leafspring car handling

[frontrunner]

Car is a little tight on entry on 1/4 mile high banked but mostly dry, car is free on entry on the 3/8 tight turns no banking but always tacky, and do run same setup at both tracks so any ideas.. my car is a stacked leafspring mod. weight with driver is 2550 and spring are 700lf 750rf 200lr 175rr shocks are 75lf 753rf 935lr 94rr so im just trying to free car up on entry on the banked track becouse it makes the car loose after that..thanks for any info

[Dirtrunner35]

lol swap the front springs

[frontrunner]

ok well is that a good idea to swap the front springs on a leaf car and what does any body think about my shock im using are the good for slick also?? Thanks

[dereksehi]

I wouldnt swap the front springs then you wont have any forward drive with a leaf car. What are you running for rear% crossweight rear bite and left side also stagger?

[frontrunner]

Thanks and the cross 50.6% rear 56.2% L/S 52.5% and lr bite is 80# Stagger i have 1 1/2 on rear and 3/4 on front... Caster i have lf 2 & rf 5 and camber i have lf 2 & rf 3 1/2.... thats all without driver...Thanks again

[dereksehi]

I also run on a 1/4 track I had to lower my bite to around 35 to get the car to rotate well and I went back up to 60 on dry seemed to work well you also may want to use an adjustable lowering block and slide rr back. What stub is under your car? Mine is metric here are the rates I run 750 lf 850 rf 185 lr 165 rr hope this will be some help to you.

[stock car driver]

U install new leafs?

[Dirtrunner35]

I wouldnt swap the front springs then you wont have any forward drive with a leaf car. What are you running for rear% crossweight rear bite and left side also stagger?

free the car up and he will be faster on entry and exit

[frontrunner]

Yes new leafs still the same...Thanks

[stock car driver]

I ran stiffer rr leaf than lr when I ran a leaf stock car on imca tires. I also ran a softer rf spring than left.

[speedbuggy]

I ran stiffer rr leaf than lr when I ran a leaf stock car on imca tires. I also ran a softer rf spring than left.

How come the car wasn't too tight going in?

[dereksehi]

If you run a softer rf than lf without a liftarm or mechanical way to jack weight back onto lr the car isn't gonna be able to get weight back onto the lr without the stiffer rf plus running a stiffer rf will keep weight on the lr longer which will loosen the chassis on entry.

[stock car driver]

If you run a softer rf than lf without a liftarm or mechanical way to jack weight back onto lr the car isn't gonna be able to get weight back onto the lr without the stiffer rf plus running a stiffer rf will keep weight on the lr longer which will loosen the chassis on entry.

If you say so.. Ive never had a problem with lr drive from a soft rf.

[RaceMentally]

If you run a softer rf than lf without a liftarm or mechanical way to jack weight back onto lr the car isn't gonna be able to get weight back onto the lr without the stiffer rf plus running a stiffer rf will keep weight on the lr longer which will loosen the chassis on entry.Lots of spring angle on chassis side, float rr, and a flat shackle that will pull forward. Longer shackle less angle long sweeping track and shorten up mounting and drop the mount lower on back of chassis so it reacts faster but maintains cross.

[DaveBauerSS6]

Put a 93 on the LR.

[frontrunner]

and what will the 93 do on lr compared to th 935 i have on lr?? and does the other shocks look alrgt???Thanks again for the help...

[DaveBauerSS6]

The 3 being compression and 5 extension, going to a 3 extension the car will roll to the right faster and roll to the front faster. this will loosen the entry and the middle.

The rear springs are too stiff. Put 150 across the rear, go to 40 bite to start.

As derek said, a little rear steer will help some.

[Dirtrunner35]

The 3 being compression and 5 extension, going to a 3 extension the car will roll to the right faster and roll to the front faster. this will loosen the entry and the middle.

The rear springs are too stiff. Put 150 across the rear, go to 40 bite to start.

As derek said, a little rear steer will help some.

If he is tight already wouldn't more right front weight make the car tighter ???

[stock car driver]

The 3 being compression and 5 extension, going to a 3 extension the car will roll to the right faster and roll to the front faster. this will loosen the entry and the middle.

The rear springs are too stiff. Put 150 across the rear, go to 40 bite to start.

As derek said, a little rear steer will help some.

How did your nova work out this year?

[DaveBauerSS6]

Raced 6 times, won 2. Started mid year and only one IMCA Stock Car track in California limits my racing. Car has more potential, and the driver needs more seat time.

[DaveBauerSS6]

If he is tight already wouldn't more right front weight make the car tighter ???

If you increase the RF spring rate, it will increase wedge during both lateral and rear to front weight transfer. This loosens the entry and tightens exit. Since he said the car was ok on the big track, I wouldn't do a spring change, but go to a softer extension shock on LR so the car sees the RF faster and to a very small degree more compression on that RF spring. It will loosen the entry and get the car rocked back on the LR faster. Leafs are pigs by design, typically over sprung and over shocked.

[frontrunner]

The 3 being compression and 5 extension, going to a 3 extension the car will roll to the right faster and roll to the front faster. this will loosen the entry and the middle.

The rear springs are too stiff. Put 150 across the rear, go to 40 bite to start.

As derek said, a little rear steer will help some.

Thanks for the help guys....

[frontrunner]

Thanks.. And how much should i pull the rr back i have it back an 3/4 inch rgt now all the time...Thanks

[Dirtrunner35]

[QUOTE=DaveBauerSS6;1751421]If you increase the RF spring rate, it will increase wedge during both lateral and rear to front weight transfer. This loosens the entry and tightens exit. Since he said the car was ok on the big track, I wouldn't do a spring change, but go to a softer extension shock on LR so the car sees the RF faster and to a very small degree more compression on that RF spring. It will loosen the entry and get the car rocked back on the LR faster. Leafs are pigs by design, typically over sprung and over shocked.[/QUR

Read this and tell me what you think. http://www.auto-ware.com/autoware-bin/techarchive.pl?noframes;read=18963

[DaveBauerSS6]

Good read.
Leafs cant be tuned as a bar car; a coil spring and short bars are mechanically different.

Agreed that more bite will loosen the entry; and increasing the RF spring rate will loosen the entry, in theory.

More LR extension keeps dynamic weight on the LR.

The fronts steer the car unless the rears are over driving them. This is based on assuming the front steering is correct, and the op said his car was good on the other track. In this case I think by changing the extension two things happen. Weight is reduced off the LR taking bite out, weight is increased on RF. The the benefit of increase in RF weight over comes the loss in bite and the car turns.

I have used this adjustment and it worked, maybe some other factors were involved and that contributed to it working. As it was discussed in the link, I think the shock mfgs and the experts differ on results due to the other variables.

As Jeff said on his setup, a lot of combos will work and it may take a different adjustment to fine tune it.

Try it if it doesn't work move on; if its good its a easy change between tracks.

[DaveBauerSS6]

Thanks.. And how much should i pull the rr back i have it back an 3/4 inch rgt now all the time...Thanks
That's the most Ive ever ran. I run a minimum of 1/4 inch and wont go over 1/2 inch any more.

[Dirtrunner35]

Good read.
Leafs cant be tuned as a bar car; a coil spring and short bars are mechanically different.

Agreed that more bite will loosen the entry; and increasing the RF spring rate will loosen the entry, in theory.

More LR extension keeps dynamic weight on the LR.

The fronts steer the car unless the rears are over driving them. This is based on assuming the front steering is correct, and the op said his car was good on the other track. In this case I think by changing the extension two things happen. Weight is reduced off the LR taking bite out, weight is increased on RF. The the benefit of increase in RF weight over comes the loss in bite and the car turns.

I have used this adjustment and it worked, maybe some other factors were involved and that contributed to it working. As it was discussed in the link, I think the shock mfgs and the experts differ on results due to the other variables.

As Jeff said on his setup, a lot of combos will work and it may take a different adjustment to fine tune it.

Try it if it doesn't work move on; if its good its a easy change between tracks.

So your saying reducing the extension or rebound on the lr takes weight off the tire ???

[DaveBauerSS6]

Yes. Just like the motion examples on the scales that Canuck was using on that link. Now magnify the examples by the force of a 2500# car rolling into the corner. There is a compounding effect with more momentum. He uses the word momentary for the time of change because he is waiting on all 4 corners to relax on the scales.Correct for the example, but on track that change lasts as long as the force of the RF spring stops compressing.

Trying the best I can to answer.

[DaveBauerSS6]

I was just wondering how a 3-9 shock would work on the LR.

[dirtrace09]

I have tried all kinds of shocks on the rear of a leaf car. I have found that the less shock you give the left rear (like a 93) the more that leaf and corner likes it. However, keep in mind that to much or to little leaf spring rate can really throw a wrench in things.

[dereksehi]

As in 9-3 which valving bilstein or other?

[Dirtrunner35]

Yes. Just like the motion examples on the scales that Canuck was using on that link. Now magnify the examples by the force of a 2500# car rolling into the corner. There is a compounding effect with more momentum. He uses the word momentary for the time of change because he is waiting on all 4 corners to relax on the scales.Correct for the example, but on track that change lasts as long as the force of the RF spring stops compressing.

Trying the best I can to answer.

In his example the more rebound on a corner reduces the cross weight

[dirtrace09]

Shock is a 9 length and a straight 3 valving. Bilstein it would be a 30-30. I have found over the years that a twin tube shock works better on leaf springs. Gas pressure does not let them move as freely. Others may have a different experience.

[dereksehi]

What would the car act like on dryslick if I was to try a 20/60 on lr and a 40/10 on rr would that tighten the car up coming out if the corner? These are bilstein numbers

[frontrunner]

Witch one would give more lr bite on exit a 93 or a 95 shock on the lr of a leaf spring car??? Thanks

[RaceMentally]

Witch one would give more lr bite on exit a 93 or a 95 shock on the lr of a leaf spring car??? ThanksThe 3 in front of lr on tacky and 5 and above behind on dry.

[frontrunner]

So a 95 shock on lr for slick behind so would the rr shock stay in the same place and who all agrees with this????Thanks

[RaceMentally]

So a 95 shock on lr for slick behind so would the rr shock stay in the same place and who all agrees with this????Thanks What you have to remember is leafs also act as a mechanical traction device. By floating the rr you also cut the rate in half of pinion wrap. you also are using the shock for and aft to control the wrap of the pinion and how fast the traction is applied. Make sure if you float rr or move leaf packs for and aft that you also change your shock mount so you do not bend any eyes of the shocks. Also leaf cars we go all the way to 4" stagger tacky to sometimes reverse stagger as well. I personally don't like reverse stagger because there are other ways to control other things that the reverse stagger is crutching. Also to add the normal 7-2 8-2 high compression shocks on a 3 link or 4 bar do not apply to leaf. Youll want the compression but also the rebound higher as well. You can tune the mid turn throttle push you always see by increasing rebound.

[stock car driver]

take your lr shock off on slick smooth tracks

[RaceMentally]

take your lr shock off on slick smooth tracksExplanation....

[dirtrace09]

I have never taken mine off but have ran a dummy shock there on the slick. Leaf cars need to let the left rear leaf move as freely as possible on the slick. That is why I suggested a straight 3 valving earlier on the left rear. It has always worked for me. Others may have different opinions.

[stock car driver]

wouldn't a dummy be the same as taking it off?

[dereksehi]

What do you run on the rr for a shock ?

[stock car driver]

3030 or 4040

[dirtrace09]

Yes it is the same. I wasn't disagreeing. I was just commenting that I have never tried to take it all the way off. I was validating to racementally the reason to remove it or run without any pressure or valving.

[dereksehi]

Would staggering the shocks lr ahead and rr behind make a difference also? I am currently running both ahead of the rearend

[Dirtrunner35]

What you have to remember is leafs also act as a mechanical traction device. By floating the rr you also cut the rate in half of pinion wrap. you also are using the shock for and aft to control the wrap of the pinion and how fast the traction is applied. Make sure if you float rr or move leaf packs for and aft that you also change your shock mount so you do not bend any eyes of the shocks. Also leaf cars we go all the way to 4" stagger tacky to sometimes reverse stagger as well. I personally don't like reverse stagger because there are other ways to control other things that the reverse stagger is crutching. Also to add the normal 7-2 8-2 high compression shocks on a 3 link or 4 bar do not apply to leaf. Youll want the compression but also the rebound higher as well. You can tune the mid turn throttle push you always see by increasing rebound.

By floating the rr , all the axle wrap is in the the lr giving you the bite like a 4 bar car if you use the shackle on the left rear. And you don't get the rear steer like a 4 bar car. I had 2 cars with the fast boy and it takes a little to get used to it. I ran a 3 link stock car for ten years and then changed to leaf, tons of bite and it did make the car alot tighter.

You can tune the mid turn throttle push you always see by increasing rebound. On what corner ??

[frontrunner]

ok then whats a good shock package then for slick or all the time or for lf...Thanks

[RaceMentally]

By floating the rr , all the axle wrap is in the the lr giving you the bite like a 4 bar car if you use the shackle on the left rear. And you don't get the rear steer like a 4 bar car. I had 2 cars with the fast boy and it takes a little to get used to it. I ran a 3 link stock car for ten years and then changed to leaf, tons of bite and it did make the car alot tighter. You can tune the mid turn throttle push you always see by increasing rebound. On what corner ??Increasing rebound on lr will slow the reaction and drive down. We run a lot more rebound than most. Why? Because most do not know what to do when the track goes dry. We shift a lot of weight to the rr and high. We also use a 3-5 rr always. I'm front off rr tacky and behind rr dry slick. We also decrease stagger immensely. 3"-4" stagger with the fast boy tacky but dry we close it up to 1" or less. The problem with the fast boy is dry slick tracks. Every car I've seen with this set up is always off on the dry slick and is always loose after 3-4 laps. There is more than just putting a fast boy set up on the car and tuning is still involved just like a 4 bar car.

[frontrunner]

Thanks and my rr is not floated just leafs and if ya run the rr shock behind on dry so do ya run the lr in front on dry then... so do i want more rebound or less on dry on th l/r and more or less compression on dry for the l/r on leaf car ?????? Thanks again

[RaceMentally]

Thanks and my rr is not floated just leafs and if ya run the rr shock behind on dry so do ya run the lr in front on dry then... so do i want more rebound or less on dry on th l/r and more or less compression on dry for the l/r on leaf car ?????? Thanks againTo keep it simple float the rr in dry and lock it up in the tack. Run lr shock behind with higher compression and rebound. If in front of lr run a more 50/50 split. I suggest to find what works best to try different tuning on shocks every race. In fact what we do at new tracks is run adjustable shocks and every caution we come in and adjust them. Yes they're illegal but we can figure out what we need sooner by times, feel, and it's in one feature race. Use the first couple of races to try new things. Don't stick with one set up. Take notes on everything from times, tires, track conditions, set up, etc.

[dereksehi]

Can you float the rr without having a liftarm on the car will the lr spring hold all of that wrap on its own? I guess I don't know what you mean by "a more 50/50 split"

[frontrunner]

Ok thanks but not going to float my rr for next year but just wondering what shocks would be ok to start with on slick some says more comp. and some say less comp for exit but not sure...Thanks

[frontrunner]

Sorry that was for the lr shock more or less comp. on slick for exit?

[speedbuggy]

Anybody had any luck with adding a member (I won't mention which one) to my ignore list. My profile won't save it when I tried to add...

[7uptruckracer]

If your only wanting to free entry drop the LF spring 50# I won't have effects in any other parts of the corner. Where as everything else will effect exit

[stock car driver]

Anybody had any luck with adding a member (I won't mention which one) to my ignore list. My profile won't save it when I tried to add...

That option has never worked for me. BUT I finally figured out if you click on their name then, view profile, it says add user to ignore list!!! walla

Got a bunch of people on that list now!

[setup479point2]

Frontrunner , your inbox is full

[DaveBauerSS6]

How did your nova work out this year?

Jeff... Check page 15 on the new November IMCA newspaper. Top right.
In all the excitement they forgot to mention the leaf springs. Chicken lips.

[frontrunner]

Pm box should be good now... thanks

[stock car driver]

Jeff... Check page 15 on the new November IMCA newspaper. Top right.
In all the excitement they forgot to mention the leaf springs. Chicken lips.

I spend about 5 minutes reading the paper when it comes. pretty much just look for up coming specials and cut out that page and recycle the rest.

[zrt84]

What is this 1982? (jokes)