Stagger calculater

CarlsonMotorsports

Premium User
LOL Pro Kart
How many big races has Pro kart won in the SE?
1 outta how many top chassis builders?
Ive used jack bolt on the front, make 1 turn in direction, make 1 turn in the opposite direction and it doesnt go back to where it was before the turn, thats why every MAJOR chassis manufacturer has or never has used them

Jamie,
Ease up there big fellow.
Where is the "major" chassis manufacturer that sponsored you for all those years now?
Not a shot, just a question.
FWIW, I still offer weight jack spindles on our chassis (have since 1993) and run them on AJs karts every weekend.
Plenty of "major" manufacturers have experimented with them (back as early as the mid '90s to my knowledge.)
The real reason not to use them is that they are simply much more time intensive to build, (time is money to a manufacturer,) which makes them costlier to replace (not desirable for rough kart racing.) They are also illegal (WKA) to be adjusted while the kart is in motion.




-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
27 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

CarlsonMotorsports

Premium User
Al's calculator simplifies the calculations (if you know the numbers) to come up with a starting point on stagger.
Now, a beginner could come up with these numbers (measure by himself) and punch in the numbers to this spread sheet and have a starting point to go from.
Or he can ask a fellow racer, local kart shop, forum reader, etc how much stagger to run at his track and go with that as his starting point.

One thing I think is safe to say is that it would be easier to ask another racer at your track "how much stagger to run" than "what is the radius of the corner?" I think the latter would get a lot of blank stares and shrugged shoulders.

Al, Question for ya...How does available grip play into your spread sheet? I see no provision for that, yet every oval car I know (dirt and pavement) changes rear stagger as the track loses grip. This is even more apparent in classes with an over abundance of power where they might start the night with 16 inches of stagger and end the night (same race track, same radius) with 10 or 11 inches of stagger.
 

alvin l nunley

Premium User
They are also illegal (WKA) to be adjusted while the kart is in motion.
Back in the early 60s I use to pit for a guy who had a super modified. That's what they called it in California. He had a weight jacker he could operate on the fly. Don't know how exactly it was hooked up, but he had a Craftsman ratchet for adjusting it during the race.
 

alvin l nunley

Premium User
Al, Question for ya...How does available grip play into your spread sheet?
It's a tool.
A theoretical starting point, for a kart. When you get to the point where you can spin the tires at will, go sideways through the turn at 100 miles per hour, working the throttle, maybe you'll need something else.

I have an idea if you talk to 10 different people at one of those races, you'll get 10 different answers on what's the hot set up for the day. Just guessing. I'll bet a lot of people are looking at the tires of the guy who's always up front. lol

Available grip is not considered. You tell me how available grip effects stagger. On a kart!!
 

CarlsonMotorsports

Premium User
Available grip is not considered. You tell me how available grip effects stagger. On a kart!!
In the same way that it does with a big car, except that it is in much smaller increments.
Think even smaller scale - fixed axle RC racing and slot car racing. You'll see the same there -- stagger is used as a tuning tool. Less grip = less rear stagger. It is NOT fixed by the turn radius. Sure, turn radius is a major component in determining rear stagger, but there are other factors to be considered as well. Rear track, available grip, aerodynamic downforce and sideboard effect, and more I'm sure.
You don't have to be going 100 miles per hour to see the effect of stagger changes. Actually speed effects the available grip, (and ultimately is affected by it) correct? I would suggest that the less power you have to work with, the less change is needed in stagger as the track loses grip. At least that's been my observation over the years. Yes, in karts as well - thinking junior class restrictor plate racing up to UAS class racing. In each example, stagger is important. As you tend to overpower the rear tires, stagger becomes "less" important, although I believe it is still very important.
I believe available grip has a LOT to do with the final determination on what stagger is the "right" amount for you to run.
FWIW, throw the idea of independent rears in and we could get into an even longer hair discussion. ;)
 

alvin l nunley

Premium User
Well, you admit stagger is a major component, and I never said that my stagger calculations were written in stone. There are many components to a racetrack that affect stagger. Turn radius is one major one. The ratio of the turn radius to the length of the straightaway is another. With a tight radius and a very long straight, you're going to have to make compromises.

I have this feeling that, once you have found a working stagger for your track, you're pretty much set. I can't see how it would be a handling tool. Once the stagger is set, if you not handling, I've got to believe that you're going to need to look elsewhere for solutions.

It sometimes amazes me how much people will go through in accomplishing various tasks that are necessary on a kart. Treating tires, cutting tires, scaling karts, and a host of other things, yet they don't have the time to walk across the infield of the kart track to find out what the radius of the turn is!! They will spent untold amounts of money on various gadgets, but they won't buy an air density gauge?? They won't buy precision jets, let alone jets that have been flow test it. I don't know how many people do it, but I hear there are people that drill the jets. Fuel is about 700 times denser than air, the slightest flaw in a jet hole can cause major disruptions in fuel flow, yet nobody addresses that, at least it's not a common practice. And where did people get the idea that the temperature under a spark plug is a major contributor to performance?? One of the first things I learned when I got into karting was the benefits of an EGT. It was from an article by Bystrom, in karter news, and I think my first or second issue of Karter News (1966). Unfortunately the gauges of the day were not conducive to Sprint kart racing. And they were crude. They were mostly for enduro racing. You had to strap the gauge on your stomach with a belt. Seems like every time I stuck a Mac I would think about that article. That was 50 years ago, and though I forgot many of the details, I retain the essence. When I built my first dyno in 1985, the EGT was an integral part of it. I proved, at least to myself, how important the EGT is.

I am a firm believer in the EGT, I don't care how much trouble it is, if you don't have one, you're not going as fast as you could in all conditions. People will laugh, but I have data, in my head, that proves to me that the EGT is essential for going fast under all conditions.

And of course there are going to be people who will say "when was the last time you raced LTO", as if this had something to do with it. lol the status quo is so hard to change. If you're serious about racing and winning, although driving is very important, tuning is close behind.
 

rre

New member
the calculator is cool, should give you a good baseline, when a track changes, most times theres not alot of time to rescale kart, like i mentioned in above post, if you know what stagger does to your kart, you can tune with stagger.. typically a tacky high grip track will need more stagger, dry/slick less stagger, small track more stagger, high bank small track more stagger, long track less stagger..

I normally have 4 right rears, different stagger.. everyone has their own way of doing things..
 
I know this for sure. We ran our 2nd races at two different tracks this weekend. We are very new to this and I learned a major lesson this weekend. The two tracks are both flat but one has a 102' Radius and the other has a 42' radius. We ran 4th both nights and the rear stagger stayed at 1" on both tracks. I'm thinking that the stagger was close on the 102' Radius track and EXTREMELY way off on the 42' radius track. I've spent the entire evening reading only about stagger and I am 100% convinced that this is the #1 issue for being tight and pushing on exit of both tracks

I'd like to see this calculator just to compare.
 
Well, you admit stagger is a major component, and I never said that my stagger calculations were written in stone. There are many components to a racetrack that affect stagger. Turn radius is one major one. The ratio of the turn radius to the length of the straightaway is another. With a tight radius and a very long straight, you're going to have to make compromises.

I have this feeling that, once you have found a working stagger for your track, you're pretty much set. I can't see how it would be a handling tool. Once the stagger is set, if you not handling, I've got to believe that you're going to need to look elsewhere for solutions.

It sometimes amazes me how much people will go through in accomplishing various tasks that are necessary on a kart. Treating tires, cutting tires, scaling karts, and a host of other things, yet they don't have the time to walk across the infield of the kart track to find out what the radius of the turn is!! They will spent untold amounts of money on various gadgets, but they won't buy an air density gauge?? They won't buy precision jets, let alone jets that have been flow test it. I don't know how many people do it, but I hear there are people that drill the jets. Fuel is about 700 times denser than air, the slightest flaw in a jet hole can cause major disruptions in fuel flow, yet nobody addresses that, at least it's not a common practice. And where did people get the idea that the temperature under a spark plug is a major contributor to performance?? One of the first things I learned when I got into karting was the benefits of an EGT. It was from an article by Bystrom, in karter news, and I think my first or second issue of Karter News (1966). Unfortunately the gauges of the day were not conducive to Sprint kart racing. And they were crude. They were mostly for enduro racing. You had to strap the gauge on your stomach with a belt. Seems like every time I stuck a Mac I would think about that article. That was 50 years ago, and though I forgot many of the details, I retain the essence. When I built my first dyno in 1985, the EGT was an integral part of it. I proved, at least to myself, how important the EGT is.

I am a firm believer in the EGT, I don't care how much trouble it is, if you don't have one, you're not going as fast as you could in all conditions. People will laugh, but I have data, in my head, that proves to me that the EGT is essential for going fast under all conditions.


And of course there are going to be people who will say "when was the last time you raced LTO", as if this had something to do with it. lol the status quo is so hard to change. If you're serious about racing and winning, although driving is very important, tuning is close behind.
Because as i have told you many many times, it is illegal in most LTO racing. Matter of fact, lots dont even run the CHT sensor at all. You will see this at most every major race across the country.
 

alvin l nunley

Premium User
"I've told you a couple of times" that's 2 times, right! "I've told you a few times" that's what, 3 or maybe 5 times?
"I've told you many many times" how many times would that be?
The point being, you haven't convinced me! I don't care how many times you've told me!
 
"I've told you a couple of times" that's 2 times, right! "I've told you a few times" that's what, 3 or maybe 5 times?
"I've told you many many times" how many times would that be?
The point being, you haven't convinced me! I don't care how many times you've told me!
Not trying to convince you at all, its a rule in the rule book that EGT is illegal. Nothing else needs to be explained.
 
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