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Author Topic:   Thinking Out Loud-3 link shocks
Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 11, 2005 11:58 AM  
Doing some out loud thinking on 3 link rear shocks...

I've been doing some real hard thinking about an off the wall shock package on my 3 bar car.

Here are my thinkings-

On the left rear when we jack a bunch of angle in the left rear trailing arm, it allows us to get more foreward bite and rear steer UNTIL we either A.Bottom out shock or B. Hit the Underslung. On the cars we run with the large droop in the underslung, and at ride height you see about 2 inches of shock... Now the foreward bite you get until one of the two things up top are mentioned. How would putting a tie down shock on the left rear affect the car as in holding it from instantly jumping up on the bar and letting it take longer to get to full extention help in foreward bite, and help to turn the car, and it will hold the car on the bar longer.


Just thinking out loud about this... In theory it should work. The normal 5 out 3 in shock would be reversed to a 3 out 5 in so that as the car got up on the bar slower it would aid in foreward bite, it would also help turn the car getting in.

ukandesperate
Dirt Full Roller

Total posts: 45
posted March 11, 2005 02:23 PM  
Hi just reading your post,we dont do the exact racing that you do although we are on dirt,we do have problems with the shock topping out,we have a standing start and sometime lift the front end coming off the start line,its classed as dangerous because of lack of steering.usually get docked one place as a result!
a way we get round this is to not bolt the shocks solid on the chassis,put a spike on the top so when it tops out the spike slides up the hole keeping the shock from falling off??!!!
could you apply this to your chassis to give more drop ?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 11, 2005 02:25 PM  
We are maxed out on drop as most people are. It's getting it to slow down as you gain thrust angle to create more bite. As soon as that rearend is dropped all the way your bite is gone. I don't think spikes would be a real good idea for this application.

ukandesperate
Dirt Full Roller

Total posts: 45
posted March 11, 2005 02:47 PM  
is it not the shock topping out that loses the forward bite,by lifting the wheels?or is it the thrust angle becoming too great to be effective? im trying to get my head round it because were going to run the same system on our car this year???

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 11, 2005 03:03 PM  
When the rearend is at its fullest extent of drop your foreward bite is minimal due to the rearend not being able to move any further. As long as your not bottoming out you can get foreward bite. It's hard to explain and the guys that are on the same page with me know what I'm talking about.

Say take a pen and hold it in both hands at the ends, imagining it is a trailing arm... now take and let one side drop, once that side is straightup and down, and notice how quick it happened. From the time you let go to the time it was straight up and down is where you get your foreward bite. now if you take and just move it down instead of dropping it, you have added quite a bit of time for foreward bite.

It's just an Idea I've been thinking of with the 3 link cars on the left rear. The left rear isn't the only place to find foreward bite, but if I am thinking correct this may add a good bit more foreward bite, or extend the bite you have further down the straight away... It's not lifting the front tires or the fact that the thrust angle is greater, it's that the rearend has stopped and the only thing that will push up on the chassis now is the rearend wrap which at this point is probably at its furthest point already...

ukandesperate
Dirt Full Roller

Total posts: 45
posted March 11, 2005 03:24 PM  
Aha i get the drift now! stiffer damping sounds logical now,would longer links help,making it harder to get over the bars? just an idea,but i dont know much so prob not!

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 11, 2005 03:31 PM  
I always thought of it differently. Weight transfer to the rear is whats making the bite. As well as anit squat.

Our 4-Bar car, we try to get the LR up under the car as far as we can, as soon as we can, without loosing alot of steering or momentum.

Then as you accelerate, and the weight rolls back to the rear it pins the LR down against the track. Running a high compression shock keeps the LR from loosing all that drop so fast. Making it slower, compressing back down to ride height, will extend the FWD bite further down the straight.

I've dont have any thoughts on a 3 link car, never run one but i would assume it would be similar.

High compression shock on the LR and maybe a high rebound on the RF, maybe a 4/5 on the RF, and 7/3 on the LR. Holding down the RF a little longer, will allow the car to get the LR up under it before you start really applying the loud pedal.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 12, 2005 09:56 AM  
The thing is on the 3 link car i don't want to get the car up in the air right away.. I wan't to slow it down which in turn will create more bite.

outside the box thinking here lol

HERNDON
Dirt Full Roller

Total posts: 73
posted March 12, 2005 12:13 PM  
Do you plug the left rear to make it shorter than the right rear?? We do, unless the track is heavy. If it's heavy we go back to the longer trailing arm on the LR. This slows the LR down significantly.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 12, 2005 01:35 PM  
Yes we plug it, mainly for the rear steer benifits over the instant bite

sanderson10
Dirt Full Roller

Total posts: 35
posted March 12, 2005 06:48 PM  
What I would do first is build a plug for the left rear shock mount on the frame. Put a chunk of 1 1/2 pipe off of your frame mount and extend it down about 1 1/2 and then weld your shock mount onto that to get more shock travel. 2nd to slow down your left rear movement up onto the bars i would go w/ a straight valve shock b/c w/ a tie down you are gonna be slow up on the bars and hard coming down on decell. I would recommend a 40/40 or 30/30 bilstien which is i believe the same as an afco 94 or 93. Hope this helps.

Jason

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 12, 2005 06:49 PM  
Sanderson..

That is what we are currently running. I am wanting to just slow it down from gettin on the bar, I ran the same shocks (94's) last year, and had the max shock travel, same thing on the new car.

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 14, 2005 06:40 AM  
You can run a straight valved shock but i think a stiffer valve on the compression side would help alot more with bite.

Maybe try a 8 compression, 4 or 5 rebound. That should slow it down getting on the bars, but still get the benifits of stiff compression shocks on the LR.

Dry slick i would think this would work well on a 3-bar car.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 14, 2005 08:14 AM  
I can see you get the drift of what i'm sayin. Does it sound like it's something worth trying?

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 14, 2005 08:17 AM  
I'd hate to buy one to try it, but if you got a rebuildable shock i would do for sure.

I think, its dangerous i know, it should do what you need, best of both worlds. Slower on the bars, and stiff once its on the bars.

JT54
Dirt Maniac

Total posts: 170
posted March 15, 2005 08:27 PM  
Hey 12x you are on the right track ....I was having trouble for about the first 4 races last year with the car getting to tight to fast because it was jumping up on the bars and rolling over on the right side hard....I was running a 94 shock ....I switched to a 93-5 and it made a huge diference without any other changes to the set up.......the thing i am wondering is if by doing this I realy just put a bandaid on a problem that could be fixed else where.....I am starting this season with the same set up......this racing deal is nothing but a bunch of comprimises....I dont think that there is a perfect setup for all situations....good luck and dont be afraid to try things unusual,you might just stumble onto the next greatest trend.

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 16, 2005 05:47 AM  
A 93-5 on the LR?

JT54
Dirt Maniac

Total posts: 170
posted March 16, 2005 04:34 PM  
Yup...it slowed things down on the throttle ....I would not have tried it but it was a last ditch idea that worked for me.

Kromulous
Dirt Forum Champ
Total posts: 796
posted March 17, 2005 06:34 AM  
Thats interesting, 3 link car?

I guess, and i have noticed this with a 4 bar car, but it seems, sometimes if you get in and get the car up on the bars and arnt far enough into the corner the car has real trouble coming out.

Seems it comes to a point where it cant turn the corner so to speak. Especially on tracks where the turns are wide and broad and you can pick up the throttle early.

Gonna keep this in mind this year, on a certain track we run.

Also, i wouldnt say its a bandaid. Sounds like a rememdy to me.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 17, 2005 10:57 AM  
Well guys, I just got a heck of a deal on about 20 pro shocks, every rate I could ever want. Looks like I'll get to try the theory out this year.

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