Ratios....Not a Debate

Wacomike04

Member
So......

My question is what does a higher ratio do? Please don't use "tip top flip flap".....like it starts slow and then has a higher top speed and slower out of the corners, etc. Thing is.....other folks at the track take off faster than me, then after a lap of getting up to speed they eventually pass me. Here's the kicker....they run wide open....I have to let off middle of the two turns to keep'er from getting loose.

What does a higher ratio do.......and what does a lower ratio do in words a beginner can understand please. And how do I find out what the middle ground is for a 1/8 mile dirt oval track is. That's what one guy said, "you gotta find the ratio for acceleration AND top speed"

Thanks,
Michael Frizzelle
 
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paulkish

old fart
What ever gear ratio you have on, your job is to do setup and driving so efficiently that you can't go any faster without either taking some gear/teeth off the axle or putting more on the clutch.

Doing the above in general will cause slower starting with higher top end.
How much of each depends again on how efficiently you get around the track.
 
^^^ this is True.
Its just like your vehicle low gets you going high gives you top speed .
Its all about potential.
If your letting off in two corners gear ratio isn't really the problem .
Well it could be... If he has a 4.11 and is just getting going the last half of the straight and everyone else is on a 4.50 it very well could be the problem. People come to me and ask a question about something racing related and i usually have 10 other questions back to them before they can get an answer out of me.
 
And i always clarify what higher or lower means to someone. Higher or lower number? Higher or lower teeth on the back? 4.50 vs 4.30? My dad says put a higher gear in it or put some more gear to it so they can catch them at the end of the straight away and then proceeds to tell me to put teeth on the back.
 

flattop1

Dawg 89
Quote the op . Though something is off , Here .. (....other folks at the track "take off faster than me, then after a lap of getting up to speed they eventually pass me.". ... Here's the kicker....they run wide open....I have to let off middle of the two turns to keep'er from getting loose.)
Here's where the questions start . ;)
 

paulkish

old fart
Don't know if this answer is correct or not but you asked what is a middle ground for you to start with for an 1/8 mile track.

I'll start off the suggestions by saying middle ground for you is 14/65.

... Next answer/suggestion and why am I wrong about the 14/65 ?
I don't mind being wrong and learning from it
.
 

OVALTECH1

Site Supporter
Paul … I’d have to first ask … am I sure my setup is dead on… is this an 1/8 mile momentum track with big sweeping turns or an 1/8 mile one lane paperclip that pinches down to the bottom in the turns … what engine combo … what weight …. This could go on forever with just the list of questions 😂
 

paulkish

old fart
Paul … I’d have to first ask … am I sure my setup is dead on… is this an 1/8 mile momentum track with big sweeping turns or an 1/8 mile one lane paperclip that pinches down to the bottom in the turns … what engine combo … what weight …. This could go on forever with just the list of questions 😂
I have no clue. I threw an answer out there to try to get help answering his question
.
 

flattop1

Dawg 89
Wakomike if your still on a 13/65 the 14/65 will give you more speed providing you can maintain the rpm on track .
 

sundog

Member
If your rear gear is too small you'll spend all your time getting up to top speed. When you finally get to top speed you'll be on part of the track where you don't want that speed so you have to lift. You want to set your gear so your top speed happens where you need it. When you put on a bigger rear gear your top speed will be lower but you'll get to top speed faster and be able to use all that speed and flat foot it all the way.
 

Surveyor

Member
That is true, I run the box stock class and think of it a little different because I have a governor that stops my engine speed. If the rest of the class is taking off faster than you maybe you need a bigger rear gear or even a smaller front gear. That will increase takeoff and lower the top end so you may not need to lift in the corner.

I would give track, class, tire info and some scale numbers and see if someone on here smarter than me could get you close.
 

Wacomike04

Member
I am home now.....

So it's 1/8 mile.....line runs 2/3 up the straights to mid track halfway through the turns to a low pass exiting. High banked. Owosso, MI is the track. OMP.

Weighed my kart on house scales and then turned the Kart around and weighed it again on even pavement and the numbers were so different, it wasn't worth it. Just finished the year, finished 2nd the last race, but I earned it through aggressive driving and blocking. Not aggressive to other drivers, just the track.

I was racing a 13/57 in practice to a 13/64 by the feature. I am 430 in clone heavy total weight. My tire prep consists of black sand Wednesday and Friday...then drpw the day of the race. I also resurface the tires with 80 grit flap sander.

I have a feeling my setup isn't right and my tires are the problem. I watch other races and they never let off either.....I can't do that. I know my engine is very powerful, sometimes I think too powerful. I raced my first 6 races ever this year and have been up the 15s, 14s, and now 13s... I can't find the magic sweet spot to run wide open.

So I am leaning to chassis setup and tires is the problem. You can't through 350 laps of practice, qualifying, heats, and features have run every single lap wrong. Expert Folks watching say I run solid lines. I just can't figure out which ratio/gear combo will let me run wide open.

Like I said.....I am down to needing to buy 1000s of $$ on rotisseries and prepping tires as well as chassis setup.

Thanks for your input.

I use the app Iraceweigh to input my scale numbers and I do have the 2005 prc phenom manufacturer suggested setup sheet.

I only have problems exiting when accelerating. So by the end of the race I enter 1 and 3 coming off the gas almost all the way.

Question: Am I supposed to stay full throttle and apply the brake at the same time? Would this hold my rpms up or ruin my brakes faster?

Tires are the typical maxxis....pink outside....blue inside. Can't remember the sizes, but it's the same as ev1 else. Rear stagger is 1.25"....front is 1", same as the top guys have for stagger. Camber and caster setup just like manufacturer suggests. I was told to drop the spindle on both sides front by 3 washers, which I have not done yet.
 
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racing promotor

Moderator
I am home now.....

So it's 1/8 mile.....line runs 2/3 up the straights to mid track halfway through the turns to a low pass exiting. High banked. Owosso, MI is the track. OMP.

Weighed my kart on house scales and then turned the Kart around and weighed it again on even pavement and the numbers were so different, it wasn't worth it. Just finished the year, finished 2nd the last race, but I earned it through aggressive driving and blocking. Not aggressive to other drivers, just the track.

I was racing a 13/57 in practice to a 13/64 by the feature. I am 430 in clone heavy total weight. My tire prep consists of black sand Wednesday and Friday...then drpw the day of the race. I also resurface the tires with 80 grit flap sander.

I have a feeling my setup isn't right and my tires are the problem. I watch other races and they never let off either.....I can't do that. I know my engine is very powerful, sometimes I think too powerful. I raced my first 6 races ever this year and have been up the 15s, 14s, and now 13s... I can't find the magic sweet spot to run wide open.

So I am leaning to chassis setup and tires is the problem. You can't through 350 laps of practice, qualifying, heats, and features have run every single lap wrong. Expert Folks watching say I run solid lines. I just can't figure out which ratio/gear combo will let me run wide open.

Like I said.....I am down to needing to buy 1000s of $$ on rotisseries and prepping tires as well as chassis setup.

Thanks for your input.

I use the app Iraceweigh to input my scale numbers and I do have the 2005 prc phenom manufacturer suggested setup sheet.

I only have problems exiting when accelerating. So by the end of the race I enter 1 and 3 coming off the gas almost all the way.

Question: Am I supposed to stay full throttle and apply the brake at the same time? Would this hold my rpms up or ruin my brakes faster?

Tires are the typical maxxis....pink outside....blue inside. Can't remember the sizes, but it's the same as ev1 else. Rear stagger is 1.25"....front is 1", same as the top guys have for stagger. Camber and caster setup just like manufacturer suggests. I was told to drop the spindle on both sides front by 3 washers, which I have not done yet.
Which chassis manufacture ? year and mode;l ? I assume fllat kart open no cage ?
 
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