disc clutch adjment

jstrawser

jstrawser

Member
just started running a disc clutch on our clone to get a lower rpm engagement do I turn more or less tension on the 5 springs I think the guy told me to back the springs off a little for the clone class the clutch is a Horstman x5 2 disc thanks for any suggestions
 
just remember that when you loosen the springs, the engagement rpm goes down. with the lock up rpm going down, it's going to take you longer to reach your top speed....because the engine will engage at say 3500 rpm, while everyone else is reaching 4500 rpm and hitting lockup....so you have to lug along until the engine rpm climbs up to what everyone else is already at. i did this thinking it was the way to go...took me about a lap and a half to get up to speed while everyone else was already at top speed. reset mine to come in at about 5000 rpm and starting running up front instead of being left at the starting line....
 
my driver floors it just before the green and holds the kart back with the brake then she lets off the brake ,, I saw 3 clones all break rods when they had the real high stall speed set up one of them did it leaving the grid all 3 were new engines @ 600.00 each ... thank you for your resp.
 
3 engines had rod failure because of clutch rpm engagement !? that sounds a little hokie to me sorry. Not looking for trouble here . but were these out of the box engines or had they been gone through by a builder ??
 
If the clutch is holding the engine at peak torque, (and remember, HP is a calculation) that torque is transferred to the rear axle through the chain. If you have maximum torque at the rear axle, you have maximum HP at the rear axle. This is while the clutch is slipping. Torque X RPM / 5252.1 equals HP. You need to know at what rpm your engine reaches peak torque.

There is a trick called the scale trick. You put a bathroom scale between the front of your kart and a strong wall. With the driver in the kart, warm up the engine, give it the gas. Read the weight number on the scale and the rpm of the engine. Write them down. Change the engagement RPM of the clutch. Try again. The highest reading on the scale is where you want your clutch set.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
By the way, holding the brakes while giving it full gas, will raise the internal temperature of the engine, which is good, heat is power. We did it with the two cycles also.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
alvin l nunley said:
If the clutch is holding the engine at peak torque, (and remember, HP is a calculation) that torque is transferred to the rear axle through the chain. If you have maximum torque at the rear axle, you have maximum HP at the rear axle. This is while the clutch is slipping. Torque X RPM / 5252.1 equals HP. You need to know at what rpm your engine reaches peak torque.

There is a trick called the scale trick. You put a bathroom scale between the front of your kart and a strong wall. With the driver in the kart, warm up the engine, give it the gas. Read the weight number on the scale and the rpm of the engine. Write them down. Change the engagement RPM of the clutch. Try again. The highest reading on the scale is where you want your clutch set.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
Click to expand...

Also a good way to burn out engine components and clutch discs...
 
JPMKarting said:
Also a good way to burn engine components and clutch discs...
Click to expand...
you might think so, and it could be true, but not if you're careful. You don't want to mash the pedal down and then go looking for a pencil. When you pull out of the pits you've got it floored, nothing gets burned up right? Same thing with the scale test. If you use your head nothing will go wrong. It only takes 2 to 3 seconds. Less time than pulling out of the pits with the gas floored. You just heard him say his driver holds the brake on the starts. Same thing with the scale.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
alvin l nunley said:
you might think so, and it could be true, but not if you're careful. You don't want to mash the pedal down and then go looking for a pencil. When you pull out of the pits you've got it floored, nothing gets burned up right? Same thing with the scale test. If you use your head nothing will go wrong. It only takes 2 to 3 seconds. Less time than pulling out of the pits with the gas floored. You just heard him say his driver holds the brake on the starts. Same thing with the scale.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
Click to expand...

When you pull out of the pits, the kart is rolling. Even if you hold the brake coming to the green, the kart is still rolling. Driving it against a scale and a solid wall, nothing is moving. Even if you do your "test" for 3 seconds at a time, and do it 5 times to find the "optimal" setting, thats 15 seconds of holding the throttle down going nowhere.

Clutch builders love this idea, your wallet will hate it :)
 
JPMKarting said:
Even if you do your "test" for 3 seconds at a time, and do it 5 times to find the "optimal" setting, thats 15 seconds of holding the throttle down going nowhere.
Click to expand...
using a false premise to prove a point will get you nowhere. Obviously, after three seconds, the clutch is going to be very hot. You're going to have to cool it off, pull it off the engine, and change the engagement settings. It does not equal 15 seconds of going nowhere. It's five individual times of three seconds. That is if it takes five times. And it makes little difference that you're going nowhere.

I've got an idea, instead of bench racing, why not try it?

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
I've got an idea, instead of bench racing, why not try it?
Click to expand...
Seriously, Al? This coming from the guy who hasn't raced in years and is easily offended when someone challenges one of your statements or suggests that you actually put one of your theories into practice. Sometimes I think you go out of your way to look for an argument. Most of us appreciate your input, but this statement was uncalled for.

While I personally don't particularly care for Al's scale idea -- it would actually give you an idea of where your clutch stall is. At least it's a fun experiment to do with the kids to show how you can measure output. How repeatable the "experiment" is would prove if the data is valuable or not. No, a bathroom scale is not a chassis dyno, nor is it as accurate, but it could give you some pleasure in trying it for yourself.



-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cuts
www.CarlsonMotorsports.com

Celebrating 25 years of service to the karting industry
765-339-4407
bcarlson@CarlsonMotorsports.com
 
You must log in or register to reply here.
Back
Top