kart steering not turning going Straight

[dalton]

hi guys just starting my kart here and i have a few concerns

when i go to turn it doesnt turn as snappy as i would like and it kind of slides foward a bit

i thought maybe it was because of my steering setup but i have to different arms one with one pivot point and the otehr one (in pic) with two pivot points and they both do it .

is it because the axle in the back is one peice and harder to turn?

i have also tried tow in and out ,

i have proper ackerman angle .

in these pic i know the one side is way out i just threw it back together before i took pic
maybe wrong weight distribution


and ideas ?

 

[B man]

lessen the length of the right tie rod.(sitting on it perspective)

 

[dalton]

like do u mean make it have a toe in ?

the right side was straight as i was tessting it just in the picture i didnt ajust it yet

 

[redsox985]

A live (solid) axle will make turning more difficult although all racers, to my knowledge, use live axles. Look into other steering principles also. Check all of the steering related gadgets on this link. They're all nicely explained and interactive.

http://www.bcot1.com/karting/

 

[Doc Sprocket]

I seem to remember your frame- weren't we previously discussing your steering setup?

There are many, many factors that affect steerability. Yes, the live axle inherently makes it harder to steer. Proper frontend geometry helps combat that. The Ackermann angles o the arms look okay, but I seem to recall your pitman arm spread being a problem. Attach both tie rods to a singular point on the pitman arm. How's the KPI set up?

 

[MrS]

Castor angle

You need about 10 deg. Castor to lift the inside rear when cornering. You are also sitting/engine over each rear wheel.

Doesn't look like you have any castor..?..

 

[dalton]

@ toystory i have it setup atm with a one piviot on the pitman arm . (just not pictured) and same thing.


so when i first built it i had a 10 degree angle , on one side of the frame and i had my spindle shaft at the same angle but fliped and it was level when the tires were flat , but when i turned the wheel it would raise or lower depending on which way i turned and was a problem because my tie rod would hit my frame , so i just put it straight. so i guess ill be putting it back .


and move seat/ engine up?

 

[Doc Sprocket]

I hesitate to point this out, but-
If you're going to post a picture and detail a problem, it would really help if the picture actually reflected the problem. In other words, "I just threw it together like this for the picture is quite possibly even less helpful than no picture at all.

 

[dalton]

I hesitate to point this out, but-
If you're going to post a picture and detail a problem, it would really help if the picture actually reflected the problem. In other words, "I just threw it together like this for the picture is quite possibly even less helpful than no picture at all.

good point i will make do that but i made a mistake as well in the post above , i made my spindle have 12 degrees camber angle

not castor angle so i will be cutting it up and adding castor angle

 

[bighead]

I think your engine and seat are fine. But if yu can move the seat up that will help. I think you are in front of the axle enough though.

 

[landuse]

I was looking at some of your welds, and I think you should maybe go over them again. In a few places it looks as if you have just tacked the pices together. I am just concerned that they might break while you are cruising at 30 mph.

 

[T-man]

looking at your #2 picture .... it looks to me like you have caster, but its going the wrong way .... positive caster I think is what you have there, negative is what you want. Or maybe I got that backwards.

 

[dalton]

I was looking at some of your welds, and I think you should maybe go over them again. In a few places it looks as if you have just tacked the pices together. I am just concerned that they might break while you are cruising at 30 mph.

i have just welded 2 out of 4 sides for the moment just because if their is any changes as i am about to make

 

[gokart14]

u may not have enough weight up front or

 

[anderkart]

when i go to turn it doesnt turn as snappy as i would like and it kind of slides foward a bit

and ideas ?

Your front track-width seems awfully wide. This pic shows the dimensions of a typical modern racekart chassis, see how your kart compares:

The others already made some good suggestions regarding caster-camber/KPI/ackerman problems you might be fighting here, but I'd suggest you first try moving your seat as far forward as possible.

That cut-out section in the front/center of your seat is there to allow the seat to be mounted as far forward as possible, and still clear your steering column support...

Look at how far forward my seat is mounted: (and I'm 6'-6' tall...)

You'll find more pics/info about this kart here:--> http://www.diygokarts.com/vb/showthread.php?t=3664


While sitting in the kart, you want to try and achieve as close to a 50-50% front-rear weight bias as possible.

Right now with your seat waaay back there, I'd guess you've got like 80% of your total weight on the back tires. Even a factory built racekart wouldn't turn worth a crap like that.

 

[dalton]

anderkart;145929

ok thanks for the advice i will move it , also curious why is your left front tire so wide compared to the right

 

[anderkart]

Oh yeah, my beisse kart was just set up for dirt oval racing in that pic.

The right-front was wider and taller than the left front.
The right-rear was wider and taller than the left-rear.

Oval racers use staggered tires like that to make the kart turn left waaay better.

The only drawback is: my tires wont grip on right turns worth a dam staggered like that. But you only need to turn left while oval racing so...

 

[DustinWolfe]

Oh yeah, my beisse kart was just set up for dirt oval racing in that pic.

The right-front was wider and taller than the left front.
The right-rear was wider and taller than the left-rear.

i have a question for you anderkart.... doesn't that mess with your gearing? i mean not like it makes it go faster but isn't 1 tire constantly either spinning faster or slower than the other. maybe im just picturing this wrong it has been a long day at work.

(edit: i mean in the rear not the front)

 

[liverider2003]

i have a question for you anderkart.... doesn't that mess with your gearing? i mean not like it makes it go faster but isn't 1 tire constantly either spinning faster or slower than the other. maybe im just picturing this wrong it has been a long day at work.

(edit: i mean in the rear not the front)

I would think not. It is a live axle...so they both rotate at the same rate. but the larger circumference tire will cover more distance with each rotation. So if you are going around an oval and are always turning left...your outside tires(right side) will cover more distance throughout the course of the race than the inside. So having taller outer tires will help offset this...thus making the kart turn left with much more ease.

but I wouldn't think it would mess with the gearing too much. It isn't a huge difference in tire sizes I don't think.

 

[anderkart]

i have a question for you anderkart.... doesn't that mess with your gearing? i mean not like it makes it go faster but isn't 1 tire constantly either spinning faster or slower than the other. maybe im just picturing this wrong it has been a long day at work.

(edit: i mean in the rear not the front)

Well yeah your right, staggered rear tires do fight each other going down the straightaways. This causes more rolling resistance and does scrub off a little top speed in the straits, but it lets you go around the corners so much faster you end up turning much faster lap times.

I was racing that kart on a very small 1/10-mile dirt oval track, so i needed a full inch of height difference in the rear tires to get around the tight corners fast. (no-stagger = kart wont turn. too much stagger = a loose kart that actually turns too well and easily spins out)

But If I was racing at a larger sized dirt oval track, I would want less rear stagger to match the wider corners. (and even less if that track was paved...)

And then with a huge sized track, it might end up turning faster laps with no rear stagger at all. (especially on a paved track)

I hope that kinda answered your question