Visit The Dirt Forum for More Information

Author Topic:   Need Help for Dry Slick
SpeedRacer73
Dirt Roller

Total posts: 7
posted June 13, 2004 12:28 AM  

I'm been reading this board for a while and it seems that lots of good advice & info. is offered on here. I'm at my wits end trying to figure out my modified. Can someone give me some advice on what to do or where to start:

It is a DW9 4 Bar/Z Link or right rear can be 4 bar. Right now I'm running this setup:

LF: 650 RF: 750
LR: 225 RR: 200
I have a 18" C/C Strait bar
8 1/2" up from bottom of frame, 2nd hole from bottom on pinion.

Shocks
LF: 75 RF: 75
LR: 93 RR: 93

58.9 Rear %

200lbs. left rear bite, & 2 1/2" stagger

1.) Lacking forward bite: I added bite & it resulted in less forward bite. How can I get more bite?

2.) Just put the strait bar after having a J-bar, but it isn't rollin over enough, & isn't picking up the LF at all. Not enough side bite.

I'd like to get lots of info. on this & all help will be greatly appreciated.

aggressive
Dirt Full Roller

Total posts: 33
posted June 13, 2004 06:20 AM  
From the amount of stagger you listed you must be on Hoosiers? If so then here is a couple of things that should help.Panhard bar,6 1/2 up on frame 2nd hole from top on pinion,your length is to long 17"c/c works well,rims 4"R.R. 3" everywhere else.85 to 100 pounds of left rear (no driver)works well, front tires should be within 30 pounds of each other with the left being heavier.These#s are with no stagger in the front and 1"in rear.If you are racing on flat to semi banked tracks here are some spring suggestions L.F.650 R.F.650 L.R.275 R.R.175 the R.R.is for a Z-link spring in front,the L.R.is for spring behind..again this is a hoosier tire setup will not work on hockey pucks,need some info on your pullrod,spring or? what holes u mounted in?

mod70
unregistered Total posts: 33
posted June 13, 2004 09:46 AM           send a private message to aggressive   Edit/Delete Message   Reply w/QuoteBBBBBB
I normaly don't deal with the 4 link setups, I've only run 2 link, but 2 things seemed to jump out at me: rear springs seemed a touch stiff, and the rear split seems kind of extreme. You might knock springs down to 225 & 175 and LR bite to 120 or less. I've seen too much split take away bite. Would also like more info on spring arm.

SpeedRacer73
Dirt Roller

Total posts: 7
posted June 13, 2004 09:56 AM  
Yes i am running hoosiers,the pull bar info. is i have a progresive spring preload at 1/4" i have a left hand pull bar mount and i'm in the second hole down. What about the front springs, they seem a bit light to me, should I change them? The car I drove last year was it's fastest on 240lbs LR, thats why I'm running so much LR. I tried 100lbs. LR on the DW9 but the car was loose off.

Should I change the pull bar spring or try a different preload?

I tried to get help on the setups from Dirtworks, but all they gave me was the basics, which wasn't enough. The guys I race with wont give me much info., I guess because I race with them. So everything I get on here is greatly appreciated. Thanks!

[This message has been edited by SpeedRacer73 (edited June 13, 2004).]

JMillerJr76
Dirt Maniac

Total posts: 128
posted June 13, 2004 08:49 PM  
I would try putting the pull bar on the longer center mount above the driveshaft loop. We have a dw8 2 link that we have tried the short left hand pull bar, and we couldnt get it to work good, I do know some guys that run the left pull bar, I dont know how they get theirs to work.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted June 13, 2004 10:17 PM  
add more angle to the short bar that will help most all the time, put the short bar on the bottom hole on the pinoin that will help.
i would consider 250 lr and 200 rr. your not to stiff for a 4 linker.
is the car clamped up? or spring behind?
less stagger.
by less forward bite are you really getting more rr and causing a on the throttle loose?
if so raise the rr trailing arm up a hole(the rearward bar)

zeroracing
Dirt Forum Champ
Total posts: 1875
posted June 13, 2004 10:24 PM  
where are your springs at?
what exactly is it doing? i mean loose on the gas or just spin tires, both the same?
and what are your bar angles?
thanks
jason

SpeedRacer73
Dirt Roller

Total posts: 7
posted June 13, 2004 10:36 PM  
Jason
What do you think about the progressive spring on the pull bar & preload? Also, are you talking about the right rear lower bar, I have it in the bottom hole. The spring is behind on left rear on birdcage & in front on right rear. The car is loose on the gas and spinning the tires. Couldn't get in gas anywhere on the track. The car isn't rollin very much at all & not even tryin to pick up the LF with strait bar. The car isn't lifting and seems like something is way off. The bar angles are at LR/Bottom: Middle hole out of 3, LR: Top 3rd hole up out of six, RR:Bottom bottom hole out of three. Zlink is about 5% down hill. Does the 4bar give more bite on RR?

Thanks

[This message has been edited by SpeedRacer73 (edited June 13, 2004).]

rocket36
Dirt Freak

Total posts: 209
posted June 14, 2004 03:08 AM  
try putting the most angle you can in your panhard bar and/or lift your left rear top rod up one hole then two if needed.

aggressive
Dirt Full Roller

Total posts: 33
posted June 14, 2004 04:50 AM  
The progressive spring is to soft the 150 bucks for a bisquit rod is well worth the money but if thats what you got I would try a 1200 in it.Longer is better when your speaking of pullrods,if your mounted in the front hole on the rearend move it to the rear,you also should try up a hole on the left upper and level your R.R. z-link bar if you want to pick the left front up and tighten the thing up with the panard bar,5 1/2 off the bottom to the bottom of the bracket and third hole down on the pinion,I,m guessing you have a plug in for the left bottom bar?If so you may want to try the long bar 20 1/4 or 20 1/2 depending on how u squared the rearend this will index the birdcage and load the spring and really put some drive in it,when you index the birdcages make sure the left birdcage is 1 degree forward at the top,the longer bar will tighten the car while on the gas it changes the roll steer on the left side.

jammin
Dirt Administrator

Total posts: 6243
posted June 14, 2004 05:46 AM  
To improve your car heres what I'd try:

-Increase your bar angles. This will help increase forward bite but you'll loose some side bite in the middle of the corners. If you feel aggressive, you might raise all the bars up a hole.

-Increase rear springs by 25lbs.

-Increase rear weight to 60%.

-Run the longer pull bar.

-Run a shorter straight bar. Put it in the second hole up from the bottom and about 2" of rake in it and start from there.

-Move the rearend out the leftside of the car more. But don't get carried away or you'll tear up ujoints.

Keep your right side z-linked. It will limit the rearsteer/rollsteer and help keep the car tighter from the middle on out.


SpeedRacer73
Dirt Roller

Total posts: 7
posted June 14, 2004 02:55 PM  
I'm going to get the percentages & wheel weights ASAP! I'm going to change the pull bar spring from a progressive to a 1200 so how much preload should I put in it? I have plugs in both the bottom bars. I had 1/2" of preload on the progressive & DirtWorks told me too back it off to a 1/4", would that have taken away forward bite?

Thank guys for all the help, bare with throughout the week as I make changes, I'll be scaling my car out and making changes with help from you all. Maybe by the weekend I'll be able to report success!

[This message has been edited by SpeedRacer73 (edited June 14, 2004).]

juliaferrell
Dirt Freak

Total posts: 370
posted June 14, 2004 09:10 PM  
I would increase all bar angles and make sure front roll center was initiating rollover.. All four bars upward is definitely the way to go here. If you go a little far you can always back it off some.

SpeedRacer73
Dirt Roller

Total posts: 7
posted June 15, 2004 11:39 AM  
Here is the info:

LF: 421 RF: 530
LR: 794 RR: 593

Pertentages
LS: 519
RP: 59.3
Cross: 56.6
Bite: 200

I'll check back later tonight.

BigBlueFord
Dirt Full Roller

Total posts: 44
posted June 15, 2004 11:50 AM  

LF vs RF weights looked reversed.

Looks like way too much bite and cross.

Try 80 - 90's bite, maybe even less bite if tacky track and cross of around 48 - 49%.


SpeedRacer73
Dirt Roller

Total posts: 7
posted June 15, 2004 02:43 PM  
I know this sounds stupid but I'm tryin to figure out how to correct that problem. I'm new at using scales, so I'm still learning. The tracks are never tacky here, it always dry slick (black).

Thanks

nolimit92
Dirt Forum Racer

Total posts: 97
posted June 15, 2004 08:21 PM  
First I assume that you know about indexing the bird cages.

First, even out the front difference in weight and get the rear to around 100# split( the problem is that your are taking away from RR bite when you add all that left rear bite . Then take your top left bar put it at 25-30 angle, move your left lower bar to around 15-20. The problem is your car isnt getting on the bars and using leverage for bite. You want to get on the bars as quick as possible on a dry track. More angle will loosen you up in the middle, but is alot faster thru and comming off the corner.

You really dont need as much rear bite with a 4 bar Z car because the left side chassis weight, bird cage indexing, along with bar angle load your left rear tire. We have change our left rear spring from 175-250 and seen very little difference on forward bite. But also I run both links on the left in the top holes.

[This message has been edited by nolimit92 (edited June 15, 2004).]

aggressive
Dirt Full Roller

Total posts: 33
posted June 16, 2004 07:32 AM  
SpeedRacer73,
There is alot of good advice on here and some differences of opinions but what works for one sometimes isn't the best advice for others but if you take a survey of the people that have posted on here I think you will find that you have got to get the wheel weights alot closer before you can start fine tuning.Here is the ride heights that I have used on the scales with no stagger in the front tires and 1 inch of stagger in the rear and these are from a dw9 on hoosiers with a scale height of 2 1/4 LF 7 7/8 RF 8 1/4 LR 8 1/4 RR 8 5/8 TO 9 with these you should be able to get the LR down to 85-100 pounds and the front tires close to weighing the same, fuel cell location, battery location, panard bar length and rim offset also play a big part of these measurements but in my opinion you got to get the wedge and the left rear out of it before you will notice any improvement

BigBlueFord
Dirt Full Roller

Total posts: 44
posted June 17, 2004 11:27 AM  

SpeedRacer73

Based on these spring that you quote earlier:

LF: 650 RF: 750
LR: 225 RR: 200

And this weight distribution:

LF: 421 RF: 530
LR: 794 RR: 593

Here's something to try:

2 Turns in LF
2 Turns out RF
4 Turns in RR
4 Turns out LR

This should shift your corner weights around. If not enuf do it the same sequence again. When you get close you may want to back down to:

1 Turn in LF
1 Turn out RF
2 Turns in RR
2 Turns out LR

By putting turns in & out on opposite corners your ride heights should be affected that much.

I've had guys tell me to do this by the scale numbers. But I haven't been to successful that way. Basically what they say is that to maintain ride heights if you add 10#'s to the LF & RR then drop 10#'s on the RF & LR.

Alot of guys will say to do the same number of turns on all four corners. But that doesn't take into account the different spring rates.

Acutally when I do it I divide the lower spring rate into the larger spring to get the ratio and then try to start off wusing that ratio: i.e. 650/200 = 3.25........1 turn in the LF would equal 3.23 turns in the RR.

Bottom line is that you can shift your corner weights around by adjusting the jack bolts on all four corners.


SpeedRacer73
Dirt Roller

Total posts: 7
posted June 17, 2004 06:15 PM  
Thanks for all the replies,this is by far the best site i've ever been to.I realy appreciate every ones adivice and willingness to help out another racer. I made some changes that yall recomended,i haven't scaled it out yet but when i do i'll post it on here for yall to take a look at. THANKS AGAIN!!!!

BigBlueFord
Dirt Full Roller

Total posts: 44
posted June 24, 2004 01:20 PM  
What's up SpeedRacer73?

How's it been going with the racecar?


Back to the Archives