Visit The Dirt Forum for More Information

Author Topic:   Mod Rookie w/ zlink/zlink setup q's help!
socaldirtmod
Member
posted November 25, 2003 06:57 PM
All right fella's, need your help, if have been following this forum for some time... decided to gather the set up info and see what the experts think!!

i'm not sure if all my terms are correct so i have attached a photo of my current left rear suspesion set-up for reference(if i didn't do it right heres the location http://www.hawksracing.com/images/MODREARSUSP1.jpg ). I'm a rookie Mod pilot with my first Mod, i have practiced 2 times and raced once with basicaly the set up listed below (The only changes i have make are front springs... had LF 850, RF 950 when i bought it and i was told that was way to stiff on a 1/4 mile basically flat dirt track with not much banking and generally dry slick by main event time??). Car seems to have decent bite coming off corners but pushes bad on entry when off the gas. In the races I have watched prior, anyone who gives up the bottom goes to the back... not much of an outside groove as a rule... so this push on entry makes it tough to keep the car on the bottom. I was advised that this type of suspension (z/z) is know for this tendency and lots of rear brake on entry is the cure?? This seem like a band-aid for an improperly set up car?? but with my lack of mod expeirience i wouldn't know. just wanted to get your opinions. On both sides the spring is in the front and the shock in the rear, z-link is floated but, is locked/bolted to the spring/shock mount wich is also floated. If that wasn't enough to think about... car also has four link brackets on both RR and LR!! Should i change the LR to a 4link? I have lots of lead for more rear if it needs it?

Metric clip

SPRINGS LF 650 RF 750
LR 250 RR 220

WEIGHTS LF 572 RF 502
LR 773 RR 607

WHEEL OFFSET LF 3 RF 2
LR 3 RR 3
TOTAL WEIGHT 2453 WET W/DRIVER
LEFT 54.8% REAR 56.2% CROSS 51.9%
PULL BAR 41" 23deg
RightRear Lead 1 1/8" at static ride Ht.
LR Z LINK LEADING 15 3/4" 12deg up
TRAILING 14 1/2" 3deg up
RR Z LINK LEADING 15 1/2" 8deg up
TRAILING 15 3/8" 2deg up

REAR MNT PANHARD 21 3/4" 10deg down

Thanks guys, i have a race this weekend at the same track... Turkey classic 1250.00 to win$$... i would be thrilled just to make the A in my second race!




boas51
Member
posted November 25, 2003 07:26 PM
a

[This message has been edited by darin_hawks (edited November 25, 2003).]

socaldirtmod
Member
posted November 25, 2003 08:25 PM
I guess i didn't term that correctly, the right side is 1 1/8" shorter from the c/l of fr spindles to the c/l of rear axle than the left side.


rocket36
Member
posted November 26, 2003 03:47 AM
make the right side wheel base the same or 1/2" longer than left side wheel base.
if i understood you correctly you currently have the left side wheel base more than an 1" longer than the right side, so the rear axle is pointing out towards the wall.
i wouldn't have thought that to be the way to go. try squaring up the rear end first and see what its like and then try making the rightside wheelbase longer by 1/2" and see if you like it better.


NJantz
Member
posted November 26, 2003 05:59 AM
ok, that sounds good/makes sense, i will square the rear end, and get set to lead the LR if needed at the track ... should i square it to the spindles... or to a chassis point... like a lower control arm pickup point?

NJantz
That is a very good question, and i think it maybe both? i will certainly try to identiy which it is for sure, if problem persists this weekend. When you say set the car, do you use the brakes to do it?

[This message has been edited by socaldirtmod (edited November 26, 2003).]

zeroracing
Member
posted November 28, 2003 08:17 PM
first of all thanks for your imput eveyone!! since i'm a mod rookie i was really hoping for some ideas to try!

PreRace Changes:
1) squared the rearend in the chassis
2) after considering NJantz's questions futher, it seemed as if i really had a brake push... so i started double checking the brake bias gauges and... DUH i had the newly installed brake bias gauges reversed when i dialed in rear... i got front!!
3)moved the RR forward bar down to the lowest hole.
4)added 50lbs to the LR corner of the car
5)took one round out of RF

RaceReport!
Saturday Heat 4 : started pole (five car heat), started conservitive staying on the bottom... started moving up track, spun unassited while leading by 4-5 cars??? (driver ran out of talent!)restarted last got under two cars finished third. good enough to make the main!!!

Sunday A Main (19 cars start 35laps): Peapick for positions, started 8th, car stayed on the bottom like a dream, seemed to have good bite off, staying on the bottom early in traffic and a couple of cautions and i'm in 5th... wow hoo!! race goes back green, spreads out a little and top four start to get away, i started moving up the track and hanging it out to try and catch up, little wigle in 2, got a little help and spun in 3/4, start at the end of the longest line on the restart. stayed on the bottom did a little rubn, but i never moved up or gave up the bottom... wound up 8th!!

thanks for all your help guys! next race: winter series imperial/el centro Jan 10th!!

jasonracin19x
Member
posted December 05, 2003 10:07 PM
hey guys , what rear springs and front springs are you running with the z link , im having problem getting bite off . and did i read it right about dropping the right side swingarm down to its lowest setting? thanks


zeroracing
Member
posted December 06, 2003 09:33 AM
rear springs i run 350 left 300right for heat to free it up when tacky put in a 250 on another eliminator that scales the same for feature when it dries out. note the car must scale the same with both rr springs so the only change is a spring rate change and not a % change on that corner


zeroracing
Member
posted December 06, 2003 05:37 PM
hi again, lowering the right side swing arm to its lowest point , is that also going to introduce more rear stear or am i looking at it wrong, and also i was running a 225lr and a 175 on the rr, and it seemed alot faster , with the panhard bar at the steepest angle i could put it, thanks for the help


zeroracing
Member
posted December 07, 2003 09:54 AM
hey again , read and have been looking at your picture, i have the same length arms front and rear on both sides, about 16 inches long. also i was thinking about softening springs up , 300 on lr and a 200 on right, ive got 350 lr and 300 rr, what do you think? and i have a long pan hard bar behind the rear end, thanks again, jason


jasonracin19x
Member
posted December 10, 2003 05:07 PM
and also the panhard bar is 34 inches long, thanks again


cd2
Member
posted December 10, 2003 08:59 PM
socaldirtmod Does your car have a rear engine plate mount? if so check from this plate to rear axel too square the rearend.drop plumbobs down at each outside end of plate & drop two from axel at same width .Then measure from front to rear bobs an set rear square.Some cars are built longer on left front or shorter on right front which ever you want to call it.This has a purpose that i will not go into now. If you measured from spindles your R.R. might be back now.This will loosen the car.If the total weight & percentages that you gave are correct you do not have enough crossweight in the car the car has 236# on the L.S.70# of this is on L.F.& 166# on L.R. Your L.R.& R.F.=1275 or 51.96 % of C.W. If you increase your C.W. to match your L.S.weight when you go in and lift off the gas the car will set or as some say the rear will kick out.This will loosen you going in and the extra C.W. will make the car bite harder through the middle and off.


cd2
Member
posted December 10, 2003 09:28 PM
socaldirtmod If this loosens the car to much going in and makes it push off just take some C.W. out till it gets like you want it.1 round off R.F.1 round down on L.F. 2 rounds off L.R. 2 rounds down on R.R. will useally change the C.W. about 50 # .Or if it is loose in & good off change the L.F. spring too same as the R.F.& this will tighten you up some going in.If this helps but is not tight enough keep going up on L.F.spring until car get in like you want it too.Rember when changing springs get a ride height measure make the change and set the ride height back the sams.When putting on lead at track like you did take ride height measure put on weight, let car settle then set ride height back to same .


cd2
Member
posted December 10, 2003 09:39 PM
socaldirtmod you can increase L.S.weight & this will make the car turn in better & help it get off the corner better also.At the track if you add stagger on the rear & this is the only change you make you will tighten the car going in & loosen it at middle & off.If you add stagger at the front you will loosen the car in & tighten it at middle & off. You do this not only by changing tire rollout but by changing C.W. also. cd2


Back to the Archives