2014 rayburn 4 bar help

[money17]

Lf 500 rf 400/700 1 1/2" gap
lr 200 rr 225
ohlins da all four corners
lf100lbs rf50lbs
lr100lbs rr50lbs
5th coil shock qa1 oil 3c7r
300 5th coil spring
28.5 front hoosier 1350
28.5 lr 29.0 rr both 1600
air 8 12
6 10
toe out 3/4
caster lf +1.5* rf + 1.5*
camber lf -6* rf +6*
lf 569lb rf 457lb
lr 685lb rr 590
l 54.49
r 55.41
cross 49.63
bite 95
4bars lub 24* rub 19*
lbb 5* rbb 3*
5 1/2" drop 44* i think it may be going past this.
All aluminum 765 hp 660 torque
4" travel available on rf shock before bottoming out
4" travel available on rr shock before bottoming out

260 lb driver

typical. Great in tacky. Can feel lr move forward and up. Feel rr go back and sidebite. Front feels good. In dry feel none of that. I can loose a second or two from time from beginning of night to feature. Leaders not losing more than a half second.feel like on ice. Maybe over adjusting.

Thanks


i move shocks to dry, adjust 4 bars for dry and trailbrake. Kind of lost right now.

[TheJet-09]

I'm not a Rayburn guy, so I apologize in advance. But in my opinion a 500# spring doesn't know if it's in a Rayburn or a GRT or whatever. Just my initial observations of your set-up (which was very detailed...excellent!): 1) You don't have any caster split in the front. While you don't need a ton, a little more caster on the RF might improve you're "feel" for the car, and there is also "spindle roll" which is taken into account (a jacking effect that positive caster has when turning the wheels to the right - increasing LR wheel weight). 2) You have your +/- mixed up on your camber (at least I hope you do...not an issue, just pointing it out). 3) My knowledge of tires is less than stellar, but it is my understanding that you should never mix LR/RF compounds. That can cause handling issues at operating temp. 4) Do you drop tire PSI at all in the slick? At least try dropping your rear 1 lb each. Increasing flex in the sidewall can speed up the heating process in the tire overall. 5) Are you adding or moving lead at all in the slick? Maybe raise it in the chassis if you can (shoulder height). I haven't looked closely at a Rayburn in forever...it was my understanding that the old ones (at least) were designed moreso with a high roll-center and low center of gravity (hence the mountain of lead they had mounted low behind the driver), as compared to most cars that had a lower roll-center and higher center of gravity (part of why the old Rayburn's were not so good in the slick). Has C.J. gotten away from that? 6) You mention the shock travel available but what are your actual travel measurements? That might tell you a lot about your weight transfer. 7) I guess lastly, what condition are your tires in? The greatest set-up in the world won't matter if it can't be transferred to the track through the tires.

[money17]

2. Mixed up sorry
camber lf +1.5* rf -6*
caster lf +1.5* rf +6*
3. Can punch 40 up front and 56 on back
4. Havent tried air pressure yet
5. 95% lead is on top frame rail over rr tire
6. On rf shock traveling all 4", barely bumping bottom. Not enouigh to feel or cause a push.
On rr shock traveling 3 3/4, almost all of 4" available
7. Tires new, cut and siped

[charcoal01]

I don't race late models and someone may tell me I don't know what I'm talking about but if 95 percent of your lead is mounted above your rr tire you're probably fast as hell for first few laps and on ice after that. All the lead above rr is probably making it work too hard, over heating too early, and the tire is giving up too quickly in the slick.

[TheJet-09]

When you say it feels like ice are you only referring to forward bite or overall, as in the car just doesn't stick at all? In looking at your second post, it seems like you could use a little more camber on the LF (more like +3*?) to be more in line with the RF amount of negative. You also have what I would consider a "ton" of caster split (4.5*). Maybe back the RF down to +3.5* or so. I only have experience with LM tires, but can you try a 1350 on the LR or is that a tire rule? All that lead over the RR may not help either. Once it's "physically" there it's staying there...it has no where to transfer but down. I believe you want some of it to be able to "recover" to the LR to help off the corner, and it can't where it's at. You're also not the smallest of drivers and neither am I. I moved my battery over to the right side to help combat my high left side % issues, especially in the slick. In the end we as racers can speculate all day. I can't stress enough that any one of our cars was designed with a specific set-up/purpose in mind. I would make sure you are right where Rayburn says you should be. I chased my tail all of last year, then went to MasterSbilt (I know, where talking about a Rayburn...but I go back to the 500# spring theory I have) and put their basic set-up on my car for this year. On paper I thought I wouldn't be able to drive it because it wouldn't have any sidebite, but it's got a ton more sidebite than it did last year. Rayburn once joked that he was going to build a car in which you could only adjust the seatbelts, because we just mess everything else up. People can say what they want about him but he was right. His proof was this (as he asked) - When are guys the fastest in his cars? When they first leave his shop. Back in the day the likes of Rick Aukland would go stay with him for two weeks, throw a car together, and go out and win like three in a row. But then they might struggle a little, start adjusting stuff, and suddenly start blaming the car. Look at Erb in Florida...I saw he was back in the Bloomquist at LaSalle last week. But in the end the "adjusting" is what keeps me interested (cuz I sure ain't winning and I'm spending more than I'm making). Good luck! Let us know what you come up with.

[DaveBauerSS6]

Get 75# off the LF and move it to the RF. Get a chain on the LR.

[money17]

1. just not sticking from center out. no grip in tires sideways or forward
2. the caster/camber settings are from rayburn. thinking of trying different.
3. have to punch hard tires on rear.
4. reason for lead over rr is to get percentage left side percentage where its at.
5. got chain on lr set at 44* which is 5 1/2"

[TheJet-09]

Do you race at just one track? If so, what size is it, and is it banked or flat? How much stagger do you end up with?

[MasterSbilt_Racer]

I would try to get the weight closer to the center of the car. Increase lr bite up to 150# if needed.

[money17]

Race at we eral tracks in south. 1/4 to 1/2 mile. Banked to flat. Going to narrow down to one 1/4 mile slight banked track and get this thing rolling.
1. Getting off stack and going to 350 rf.
2. Add bite to 150
3. Drop left rear lower bar a hole.
4. Move j bar on frame up to 9".
5. Thinking if indexing lub. Never done that.
6. Go to 250 on RR.
7. Maybe 175 or 250 on left rear.

I know its a lot but not scared to throw something at it.

[TheJet-09]

Exactly. Don't let numbers get in the way. If the car is telling you it needs more or less of something give it more or less of that. As for indexing the LR bar, from what I've felt/seen it is has a more instantaneous effect but goes away quickly.

[money17]

thanks for help guys.

[mod2x]

4 bar help

money please up date when you try this..... were in the same boat. thanks....

[JustAddDirt]

Does this car still have a 34/36" axle tubes in it like the swing arm cars have?
might try to shorten RR axle tube to a 32-34"
that will make car scotch up in the slick.
You will definitely have to take off the weight you currently have over RR.

Rayburn cars are wide and low. to combat that you have to narrow up the RR width to get them to work.

[money17]

Have a 33/35" axle tubes on rearend.
Changes made for this weekend:

1. Moved weight center of car up high in x bracing in front to rearend.
Lf 571 rf 465
lr 721 rr 571
l 55.5
r 55.5
c 50.9
bite 150

j-bar up 9" on frame
rr 250 spring
rf 350 spring
camber lf +5* rf -4*
caster lf +5* rf +7
toe out 1/2"
going to see what happens maybe friday but definitely saturday
if still having problems with sidebite will use a 6" backspace rr rim.