lets talk axle size

There will be a lot more to it than just changing the axle.
Chances are that if you change the axle you will also have to make other changes to make it work.
You may have to change wheel widths, track width, caster and or camber, weight distribution, seat height and son and on.
Talk to Paul!!
 
It’s reasonable to assume 1.5 seconds of your margin or more is simply driving unless the brake is dragging etc. Have someone fast drive your kart and give feedback. Many older mgms ran better on 1 1/4 axles so I wouldn’t expect a miracle. Ask Paul
 
I will reach out to Paul at MGM. He has been very helpful with other questions I have had. I may also try and get one of the fast guys to turn some laps.
 
Your not getting beat by the axle size difference. If I was you I would not worry about switching from the 1 1/4 axle to a 40mm. It will cost you a bit of money to swap everything over. Your best bet would be to find another 1 1/4 axle in a different thickness than what you have and give that a try.

Like some other people have said let someone else driver you kart. That will give you some feedback.

I've ran a bit of 206 in Masters weight at 390 and Senior at 360 with a few different chassis and axle sizes. Honestly if I was to order a new frame I'd get a 1 1/4 axle setup for 206. If the chassis only came with a 40mm then I'd stick with that.
 
It’s reasonable to assume 1.5 seconds of your margin or more is simply driving unless the brake is dragging etc. Have someone fast drive your kart and give feedback. Many older mgms ran better on 1 1/4 axles so I wouldn’t expect a miracle. Ask Paul
I would take that one second! I am sure I am most of the problem.
 
Hi Pete
The axle isn’t going to give you 3 seconds. More than likely, you have a 3/16 wall 1 1/4.
You can put a40mm in your kart and it will help if your kart is tight.
But, 3 seconds will be mostly driver and setup.

where are you racing at?
 
Hi Pete
The axle isn’t going to give you 3 seconds. More than likely, you have a 3/16 wall 1 1/4.
You can put a40mm in your kart and it will help if your kart is tight.
But, 3 seconds will be mostly driver and setup.

where are you racing at?
Bushnell. I am trying to eliminate factors to get the gap down to just my driving. At this point, I probably have 300 - 400 laps at Bushnell, and now I am stuck at 3 seconds off the pace.
 
I'll bet most of the problem is with your inexperience.
Find someone close to your size and ask them to make several laps or a couple of complete practice sessions in you kart.
 
From a coaching perspectives, just putting in more laps will not yield you the results to make up the gap. You need to practice "good" laps or you are just crateing "muscle memory" for bad laps. Again, I strongly encourage you to find someone at your track who either does driver coaching, or a fellow competitor who will work with you to show you some of the lines or driving techniques that may be counter intuitive.
 
One of the first things I did was to check ratios with the other drivers. I am close
"Close" what does that mean? Axle/engine? = Ratio?

Loose? What to do? Quick fix is widen the front/narrow the rear. A little harder is, weight distribution, front to back. Moving the seat, forward or backwards, 1/2 inch, can make a noticeable difference. How adjustable is the kart? Camber, castor, wheelbase, height?

Compression pressure, check it often!!

Jetting, very important!!

Clutch engagement (stall RPM). Coming out of a tight corner, clutch slipping, that's stall RPM. It should be at peak torque RPM.

Answering all these questions is part of tuning and "tuning is tough" (Al Nunley)

The smarter amongst us use an exhaust gas temperature gauge (EGT), too tune the carburetor, i.e. get the jetting right!! An air density gauge tells us when to change it.
 
( The smarter amongst us use an exhaust gas temperature gauge (EGT), too tune the carburetor, i.e. get the jetting right!! An air density gauge tells us when to change it.
From the desk of Al Nunley )

I have a question pertaining to this . I have an air density gauge and a Yamaha kt 100 . The air density changes 5% . How far would I turn the needle's . Have you mapped the change in fuel delivery vs the thread pitch ?
 
I'm a very experienced (multi championship) driver with a perfectly tuned kart/engine and on certain tracks I'm off by 6 sec a lap because of aero drag. Some things you can't do nothing about like being big and tall. On tracks with short straights I can win be it's still a challenge because of high vertical weight.

1-1/4" axle is a good axle. If you have a fairly modern kart with a basic set up, that's all you need.

When I hear a rookie say he's loose, first thing I think is driving technique. Snap oversteer: You go into the turn too shallow and fast then try to turn all at once 2/3's the way through and the back end steps out killing your speed. Slow down a little, go in as wide as you can, keep the steering wheel steady and drive a perfect radius without slipping the tires and you will come off the turn fast and be faster on the straight.

Sundog
 
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( The smarter amongst us use an exhaust gas temperature gauge (EGT), too tune the carburetor, i.e. get the jetting right!! An air density gauge tells us when to change it.
From the desk of Al Nunley )

I have a question pertaining to this . I have an air density gauge and a Yamaha kt 100 . The air density changes 5% . How far would I turn the needle's . Have you mapped the change in fuel delivery vs the thread pitch ?
No, too many variables. I leave it up to the EGT to tell me if I'm lean or rich. The air density gauge, With an adjustable carb, Is only a guide.
 
1-1/4" axle is a good axle. If you have a fairly modern kart with a basic set up, that's all you need.

We have the track record in senior briggs boxstock kart sprint racing and will always have because the track "Columbiana Speedway" in Columbina Ohio is now closed.
It was set with an 1.25 aluminum axle[ ... :) ] in a Coyote Wide Track.
We also use an 1.25 aluminum axle in UAS racing with a chassis design altered by me to use an aluminum axle, winning the points in 2000.

Fast is about preparation, driving, tires and setup combined to enable you to make your tires do what you need them to do on the track.
If we could make an aluminum axle work you certainly will be able to make your 1.25 steel axle work. ... :)

edit: Dang i'm gettin old that's over 20 years ago. ... :)
 
I'm a very experienced (multi championship) driver with a perfectly tuned kart/engine and on certain tracks I'm off by 6 sec a lap because of aero drag. Some things you can't do nothing about like being big and tall. On tracks with short straights I can win be it's still a challenge because of high vertical weight.

1-1/4" axle is a good axle. If you have a fairly modern kart with a basic set up, that's all you need.

When I hear a rookie say he's loose, first thing I think is driving technique. Snap oversteer: You go into the turn too shallow and fast then try to turn all at once 2/3's the way through and the back end steps out killing your speed. Slow down a little, go in as wide as you can, keep the steering wheel steady and drive a perfect radius without slipping the tires and you will come off the turn fast and be faster on the straight.

Sundog

You spew this BS all the time. There is not a single sprint track in the US where aero drag is worth 6 seconds.

I’m 6’3” and have never lost a race due toaero drag.
 
LOL You've been racing bums! The track I'm talking about is 1 mile and has 4 long straights, not your average sprint track I guess.
 
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