LR spring where?

[Lizardracing]

I have two races left this year. I feel like I got about all I can get outa my current 3 link with the spring in front on the left rear with my spring combo. I could buy more spring combo's to try but that's going to take more time then I have to nail down a faster package. We currently run mid pack and I want a top ten personal best finish before the end of the year. I'm thinking that since the track doesn't slick off like it used to, where a LR in front made a noticable difference, that going with a LR behind might make us faster. The problem with LR in front? In order to loosen the car enough on entry we are tight in the middle on the throttle without buying and trying new springs. Using the springs I have available I'm wondering if LR behind would free the car in the center so we could keep momentum and using bar angle and pull bar settings will make us faster sooner then trail and error with spring combos.

My situation,

4/10 mile high bank track,
Goes slick very late at night but mostly rubbers up this time of year,


Car,

2002 American Made 3 link small metric with metric lowers,
RF 900 (have a 750) 1275 shock
LF 800 (have a 650) 1276 shock
LR 225 1093 shock
RR 150 1293 shock
LR in front
RR behind
Pull bar 800 pound spring and gettin 2 inches travel. NO 9010
58% rear
54% LS
60 pounds LR bite
4.5 inches rake in J bar. mounted even with pinion.
15' in LR bar
level in RR bar

Problem with this set up,
Tight in center hurting corner exit. tried less bite, more body roll, stagger, but all these still kept the car a little tight either on entry or in the center.

Possible cure, LR spring behind to free up center for better mid corner speeds so we don't need as much bite off. The lower bars and pull bar would be enough mech. bite. Same frame height same precentages, same springs, more or less bite i don't know?

What do you think?

[race81]

if it were me, id lighten up the rf spring to give less bite while in the center of the corner. maybe try spring rates even across the front to see how that feels. then maybe try a reverse front spring rate(lf850,rf750) the rest of your setup looks good. sounds like you just need a better spring combo.

[Timmay]

Lizard,

I think you're on the right track. If you want to free your car up everywhere, either put the LR spring on the back of the axle, or put the RR in front of the axle. You'll feel a huge difference.

If you don't want that big of a jump, then put the RR spring on top of the axle.

Every 3-link car I've messed with with a front-LR/rear-RR set up, has always been too tight. It was always a struggle to free these cars up without un-staggering the springs. (my personal preference is to stay a little on the loose side)

Hang Loose Bro!

[Lizardracing]

Timmey,

I'm gonna get a 200 RR and try closing up the rear spring split to free a bit thru the center. If that doesn't work I'm gonna put the LR behind where I started. The LR in front works okay up top on the slick I'm learning it's just to tight this time of year when the track takes on rubber and the speeds start going up agian. I'm still pretty new so loose scares me a little haha.

[Timmay]

Lizard,

I have been wrong before, but with those staggered springs, I don't think you'll see much of an improvement stiffening your RR. In fact it may make the car tighter on entry through the middle. It doesn't hurt to try it. It may work for you. If not, you would have at least learned something.

I would urge you to at least trying the RR on top of the axle. Most of the winning mods around here are doing that.

As far as you being kind of new, you'd be far better off in the long run if you develop your driving style around a loose car. A tight car feels comfortable to a driver, but it develops bad driving habits and ultimately slower lap times.

Good Luck!

[Lizardracing]

I have a freind who will test the springs I have now and confirm I have what I think I do. I wonder if one of those spring are weak and any of my small adjustments are to small to make any difference. Till i go over aboard and the opposite happens of what I expect. Say, what if my 150RR is really a 100. Ain't nothing gonna help that.

I see you point about the stiffer right rear keeping the on the left side and making the car feel tight. Some one elses theory says that the car might be falling on the RR and never getting back over on the LR to build left rear bite on entry. I do turn before dragging the brake to get he rear to come around. I mean drag, like rest my foot on the pedel. I'm thinking of asking if one if the other experianced mod guys might hot lap my car and see what they think. To me the front feels "heavy" on entry and thru the middle. Like the front is digging into the track but it's still not turnig. I used to think that was because of the slight incline up the bank and inertia keeping both front spring severly loaded. That's why the slightly heavy front ones now.

One last thing, I'm not opposed to putting the RR on top. It's just with three races left I want a personal best finish and My chassis doesnt accept a spring on top. I could make one but I preferr to exhaust all my other options first. If this week doesn't get a best finish or at least a promise of one, then I'll go spring on top RR on the last race of this year.

Thanks for sharing.

[Timmay]

Lizard,

I've personally never seen any brand of spring ever be more than 10 lbs off of it's advertised rate (new or used).

You shouldn't be using your brakes to turn the car. You can get away with turning the car with the brakes when there's some bite left in the track, but when it gets dryer it's a bad deal. Ideally you would like the car to turn itself into the corner.

If you can't mount the RR spring on top, I would try to at least mount both springs on the same side of the axle (both in front or both in rear). Then I would run the springs like this:
LF=900, RF=800
LR=200, RR=225

If it gets really slick you can put your 150 spring on the LR.

Good Luck!

[Lizardracing]

Only ten pounds off? I as under the impression that it happened quite frequently. And these springs are at least 5 years old. Well, in any case, it ain't gonna cost anything to see. My chassis has spring mounts front or back on either side. It's built so moving the spring from front to back doesn't change ride hieght or weight or anything else. Shocks are the same way. Freely interchangable. I'll try the RR spring in front. Would you soften the pull bar spring?


I don't wanna use the brakes to turn the car, that's what I'm saying the problem is now. If I can get the car to turn on it's own, then the middle won't need as much LR weight(to regain traction lost when I drag the brake to make entry) and I'll be better off the corner because the center was faster. The queston goes, how do I add left rear bite on entry so the car to turn in, and then release that LR grip so the car will turn on the throttle thru the center. I guess that's what every body is trying to do huh?

[Timmay]

Lizard, Linear springs don't lose rate. They may lose their height.

When you have both springs on the same side of the axle, softening the pullbar spring won't have much affect. Try it if you want to. I always try to stay a little on the stiffer side and keep travel less than 1-3/4"

Good Luck

[Lizardracing]

Okay, I'm gonna put the RR in front for this week. Then run the springs like you said in an earlier post. Then the next week I will swap the front springs and for the final week, choose the one that made us faster and see what I gotta to do to make it even better.


Thanks you agian for sharing your experiances.

[profab00]

Question for Timmay. Why in the world would it make sense to put the spring on top of the rear end like a Buick Riveria? Why would you not put the spring on the birdcage so that indexing takes place with the movement of the birdcage? I'm talking rr here.

[Timmay]

Profab,

1. What's that indexing going to do for me?

2. I guess Bob Pierce cars are no better than a Buick Riviera

Putting the spring on top, floated on birdcage, on a swingarm will all accomplish the same thing by not letting the RR spring take on any of the torque reaction of the rearend. Obviously, you can't run the same spring rate in all these mounting configs, but there's not a lot of advantage to any of them once you get the spring rate right. The exception to this is when you mount a spring to the birdcage of a Z-link, then your wheel rates get progressive.

[profab00]

1. Tighten corner entry and corner exit is what the indexing does for you if one has the right bar angles and desires that action. My question was, why would one want to give that action up on the right rear? You are right, a three bar also works on the left rear so why go to a 4 bar where the spring is being indexed?

[Timmay]

Indexing on a 4bar effects wheelrate only. You can correct or compensate that with the proper spring. There's no magic there.

[profab00]

You are right in that it affects wheel rate. Mods are no different than a late model and no late models are fast that have a spring on top of the rear. My mod is a z-link on the right rear and the scuttlebutt in the pits is that most mod manufacturers will drop the spring on top of the rear next year in favor of the spring on the birdcage. I respect your advice and opinions and have followed your posts but have to respectfully say that in given points in the corner, striffer wheel rates are what we as racers are after. Indexing does work, at least in the dry-slick area I race in. Perhaps on a hooked up or rough track, indexing is an enemy.....I dunno.

[MasterSbilt_Racer]

The spring on top of the axle is as linear throughout travel as you can get. A car with linear wheel rates is much more predictable and easier to drive when compared to one with progressive rates.

[Mason5]

I can tell you guys know your stuff . What works the best a spring on top or floated on the bc I have see when a track is tacky i seen were the spring on top could hurt you. I can also see floated in front could tighten the car up on entry. Also how much differt spring rate if you had spring ontop say 200 then went to the bc. It looks to me the spring on top is there for a ride and does nothing but hold the car up. If you needed more side bite go to the spring in front on bc but it may affect exit more then the spring on top. I am just a racer trying to learn all of you guys have help alot keep up the good work. thanks Mason5

[Timmay]

Mason,

If you put the spring on top of the rearend, you can adjust the bars to your heart's content, and not effect the wheel rate. The advantage of this is that you can isolate your "middle-on-out" tuning with the bars, and not effect entry.

If you put the spring on the birdcage, tuning can get more complicated. That's fine, if you know what to expect. If you don't know what to expect, make small changes and keep good records. Also, practice your bar changes on the scales, because it will affect wedge as well. My personal preference is to reset the wedge after a bar adjustment.

As far as trying to match the same performance of a BC-mounted spring and a 200 on top, you have to know bar angles and BC mounting dimensions to do that.

Good Luck!