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Author Topic:   changing from sliders to coilovers/rates
36modracer
Dirt Maniac

Total posts: 126
posted February 28, 2005 11:16 AM  
my new car is set up on Gaerte ball bearing sliders which im going to start with. car is a 4bar/zlink and running on 3/8 relatively flat tight corners(fairbury ill). car has 30/30 bilstein shocks on rear. Question is what spring rates would i change too compared to whats on. at the moment 225 lr and 175rr. lr is behind rearend. As i said im going to start with the sliders as they are freshly rebuilt and better than the afco brand i had on last yrs car. this car is new to me as well as this 4/z set up so im just looking at ideas. It was also suggested to maybe just put a coilover on the rr if i wanted to start out with a little change at a time. Also would you put the coilover package where the spring or shocks are then. thanks for any suggestions.

NJantz
Dirt Forum Champ
Total posts: 755
posted February 28, 2005 11:28 AM  
Changing from a slider to a c/o won't require a change in your spring rate.

However if you want to relocate the spring/shock, that all depends on what you are trying to achieve and on what type of surface.

rrrrick
Dirt Maniac

Total posts: 192
posted February 28, 2005 11:28 AM  
If you put your coilovers in place of the Sliders, your springs should stay the same.


dirtbuster
Dirt Forum Champ
Total posts: 2007
posted February 28, 2005 11:30 AM  
Where is you RR spring at now?


36modracer
Dirt Maniac

Total posts: 126
posted February 28, 2005 11:47 AM  
rr spring on birdcage in front of rearend.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted February 28, 2005 12:00 PM  
like mentioned above spring rate shouldnt change any if your not moving the spring. I think having the RR spring and shock together will help to control that corner better. IF you dont want to do both then I would start with the RR like you planned.

Chad
Dirt Freak

Total posts: 269
posted February 28, 2005 12:20 PM  
I agree with Dirtbuster, but you need to understand what the shock is doing relative to its position. Currently, with the shocks and springs located on opposite sides of the birdcages, and with the influence of indexing on the birdcages, you need to understand how moving the shock to the rear (LR) of the birdcage on a coilover might affect the chassis. The RR on a coilover would be no problem, but you may need to think through the coilover on the LR. Many late models run a coil over in the rear and a shock in front on the LR.

Kromulous
Dirt Forum Champ
Total posts: 796
posted February 28, 2005 12:33 PM  
Yep, they run a dummy coil-over on the LR behind, and a real or live shock on the front, floated on the birdcage, or sometimes clamped.

I've thought about running a coil over LR, and running a straight valved 4 or 3 shock. Then when the track slicks off putting an additional shock on the front thats valved like 8 comp 1 rebound or some such.

Although i think the rules say, one shock per wheel, and 5 shocks total, one on the lift bar etc. So that may be illegal.

36modracer
Dirt Maniac

Total posts: 126
posted February 28, 2005 12:43 PM  
thats why i asked the question,as we have run swingarm since 98 and am new to the 4/z set up. this 04 car was the track champ this past season so well start with what he ran good with as far as set ups other than him having about 100 hp more than we have.

A&M Motorsports
Dirt Maniac

Total posts: 117
posted February 28, 2005 01:39 PM  
What about running a c/o eliminator behind and a live shock in front on the left rear, 4 bar of course.

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Artie Perilloux
A & M Motorsports

mod52
Dirt Full Roller

Total posts: 30
posted February 28, 2005 05:26 PM  
Another thing I ran into, that I didn't anticipate, was the fact that the shocks will now be installed when scaling. And a new shock acts like a dirty slider when scaling. How does one deal with this??
36mod..sorry about jumping in on your C/O question but these guys were on a roll!!

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted February 28, 2005 07:30 PM  
It is a good idea to either pull an axle out or jack up the rearend until the tires clear to release any bind due to stagger. then set it down on the scale pads. Then bounce the car front and rear or grab the cage in the middle and shake back and forth. This will help settle the car. If you let the car sit the shocks will eventually bleed off the little bit of pressure left on them and you will get your true numbers. You cant just set it on the scales adn go like before. It takes time to do it properly and let the car settle completely, but you should get the same numbers. All the late models have to deal with it front and rear, at least we only have the rear to worry about.

mod52
Dirt Full Roller

Total posts: 30
posted February 28, 2005 09:18 PM  
I had a feeling it would involve patience. Thanks!

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 01, 2005 07:25 AM  
A&M, i think that will be the best set up for now. Coil-slider in the back, and then the shock in front.

THe only real benefit on coil-overs right now that i can see is on the RR. Swing arms, and Z-links should love the coil-over set up.

Another thing i want to try is the LR in front (floated) on a coil-over. As well clamped. Interested in seeing how this runs.

One last question / comment? Why would you scale a car with the shocks off or disconnected? The rod pressure is there, i would think it has to be accounted for. Sure it changes the readings, and thats precisley my point.

wfoondirt
Dirt Forum Champ
Total posts: 505
posted March 01, 2005 07:41 AM  
Gas shocks tend to extend some when sitting so some people would take them off when scaling. I use ramps and roll the car onto the scales, this lets the suspension settle and then bounce the car to settle the shocks.

A&M Motorsports
Dirt Maniac

Total posts: 117
posted March 01, 2005 07:44 AM  
Kromulous, I don't want to get in a ****in match about the shocks.
There is very limited room on my car to run the spring in front on the LR but I can fit it. I fully intend to run a coilover on the RR (Z-LINK SWING ARM)I just don't have the room to put the RR spring on top of the housing so it will have to go on the swingarm. Any comments on 4 bar LR z-link swing arm RR? spring, shock rates etc.

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Artie Perilloux
A & M Motorsports

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted March 01, 2005 07:44 AM  
With gas pressure shocks like Bilsteins you would want to leave them hooked up. With a non pressureized shock there isnt any rod pressure to speak of so all the shock does is slow the car from settling while on the scales.

I agree on the LR the shock in front on the BC and spring behind on the slider woudl prob have better control at that corner. We are going to try spring/shock behind and see how it works then maybe try it the other way. We are trying to keep it simple and avoid running a shock and slider to try and keep the car freer, more bind free.

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 01, 2005 09:44 AM  
That may be the dilema right there, bind (better shock location) vs free-er suspension (coil-over) by not using a slider.

A&M, i'm planning on running the same set-up as you this year. Here are my intial ideas on a starter set-up.

RR, swing arm / Z-link, coil-over on the arm, 13" - 250lb spring, and a straight 4 on the valving of the shock.

LR, 4-bar, spring behind on a slider with a 200lb 13" spring. Shock in front on the birdcage with a 4 valve on the shock.

Also, i am going to run a shorty panard bar, length not set in stone yet, but will be around 14" long.

Rod angles, not sure yet either.

A&M Motorsports
Dirt Maniac

Total posts: 117
posted March 01, 2005 12:54 PM  
Kromulous, I am going with the standard 15" left lower and the 17" left upper bar to attempt to keep the car not so radical. On the right rear I have a 15" swingarm and a 21" upper rear link. I'll have to check the numbers on my Bilstiens. 18" j-bar but I think I have to move my rear housing a little to the left so I,ll adjust the jbar accordingly. I sure hope all this major fabricaton works. Was 3 link and I had a lot of help from one of the guys on this forum. I must say I didn't figure it out all by myself. Keep it coming guys, you have a great forum here.

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Artie Perilloux
A & M Motorsports

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