Tires come up twice. Travel limiters?

To add to Dave's post....


I still dont think the problem is in the front based on the video. We can only assume that the bases are covered i.e. rear is square, A/R bar is preloaded correctly (which means very little preload...it appears so), lower control arm angle is correct (it should be paralell with the ground at race weight or have a very slight upward angle at he front mounting point), ride height is correct, etc. The front strut rebound needs to be at full loose (for now, can change later) and the front spring needs to be correct. What is it? I assume a 14" 150-175? These things will promote all the weight transfer possible that comes out of the front. On to the rear....

If the tire psi is at 12 and the car is almost at dead-hook, which it looked to be, then take a big swing at tire psi. I'd go 2lbs DOWN and see what happens. My guess is that the car dead-hood but as the seperation goes into phase 2, the squat (and you ain't got much), the car will stay in the air and not bounce. Try it as it's easy.

The problem with single adj rears is that they are only rebound and not compression. The secret is in getting the rear to seperate efficiently enough (rebound or "extension"....remeber the purpose of a shock is PLANT THE TIRE TO THE SURFACE), compress as the car settles down (compression) and stay there (rebound again). The cars IC plays a huge role in this. The IC is an imagionary line going towards the front of the car where the upper and lower control arms meet. To long IC as the car will never transfer weight. To short IC and it will be on the bumper BUT a shorter IC helps to keep the tire planted longer. The IC must be correct i.e. correct for YOUR car. A wise man named Dave Zimmerman once told me that every car is different I would direct you over to the Bullet to a particular thread but said thread has a ton of BAD info in it so I'd ve concerned that it would just complicate things too much.

Get better vids, play with tire psi and shock setting (one at a time though) in BIG swings so that you can see if something chnaged. We'll be here waiting with more help

soupbean wrote:That pass was 12 psi I believe in the tires. It does tend to pull to the left on nearly every launch. What would be your suggestions in trying?

http://www.teamzmotorsports.net/v/ARB_setup.pdf


ARB setup. Was your done this way?

are the slicks a stiffwall? tunes or no tubes? I know with out smallblock fox we had to put some preload in the rr, all the cornerweights were set and the ar run with no preload in it. As mentioned the bounce could be from the shock valving...........also what spring rate are you using on the front?

All in all it dont look just horrible.

Good da shocks and struts are your friend.

richter69 wrote:are the slicks a stiffwall? tunes or no tubes? I know with out smallblock fox we had to put some preload in the rr, all the cornerweights were set and the ar run with no preload in it. As mentioned the bounce could be from the shock valving...........also what spring rate are you using on the front?

All in all it dont look just horrible.

Good da shocks and struts are your friend.

X2 on the tire question...

No these are not stiff walls but my next set will be. I am not sure of the spring rate. I bought the car turnkey last year pretty much how it sets except engine and the owner didn't know much about the car.

soupbean wrote:No these are not stiff walls but my next set will be. I am not sure of the spring rate. I bought the car turnkey last year pretty much how it sets except engine and the owner didn't know much about the car.

For not knowing much about the car it works fairly well, lol. What kinda power does it make? Stiff may not be needed....

yellowhorse7 wrote:

soupbean wrote:No these are not stiff walls but my next set will be. I am not sure of the spring rate. I bought the car turnkey last year pretty much how it sets except engine and the owner didn't know much about the car.

For not knowing much about the car it works fairly well, lol. What kinda power does it make? Stiff may not be needed....

It made 838 @6300 on the engine dyno. Weighs 3240 with me in it.

The Snakes old street head motor sure beat the hell out of those 10.5 tires he had, I know it was a ladder bar car, but adding tubes to his tires seemed to help a ton. If the tires are old a new set is in order anyway, I'd give a stiffwall a shot, and tubes would be better if you don't already have um. You need to make damn sure the rollout is within a 1/4", measure it don't count on the markings to be always correct.

Done some playing tonight. First launch with the travel limiters the front end bounced around like a low rider with cut springs. Pulled the travel limiters back off (after watching the launch video there doesn't seem to be much travel anyway) and adjusted the front QA1's to the stiffest valve setting and no more second bounce although front picks up very little now (maybe and inch or two) and hurt 60' a little. Next pass bumped the 2 step up to 3600, left a bit soft with a 1.40 60 foot but ran a 6.06 with no bounce or any craziness going on. Hopefully it sill stay there and be consistent tommorrow for the race. The left front touchs a bit before the right front so we made a anti roll adjustment but the rain made it's presense known again. We'll see what it does tommorrow . Held it down a bit longer today lifting just before the quarter (lifted when I saw it hit 7K) and with a lazy 60 foot she went 9.54. Fastest I've ever been. Good times

richter69 wrote:The Snakes old street head motor sure beat the hell out of those 10.5 tires he had, I know it was a ladder bar car, but adding tubes to his tires seemed to help a ton. If the tires are old a new set is in order anyway, I'd give a stiffwall a shot, and tubes would be better if you don't already have um. You need to make damn sure the rollout is within a 1/4", measure it don't count on the markings to be always correct.

Yeah it's about time for a set. I'm going to give them a try. By roll out are you meaning tire diameter? If not, please elaborate. I also notice you run alot of screws and read the link someone posted as to why. For some reason, this car has 5 screws each side on the LR on 4 each side on the RR. Think that may have something to do with the car wanting to pull to the left on launch?

You should have 16 you'll be surprised what a difference it will make. I would say with 800 plus hp that stiffs will help you out.

Barney wrote:You should have 16 you'll be surprised what a difference it will make. I would say with 800 plus hp that stiffs will help you out.

16 inside and 16 outside of each rim?

yes more screws, hell I run 36 per rim. The rollout is the diameter, make sure both are at the same psi, They make small thin tape measure's for this, if you dont have one wrap a length of good spring or twine that wont stretch and give a false reading, where they meet use a paint pen or the like to make the string, you can then measure it with a reg tape measure or simple wrap it around the other slick and see where the marks come out at.

richter69 wrote:yes more screws, hell I run 36 per rim. The rollout is the diameter, make sure both are at the same psi, They make small thin tape measure's for this, if you dont have one wrap a length of good spring or twine that wont stretch and give a false reading, where they meet use a paint pen or the like to make the string, you can then measure it with a reg tape measure or simple wrap it around the other slick and see where the marks come out at.

Will do when I replace tires next week. So, do you think the 10 screws on the LR versus the 8 screws on the RR can attribute to the car pulling to the left on launch? Assuming the rear end is square...

soupbean wrote:

richter69 wrote:yes more screws, hell I run 36 per rim. The rollout is the diameter, make sure both are at the same psi, They make small thin tape measure's for this, if you dont have one wrap a length of good spring or twine that wont stretch and give a false reading, where they meet use a paint pen or the like to make the string, you can then measure it with a reg tape measure or simple wrap it around the other slick and see where the marks come out at.

Will do when I replace tires next week. So, do you think the 10 screws on the LR versus the 8 screws on the RR can attribute to the car pulling to the left on launch? Assuming the rear end is square...

I doubt it, and even the rollout being off wouldn't really matter at the hit that much, but its not gonna hurt any making sure its right. I even like to make sure the screws on the outside of the rim are even with the inside. Its splitting hairs but what the hell..........

I also like to rotate the slicks also, I do it after every race.

richter69 wrote:

soupbean wrote:

richter69 wrote:yes more screws, hell I run 36 per rim. The rollout is the diameter, make sure both are at the same psi, They make small thin tape measure's for this, if you dont have one wrap a length of good spring or twine that wont stretch and give a false reading, where they meet use a paint pen or the like to make the string, you can then measure it with a reg tape measure or simple wrap it around the other slick and see where the marks come out at.

Will do when I replace tires next week. So, do you think the 10 screws on the LR versus the 8 screws on the RR can attribute to the car pulling to the left on launch? Assuming the rear end is square...

I doubt it, and even the rollout being off wouldn't really matter at the hit that much, but its not gonna hurt any making sure its right. I even like to make sure the screws on the outside of the rim are even with the inside. Its splitting hairs but what the hell..........

I also like to rotate the slicks also, I do it after every race.

Interesting... I've never heard of rotating slicks. I assume to keep even wear if weight/force is uneven from left to right?

soupbean wrote:

richter69 wrote:

soupbean wrote:

richter69 wrote:yes more screws, hell I run 36 per rim. The rollout is the diameter, make sure both are at the same psi, They make small thin tape measure's for this, if you dont have one wrap a length of good spring or twine that wont stretch and give a false reading, where they meet use a paint pen or the like to make the string, you can then measure it with a reg tape measure or simple wrap it around the other slick and see where the marks come out at.

Will do when I replace tires next week. So, do you think the 10 screws on the LR versus the 8 screws on the RR can attribute to the car pulling to the left on launch? Assuming the rear end is square...

I doubt it, and even the rollout being off wouldn't really matter at the hit that much, but its not gonna hurt any making sure its right. I even like to make sure the screws on the outside of the rim are even with the inside. Its splitting hairs but what the hell..........

I also like to rotate the slicks also, I do it after every race.

Interesting... I've never heard of rotating slicks. I assume to keep even wear if weight/force is uneven from left to right?

I rotate slicks every 5passes. It helps the sidewall. With slicks especially smaller ones it's the sidewall that goes away before the contact surface.

Since ancient times there has always been some disagreement as to the benefits to the sidewalls of swapping/not swapping the slicks every so often.

The "swap" camp maintains that never swapping the slicks will over time damage the structure of the sidewalls from the repeated rotational pulls on the sidewall always going/pulling the same direction pass after pass.

And the "no swap" camp maintains that swapping the slicks repeatedly over time will wear out the sidewalls prematurely from the repeated rotational pulls on the sidewalls going/pulling in both directions (as if the sidewall structure was seeing double the number of passes).

But in my opinion as far as sidewall life goes, I can see where both sides of the debate could be right.

But in the past I never really swapped slicks around just concerning sidewall life anyway. It was usually done just to clean the tread surface off if going one direction had started to develop too much of a feather/rip/rutt/ocean wave (or whatever you want to call it) pattern on the tread surface.

That car needs a tube and a stiff sidewall at that power and weight. I like 20-24 screws per wheel....10-12 in and out.....

soupbean wrote:Done some playing tonight. First launch with the travel limiters the front end bounced around like a low rider with cut springs. Pulled the travel limiters back off (after watching the launch video there doesn't seem to be much travel anyway) and adjusted the front QA1's to the stiffest valve setting and no more second bounce although front picks up very little now (maybe and inch or two) and hurt 60' a little. Next pass bumped the 2 step up to 3600, left a bit soft with a 1.40 60 foot but ran a 6.06 with no bounce or any craziness going on. Hopefully it sill stay there and be consistent tommorrow for the race. The left front touchs a bit before the right front so we made a anti roll adjustment but the rain made it's presense known again. We'll see what it does tommorrow . Held it down a bit longer today lifting just before the quarter (lifted when I saw it hit 7K) and with a lazy 60 foot she went 9.54. Fastest I've ever been. Good times

Why did you adjust the fronts to the stiffest setting? You're talking rebound I assume and they should be (for testing) at full loose

yellowhorse7 wrote:

soupbean wrote:Done some playing tonight. First launch with the travel limiters the front end bounced around like a low rider with cut springs. Pulled the travel limiters back off (after watching the launch video there doesn't seem to be much travel anyway) and adjusted the front QA1's to the stiffest valve setting and no more second bounce although front picks up very little now (maybe and inch or two) and hurt 60' a little. Next pass bumped the 2 step up to 3600, left a bit soft with a 1.40 60 foot but ran a 6.06 with no bounce or any craziness going on. Hopefully it sill stay there and be consistent tommorrow for the race. The left front touchs a bit before the right front so we made a anti roll adjustment but the rain made it's presense known again. We'll see what it does tommorrow . Held it down a bit longer today lifting just before the quarter (lifted when I saw it hit 7K) and with a lazy 60 foot she went 9.54. Fastest I've ever been. Good times

Why did you adjust the fronts to the stiffest setting? You're talking rebound I assume and they should be (for testing) at full loose

QA1 told me to To see if it would take the second hop out. It did.

Here is my first time trial for this past Sat race straight off the trailer after Fri tuning. Bracket class limited to 6.00 ran a 6.02 with a 60' of 1.38 and a .004 light on this pass (looks like a red light in slow mo). Looks better than before. The stiff walls will be here this week. Any suggestions?

stiff side walls and can you leave any harder ? also ck your front end there seems to be a lot of wobble .......

If I leave any harder, I will break out. I've noticed that wobble too in the slow mo videos. Can't feel it in the car. Gonna check it out today.

richter69 wrote:The Snakes old street head motor sure beat the hell out of those 10.5 tires he had, I know it was a ladder bar car, but adding tubes to his tires seemed to help a ton. If the tires are old a new set is in order anyway, I'd give a stiffwall a shot, and tubes would be better if you don't already have um. You need to make damn sure the rollout is within a 1/4", measure it don't count on the markings to be always correct.

Tires came in today. The written roll out is 87 3/4 on one and 86 1/2 on the other! Bout to get on the horn