Driver 11 verses 12 question
- Thread starter dirttrax
- Start date
poboyracer
Member
I could be wrong but i believe you will lose a little torque which would help with breaking loose. Please someone correct me if im wrong.
CarlsonMotorsports
Site Supporter
You may find the 12T helping some to hook the car up better and not blow off the tires, but doubtful that you will feel the difference you are hoping for since you are not changing the final drive ratio. Keeping the same ratio and changing from 11 to 16 tooth driver would be noticeable (seat of the pants) but likely that won't be possible to fit that big of a gear on the axle and maintain the same ratio.
Try it, you may like it, you may not notice any difference. With most any change, there will be a trade-off in performance that may or may not be worth it. Will your new rear gear used with the 12T driver now be too close to the track (especially if it gets rough?)
That would be a bigger concern to me.
If you really want to keep from blowing off the tires, you can: change the final drive ratio, de-tune (lean) the engine at peak torque, change the clutch engage to be above peak torque, simply soften the clutch (make it hit less hard.) I think you would find any of these methods to be considerably more significant than simply changing 1 tooth on the driver while maintaining the same final drive ratio.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
28 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Try it, you may like it, you may not notice any difference. With most any change, there will be a trade-off in performance that may or may not be worth it. Will your new rear gear used with the 12T driver now be too close to the track (especially if it gets rough?)
That would be a bigger concern to me.
If you really want to keep from blowing off the tires, you can: change the final drive ratio, de-tune (lean) the engine at peak torque, change the clutch engage to be above peak torque, simply soften the clutch (make it hit less hard.) I think you would find any of these methods to be considerably more significant than simply changing 1 tooth on the driver while maintaining the same final drive ratio.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
28 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
alvin l nunley
Site Supporter
11/60 = 5.45
12/65 = 5.42
12/66 = 5.50
What axle gear do you have now? Can you add 5 or 6 teeth and still have adequate ground clearance?
12/65 = 5.42
12/66 = 5.50
What axle gear do you have now? Can you add 5 or 6 teeth and still have adequate ground clearance?
paulkish
old fart
I think it might help. Try it and let us know. Over the years on all the pages and pages and pages, the general consensus is it will make a difference. A difference good or bad or none at all, only you can decide and then per what ever experience you have, you may want to try it again in the future if you do not see a 'difference'.
JPMKarting
Site Supporter
With any stock animal, clone, or flathead, you arent going to see a difference in regards to "shocking" the tires
That part isnt making sense to me....if you ran 11/69 with the stocker 208cc, you should be needing more gear not less gear, for the big bore stroker, since the big bore stroker is going to make more power and at a higher rpm, with a higher peak torque than the stock engine did. What rpm do you have the clutch engaging at and what is your target rpm on the track, how big is the track, and what air pressure are you using?
A big bore Honda stroker should be making peak torque around 4400-5000rpm, maybe more or less depending on the cam and rest of the build, i would not have the clutch engaging anywhere less than 4500 if it is a true open honda big bore stroker. I had one of these engines last year that was 3" bore .175 stroker with a .356 cam and it was making peak torque around 5000rpm, turning 9500rpm on the small tracks.
alvin l nunley
Site Supporter
I can understand that, you got a lot more torque so you can run less gear. What rpm range are you seeing with the big engine? How does that range compared to the small engine?
alvin l nunley
Site Supporter
In my world, clutch engagement is always at peak torque, where does your big engine reach peak torque?
I'm impressed with that almost 5000 RPM operating range.
paulkish
old fart
Al wrote: "I can understand that, you got a lot more torque so you can run less gear."
Al, would you please give some logic or numbers on why the 'amount' of torque has anything to do with the gear you use?
I think I really don't need numbers on this to gain understanding of how the 'amount' of torque has anything to do with gearing. I think just some workbench logic would help. I'm Dumb about it and asking the question to understand instead or arguing about something I'm clueless on.
thanks
edit Al: I'm going to take a try at answering my own question not fearing my tongue on it or worrying about being wrong, hoping what's wrong will be corrected for me. It might even lead to gaining understanding of your understanding Al.
Ok... Gearing with a clutch is always two considerations, plus one more if your direct drive. The first is your gearing needs to best use your engines output between the distance from start of acceleration and to the end of acceleration. Ideally your clutch never lets your engine drop below peak torque anywhere in between those to points and your gearing allows for peak torque to occur at the start of acceleration, with the only slipping involved happening during starts.
There is also a given amount of time occurring between the start of acceleration and end of acceleration. Your gearing is actually matching up your engine output to the amount of time it takes your engine to wind up to it's max between the start of acceleration and the end of acceleration. ... ok I now think I can bring in and talk dumb about torque. I'm first going to think about hey what if I now have more torque, what will happen? My guess is if there more torque or twisting power then the engine will wind up sooner and you'll be out of engine is a gear bind before you get to where you need to finish up your acceleration. If that's the case and you need to be farther down the straight when your engine peaks out, then I'll guess you also need to take gear off when there is an increase in torque. ... if that's the case and how your thinking about it Al I do see your logic.
Did I get to your logic on why when there is a torque increase less gear will be needed Al?
... I'll wait to see before I next reply to see if I get a reply of "yes that's how I'm seeing it" from you.
By the way while writing this and it working towards the conclusion of the above sentence I realized per the information dirttrax gave us, my conclusion and if I'm thinking correctly your offering of needing to take gear off is not correct.
I'll get back in here about why I think my conclusion is not correct later giving you a chance to logic through dirttrax's input and see if you come to a different conclusion. Yes I see it as a general rule to take gear off when torque is increased, but I'm not seeing the rule if it is a rule apply in the case of this thread. I'm thinking now he should be on the same or similar gear ratio and his thoughts about a taller driver to try to keep from shocking the tires is still correct.
... yeah a lot of bull and long reading so thanks to who ever read this far and even more thanks to anyone who replies they might see my logic and how 'why' it differs from Al's. I really hope Al sees what I am about a flaw of not considering all the input from dirttrax. ?????
or, I'm just flat out wrong again. ...
Al, would you please give some logic or numbers on why the 'amount' of torque has anything to do with the gear you use?
I think I really don't need numbers on this to gain understanding of how the 'amount' of torque has anything to do with gearing. I think just some workbench logic would help. I'm Dumb about it and asking the question to understand instead or arguing about something I'm clueless on.
thanks
edit Al: I'm going to take a try at answering my own question not fearing my tongue on it or worrying about being wrong, hoping what's wrong will be corrected for me. It might even lead to gaining understanding of your understanding Al.
Ok... Gearing with a clutch is always two considerations, plus one more if your direct drive. The first is your gearing needs to best use your engines output between the distance from start of acceleration and to the end of acceleration. Ideally your clutch never lets your engine drop below peak torque anywhere in between those to points and your gearing allows for peak torque to occur at the start of acceleration, with the only slipping involved happening during starts.
There is also a given amount of time occurring between the start of acceleration and end of acceleration. Your gearing is actually matching up your engine output to the amount of time it takes your engine to wind up to it's max between the start of acceleration and the end of acceleration. ... ok I now think I can bring in and talk dumb about torque. I'm first going to think about hey what if I now have more torque, what will happen? My guess is if there more torque or twisting power then the engine will wind up sooner and you'll be out of engine is a gear bind before you get to where you need to finish up your acceleration. If that's the case and you need to be farther down the straight when your engine peaks out, then I'll guess you also need to take gear off when there is an increase in torque. ... if that's the case and how your thinking about it Al I do see your logic.
Did I get to your logic on why when there is a torque increase less gear will be needed Al?
... I'll wait to see before I next reply to see if I get a reply of "yes that's how I'm seeing it" from you.
By the way while writing this and it working towards the conclusion of the above sentence I realized per the information dirttrax gave us, my conclusion and if I'm thinking correctly your offering of needing to take gear off is not correct.
I'll get back in here about why I think my conclusion is not correct later giving you a chance to logic through dirttrax's input and see if you come to a different conclusion. Yes I see it as a general rule to take gear off when torque is increased, but I'm not seeing the rule if it is a rule apply in the case of this thread. I'm thinking now he should be on the same or similar gear ratio and his thoughts about a taller driver to try to keep from shocking the tires is still correct.
... yeah a lot of bull and long reading so thanks to who ever read this far and even more thanks to anyone who replies they might see my logic and how 'why' it differs from Al's. I really hope Al sees what I am about a flaw of not considering all the input from dirttrax. ?????
or, I'm just flat out wrong again. ...
Last edited:
alvin l nunley
Site Supporter
I'm hesitant to do that Paul, simply because of the way you have treated me, and my advice, in the past!
In any case, it's such a simple piece of advice, I'm pretty amazed that you don't understand it.
paulkish
old fart
I agree with you.
- - - Updated - - -
What ever you like Al, i'm comfortable with your reply.
Maybe Al myself and others would treat you better if you didn't have the need so often to throw in words of how your master of others by saying things like, "I'm pretty amazed that you don't understand it.".
Everyone is not against you Al.
When they/we offer differences to your understanding, they/we are only offering our understanding and when the understanding of others is different then your's it's not an attack or miss treatment it's just their ideas and thoughts.
It really does not matter if you reply to my ramblings or not you as well as I know I presented it as a lead into the error I see in your logic setting up the possibility of 'why' taking off gear in the case of what was presented, may not be needed.
Since you have no interest in responding I'm going to give what I think I see which you did not include in your statement of the need to take gear off.
What you did not include and I saw as a flaw in your offering of taking gear off is rpm increased. I think the increase in rpm may negate the need to take gear off. If that's the case which will only be proven by on track trial and not calculated numbers, then I think dirttrax's thoughts on going to a taller driver only for reasons of reducing 'shock' to the tires is correct. ... or it ain't, it's just my thoughts on it offered to help not to argue.
Al I think if you had some or more time racing dirt oval you would be more seeing of the need to be concerned about how tires are applied to the track. Sprint racing unless it's under rain conditions or unless you use sprint racing a high hp engine is not conducive to learning about how tires are applied to the track. I think Al from your input on here over the years you have little or no experience with either dirt oval or high hp engines and will have a hard time understanding variables of tire presentation.
I think I wrote enough to explain my thoughts on it to 'help' dirttrax and not start or continue banter back and forth with you. ...
paulkish
old fart
My only interest in this is if my bull has helped answer dirttrax's question.
And I have to admit another reason is I get a lot of fun out of writing, i'm retired and it's a great way to make my morning coffee more enjoyable. Even as in this case when the writing runs into the afternoon. ...
And I have to admit another reason is I get a lot of fun out of writing, i'm retired and it's a great way to make my morning coffee more enjoyable. Even as in this case when the writing runs into the afternoon. ...
You guys def put some thought into and have me rethinking it also. One thing I should have mentioned I guess is this particular track is stop and go. its short tight turns you really can keep momentum up unless your out front.
As far as peak torque of motor I don't know because I built the motor not someone who has a dyno. The kart timed in 2nd fastest of the night and I believe could easily turn the fastest lap if I can hook it a little better. Which it has been on the scales this week to see if that helps and brings down top rpms. I went ahead and set my spare clutch up with a 12 driver to try also. Should have more info in the morning. Thanks.
As far as peak torque of motor I don't know because I built the motor not someone who has a dyno. The kart timed in 2nd fastest of the night and I believe could easily turn the fastest lap if I can hook it a little better. Which it has been on the scales this week to see if that helps and brings down top rpms. I went ahead and set my spare clutch up with a 12 driver to try also. Should have more info in the morning. Thanks.