What are your go-to adjustments at the track ?

[RacerX10]

@RacerX10, I was in your position three years ago..hadn't raced in over ten years and a lot had changed when I decided to try it again. At first I messed with the RF spring often but it just screwed me up worse in the end. You'll probably do just fine with a 350# or 325# on the RF. Any bar adjustments for me are typically RR lower (entry) and LR upper (exit). Maybe lowering the J-Bar on the pinion side a little (about 1/2") for the feature. Shock adjustments for me are just the recommendations from the manufacturer/shock guy. Your biggest obstacle will probably be knocking the rust off your driving skills. From what I saw of the pictures you posted in another post, looks like you found a nice car. We need more people coming back to racing...too many are leaving. Good luck!

Thanks a lot ! I really appreciate that. I'm not trying to light the world on fire, I just wanna go drive around in circles fast and have a good time

I think I'll leave the bump-stop and stack stuff to the pros and just try and get where I'm not embarrassing myself out there .. which in itself is probably about all I can handle. Age has taught me to try and keep reasonable expectations.

[RacerX10]

The smashers are nice though but nothing you can't do in the shop using some extra work and time

When I first saw that machine, this was my exact thought. "Can't I do the same thing while the car is on the scales with a tape measure (or just counting turns on the adjuster ring) ?"

[A ron]

How about adjustments on a typical night from hot laps to qualifying to heat race to feature? (with the car driving like you want it to in the previous session, even though this is seldom the case) I realize there may not be an answer because of the million variables, but the other teams I've watched always seem to be working on the same areas of the car after the each session, week after week.

[King1]

The stack isn't complicated at all. Just gotta set the lockout nut in the right place and that's where a smasher comes in. I bought a rebel pulse real cheap from Vic hill. It actually made things simple once I got it lined out because really all I had to adjust was my lock out nut and that was my loose and tight adjustment without messing with static ride height and was really successful. I don't use my spring rater like most people do, I change springs with a tape measure. But I do check my wheel load when setting the lockout nut. And it's not impossible to go without the smasher, I ran two seasons without one and ran stack 5th and rf. But I did have some really good help from really good people.

[7uptruckracer]

I'm assuming you ran the Digressive stack on the 5th? How did you like it? I had someone try to set me up on it but I didn't bite he wanted to valve a "special shock" to sell with it....

The stack isn't complicated at all. Just gotta set the lockout nut in the right place and that's where a smasher comes in. I bought a rebel pulse real cheap from Vic hill. It actually made things simple once I got it lined out because really all I had to adjust was my lock out nut and that was my loose and tight adjustment without messing with static ride height and was really successful. I don't use my spring rater like most people do, I change springs with a tape measure. But I do check my wheel load when setting the lockout nut. And it's not impossible to go without the smasher, I ran two seasons without one and ran stack 5th and rf. But I did have some really good help from really good people.

[Kromulous]

Lock out nut is where the spring rate changes over to the non-locked out spring?

My question, when 2 springs are ran in conjunction via a stack, do both compress an equal distance?

Example, 500lb top spring, 600lb lower spring rate together is 273lb. Lockout nut is set to 2" travel, if you compress it 2" inches do both springs see the same amount of movement?

Looking at the math, 273lbs @ 2" movement would be 546lbs on the spring. Once it locks out, shifts to the 600lb spring is there already 1" of travel there, so your beginning rate is 600? aka 600lb spring compressed 1" has 600lb load on it.

Thanks, Krom.

[MasterSbilt_Racer]

Lock out nut is where the spring rate changes over to the non-locked out spring?

My question, when 2 springs are ran in conjunction via a stack, do both compress an equal distance?

Example, 500lb top spring, 600lb lower spring rate together is 273lb. Lockout nut is set to 2" travel, if you compress it 2" inches do both springs see the same amount of movement?

Looking at the math, 273lbs @ 2" movement would be 546lbs on the spring. Once it locks out, shifts to the 600lb spring is there already 1" of travel there, so your beginning rate is 600? aka 600lb spring compressed 1" has 600lb load on it.

Thanks, Krom.

The springs compress very close to what they would individually.

400/200 stack = 133.33 rate

400# on this stack (133.33#) = 3" of travel
400# on 400 = 1" of travel
400# on 200 = 2" of travel

So, you can do the math and don't really need a spring smasher. When you get into bump stops, if you have the curves, you can mesh that in too.

The first time I ever ran a dual stage rf, I started with the travel I was getting with a conventional spring. I calculated a dynamic load at max weight transfer. I installed the stack. I calculated an expected shock travel based on all these knowns. I set the lockout to get what I wanted. Put the car on the same track. I was off on travel by 3/16". This was without actually rating the springs and using nominal values. And the car was several tenths faster and a second place car instead of 5/6.

[Kromulous]

Ok MB, i like them results, your hired LOL come on by our pit.

Looks like i need to venture into the stack realm.

[Matt49]

MBRacer is exactly right. You can do the math can calculate how far each spring travels (and hence how far the slider move relative to the nut) relative to the compression of the entire stack. I created a spreadsheet that did it for me and then I could enter the gap and it would tell me the exact amount (from ride height) the entire stack would compress before the lock-out nut was engaged. So then if you knew the combined spring rate (which you would) and the spring rate of the primary spring, you could essentially map the load just like a spring smasher.
All good data to have but it's simply a line graph with a bend it it
The only problem we had really getting the RF dual-stage deal dialed in was lack of track consistency. If you have a track that is the least bit choppy, it is difficult to tune the shock to make the RF behave the way you want it to. It's best used on a really glass slick track with consistent banking top to bottom so that the compression travel on corner entry is very predictable and repeatable. A spring smasher won't really help you with this. Data acquisition and a 7-post shaker rig maybe would get you the data you need :-)

[Kromulous]

Care to share that spreadsheet LOL? I could ask one of my Eng buddy's here at work to make me one i guess.

We race mainly at Florence Speedway (North / South 100 track), its not always smooth, but thru the summer it pretty much is every week.

[Matt49]

Care to share that spreadsheet LOL? I could ask one of my Eng buddy's here at work to make me one i guess.

We race mainly at Florence Speedway (North / South 100 track), its not always smooth, but thru the summer it pretty much is every week.

I actually don't mind sharing it at all. What I need to do is make it a little more user friendly first. I'm semi off work today so I may work on that this afternoon.

[muddychevy98]

Hey Matt, did you ever get a chance to work on the spreadsheet? Would be interested in getting a copy if you don't mind.

[stevensracing_6]

I myself wouldn't mind having that on file

[Krooser]

Kromulus... You can't have MBR... He summer assignment is to get my fat ass competitive after a 29 year vacation from the drivers seat!

[Kromulous]

Well, u got a good start then. MB had his car rolling pretty good last year.

I would like to see my Brother get a win this year, but it's getting harder each year $ wise. Doing it yourself on your own dime is rough, but it is nice to see the car run well and finish top 5 to 10.