What are your go-to adjustments at the track ?

[RacerX10]

I've been out of it for a while, looking to start racing again this summer. Everything is different then what it was last time I was racing a lot.

Just curious what everybody's most common adjustments are at the track ?

Seems like people talk about the Left Rear Upper radius rod a lot, and of course right front spring rate adjustments.

Also, do you make bar / spring / radius rod changes, or shock changes ? Maybe both ?

If you don't mind sharing, I'd love to hear what you change at the track, and why you change it.


Thanks !!

[7uptruckracer]

Bite, Tilt, Front Rebound, RF Compression, and RS Bar Length, RR Spring for sidebite. All minor tweaks but that is it.

[RacerX10]

Bite, Tilt, Front Rebound, RF Compression, and RS Bar Length, RR Spring for sidebite. All minor tweaks but that is it.

No bar angle changes ?

[7uptruckracer]

Not as much as we use to. Take good notes track to track. If you go to a quarter mile bullring then a 1/2 mile sweeper then probably. Same track nope. You're mostly accounting for travel changes as the track slows down and doing small things to change a little weight transfer and taking some dynamic rear steer out with the RS Bar Length. These newer cars utilize the front so much more then they use to so keeping them sealed off is key. You don't have to do as much in the rear to get them to turn like you use to. This is just my opinion get as many as you can and think through what we all say and decide for your own what you want to test.

No bar angle changes ?

[MasterSbilt_Racer]

7up is giving very good advise here.

[PushinTheLimit]

Small changes, I make rebound and compression changes, minor rear bar changes, and play with the bite. Bigger changes I'll change a spring rate or j-bar or weights. Pretty rare that I move weights... once I found what the car likes with my driving style, I really don't change much during the night.

[phenom08]

Lr wheel spacer, shock adjustment,

[King1]

rear end lead, rr spring, stack lock out nut or bump stop height (whichever one you run)

[RacerX10]

These newer cars utilize the front so much more then they use to so keeping them sealed off is key.

What does "keeping them sealed off" mean ?

Thanks for your comments !

[RacerX10]

rear end lead, rr spring, stack lock out nut or bump stop height (whichever one you run)

Had a slight laugh about this. Isn't anybody NOT running a stack or bump stop these days ? I got the impression it was terribly complicated to get the setup right running either.

[7uptruckracer]

What does "keeping them sealed off" mean ?

Thanks for your comments !

Aerodynamic nose all the way across as close to the track without hitting and right side skirts all the way to the ground as close as it can get without hitting. Sealed to the track. Keeps air from getting under the car and creating lift. This is why they have body deck drop rules now, fender rake rules roof rake rules filler panel rules etc aero is king lol

[MasterSbilt_Racer]

Had a slight laugh about this. Isn't anybody NOT running a stack or bump stop these days ? I got the impression it was terribly complicated to get the setup right running either.

People who hope to separate you from your cash will tell you that it is terribly difficult. They will tell you that it is impossible to race without a spring smasher.

[TheJet-09]

@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 thread, looks like you found a nice car. We need more people coming back to racing...too many are leaving. Good luck!

[7uptruckracer]

The smashers are nice though but nothing you can't do in the shop using some extra work and time, but time is money to the big guys i don't have the money so i just spend the extra time lol

People who hope to separate you from your cash will tell you that it is terribly difficult. They will tell you that it is impossible to race without a spring smasher.

[MasterSbilt_Racer]

The smashers are nice though but nothing you can't do in the shop using some extra work and time, but time is money to the big guys i don't have the money so i just spend the extra time lol
They are putting a lot of importance on one data point on 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.

[Matt49]

About this spreadsheet... I spent several hours last weekend tweaking on it and I was showing it to somebody to get a second set of eyes on the math. He asked why I was doing this and suggested that I get a copyright on it and sell it rather than giving it away. I haven't done that and may never but what I have done is created a password protected copy with most everything hidden except the data entry and the results graph.
At this point, I want to figure out a way to publish it online so that I can take it down in the event that I feel someone might take it and use it for profit. What I've also considered doing is creating additional useful spreadsheets (or ultimately having a program written) and packaging that as something that could be sold (by me) in the future. Kind of like a dirt racers math application. I could provide all of the formulas for how to calculate all kinds of things but ultimately, most people just want to input some stuff and see the results. The fact there is an actual MARKET for that makes me hesitant to publish my work for free.
Anyway...more to come on this as I think more about it.
If I can figure out how to post a picture on here I'll provide a screenshot of what it looks like with some sample output to see how interested folks really are.

[Matt49]

Let's see if this works

[Matt49]

Smaller this time

[race4dad 31]

Here is the trouble with things today. At first you say you don't mind sharing then get the idea that there could be a profit to be made and want to test the water to see if any fish will bite. Now to be honest I would want to get compensated if I thought I had something that could be marketed but I was tought to be of my word and if I said I would share my pappy would smack me if I backed out on that.

[Kromulous]

Looking at it on my phone, but it looks really cool. I wouldn't mind paying for it at all. I would think alot if big teams would have something like this already.

I like the graph alot. Package it up better and sell it, I say.

[Lizardracing]

You can't patent math.....or google calculators.....or spread sheets.

I use Excell and make them all the time. If you don't know how, the help section will tell you.

[Matt49]

Yes, at first I said I didn’t mind sharing. My initial spreadsheet was unreadable to anybody but me. I spent several hour cleaning it up and making into something that a person might actually be able to use (the screenshot I provided is an example). I then had it reviewed by somebody that I trust (mostly to verify my formulas) but they made the suggestion that I copyright the material before sharing it because it could reasonably be considered “intellectual property”.
I’m sorry if you think that “my word” on 4m means something but I assure you it doesn’t (in this context). If a handshake is what you need, I’ll give it to you…but not online. I don’t owe anybody anything for reconsidering my willingness to give away what I spent significant time developing.
To Lizard’s point, you can’t “patent” math. That is true. But you CAN copyright materials (that includes software or files) that generate output based on math. This is the entire reason the idea of a spreadsheet distribution stopped. Because you can’t copyright a spreadsheet. You can however copyright software code which is what I’ll take this to if that is required.
I know there will be people that say, “we’ve done this already”. Call them and have them share their results for free and please let me know how that phone call goes.

[race4dad 31]

Actually Matt I wasn't even judging you directly. And this was not meant to seem like a personal attack. You seem to try and help folks when you can with a simple answer to their questions. What I am pointing out is the way things are today. I run a successful business and if I say something on the phone or even on the Internet I feel I have to honor it even if I realize later that I made a mistake. Again Matt it was nothing personal.

[RacerX10]

I could probably run that data through some polynomial interpolation and generate the same thing .. but I'm *way* too lazy to do that :)

[Hi-Line BRC]

Market it as a cell phone app, with the ability to email the results to yourself. That concept works great with some of the scaling calculators out there. Id spend under $10 for that app in a heartbeat. Not worth my time, and you can make some coin!

[let-r-eat]

I always wonder why there aren't more apps for google racers. That's a nice simple spreadsheet Matt49. Host it on a webpage or something.

[Matt49]

Take your spammy sales pitch to the classifieds.

Now that is comical coming from a guy that pretty consistently advertises that fact that he's a Motorstate dealer and even quotes prices on parts in the tech forum.

[Matt49]

I really would like to create a way to publish this type of thing online. Just trying not to give away too much work for nothing. Obviously there are people out there that can appreciate that.

[keeks]

Just Stop SCD. Be good for the forum.

[Matt49]

Just a quick update on this. I didn't realize this but apparently you can "copyright" something yourself in the US. Sounds too easy but its just a matter of putting a copyright on it (the little C symbol and the year). So my next step will be to create a final copy of this which I won't really consider completed until I've had an opportunity to test it against actual spring smasher results. I believe all of my math is correct to this point but I think it's worth checking. One thing I haven't accounted for yet is the thickness of the slider between the springs. My current version assumes a slider with no real gap between the springs but a 1/4 inch is pretty substantial if we're going for accuracy.

[RacerX10]

Can we go back to discussing go-to adjustments at the track ? :) This was a great thread till all the spreadsheet bru-ha-ha started !

[Matt49]

Mostly shocks.
Pinion side of j-bar
Top left bar to add rear-steer and help with drive off

[RacerX10]

Mostly shocks.
Pinion side of j-bar
Top left bar to add rear-steer and help with drive off

Thanks Matt ! I'm making a notebook with all this good info to take to the track :)

[Kromulous]

Does anybody adjust stagger at all? front or rear, or so you just set it per the tires you have a move on.

Thanks, Krom.

[MasterSbilt_Racer]

Does anybody adjust stagger at all? front or rear, or so you just set it per the tires you have a move on.

Thanks, Krom.

You have to leave some things alone to be able to have some consistency. There is a lot going on with a simple stagger change. I avoid that as much as possible.

[Kromulous]

I have always followed that rule MB Racer, but i know a few guys at the track, that win, and that's one of their main adjustments. Always sort of puzzled me.

Think i will start scaling the car with different sets of tires to see where i am with different staggers.

Also, anyone ever miss with spoiler adjustments? stand it up or lay it down?

[MasterSbilt_Racer]

I have always followed that rule MB Racer, but i know a few guys at the track, that win, and that's one of their main adjustments. Always sort of puzzled me.

Think i will start scaling the car with different sets of tires to see where i am with different staggers.

Also, anyone ever miss with spoiler adjustments? stand it up or lay it down?

I don't typically mess with spoiler. But, I have never been above some crazy stuff. 15 years ago I was racing one night on a small bullring and couldn't loosen my car up all night. Qualified terrible. Terrible in heat. Luckily, all cars made the feature. I took the spoiler off for the A main. People laughed at me. I started 20th and finished 3rd. I was working on 2nd with about 5 laps to go and the track finally started going away. I was hanging on the last few laps. LOL

[Kromulous]

I rode one of my motorcycles behind my brothers car on an open trailer one night, you wouldnt believe the amount air they move. I got close enough, say 6 foot behind the spoiler, the rear end of the bike would actually come off the ground LOL. I couldnt believe it.

Once i got in the low pressure area, i could almost let all the way out of the throttle and get pulled along. thats when i started feeling the rear end wobbling sort of, then i noticed the rpm fluctuating, it was intense LOL.

[tworrick]

That is a fact. Most people don't believe air has much effect. Your car will run much better by itself then in traffic .even on a small track.