RF spring rate

[jr18]

I run on a very high bank track that get dry slick. I have been trying to figure out what spring to use on the RF I have ask different people that run at the same track and I get different rates (From a 425 to 650) I have a 500 on the RF know. What I am trying to do is get more forward drive. I can't touch the feul when I need to. I can hear the motor rev. high and the tires spin when i get on the fuel for about 50 to 75 feet out of the turn. When we run the hot lap and the track is tacky the car hooks pretty good and I don't hear the rev. and tire spin. I have noticed that other car have alot of momentum coming off the truns and when are going in to the truns I feel like i am going to run over the guy in front of me but when we come out of the trun he just pulls off and leves me sitting. I run a 421 18deg. motor that is pushing good HP and Torque. I think I have started rambleing and I hope every one can figure out what I am trying to say and explan.

[MasterSbilt_Racer]

We would need your whole setup to help. Forward bite is not really corrected with front springs. A stiffer right front will make the car tighter, but not really give the car more traction.

How much experience do you have? If you are running them over getting in the corner, maybe you are charging in too hard and getting the rear tires sliding on early or late entry. They can't hook back up once they are sliding across the track.

[jr18]

LF spring 500 RF spring 450
LF shock 76-3 RF shock 75

LR spring 275 RR spring 225
LR shock 94.5 RR shock 94

Left% 52.4
REAR% 54.9
Cross% 43
Bite 99
Front stager 1
Rear stager 4
5th coil 350

The track is very high bank
Dry slick

[Rocket Bonehead]

You'd notice a HUGE improvement in forward drive (and lift) if you flopped the rear springs (yes, 225 LR and 275 RR).


Without knowing the chassis brand, PH Bar rake, and bar angles, it's hard to suggest more.



RB

[WestlingRacing]

Change Gear ratio

[Ridin Dirty]

There is no left side or wedge(cross) in the car. get LS up to 54 (especially on a banked track) and wedge near 50-52% this will get you traction. Also look to increase the LR bar angles. RF spring rate is in the ball park.

[billetbirdcage]

You didn;t say if the car is a LR behind or LR in front?

[jr18]

There is no left side or wedge(cross) in the car. get LS up to 54 (especially on a banked track) and wedge near 50-52% this will get you traction. Also look to increase the LR bar angles. RF spring rate is in the ball park.

I run the shock LR behind. I know this may sound dumd but I wont to get it right to increase wedge you add bite. If I get the wedge up to 50-52% I think I would be around 250 -275lbs of bite in the car that is more than i have ever ran in a car. Will adding wedge help the nose from plowing the race surface. or will I need to increase the RF spring rate.

Someone ask about my experience i have ran about 70-75 races. Out of those less than 30 of them is with a big motor.

[billetbirdcage]

Well, since nobody else has caught this yet.


Something is severly wrong with your scale numbers.

Too have the rear and left percent with that cross wieght you would have a 105# of RR wieght NOT LR BITE. This is assuming the car is around 2300# total.

You need to do some investigating because if the car is close to 2300 it is impossible to have 99# of LR bite with those rear, left, and cross percents.

To have those percents the wheel wieghts would be as follows

LF 626 RF 410
LR 578 RR 684

Sure you didn't have the scales plugged in with the rear tires reversed (electronic scales) or just miss read the readings

[Rocket Bonehead]

Billet makes a good point. I missed that. That said, if those are your true numbers, they don't look all that out of whack to me for a really high banked track. I'd disagree with RD on the L%. Yes, you are low, but for a high banked track, that isn't hurting you.



RB

[cheater35]

Jr18: It sounds to me like you need to take some turns out of the RR and put some in the LR if your scales #s are correct. That should keep your ride heights the same and get you LR bite not RR bite. The LR should be heavier than the RR. I've had this happen to me before.

[jr18]

I keep a records of every time I scale the car i will look again and see.
this evening i am going to put the car back on the scales and see what i did. I have the old feed scale.

[jr18]

If you guy where running a 3/8 high bank track what would you run on a GRT (My car is a GRT copy "STRINGER CHASSIS") like the springs, shocks, bars, Left%, Rear%, Cross%, 5 Coil spring and shock, J Bar and rear stager. This car is Z link on the RR. Should I go back to the RR 4Bar? I know this is alot of infomation.

Just in case I miss it THANKS !!!!

[billetbirdcage]

Before you change everything, check out those scale numbers.

If it is like I think it is with 105# of RR, just switching to 100 to 120# of LR will probably fix most of your problems.

Let us know the correct scale number if those were wrong.

[jr18]

I was going to try to get the car back on the scales this evening but ran out of time i will have to do it tomorrow evening. But i did look at my records and i do have reverse bite in the car I can't believe i didn't catch that last week i don't know if I type the # in the wrong side or not I wrote a excel file the does the math for me and all i have to plug in the #s and it does all of the %s for me.

I think i am going to put last years set up back on the car. because i do not know what i did!!!!!!!!!!!

When i get done scaling the car i will post my # and see what happen from there.

[jr18]

Well, since nobody else has caught this yet.


Something is severly wrong with your scale numbers.

Too have the rear and left percent with that cross wieght you would have a 105# of RR wieght NOT LR BITE. This is assuming the car is around 2300# total.

You need to do some investigating because if the car is close to 2300 it is impossible to have 99# of LR bite with those rear, left, and cross percents.

To have those percents the wheel wieghts would be as follows

LF 626 RF 410
LR 578 RR 684

Sure you didn't have the scales plugged in with the rear tires reversed (electronic scales) or just miss read the readings

with me out of the car it's 2137 and my wieghts is 215
Yes something is very wrong with my # or I have lost my mind!!!!!!

[jr18]

Here the correct #s I found that I made a big mistake when i set the car up I tryed to go back to last years setup and I think I looked at the bite and left and rear % and didn't look at any thing else. I did notice that I was getting a -# when this happened I should have look in to it more but i just blowed it off.

I rescaled the car this evening and this is what I came up with the Ride heights are with in an 1/16" or should the Ride height be on the money.


LF LBS 465 RF LBS 494
Spring 500 Spring 450
Shock 76-3 Shock 75
90" Tire @8psi 91" Tire @ 10psi



LR LBS 659 RR LBS 519
Spring 225 Spring 225
Shock 941/2 Shock 93-5
87" Tire @7psi 91" Tire @10psi


Total with me out of the car 2137
Bite 140
Left% 52.6
Rear% 55.1
Wedge 165
Cross% 54
J-bar is 7.5 on Frame and bottom hole on pinion


What or if any changes should I make on the setup?

[MasterSbilt_Racer]

This is without you right? I'd say the cross is now a bit high. It will go up some with you in there. I'd say 150# with you is the most wedge I would start with.

[jr18]

I know this might be a dumb question but can you raise and lower the wedge and still keep the bite that you have.

[MasterSbilt_Racer]

You can have the same bite (lr-rr) and have less wedge or cross if you add left side weight. You would have to move weight on the car or add a weight to the left side. Then you would need to remove lr weight with the coilover adjusters.

In your case I would just go 2 turns down on the rr and 2 off the lr. I think you will be close for starters.

[jr18]

I would like to Thank every one for there time and help. This is how the night went.

The setup was a big improvement. The supers ran twin 20's and I used it as a test and tune. I set the car up and ran it just like I jot it of the scales. After the hot laps I uped the RF spring (becease the car was plawing the ground and destored the RF nose) rate to a 500 and decreased the RR to a 250 from a 275 and put 3 rounds of title on the left side(Last year for the last race I put 8 rounds of title in and the car did the better than it did all year I beleave this car like a lot of title).
Then qualified and the car started loading up and cuting out looked to see what the problem was and found a tear off raped around the back pump and was holding the pump open. After started last for the first feature i gained two spots and then ran over the nose again and it put the car in the wall on turn 3. Brung the car in and fixed it back and added 2 more rounds of title in the car. All in All the all of the bad luck for one night the car handle alot better than normal.

Again Thanks.

[billetbirdcage]

I thought I used to have some bad nights, LOL


Have you looked at the way you are installing the nose/body? if you are digging the nose in but aren't nowhere close to bottoming the RF shock out you likely don't have the nose installed at the proper hieght?

Just a thought.

[Chris Steele]

I mount my nose about 8 1/2 inches off the ground on the right side.

Wouldn't adding tilt make the car get over on the RF even more?

[billetbirdcage]

Yes and No really!

It will make the car roll easier but really doesn't make to roll farther. It just gives the car an easier start to the rolling process but in the end it isn't going to roll more total. You would have to add alot to really see much difference in total roll. But it the car isn't rolling and adding the tilt does induce the roll then it might increase the travel at the RF but it should be minimal unless the car goes from a 4 wheel drift to sticking the right tires and therefore induce a lot of roll.

[jr18]

The track had a big hole in the middle of trun 1 and 2 and I didn't realize that it was that big. IT hite so hard it broke the top ball joint bolts out im glade that I have a good crew and they cought it before the feature I can't beleave it didn't break the top control arm off or bend everything.

[Kromulous]

Not to be critical, but there is no reason to hit a hole that big twice.

If my driver does it i am all over him. In a form of racing i did years ago, a guy would have to remember where all the big ruts were, and what was hitable and what was not. hitting one twice could result in breakage, and loosing.

Krom.

[jr18]

I didn't mean that i hit the hole twice the first time i pushed the nose back when i hit the hole.
The second time i ran over it I didn't get off the ground.

But anyways I appreciate all the imput.

[Rocket Bonehead]

Not to be critical, but there is no reason to hit a hole that big twice.

If my driver does it i am all over him. In a form of racing i did years ago, a guy would have to remember where all the big ruts were, and what was hitable and what was not. hitting one twice could result in breakage, and loosing.

Krom.


I understand where you're coming from Krom, but I'd be careful on the criticism. Sometimes on tracks like that the fastest line is thru the holes instead of around them. These cars are very durable and can sustain quite a bit of punishment provided you have quality parts on the car.


The biggest cause of damage isn't due to the ruts, but rather coil-binding the spring when you hit the rut. If you're too soft on a corner for the track, and coil-binding that corner, you can expect some damage to occur because there is nothing absorbing the shock of the bump.



I am not knocking your stance, but rather just offering up the other side of it.



RB

[ajb59]

i've never heard the term title before. where does it come from. just curous.

[MasterSbilt_Racer]

i've never heard the term title before. where does it come from. just curous.


He means "tilt". That refers to raising the left side ride heights up.

[ajb59]

...thanks...

[Kromulous]

I understand where you're coming from Krom, but I'd be careful on the criticism. Sometimes on tracks like that the fastest line is thru the holes instead of around them. These cars are very durable and can sustain quite a bit of punishment provided you have quality parts on the car.


The biggest cause of damage isn't due to the ruts, but rather coil-binding the spring when you hit the rut. If you're too soft on a corner for the track, and coil-binding that corner, you can expect some damage to occur because there is nothing absorbing the shock of the bump.



I am not knocking your stance, but rather just offering up the other side of it.



RB

I understand, in our short time on dirt ovals, we hit a few mamouth ruts out there and severly hurt some parts. Broke a clip even. You just gotta learn to avoid them, hit em once and cant afford to do it twice. I didnt mean to sound harsh, typed words...

I do agree with your point, sometimes there is a rut line, thats what i call it, that develops in a track, that you can lay your RR in and then mash on it. It will hold you right in there if you find it, we run some sprinter tracks so these are common.

Krom.

[jr18]

Not to up hold any one but sometimes criticism is a good thing.

When I bought my first chassis I got schooled real good. The person that I bought it from said when I get it done that he would look at it and see if I had missed anything. So I took it to his shop and he put it on the rack and he walked under it and then ask me to get something to make a list with when he got done my list was a mile long. I believe he could tell that I was very dispointed, he said that he didn't mean to hurt my pride. I found something out that day if a person is really trying to help sometimes it might hurt.