Track Tac

Gearing

MO Predator Racer

MO Predator Racer

Member
I was on a 14-60
We had a few things done to our motor and got a new chassis over the winter. I went out and floated springs with that gear. Went to 14-58. Still pulled good but my tach stopped working for some reason so I was just going off feel and hearing. I heard it float valves a few times. This motor has billet flywheel and more timing in it so it makes more power. Should I drop to 14-57-56 or should I go up a tooth on driver? What affect will going up on the driver have? Just want to make sure I am prepared. I was good on the starts and good overall really all the way around track but just didn’t have enough speed to catch guy in front and so I ran second the rest of race. What would you do if you were in my position. Track is 1/8th mile and me and kart weigh. 355. I am lost and don’t know how it will affect the kart? I am putting an old tach on to get by this weekend so I can just read rpm to try and have that help me choose gear aswell. But with this setup I don’t have lap timer. I am gonna run the light and medium class this weekend so I will have enough track time to try a few different gear setups.
 
What RPM were you turning? What motor? Cant really for sure say what to do unless we know why you were floating the valves. 10.8 lb. springs will go pretty high before floating so i cant imagine a clone, unless your gearing is way off. Predator, a lot are also using the clone springs, plus shimming them, and then they dont turn much RPM anyways, so i cant imagine a Predator floating even with a disabled governor.
SA, Limited, then knowing what RPM would help choosing whether to go up a driver or down on teeth.
You ran 2nd, did you happen to ask the winner what he had for gear? Sometimes a simple question at the track will answer a lot of unknown.
 
MO Predator Racer said:
I was on a 14-60
We had a few things done to our motor and got a new chassis over the winter. I went out and floated springs with that gear. Went to 14-58. Still pulled good but my tach stopped working for some reason so I was just going off feel and hearing. I heard it float valves a few times. This motor has billet flywheel and more timing in it so it makes more power. Should I drop to 14-57-56 or should I go up a tooth on driver? What affect will going up on the driver have? Just want to make sure I am prepared. I was good on the starts and good overall really all the way around track but just didn’t have enough speed to catch guy in front and so I ran second the rest of race. What would you do if you were in my position. Track is 1/8th mile and me and kart weigh. 355. I am lost and don’t know how it will affect the kart? I am putting an old tach on to get by this weekend so I can just read rpm to try and have that help me choose gear aswell. But with this setup I don’t have lap timer. I am gonna run the light and medium class this weekend so I will have enough track time to try a few different gear setups.
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I also have issues with gearing for 1/8 mile track and Predator 212cc class, definitly dont do what I did and run a 12 66 that will float them valves hard, I turned 6,700 RPM max, & my engine turns 6,300 max, it was a short practice, but still im suprised I didn't blow a motor, I suggest a 14 57 - 61 for stock predator but IDK if it will work because you had issues with it, I turn 6,300 RPMs max
 
SoCo Tire Treatments said:
What RPM were you turning? What motor? Cant really for sure say what to do unless we know why you were floating the valves. 10.8 lb. springs will go pretty high before floating so i cant imagine a clone, unless your gearing is way off. Predator, a lot are also using the clone springs, plus shimming them, and then they dont turn much RPM anyways, so i cant imagine a Predator floating even with a disabled governor.
SA, Limited, then knowing what RPM would help choosing whether to go up a driver or down on teeth.
You ran 2nd, did you happen to ask the winner what he had for gear? Sometimes a simple question at the track will answer a lot of unknown.
Click to expand...
Let me rephrase it. Sorry about that. It is a predator 212 has header pipe and different air filter. Billet flywheel, 10.8 springs. It is just straight up 10.8 springs. We arnt allowed shims. With the stock cam it is like you hit a certain rpm range and it just stops pulling. That is what was happening. I don’t know what rpm was as my tach wouldn’t work but it was pretty high for a stock cam like 5600 if I had to guess.
 
MO Predator Racer said:
Let me rephrase it. Sorry about that. It is a predator 212 has header pipe and different air filter. Billet flywheel, 10.8 springs. It is just straight up 10.8 springs. We arnt allowed shims. With the stock cam it is like you hit a certain rpm range and it just stops pulling. That is what was happening. I don’t know what rpm was as my tach wouldn’t work but it was pretty high for a stock cam like 5600 if I had to guess.
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My build is pretty much like yours accept a PLV flywheel and an AKRA DJ-2225 CNC Bored 0.615 carburator and I turn 6,300, does your kart feel slower than the others
 
Shorttrackthing said:
My build is pretty much like yours accept a PLV flywheel and an AKRA DJ-2225 CNC Bored 0.615 carburator and I turn 6,300, does your kart feel slower than the others
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Wait you turn 6300 with stock predator cam? There isn’t any power up there.
It felt faster than everyone else but about the same speed as the guy that got first. He didn’t pull away from me I was just about 5 foot back from him and couldn’t make up the ground and I was running the fasted lane in the track. It felt like it was running out of power towards end of straight. I want it to pull harder there but without giving up my power on the restarts.
 
MO Predator Racer said:
Wait you turn 6300 with stock predator cam? There isn’t any power up there.
It felt faster than everyone else but about the same speed as the guy that got first. He didn’t pull away from me I was just about 5 foot back from him and couldn’t make up the ground and I was running the fasted lane in the track. It felt like it was running out of power towards end of straight. I want it to pull harder there but without giving up my power on the restarts.
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Have you tried a 14 61 yet
 
You can't have both .
Being that close small adjustments are best .
run the 14/60 in the 1st heat then drop a tooth each time out .
Or throw the kitchen sink at it put the 15/62 on .
 
flattop1 said:
You can't have both .
Being that close small adjustments are best .
run the 14/60 in the 1st heat then drop a tooth each time out .
Or throw the kitchen sink at it put the 15/62 on .
Click to expand...
Pretty much says it right there^^^

If you didn't gain or lose ground it sounds like it was a pretty even match up between the two of you. At that point it's really a matter of driving ability...and again, if he never pulled away and you never gained ground, it sounds even.
 
Reign-Check said:
Pretty much says it right there^^^

If you didn't gain or lose ground it sounds like it was a pretty even match up between the two of you. At that point it's really a matter of driving ability...and again, if he never pulled away and you never gained ground, it sounds even.
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Id say he should keep his gearing the same, no need to change it if your that close
 
I’m not going to pretend to know anything about that motor. But, if I was floating valves I’d drop a tooth and a time until it was happy. The motor will reach an rpm range in any gear where the increased rpm doesn’t gain much in linear speed. That’s when I need a tooth or two. Slowing the motor down with a different rear gear may produce more speed at the end of the straight.

On top of that. If you hit your tires and are able to maximize your corner speed you don’t want that gear to be slowing you down. The only time I’ve ever had my hearing that low was when we were bad through the turns and needed as much acceleration off the corners as we could get. Trying to mask outlet handling issues.
 
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