Track Tac

Gearing for plates

T

TritonJrBluePlate

Member
So this has been on my mind all year.

Was told to run a 4.5 ratio on a clone un-restricted and drop two teeth for a blue plate class at the same track.

My general thoughts are the restricted plate motor would need less gear to maintain the speed and help drive off the corner. However, I’ve been told by some successful folks that I got it backwards. The plate will need more more gear for the targeted rpm for a plate is less that in restricted.

Thoughts and comments
 
SoCo Tire Treatments said:
Gear for what the particular track calls for, for whatever class you race in. You overthink things too much, do whats needed to go fast and keep it as simple as that.
Click to expand...
AMEN !! Let your stop watch dictate what's best, then let that lead you to your tach check your rpm feed back and your drops, the 2 less rear teeth for blue plate than Sr Clone unrestricted is a starting point, however I'll say this I've monitored I'll just say A LOT of blue plate races , and helped win A LOT of blue plate races , and A LOT of the time the blue plate front runners are 2 teeth less on the rear than Sr Clone, Example at our 1/8 th mile here Sr Clone is 14/60 turning 6850 to 6950, and Blue plate is 14/58 turning 6500 to 6600. To many people chase gearing and H.P when they should be chasing TIRES !!
 
You can say I “Over Think” things. I’d much rather overthink things than blindly play follow the leader. Our success during our two years of racing is a result of Independent thinking.

All this stop watch stuff is all good and fun to post on this page. Sure lap times tell you everything. Lap time comments trump every thing. However, it’s only as good as the track is consistent. Lap Times doesn’t explain “why”.

This weekend we will get on the track for Hot Laps, Qualifying and feature. This track is going to be completely different in each of the three stages. Then when I go back it’ll be different again. I can adjust gearing based on my tach while at the track. That’s the easy part.

Maybe I mis-typed the question. I wasn’t asking when and why to change my gearing. I’d like to know the theory of why a plate needs a bigger gear. Seems like a weaker motor would require less gear if anything.

What are the dynamics that occur that allows better lap times with the bigger gear?
 
TritonJrBluePlate said:
You can say I “Over Think” things. I’d much rather overthink things than blindly play follow the leader. Our success during our two years of racing is a result of Independent thinking.

All this stop watch stuff is all good and fun to post on this page. Sure lap times tell you everything. Lap time comments trump every thing. However, it’s only as good as the track is consistent. Lap Times doesn’t explain “why”.

This weekend we will get on the track for Hot Laps, Qualifying and feature. This track is going to be completely different in each of the three stages. Then when I go back it’ll be different again. I can adjust gearing based on my tach while at the track. That’s the easy part.

Maybe I mis-typed the question. I wasn’t asking when and why to change my gearing. I’d like to know the theory of why a plate needs a bigger gear. Seems like a weaker motor would require less gear if anything.

What are the dynamics that occur that allows better lap times with the bigger gear?
Click to expand...
Comparing 100 % apples to apples, it doesn't. Guess we're different if I know what works, and when it works, I could care less why !!
 
I wonder if the confusion is in wording or interpretation. So example, the 4.5 ratio is a 14/63. Dropping 2 teeth is 14/61. That ratio is 4.35(smaller gear/smaller ratio). The 14/61 will have more top end with the same setup. But if the blue plate can not turn the same rpm as an unrestricted it will need the smaller gear(drop 2 teeth) in order to go the same speed. I don't know for sure on all this. chiming in to understand also. the Blue plate weight is less so it has a chance at getting up to speed with the smaller gear. I've heard often to keep the engine in its power band and to let it keep pulling....go beyond and your losing. When i look back thru the mycron at our fastsest races, i see our lowest rpms and lowest drops.
 
So here is my interpretation. The gearing has a lot to do with the restriction of the carb. So dropping 2 teeth on the rear will make the engine get up to target rpm quicker. It is just like when you drop the front driver to get off the corner quicker and get up to speed faster. If I am wrong let me know.
 
TritonJrBluePlate said:
So this has been on my mind all year.

Was told to run a 4.5 ratio on a clone un-restricted and drop two teeth for a blue plate class at the same track.

My general thoughts are the restricted plate motor would need less gear to maintain the speed and help drive off the corner. However, I’ve been told by some successful folks that I got it backwards. The plate will need more more gear for the targeted rpm for a plate is less that in restricted.

Thoughts and comments
Click to expand...
I'd be interested to hear what explanation of WHY the people that told you 2 more teeth gave you.
 
Maybe I mis-typed the question. I wasn’t asking when and why to change my gearing. I’d like to know the theory of why a plate needs a bigger gear. Seems like a weaker motor would require less gear if anything.

What are the dynamics that occur that allows better lap times with the bigger gear? ::::..
_------_-------------------------------------------------
I can't say i have ever seen more gear recommend.
racing promotor said:
I'd be interested to hear what explanation of WHY the people that told you 2 more teeth gave you.
Click to expand...
 
Habanero tires said:
I wonder if the confusion is in wording or interpretation. So example, the 4.5 ratio is a 14/63. Dropping 2 teeth is 14/61. That ratio is 4.35(smaller gear/smaller ratio). The 14/61 will have more top end with the same setup. But if the blue plate can not turn the same rpm as an unrestricted it will need the smaller gear(drop 2 teeth) in order to go the same speed. I don't know for sure on all this. chiming in to understand also. the Blue plate weight is less so it has a chance at getting up to speed with the smaller gear. I've heard often to keep the engine in its power band and to let it keep pulling....go beyond and your losing. When i look back thru the mycron at our fastsest races, i see our lowest rpms and lowest drops.
Click to expand...
Habanero tires said:
Blue plate weight is less so it has a chance at getting up to speed with the smaller gear. I've heard often to keep the engine in its power band and to let it keep pulling....go beyond and your losing. When i look back thru the mycron at our fastsest races, i see our lowest rpms and lowest drops.
Click to expand...

When you say “drop two teeth” that is actually going up in gear. Ratio is lower but gearing is a taller gear. (Less rpm, more top end)

Smaller rear gear is actually bigger gear.

I do think you hit on something with the power band. I don’t think a plate motor can turn the same rpm’s. So the bigger gear may be easier to minimize the drops as you mentioned.

I just have a hard time understanding how less power needs more gear. 🤷🏻‍♂️
 
TritonJrBluePlate said:
When you say “drop two teeth” that is actually going up in gear. Ratio is lower but gearing is a taller gear. (Less rpm, more top end)

Smaller rear gear is actually bigger gear.

I do think you hit on something with the power band. I don’t think a plate motor can turn the same rpm’s. So the bigger gear may be easier to minimize the drops as you mentioned.

I just have a hard time understanding how less power needs more gear. 🤷🏻‍♂️
Click to expand...
You have your karting terminology backwards, smaller ratio than a ratio you had is dropping gear (smaller gear), larger ratio than what you had is adding gear (taller gear).
Reason is its a restricted motor with much lighter weight, so it dont need the amount of gear an unrestricted would since theres so much less weight. Weight makes a lot of difference here, ever notice that lots of times blue plates are about same in lap times.
 
To add some clarity, a blue plate on the dyno will make the meat of it's torque and power curves significantly lower (500 or so) in rpm than an unrestricted engine of the same platform. It doesn't make sense to turn it any higher rpm than it makes good power in. Likewise, a purple, red, green plate, etc all make power at even less rpm, so in turn they will need geared accordingly.
Like someone else said, I don't think I've ever seen, (or heard) someone suggest adding teeth to the rear gear on a plate engine over adult class gearing. If someone suggested that, I'd question everything else they suggest as well. Don't be so easily offended by my suggestion to follow your stop watch. You know, it's not wrong. ;)
 
No rhyme or reason I’m finding. Just do what works. On Friday nights we run a local track. We’ve won 50% of the blue plate races. We are consistently on a 12/63. We set pole every Friday. Last week we decided to run adult medium. (No one in lite) we added 30lbs. And ended up on a 12/59 in unrestricted. BTW we set pole.

With that said. Tires are key
 
Just because your able to win with running a certain set up, or gearing combo does not mean your maximizing your potential speed
 
Just because your winning don't find yourself not searching for more speed , chase the
stop watch especially with tires, even if you are on perfect gearing now for every 3th quicker you can go would require removing 1 tooth off the rear.
Good example of this is local points racer winning a lot on a regular Friday or Saturday night points show thinks they got it figured out, the go to a money series race or a state series race and get there butt served up to them on a silver platter.
 
You must log in or register to reply here.
Back
Top