problems of it separating the body too high Kevin please help !!!

[@KevinWilsonSBC]

Take a look at samsonperformance.com/services.html and see if one those services make sense for you. Thanks!! Go fast, go straight! Be SAFE!!

[@fitzonabike2080]

Kevin I just found this video, I have a 72 mustang that I need some help with, do you have an email I can send you a video of the launch and see what you think?

[@ericschumacher5189]

Question; if you were to lower the car by adding blocks between the rear-end housing and spring pad but, adjusted the front spring eye mounting location and shackle length to achieve the same amount of anti-squat %, THEN wouldn’t the cal-trac’s be LESS effective because of the LONGER lever arm (created by the blocks) between the rear end housing and leaf-spring??? The reason I ask is is the mounting hole for the cal-trac’s is about 4” from the axle tube centerline without blocks, but with 3” blocks the leaf-spring is basically centered between the housing and cal-trac’s bar mount (equidistant)...

[@KevinWilsonSBC]

The actual change in force is not a big as one might think. Unless there is some severe flexing due to the extended length. If the angles are relatively the same, then the reaction on the chassis will not be much different. The rotational forces will still exist and the force on the chassis should be close to the same. Just my $.02. Go fast, go straight! Be SAFE!!

[@ericschumacher5189]

Thank you; I much appreciate your reply!!!

[@bradenfennell]

What happens when you have a rear shackle and you install a longer shackle to lower the rear?

[@KevinWilsonSBC]

I would need more info on specifically what you are looking info on with this change. There are a bunch of changes when you lower the rear. The pinion angle changes, and the CG of the car changes. This means weight bias front to rear also changes. Make sense? Go fast, go straight! Be SAFE!

[@thetrakhoeturbotahoe714]

So people always say there’s no such thing as a dumb question if you don’t know. So here goes one that’s going to be pretty close. I have a 1st gen s10, it sits really low mainly because it helps give me a little better piece of security in helping it from rolling if I get out of control. The way it sits caltracs hit and drag everything driving on the street. Is there anyway to incorporate some kind of upper mounted bar to increase separation? The class I run requires dot tires and factory style and location suspension but has no rules about adding to it. Any information rather it’s good luck or a solution is greatly appreciated.

[@KevinWilsonSBC]

This is a great question!! Can you shoot me some pics of your setup so I can talk more intelligently about your setup. My email is [e-mail] Go fast, go straight! Be SAFE!!

[@Nova-1977]

Yes they do work I had leafs with cal tracks .decided to back half my nova with ladder bars it made zero difference it still hooks the same 1.25 short time NA small block with a Glide. I feel I wasted my time and money . I ran a 9 inch slick now a13 inch slick . They just last longer and weigh more .

[@KevinWilsonSBC]

Great, great comment!!! I agree! Go fast, go straight! Be SAFE!!