Karting??..

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So day before yesterday I went and got my kart aligned. We put it on a four corner scale and tweak the frame just a little bit to get the front even..
He took the old style spark plug out and put a newer four-cornered style spark plug in... Did some adjustments on the carburetor but I had to do more once I got to the track to get it to run well...
There's a strong possibility even after I cleaned it that it could still have some issues from the previous owner leaving bad gas in it..
Anyways I took a wild swing at my gearing and added about 4 teeth to my rear sprocket to get it to hit the rev limiter before the end of the long straight away. Again our local Sprint track is very technical. Has seven corners two short straightaways and one long one.. previously I was never hitting the rev limiter at the end of the long straight away.
With the new gearing I was hitting it way too long before the end of the straight away.. on those few passes I barely got the time to warm up the tires and was flagged in for the rentals to go out... Knowing I had taken too big of a swing that's a gearing put another sprocket on and lost two teeth on the rear...
This next time I got a full session of laps warming up the tires and getting my rhythm going.. I pulled off my fastest laps yet...(47 second range) But was still hitting the rev limiter a good ways before the end of the long straight.. which follows along with my personal theory that I need more zip and all of those corners and the end of the long straight away is a small portion of the track..
So now to tell the difference if it was the alignment or carb tune or spark plug I went back to the previous gearing that was yielding me 49's and one 48... I hit the rev limiter long before the end of the straight away again! And it didn't do this before so something in the alignment spark plug carburetor or whatever I feel contributes??.. but back up to the 48 second laps..?
BUT... Am I now getting more seat time and exiting the corner faster to reach a better speed at the end of the straight away?...
Well as you can see by this post I'm all over the map LOL
 
Did you get to try the original gearing to see how it did? It may be possible the engine was sluggish before due to carb/spark issues, but it seems like it was very sluggish before if that's the case. Does your Mychron 4 (if I remember right?) retain the highest RPM? Just a thought to verify it's actually hitting rev-limit or having fuel/spark issues. The 47 second lap is 2 seconds quicker than your previous best right?
 
Sounds like it likes those 2 extra teeth. Should give it better acceleration off the corners and keep it in the power while cornering. Are there any lack of bite issues in any particular corner on a regular basis?
 
RammerJammer75 said:
Did you get to try the original gearing to see how it did? It may be possible the engine was sluggish before due to carb/spark issues, but it seems like it was very sluggish before if that's the case. Does your Mychron 4 (if I remember right?) retain the highest RPM? Just a thought to verify it's actually hitting rev-limit or having fuel/spark issues. The 47 second lap is 2 seconds quicker than your previous best right?
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Yes I did get back to the original gearing and it was hitting the rev limiter but my time has slowed down by a firm second to 48's.. the microphone for did confirm it was hitting the rev limiter at about 6030..
I thought the rev limiter was 6100 but I confirmed with an engine builder of these types that 6050 or so is about the normal...
 
j par said:
Yes I did get back to the original gearing and it was hitting the rev limiter but my time has slowed down by a firm second to 48's.. the microphone for did confirm it was hitting the rev limiter at about 6030..
I thought the rev limiter was 6100 but I confirmed with an engine builder of these types that 6050 or so is about the normal...
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Ok. Sounds like the engine was a little down on power. I would go back up 2 teeth and try to keep it off the limiter. Sounds like it wants the better torque multiplication for the corners.
 
Unconventional said:
Sounds like it likes those 2 extra teeth. Should give it better acceleration off the corners and keep it in the power while cornering. Are there any lack of bite issues in any particular corner on a regular basis?
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This is what I'm seeing on my micron that its liking the lower gearing setup with the extra teeth..
Here let me post a picture of my gearing setups and it will be easier to follow...
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So I inherited the kart with the 16 on the front and a 59 on the back.. this I'm told by racers and gurus that should be the ultimate gear for that motor on that track... May I remind everybody now the minimum weight for that class is 360 lb which most drivers are much lighter than that and have weights hanging off their seat... Me and kart are about 415 pounds..
I took the kart out the very first time with the original gearing and no beacon for the microphone so all I could see was my RPMs. Right away I could tell that I was not getting close to the rev limiter but maxing at about 5,500... So I go buy a 61 and 62 gear and put the 62 on with the 16.. could it be confirm I micron and still only hit about 6,800.. was doing consistent 49 second laps with one high 48 second..
The third time I took the kart out I left this setup on and was doing about 50 seconds with 149 but it was colder and the track was much more slippery...
So again Friday I took it up and had said work done to it and bought a 14 for the front and a 58 and a 56 for the rear.. this fourth timeout I started with the 58 first and I was hitting rev limiter way way too far before the end of the straight away and didn't get very many laps in and decide to change immediately to the 56..
I'm still hitting the rev limiter long before the end of the straight away but not as far away. I was holding it on the rev limiter until I had to break in the first corner and that is where I was getting my constant 47s...
And flat curiosity I go back to my 16-62 and I'm back to constant 48's..
Those were my last laps on Saturday and the way it's currently left set up until I decide different..
I was at the last official race at another track which I haven't driven. Just to watch the races and see how all that goes down. Of course the guy that did my setup was there and I was telling him of these results. He's an older gentleman that's been karting for more years than I've been alive. He doesn't race but his team what is the FrontRunner and all the races.. he's more of the school that I should be running like the 16-61 or 16-62 and improve my driving... He was talking about only two extra teeth for an extra 40 lb of weight...
I felt I like the extra teeth because it was seemingly keeping the RPMs at through all the multiple corners which again is the majority of the track.. and of course using my best times...
as far as traction I want to start looking at wiping out the front wheels to get the rears to grip a little better in the exit.
I talked to him about this and this could be understeer in the beginning of the corner forcing oversteer in the end...
 
RammerJammer75 said:
Ok. Sounds like the engine was a little down on power. I would go back up 2 teeth and try to keep it off the limiter. Sounds like it wants the better torque multiplication for the corners.
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I'm all screwed up! LOL I was thinking the opposite... I did have one self-proclaimed Guru at the track who does own his shop saying cuz I should be hitting the rev limiter long before the straight away and holding it.. and so far that's proved to be the best times I've gotten...
 
Screenshot_20201102-084159.png

Just to give an idea of the track this is a picture from above. The upper right-hand loop is not open, it's just the short track is they call it..
 
I would back it off the limiter and I would daresay you'll pick up a little time rather than keeping it on the limiter. Was the seat moved when the kart was scaled? Honestly, I know it might make your kart a little heavier, but if you had to add some weight to get it balanced better you could always play with gearing to get some speed back. Is 81 on the front left and 79 on front right what you got on the scales? If I'm right, it looks like you're roughly 40% front and 60% rear. It's pretty close to a 50/50 split from side to side which is good. If I remember right, we always shot for 45/55 front/rear weight balance or something close to that.
 
RammerJammer75 said:
I would back it off the limiter and I would daresay you'll pick up a little time rather than keeping it on the limiter. Was the seat moved when the kart was scaled? Honestly, I know it might make your kart a little heavier, but if you had to add some weight to get it balanced better you could always play with gearing to get some speed back. Is 81 on the front left and 79 on front right what you got on the scales? If I'm right, it looks like you're roughly 40% front and 60% rear. It's pretty close to a 50/50 split from side to side which is good. If I remember right, we always shot for 45/55 front/rear weight balance or something close to that.
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Well I've stopped drinking a 2 liter of squirt everyday and put the kibosh on my wife making chocolate chip cookies all the time.. I'm currently working on the weight in the rear of the kart LOL...
 
The front of the kart is not pushing in the corners whatsoever.. if anything the rear kicks out which I've always been able to counter steer out of but of course that scrubs off momentum and ultimately pisses me off...
 
I bought two things on Amazon yesterday that should be here tomorrow. First was a book on karting... And the second was a log book... Being only four sessions into my kart I can still remember stuff, but as time goes by I'll need to be writing the stuff down..
 
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One thing I did notice just a few minutes ago when I walk to the garage and was looking at the kart... I pushed down on the choke lever and it went about almost 1/2 inch?.. now that leaves me thinking is that the one second extra on those final laps with the new gear?..
 
j par said:
One thing I did notice just a few minutes ago when I walk to the garage and was looking at the kart... I pushed down on the choke lever and it went about almost 1/2 inch?.. now that leaves me thinking is that the one second extra on those final laps with the new gear?..
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Sounds like it needs more fuel. You can't mess with the carb cab you? Or is it just internal engine parts you can't mess with? We never did run box stock stuff so I'm not as familiar with the rules.
 
j par said:
The front of the kart is not pushing in the corners whatsoever.. if anything the rear kicks out which I've always been able to counter steer out of but of course that scrubs off momentum and ultimately pisses me off...
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If it's loose in rights and lefts, scoot the rear tires in 1/4" and see if that makes it more to your liking. Towards the center line of kart=tight. Away from center line=loose. That choke lever issue, pull the plug and see if it looks like it was a little on the fat side.
 
RammerJammer75 said:
Sounds like it needs more fuel. You can't mess with the carb cab you? Or is it just internal engine parts you can't mess with? We never did run box stock stuff so I'm not as familiar with the rules.
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Air bleed and idol that's all I get..
 
Unconventional said:
If it's loose in rights and lefts, scoot the rear tires in 1/4" and see if that makes it more to your liking. Towards the center line of kart=tight. Away from center line=loose. That choke lever issue, pull the plug and see if it looks like it was a little on the fat side.
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I'm under the understanding that the more you raise the front end the more the rear wheels will stick and the more you lower the front end the looser the rear will get.. so as I move the front tires outwards it will raise the front more as I turn?... And make the rear stick?...
 
j par said:
I'm under the understanding that the more you raise the front end the more the rear wheels will stick and the more you lower the front end the looser the rear will get.. so as I move the front tires outwards it will raise the front more as I turn?... And make the rear stick?...
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Changing the spindle height will change the weight in a diagonal fashion. Changing the wheel locations on the axles/spindles will mostly affect only that corner. Fer instance, it pushes in left handers when you're on the gas, slide the right rear out just a bit to loosen that drive tire, or move the right front in by changing the shims on the spindle. If it gets to the point where it bicycles, loosen up that side. Changing tire compounds can be a real eye opener.
 
Unconventional said:
Changing the spindle height will change the weight in a diagonal fashion. Changing the wheel locations on the axles/spindles will mostly affect only that corner. Fer instance, it pushes in left handers when you're on the gas, slide the right rear out just a bit to loosen that drive tire, or move the right front in by changing the shims on the spindle. If it gets to the point where it bicycles, loosen up that side. Changing tire compounds can be a real eye opener.
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Tires are very track specific.. MG's at the one one normally go to (also what I inherited on the kart) and Le Conte at the track in McMinnville...
 
Also you must race the tires you practiced on.. I really trying to keep things from being who has the biggest wallet..
 
When I was sprint racing the IKF rules we went by many of the guys were on the "One Race Weekend" brand tires. I ran Burris and that was 3 months of racing plus practices. We got to do the big dirt track at the speedway one Saturday night, they were scrounging for dirt tires, I ran my seasoned asphalt slicks. I knew the Sprint Cars and Midgets were going to lay down a ton of rubber on the track before we got to it :steering:Motorwise it was a RWYB type night, I could pass the big motors in the corners but they would pull me down the straights :lol:
 
Unconventional said:
When I was sprint racing the IKF rules we went by many of the guys were on the "One Race Weekend" brand tires. I ran Burris and that was 3 months of racing plus practices. We got to do the big dirt track at the speedway one Saturday night, they were scrounging for dirt tires, I ran my seasoned asphalt slicks. I knew the Sprint Cars and Midgets were going to lay down a ton of rubber on the track before we got to it :steering:Motorwise it was a RWYB type night, I could pass the big motors in the corners but they would pull me down the straights :lol:
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This last time at the track it was kind of fun because there was a new guy and we become friends. I have the lowly lo206 animal and he has two carts a tag kart which is a water cooled 100cc 2-stroke 1 speed with disc brakes up front and the other is a shifter kart. Anyways with his tag kart which he's a little bit scared of the shifter kart LOL he followed me around the track on the first session and I slowly walked away from him on the corners and he couldn't catch me on the straits. Then on the 2nd Time he was able to pass me towards the end of the long straight and he could not get away from me on the corners and he was barely able to stay ahead of me enough to pull away on the long straight but by the end of all the corners I was right back on him again LOL...
 
I always liked a "wide" front end. Moving the wheels out a few spacers will help slow your turn in. This will make the steering less sensitive and assist you in smooth turn in.
 
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