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RACR_73s
07-03-2011, 08:44 AM
Could someone please tell me what moving the swing arms up or down on the chassis will do to the car? I have an 08 Rayburn combo car and need to tighten entry(alot) and nothing Rayburn has said has helped and can't get anyone to tell me what moving these will do? ~Thanks~

racin6mod
07-03-2011, 10:03 AM
they control forward bite the upper bars going back control the rearsteer. has cj told you to go to a 6 or 7 inch offset wheel on the rr or to adjust the wheel base on the r side.our car was way to tigt going in so we ended up spacing the rr out to loosen it up on entry.

RACR_73s
07-03-2011, 10:12 AM
they control forward bite the upper bars going back control the rearsteer. has cj told you to go to a 6 or 7 inch offset wheel on the rr or to adjust the wheel base on the r side.our car was way to tigt going in so we ended up spacing the rr out to loosen it up on entry.

Moved rearend left 1" and LR swing arm is 1" longer than RR.
LF 650 RF 450
LR 350 RR 500

dirtdiggerracing
07-03-2011, 12:39 PM
try pulling rr foward to shorten rr wheel base ! and may also try more comp. in lr shock! do you have 2 10/90 shocks on top of rearend ? is it good center off ? is it slamming down ?

RACR_73s
07-03-2011, 10:16 PM
try pulling rr foward to shorten rr wheel base ! and may also try more comp. in lr shock! do you have 2 10/90 shocks on top of rearend ? is it good center off ? is it slamming down ?

My rr swing arm is as short as it can go @ 15" and the left is 16". I have 2 of the shocks Rayburn uses on top of the rear end. I am going to use a 7/2 shock on LR this Sat. Yes its good center off, Its picking the LF up on throttle and doesnt put it down until I let off. Someone on here said raise the ride hight and I did and it pulls the LF up so high I can't see the car below me so I am getting away from that. Somebody else suggested dragging the brake entering and it helped a little but made me slower.

My problem is corner entry and I want to know what changing the swing arms on the chassis will do??????

~Thanks~

washeduptoo
07-03-2011, 10:28 PM
I'm a mod guy but it should work the same, you can lower the rr forward bar down on the chassis to tighten up the car on entry. We had to reset the ride ht and scale numbers when we did that. You could use a heavier spring to help entry. On a mod, when you raise the forward bar on rr it increase forward bite and loosens and downward on frame does the opposite. The rearward bar up on frame tightens car and downward on frame increase forward and loosens. This again was on a mod, but it should be close to what a late model does IMO.Maybe this helps some and good luck.

dualdj1
07-05-2011, 09:26 AM
Give me a little more detail on your setup. Is this when it's tacky or slick? you runnin up on the bank or down on the flat? Where is the pull bar at? how are your trailing arms set on left and right? J-bar puple bar or left side straight bar?

And does it feel loose letting off coming in, or when you're picking up the throttle?

If you're still running swingarm RR I'd consider going to Z and putting the shock/spring on the birdcage, see if you like that better. start off with like a 275-300.

MasterSbilt_Racer
07-05-2011, 12:12 PM
Give me a little more detail on your setup. Is this when it's tacky or slick? you runnin up on the bank or down on the flat? Where is the pull bar at? how are your trailing arms set on left and right? J-bar puple bar or left side straight bar?

And does it feel loose letting off coming in, or when you're picking up the throttle?

If you're still running swingarm RR I'd consider going to Z and putting the shock/spring on the birdcage, see if you like that better. start off with like a 275-300.

I agree. Going to z on rr would immediately help with the spring layed in. Then you can lower the rr swing arm without effecting ride height/bite as well.

RACR_73s
07-08-2011, 12:06 AM
Give me a little more detail on your setup. Is this when it's tacky or slick? you runnin up on the bank or down on the flat? Where is the pull bar at? how are your trailing arms set on left and right? J-bar puple bar or left side straight bar?

And does it feel loose letting off coming in, or when you're picking up the throttle?

If you're still running swingarm RR I'd consider going to Z and putting the shock/spring on the birdcage, see if you like that better. start off with like a 275-300.


It never feels tight going in(tacky or slick) but is extremely loose in the slick. Start with trailing arms in positions according to Rayburn and then drop LR down 4(bottom) and have moved RR up to top(2 I think) and have left it alone(Can't tell any difference). On purple bar except for one week on J(car was still extremely loose and lost forward drive) so went back to purple bar. Race @ Peoria which lends it self to alot of bottom but have tried moving up and makes no difference.

Going to do what CJ says this week
put 400 on RF
compression sock on LR
change the swing arm lenghts to 15 1/2" on RR and 15" on LR

~Thanks~

I have thought of going to birdcage on RR...what will that change? How will I be able to use the "swingarm" bar to adjust the car with it on the Z?

dualdj1
07-08-2011, 01:14 PM
Yeah knew you were at peoria, wasn't sure if you were trying high or low groove.

Going to the cage will tighten it, because it moves your moment center left, which lets the car roll more. Remember though that your spring rate needs to be about half that of swingarm, i like about a 200-250 there. You can still leave the swingarm on there and just mount the shock to the cage with no probs.

How's the purple bar set? clear down on the frame?

Where's your pull bar at? Further left is more drive, and we go clear out with it at times.

softer right front will help, we're goin down to 450, but i was thinking about trying a 400. And they seem to respond well to adding rear weight if you have some.

That RR bar won't really affect your drive much, just how much the tail is hanging out as you corner. As banked as Peoria is you can put it to 2 on the slick.

let me know how the compression shock helps, been contemplating getting one of those, and how well the soft rf does.

RACR_73s
07-08-2011, 02:54 PM
Yeah knew you were at peoria, wasn't sure if you were trying high or low groove.

Going to the cage will tighten it, because it moves your moment center left, which lets the car roll more. Remember though that your spring rate needs to be about half that of swingarm, i like about a 200-250 there. You can still leave the swingarm on there and just mount the shock to the cage with no probs.

How's the purple bar set? clear down on the frame?

Where's your pull bar at? Further left is more drive, and we go clear out with it at times.

softer right front will help, we're goin down to 450, but i was thinking about trying a 400. And they seem to respond well to adding rear weight if you have some.

That RR bar won't really affect your drive much, just how much the tail is hanging out as you corner. As banked as Peoria is you can put it to 2 on the slick.

let me know how the compression shock helps, been contemplating getting one of those, and how well the soft rf does.


Purple starts @ 2 1/2" and then goes to framerail at feature but may start at frame this week.

Pull bar left 1 to start then 1 more left for feature.

What do you mean by put it(swingarm bar?) on 2 for slick? 2 from top/bottom?

~Thanks~

dualdj1
07-08-2011, 03:01 PM
sorry meant your right trailing (back) bar on 2 (top of the 3 that are together, not the clear top).

down with purple should be tighter, lowers roll center.

And most Rayburn guys I've talked to are now running right side on the bird cage, and like it much better. swing left still, and z right.

but I'd try the changes CJ says, that should help you going in. if it's still loose rolling in, you can stiffen LF too, which will help keep it good coming out. Taking some bite out should help it going in too.

britt77
07-09-2011, 12:21 PM
Try raising the purple bar as high as you can get it on the chassis, make sure you leave clearance for the fifth arm. Helped me out alot in the slick.

stevo
07-09-2011, 01:36 PM
Higher pan bar on frame more side bite.

racin6mod
07-09-2011, 06:08 PM
the purle bar comes of the right side frame rail so you adjust the opp. of say a j-bar(down to tighten up to loosen) we ran double swingarm and a couple other rayburn guy's at our track ran the z-link rr. they ran hard in the heats and were tough but we ran off and left them in the features.the track champion was also on double swing arm with the long lr top bar. what's steve l on over at peoria this year?

4bangerhotrod
07-09-2011, 09:22 PM
sorry racin6mod but you are wrong up on the frame adds sidebite but kills forward traction and down takes away sidebite but keeps the traction in the car. the purple bar attach's to the left side of the rearend so when it is high on the frame it is pulling the LR tire up which in return plants the RR tire, but when it pulls the LR up it takes the traction away from that tire. when the bar is down on the frame it is pulling straight across and not trying to pick up the LR tire which holds more weight on the LR tire adding traction to that tire. if people are going to give advice you should really know what your talking about before you do. all you have to do is have a mechanical mind and visualize what the change is doing this is the reason some of us can setup a car and when big races and some cant. take a pencil lay it down, tie a string to the left side of it and hold it to the right side about a inch above the pencil and pull on it, it will try to pick the left side up. then hold the string down against the pencil and pull on it, it will not try to pick the left side up. this is the same thing the purple bar is doing to the rearend.
thanks,
4bangerhotrod

dualdj1
07-10-2011, 08:09 PM
4 banger you're partially right, the purple bar is a pulling action. as the car goes into the corner, the axle is trying to move left to the driver side, and in turn the purple bar applies tension between the right side frame and the left side of the axle. This can effectively cause a slight lifting on left sid axle, and extra downward force on right side frame. On the opposite side, J-bar or left side straight bar applies pressure outward between the left side frame and the left/right side of the pinion as the axle tries to move left. This can effectively cause left side hike, and extra either LR (left short) or RR (j-bar) force.

When you change mounting points on the panhard bar, it raises or lowers the moment (roll) center of the rear end. the height is the middle of the mounting points. The higher it is, the more resistance to roll the rear suspension applies. The lower the height, the more efficient the suspension works allowing for "easier" roll. Less roll generally equates to more side bite, more roll to more forward drive; but it is also dependent on other settings.


Believe Steve is still on the purple bar, but not positive.

RACR_73s
07-10-2011, 10:10 PM
Here is how this week went...

LF650 (same) RF450(was 500)
LR300(was 350) RR600(was 500)
pull bar left 1(same)
purple bar 2 1/4" up on frame(same)
RR swing arm down 1 hole(4th hole from top)
LR 7/2 Pro compression shock(was standard Koni)
#158 LR(been anywhere between 140-186)
2 1/2" stagger(same)
12" fuel

Car was much better going in, first time that I felt that it was putting the RR in the track. Led 1/2 the heat before caution and never could get rhythum back and faded to 4th.

Feature changes....
RF 375
pull bar left 1 more
LR rear bar down 4 to bottom
RR rear bar up 2 to top
4 round out of LR
grind rear tires
No fuel added(less rear to tighten, correct ???)
forgot(ran out of time) to lower purple bar.

Track was the best it has been all year for the feature so can't compare apples to apples but car was good in feature. Started 8th and after a couple of laps started to come to the front. Got caught in lapped traffic(new driver all over the track and didn't want to dump him or wreck car any worse than what he was doing to it...lol) for a few laps and lost several spots. After caution started moving back up and spun with a few to go trying to get under another car.

washeduptoo - Thank you for telling me what the swing arms will do. I was wanting to lower the RR but wasn't sure if that was right.

dualdj1 - not sure on front spring and compression shock but it seems to be a step in the right direction. Going to leave 600#RR spring, 375# LF and 4 rounds out of left rear at start of next week and move everything else back. Maybe this will be a good starting point.

wishiwasfast
07-11-2011, 12:42 AM
So you went down on RF, down on LR, and up on RR, but the LR bite # stayed pretty much the same? All that should've taken quite a bit of LR bite out of the car, right?

dualdj1
07-11-2011, 08:41 AM
wish, there's really no way to measure bite at the track, but yes taking rounds out of the left will take bite out.

Glad you're making progress. On the fuel thing, add fuel to tighten. More rear percentage = more drive, by planting both rear wheels more so you get more straight line "push". less fuel/weight will loosen you. So if it felt good without putting more fuel in, you may need to go back up on that RF since you may develop a push with a full(ish) tank of fuel.

Just keep good track of all your settings. That way next week if you try something different and it's better/worse, you can have a better chance at figuring out what changes actually gave you the effect you wanted.

racin6mod
07-11-2011, 05:17 PM
sorry racin6mod but you are wrong up on the frame adds sidebite but kills forward traction and down takes away sidebite but keeps the traction in the car. the purple bar attach's to the left side of the rearend so when it is high on the frame it is pulling the LR tire up which in return plants the RR tire, but when it pulls the LR up it takes the traction away from that tire. when the bar is down on the frame it is pulling straight across and not trying to pick up the LR tire which holds more weight on the LR tire adding traction to that tire. if people are going to give advice you should really know what your talking about before you do. all you have to do is have a mechanical mind and visualize what the change is doing this is the reason some of us can setup a car and when big races and some cant. take a pencil lay it down, tie a string to the left side of it and hold it to the right side about a inch above the pencil and pull on it, it will try to pick the left side up. then hold the string down against the pencil and pull on it, it will not try to pick the left side up. this is the same thing the purple bar is doing to the rearend.
thanks,
4bangerhotrod

Well hell I only post my oppinion and what worked for us.and when ever I lowered the bar on the rside it helped side bite.but like you said I've never won a $100,000.00 show and most likely never will.

maybe you could post your big when on win....

4bangerhotrod
07-11-2011, 05:41 PM
it might have helped sidebite but it was most likely from other factors and not the panhard bar angle

RACR_73s
07-11-2011, 10:07 PM
So you went down on RF, down on LR, and up on RR, but the LR bite # stayed pretty much the same? All that should've taken quite a bit of LR bite out of the car, right?

I did all those changes @ home on the scales. The only thing I did @ the track that would change the LR bite was change the RF spring(which I reset the ride hight on the RF when I did...shouldn't change it much) and take 4 rounds out of the left rear(which should put me around 130-135#). I will find out the exact #'s when I put it back on the scales later this week.

RACR_73s
07-11-2011, 11:20 PM
wish, there's really no way to measure bite at the track, but yes taking rounds out of the left will take bite out.

Glad you're making progress. On the fuel thing, add fuel to tighten. More rear percentage = more drive, by planting both rear wheels more so you get more straight line "push". less fuel/weight will loosen you. So if it felt good without putting more fuel in, you may need to go back up on that RF since you may develop a push with a full(ish) tank of fuel.

Just keep good track of all your settings. That way next week if you try something different and it's better/worse, you can have a better chance at figuring out what changes actually gave you the effect you wanted.


I have always added fuel for feature but I was sure CJ told me to take rear % out for feature(That's what I wrote down anyway). That is why I questioned it in my post. We don't run a long feature(15 laps) so I hope it didn't hurt me too much. Usually go through about 7 gal. of fuel a night. I make a setup sheet(Longacre) every time the car goes out. I log what I did different for the coming night as compared to the last race. When I am at the track I log what I did there and what I thought of the car at the end of the night. ~Thanks~

dualdj1
07-12-2011, 08:07 AM
cool thanks for the info. we're gonna try a different setup this week too if it slicks, so I may try leaving fuel a little lower and see what it does.

lil jimmie
07-12-2011, 09:35 AM
Well whatever Lance jr.is doing in the late models and Bauman jr. is doing in his limited late models those two Rayburns sure have been running good. Sorry to hear that Bauman jr. is done for the year due to havimg surgery. I would ask those guys for a little imput.

RACR_73s
07-24-2011, 04:53 PM
Took the RR off the swing arm and put it on the birdcage...

Went with
LF550(546#) RF500(525#)
LR400(771#) RR400(631#) on birdcage
52.2 cross
53.2 left
56.7 rear(12.5" fuel/move weight to back)
pull bar left 1/ 3" blue spring(usually on 2" green)
purple bar 2" off frame
Both lower bars 15 1/2" uppers 17"
rearend left 1"

The difference of being on the birdcage was not as big a difference that I was hoping for. I went with a 400LR just to be safe(Not to tight) and have some adjustability. Car was still tail happy loose.

Feature time
LF650 RF500
LR350 RR50014" of fuel(should be around 57.5 rear)
pull bar left 1 more
LR rear bar down to bottom
car was ok but not enough to get into top 5(started 5th), ran just outside of it until crash. Still can't keep tail of the car under me.

Going to run with the LM next week if the car count is low enough to ensure a feature start. No idea what I am going to do for a setup!!!!

Now that I am on Z on the RR is there any way by moving the front lower bar that will keep the rear of the car straighter and tighter on entry???? What do you see that I did wrong? What can I do to make it better?

~Thanks~

washeduptoo
07-24-2011, 05:40 PM
Again I'm a mod guy but I don't think you need that high of a spring when its on b/c, probably around 175-225 range would work. Hopefully someone will with better knowledge will help you. Good luck.

fox1162002
07-24-2011, 08:34 PM
Ill tell you that Rayburns are a trip to work on our car was super free and we put a 6/0 & 9/0 afco behind with a koni shock and spring on swing arm then we use a 600lb spring on rr to help tighten it in. Ours was real free and when we put the compression shock behind it freed it up but driver was able to pick the throttle up real quick said it wasnt an un nerving feeling.

abe_05
07-27-2011, 07:53 PM
Track bar to frame on right normally loose on entry and tight coming off, J-bar to left frame normally tighter entry looser off. Normally start out with 500's on front, 400 lr, and 275 rr on swing arms with j-bar. Normally as track gets slick I drop left rear trailing arm and go up on lf spring to 550 or 600 and drop track bar on rear end. I have all side bite I need with j-bar. I do run afco m2 from envy and crank up the compression.

money17
07-27-2011, 11:26 PM
Will rr swingarm adjustment, up adding bite and loosen car and down take away bite and tighten entry, be the same whether the shock and spring are on swingarm or birdcage?

abe_05
07-28-2011, 08:30 PM
Rear springs adjustment on swing arm affects entry more than anything. When in throttle the car is up on bars and as you get out of throttle the car comes down on springs. This slamming effect gives most problems. Putting compression shock on left rear helps but putting softer springs makes it more forgiving and universal on dry and wet track (run 325-400 lr and 250-350 rr on swing arm) . Body roll is a big concern to control. Running stiff rr springs keeps bars fairly level and car level but can hurt drive but gives better side bite in slick. I go softer on rr when wet or tacky but never go over 350 rr in dry. As body rolls rr trailing arm drops hence giving more rr drive(same as dropping down a hole or two), only problem with going too soft is front pointing to the moon at times if too soft but as body rolls also gains in roll steer. Just a thought to give, I run smaller tracks were car stays rolled over.

late96
07-30-2011, 10:07 AM
Can someone explain more on the compression shock cj is talking about?? Thanks

dualdj1
08-01-2011, 02:22 PM
compression shock is to keep LR stood up when getting off the throttle.

late96
08-01-2011, 04:37 PM
what is cj recomending and scale numbers with it? Thanks

dualdj1
08-02-2011, 08:17 AM
no idea, don't ever talk to cj. use in the dry slick. smooths out the car for more consistent traction

abe_05
08-02-2011, 06:17 PM
First, use compression on lr to loose up the car on entry. Use it in slick and you going to spin on entry. Using compression on lr keeps rear end rolled up and keeps roll steer in car, which will help car turn on entry on wet or tacky track. If you are loose in softin compression on lr, if tight on entry increase compression on lr shock (4 bar cars use compression lr on slick but not swing arm). For a good starting point on setup: 500lf 500rf 400lr 350rr, if track is fast or rough go 550 rf and 400rr. Keep 200-285 lbs lr 54.5 left 56 rear. Hopes this helps.

dualdj1
08-03-2011, 10:09 AM
all depends on the setup. if you're on the purple bar (right side panhard) or the j-bar i'd tend to agree with you. running short left side bar car acts much more like 4-bar, even with swingarm lr, and you don't gain much roll steer from the left side. how much roll steer you gain from the right side depends on how much your car rolls over, ie rr spring. So the quantifying factor is not whether or not you are on swingarm, its which panhard bar you are using as well as rr spring, as to when you want compression shock.