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Author Topic:   2x4 Set-up ideas?
Kromulous
Dirt Forum Champ
Total posts: 873
posted December 14, 2005 08:19 AM  
I'm thinking of trying a 2x4 set up this year, and wanted to ask for some input from others on the board.

18" 2-link RR
Spring on coil-over, behind, to much? Dont want to 3 wheel to much.

LR 4-Bar, 18" Long lower LR, and a 16" upper, or a 14" lower, and 16" upper (plug).
Spring behind (elminator) and shock in front.

Short Panhard bar, in front, 12" long or so.

Questions, what springs? What shocks? and arm angles?

I'm thinking 10* up on the RR, and about 5* up with LR lower with the long bar, and about 20* up on the upper.

Springs, i usually run a 225LR. The LR behind, i guess would be somewhere close?

Shocks, i usually run a 7 comp, 3 rebound on the LR and a 3 comp, and 5 rebound on the RR. Think there will work, i can adjust them to any number.

Driving input? i hear this set up is different to drive, how so?

Any thoughts or ideas are appreciated.

Thanks, Krom.

[This message has been edited by Kromulous (edited December 14, 2005).]

52mod
Dirt Roller

Total posts: 14
posted December 14, 2005 01:25 PM  
I ran this setup last year. Worked excellent on dry slick and easy to adjust. This was not the fastest setup on a tacky track but rode the bumps out realy well on the 2 link RR. My 2 link setup came off the center of the rearend housing and the 4 bar side I ran the shock clamped up.

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 14, 2005 02:30 PM  
Interesting, thanks.

The shock clamped in front i assume, i heard that before but never tried it. I'll throw that on there and see what its all about.

You run the RR on a coil-over, or on a elminator? or spring on housing?

Thanks, Krom.

washeduptoo
Dirt Maniac

Total posts: 186
posted December 14, 2005 07:47 PM  
We ran on our metric clip car, 4-2 with lr spring behind on b/c using a slider 225spring,20-60shock, rr behind on c/o 200spring 30-30shock, with about 50lbs lr bite this worked well on dry slick, not as fast on tacky. A lot faster on tacky with rr on top, same spring. 18in straight bar mounted under center of pinion. RR bar about level and lr top 15, lower lr 5. Hopes this helps.

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 15, 2005 06:22 AM  
Washedup, you run on IMCA tires or Hoosiers?


FFMM
Dirt Roller

Total posts: 22
posted December 15, 2005 07:44 AM  
Krom,
thanks for asking i am thinking of running almost the same thing
How come you dont want to run the LR spring clamped on the front as opposed to on a BC on the rear? just wondering dont have an opinion yet, and ill be using a rear mounted bar 19"

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 15, 2005 08:20 AM  
Well, the main reason on our current car is i dont have room in front, to run it clamped up in front.

Plus i have been running it behind for sometime now and i like it. We run the long bar on the bottom of the LR and it indexes (the birdcage) really hard into the spring when its behind.

I would like to try it clamped in front, i think our new chassis will be able to do it, so i think we will play around wiht both this coming year. Thou i dont much about it, spring rates, and bite etc.

Also i want to try the rear mounted bar, after the discussion we had about it on another thread, that option seems appealing.

Krom.

52mod
Dirt Roller

Total posts: 14
posted December 15, 2005 12:50 PM  
Kromulous, if you have any questions you can PM me I've don alot of tuning and I've been pretty successful on the 4 - 2 setup.

On the LR I ran it clamped in front because there is no room on the rear and a coil over will not work in my application because I set my BC up to index at the same rate as the rearend travels. Only in "bump" would the shock be effective, not as it travels when the car hiked or rolled.

washeduptoo
Dirt Maniac

Total posts: 186
posted December 15, 2005 05:58 PM  
AR G-60, we've got a used Allen chassis now and it is clamped with spring in front on lr and spring on top rr. I don't have the set up sheets in front of me or specs, also haven't run this car yet. The metric clip car was smooth thru the turns with that set up we ran on it compared to the 4-z with spring on top.

[This message has been edited by washeduptoo (edited December 15, 2005).]

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 16, 2005 10:28 AM  
I'm pretty sold on this set up so far, i talked to a guy at Midwest Motors once about it and he said its a set up that likes to be driven on the throttle.

I'm looking for alot more steering on power, i dont want to have to allow the car to drop off the LR bars to turn.

The MWM guy told me that when you get on the gas with this set up it steers more. You guys find this to be true?

Krom.

(man do i need to proof read more LOL.)

[This message has been edited by Kromulous (edited December 16, 2005).]

WPP
Dirt Freak

Total posts: 472
posted December 16, 2005 11:36 AM  
Thats what i found out when i had too much angle in the upper bar it steered pretty bad.But it had a lot of bite you will have to put more gear in the car.With this set-up you will not have to use a lot of angle in the upper bar to have bite.

Throwin Dirt
Dirt Newbie

Total posts: 3
posted December 17, 2005 05:25 PM  
Have not heard anyone say they are running the spring in front.My buddy runs it in front on the 4/2 on rr.Says its much better than behind.One of the top guys in the nation.im trying the 4-2 also.thats where i was going to start.Is it really throttle tight with the spring behind?

MrHP1
Dirt Full Roller

Total posts: 28
posted December 17, 2005 06:19 PM  
Kromulous, I read all your posts on this site and you have good old common sense. I would appreciate your advice. We took our Z-link LR, 4 link RR car and converted it to a 4 bar both sides. The trouble I have is, we make so much power, I can't get enough forward bite. It's up on the bars and just smoking the tires. Any ideas?

WPP
Dirt Freak

Total posts: 472
posted December 17, 2005 08:33 PM  
I can see running the spring in front in the tacky could help but would it make the car loose off the corner in the slick what bar angle would you run and spring rate .The only way i could see it working is if went really soft. Fill us in with the spring in front deal.I am open for suggetions i would like to try it.

chickenlittle
Dirt Forum Racer

Total posts: 76
posted December 18, 2005 08:49 AM  
MrHP1 you might need some traction control. In other words a lighter right foot. Sounds like with the motor you have and the hard tires you need to ease on the gas instead of just stomping it. You might also need to stiffen the LR spring and mount the spring behind on the bird cage or even clamp it in front. That will really push the LR down.

MrHP1
Dirt Full Roller

Total posts: 28
posted December 18, 2005 12:10 PM  
I have the spring clamped in front on the LR. The springs on top on the right. Getting my driver to let off the gas is not what I really want. I want to figure out how to make the car hook better. I'm used to having a race car with tires. Most of what we run is dryslick or meely sand. Arizona doesn't have real clay like I'm used to back east, and these Mccrearys are just up from running bicycle tires.

[This message has been edited by MrHP1 (edited December 18, 2005).]

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 19, 2005 06:49 AM  
That RR spring on top may be the trouble MRhp1, take that off and put it on a coil-over or an elminator in front, on that 4 bar RR.

Also dont be afraid to run 9 or 10 compression shock on the LR on a smooth track.

Another idea use the new AFCO pinion mount with the hole up under the yoke, and run it with about 4 to 5" up to the frame. I hear that mount makes loads of bite.

I have more expierence with spring behind LR 4 bar, so i would suggest to run it behind, with a 225 or so spring on the cage with an elminator, shock in front on a clamp bracket, clamped up to the housing. Shock should be at least a 8 compression and 2 rebound or so. Then jack some serious wedge in it, 225lbs or so.

It will teach him not to drop off the throttle so fast and all the way, but when you go to come off the corner it bites hard.

Also you may consider going to a long bar lower on the LR, it will help a great deal on the dry slick.

Just some ides, Krom.

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 19, 2005 06:50 AM  
quote:
Originally posted by Throwin Dirt:
Have not heard anyone say they are running the spring in front.My buddy runs it in front on the 4/2 on rr.Says its much better than behind.One of the top guys in the nation.im trying the 4-2 also.thats where i was going to start.Is it really throttle tight with the spring behind?

I hear just the opposite, its throttle loose, the more you get after the gas the more it steers. Which is exactley what i need.

Krom.


MrHP1
Dirt Full Roller

Total posts: 28
posted December 19, 2005 07:09 PM  
quote:
Originally posted by Kromulous:
That RR spring on top may be the trouble MRhp1, take that off and put it on a coil-over or an elminator in front, on that 4 bar RR.

Also dont be afraid to run 9 or 10 compression shock on the LR on a smooth track.

Another idea use the new AFCO pinion mount with the hole up under the yoke, and run it with about 4 to 5" up to the frame. I hear that mount makes loads of bite.

I have more expierence with spring behind LR 4 bar, so i would suggest to run it behind, with a 225 or so spring on the cage with an elminator, shock in front on a clamp bracket, clamped up to the housing. Shock should be at least a 8 compression and 2 rebound or so. Then jack some serious wedge in it, 225lbs or so.

It will teach him not to drop off the throttle so fast and all the way, but when you go to come off the corner it bites hard.

Also you may consider going to a long bar lower on the LR, it will help a great deal on the dry slick.

Just some ides, Krom.


I've got a 2080 Bilstien (2 rebound, 8 compression) on the LR now. You think if I run the LR spring clamped in back it will hook harder? I had the RR bars 17" top 15" lower, LR bars we're both 16" per D&M. I just switched the LR to 15" upper, 17" lower to try and make it idex better. Haven't tried it yet. I also just put the RR spring in front clamped up. I run a short panhard on the left about 4" of rake. I'm also putting 1090 (10 rebound 90 compression) shock on the RF. Trying to get the left rear more loaded. No matter what I try I can never get the LR tire temp up. Thanks for your ideas.


Kromulous
Dirt Forum Champ
Total posts: 873
posted December 20, 2005 05:57 AM  
What kinda track, is it bigger than a 1/4
mile bull ring?

IMCA tires, or UMP Hoosier's?

Well its winter time, so there is plenty of time to brew. If it where my car, here is what i would do.

LR, 17" lower bar, 15" upper. Set it up with a plug type deal so you can switch back and forth from the short lower to the long lower.

Run the short on heavy, tight bull rings and long lower on slick and bigger tracks, it takes out alot of roll steer, which is good for dry slick. I run a 18" lower, and 16" upper, love it.

Spring behind on a good elminator, shock in front on a clamp bracket. That 8/2 Bilstien is perfect. Run about a 225 spring. There are a couple of trains of thought on the LR spring, but what it boils down to me is, lighter the spring the faster it gets up and on the bars. So remember that, sometimes a car wants to hop up on the bars to fast and gets tight, stiffen the spring and it will slow it down. Plus the stiffer LR will help it steer in better, react better.

You gotta remember that 4-Bar cars are roll steer dependent, they have to have it to work, and if there is to much body roll it will get loose because of all the roll steer a 4-bar generates. So when it gets slick, you need to keep the body roll in check.

Scale it in with about 56% rear, with 53% left, and put about 200lbs LR bite in it. This is with the long bar on the LR lower.

Another thing, a clamped up LR 4 bar spring infront, is what i call an extreme set up. I see alot of people run them, with little expierence and get real aggrevated with it. There very tempermental, and if your driver is aggresive with the throttle can lead to trouble, and more aggrevation.

Krom.

[This message has been edited by Kromulous (edited December 20, 2005).]

MrHP1
Dirt Full Roller

Total posts: 28
posted December 20, 2005 06:56 AM  
Well Krom, unfortunately, I don't have a winter to think about it. We've got 3 races in January at 3 different tracks. All multiday events. We run IMCA tires. All 3/8 mile fast tracks. One is meely sand. The other starts off tacky but goes dry slick at feature time. The other is pretty slick till it gets rubbered up then grips like asphalt. I had 225 on the left rear clamped in front before. Seemed it was more violent then when I had a 200 in the car. I don't know if the car even has brackets to mount a spring behind. I suppose I could use an elinator on the shock mount if there's clearance. Car is in Phoenix where the driver lives, I'm in San Diego. I fly out there the 30th to set up the car for the Roger Mclusky Classic in Tucson. I'll see what I can figure out then. Thanks for all your help!

WPP
Dirt Freak

Total posts: 472
posted December 20, 2005 07:08 AM  
How much angle do you have in the upper and lower bar on the rr .The way i see it if the rr is clamped in front you are going to take bite away from the lr during wrap-up.You will be loading the rr too. For this to work the driver is going to have to be smooth.He will not be able to dump the throttle on entry or the car will be very loose.Running the tire you run i would run both lower bar below level if your in the sand there is nothing to grab too..

WPP
Dirt Freak

Total posts: 472
posted December 20, 2005 07:23 AM  
Kromulous what do you know about the rr spring clamped in front on the 4-bar i have not seen this very much i was always told not to run this in dry slick. thanks

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 20, 2005 07:57 AM  
Ya know, i just now noticed that.

All i know about a double clamped set up is, that there good on paper clips, because it loads both tires pretty hard, plus when you let off it all unwraps, and gets loose big time.

Put that RR on a coil-over and attach it to the birdcage so you can get the indexing affect, not clamped up to the axle housing. Put a 225 spring on there. Something like a 3 Comp 5 rebound should be good for a shock.

LR leave it clamped in front, with a 200lb spring, and throw about 40lbs of LR bite in it. Bite numbers on a LR clamped in front 4-bar is critical. If its tacky you may want to run reverse bite, RR numbers higher then the LR. On these slicker tracks put some LR bite in it, about 40lbs should do.

Then you may want to bias your pull bar towards the LR tire, moving it left will help it load the LR tire more.

Krom.

shopboss
Dirt Roller

Total posts: 14
posted December 20, 2005 09:40 AM  
MrHP1, what kind of bar angles are you running on both sides? also what pullbar spring? pullbar spring very important when your clamped on LR

FFMM
Dirt Roller

Total posts: 22
posted December 20, 2005 10:38 AM  
im sure this get posted alot.
but we are building a new car and are open to anything imca, i intend to run the 4-2 with the rear panhard bar 19" and coil overs.
i havnt seen anyone with the long lower, that is new to me but it sounds good,
we primarily run 1/2 milers 2 are big corners normally dry for feature one is flat dry and tight corners.
what do you think would be optimum
thanks in advance

aggressive
Dirt Full Roller

Total posts: 39
posted December 20, 2005 11:34 AM  
and on a side note about pullrod springs and being clamped up........we wore out 6 of them in about 42 nites and that was 600 to 1500 my belief has always been if u can't junk a pullrod spring then u are to stiff.

Kromulous
Dirt Forum Champ
Total posts: 873
posted December 20, 2005 12:03 PM  
quote:
Originally posted by FFMM:
im sure this get posted alot.
but we are building a new car and are open to anything imca, i intend to run the 4-2 with the rear panhard bar 19" and coil overs.
i havnt seen anyone with the long lower, that is new to me but it sounds good,
we primarily run 1/2 milers 2 are big corners normally dry for feature one is flat dry and tight corners.
what do you think would be optimum
thanks in advance

Try the 18" lower, with a 16 3/8ths upper, or just 16". the same as what Rocket Lm's run. On them big tracks you'll love it, you will be fighting a tight condition all the time thou, but thats better than loose i guess.

Let me know how your 4/2 and the rear mounted panhard bar runs, kinda thought about running that myself. I like the idea of the rear mounted bar, see the other thread (trick in 06 redux) for a lengthy read about it.

Krom.


rpm20
Dirt Freak

Total posts: 351
posted December 28, 2005 05:34 AM  
e mail me and i will tell you my 4 bar setup. ron.paulick@hydrite.com
that will get you close.

quote:
Originally posted by Kromulous:
I'm thinking of trying a 2x4 set up this year, and wanted to ask for some input from others on the board.

18" 2-link RR
Spring on coil-over, behind, to much? Dont want to 3 wheel to much.

LR 4-Bar, 18" Long lower LR, and a 16" upper, or a 14" lower, and 16" upper (plug).
Spring behind (elminator) and shock in front.

Short Panhard bar, in front, 12" long or so.

Questions, what springs? What shocks? and arm angles?

I'm thinking 10* up on the RR, and about 5* up with LR lower with the long bar, and about 20* up on the upper.

Springs, i usually run a 225LR. The LR behind, i guess would be somewhere close?

Shocks, i usually run a 7 comp, 3 rebound on the LR and a 3 comp, and 5 rebound on the RR. Think there will work, i can adjust them to any number.

Driving input? i hear this set up is different to drive, how so?

Any thoughts or ideas are appreciated.

Thanks, Krom.

[This message has been edited by Kromulous (edited December 14, 2005).]



Kromulous
Dirt Forum Champ
Total posts: 873
posted December 28, 2005 10:00 AM  
RPM, you gonna run a 2x4 deal this next year?

Krom.

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