Track Tac

A GO TO thread for the new or newer dirt oval racers offering Info & Support

Some Tips for the Stock Predator racers ( our rule here is governor in tact and 5500 max rpm rule )

This class with this motor ( less power ) is ALL about MOMENTUM ( which is important in all classes but especially predator ), Good Handling set-up on the edge of being to free, being Smooooooooth on the wheel is a must and never mash breaks or totally get out of throttle except for caution of course, Learn throttle control slight burbs where needed will help keep momentum. Stay Focused on MAXIMIZING MOMENTUM EVERY GREEN FLAG LAP !!
Gearing is more critical in this class than any other I've seen, In general If your track runs Sr Clones or even Flatheads the Front driver on the clutch will be 2 for sure AVG 3 and sometimes 4 sizes BIGGER than those classes, EXAMPLE Some Tracks around here Clones are 14/62 or 15/66 Predator guy's are best on 17/62 or what's winning most is 18/66, another Track is 16/65 for Sr Clones and a 20 front driver is best, the more natural Momentum the Track makes because of it's grip level and shape will dictate the biggest difference in front driver. Kart will take off little slower,
( bouncing in your seat a few times will help get it rolling ).
In general Air Pressures will be DOUBLE even more than the SR Clone classes, Example again here one track is 4 to 5 lb max on 11's and Predator class is 9 to 10 lb on 33's ( per rule ) so even with lower grip track using 11's prepped hard, you get away with 33's yes still prepped hard BUT double the air, the MORE that track would grip up the more pressure they would use maybe as much as 2 to 3 lb above double.
This INFO is based on Burris Slicks IF treads it will still be higher but maybe not quite as much, I've never run slicks to know comparison for sure.

SO What I'm telling you here guy's in predator classes GO rub shoulders with the fast Clone guy's and get as much of there gearing & tire info as possible.

Again experienced guy's feel free to chime in, Maybe a Clutch guy could give Clutch Engagements one If Shoe & one If disc, I think I read in general it's around 2600 rpm.
 
Clutch Maintenance - Disc Clutch

There are a variety of disc clutches on the market, but they all work off the same basic principle...centrifugal force at a certain RPM locks the discs together to create direct drive.

The key to a clutch that works at its maximum is tolerances and regular maintaining. Below are some very basic measurements to keep an eye on when it comes to how the clutch should be set up:

-New friction discs are app. .125 thick when new. When they get down to .110, it's time to replace them.
-The center floater plate varies from .065-.105 thick. While this plate wont really "wear" it can warp due to excessive heat.
-The air gap (distance between the discs and pressure plate) should be app. .035 thick. Every clutch is a little different in what it likes, but .035 is a very good base. Once it gets to .055 or more (from the discs wearing) its time to rebuild.

Spring Heights:

The springs on the clutch are what adjust the engagement RPM. Counter clockwise decreases RPM engagement...clockwise increases. Clutchs will vary on how many RPM is changed per 1 turn, as well as the thickness of the spring and the amount on the lever, but below are some "target" engagement RPM's to shoot for depending upon engine:

Flathead: 3800-4000
Animal: 3700-3900
Clone: 3600-3800
Predator: 2600-2800

Again, these are just starting points, not absolutes. Consult a clutch builder or your manufacturer for more specifics on RPM, springs, and weight.

Below is a very simple procedure to maintain your clutch week to week:

-Remove the clutch from the engine, as well as the end snap ring and basket. NEVER use water on any clutch components.
-Visually inspect for wear (ex. crack in the drive hub, bent/stuck levers, basket wear, driver wear, etc)
-Wipe off any excess dirt/grease
-Spray clutch with brake cleaner in between the discs to remove any dirt/oils/etc. Blow dry with compressed air
-Repeat the same process for the basket. The basket should have very little, if any "grey" dust/dirt under the basket. If it is covered in black, you are using too much grease on the bearings
-Remove the needle bearing from the driver and the flat bearing on the drive hub, spray with brake clean and blow with compressed air
-LIGHTLY use a thin coat of grease to cover the needle bearing for the driver, and the flat bearing on the drive hub. LIGHTLY dab a little bit of TriFlo or WD40 after grease is applied, and rotate the bearings to work it in. Wipe off any excess
-Re-assemble

Utilize a set of feeler gauges to check the air gap for wear, and you can use either a dial indicator OR a spring height gauge to check the spring height. Make sure springs are all the same...variable heights will cause uneven lock up and wear.

Again....this is all a very basic tutorial and guide for the beginner. It is always helpful to have your clutch built by a reputable builder (shameless plug) to make sure you have a good base to start with and that you arent trying to polish a turd.
 
Love the idea of this thread. First thing I check when I get on now. A man can drain his pocket and never see the front of the pack without some of this knowledge that is so basic to veterans its like second hand nature. People always say ask the fast guy at the track, which works with some stuff, but no "fast guy" has the time to give you the full run down of this stuff for 20 minutes before hotlaps. Always gotta have some good old fashion trial and error, but boy can this stuff help! Much appreciated from a rookie like me fellas!
 
I'll offer one small bit of advice.

You can only win the races you finish.

The first goal must be to reach the checkered flag.
Start by finishing consistently.
Then work on speed. This will help learning curve immensely.
Championships are won by driving under the checkers every week, no matter where you finish in the order.
 
XXX#40 said:
4 foot level held square against the RR tire, make sure the rim isn't bent
Click to expand...

BINGO !! Remember it's OK if the fronts are offset in, just take measurements on both sides of front wheels where rim is true, then square which ever side you choose most square the right side and toe the left.
Heads up IF the level hits the body side panel just put a short 2x4 block against rear wheels then pinch level against block.
 
how about some tips on drum clutches? I feel like most beginners are going to start on a drum before dropping coin on the disc style.

JPMKarting said:
Clutch Maintenance - Disc Clutch

There are a variety of disc clutches on the market, but they all work off the same basic principle...centrifugal force at a certain RPM locks the discs together to create direct drive.

The key to a clutch that works at its maximum is tolerances and regular maintaining. Below are some very basic measurements to keep an eye on when it comes to how the clutch should be set up:

-New friction discs are app. .125 thick when new. When they get down to .110, it's time to replace them.
-The center floater plate varies from .065-.105 thick. While this plate wont really "wear" it can warp due to excessive heat.
-The air gap (distance between the discs and pressure plate) should be app. .035 thick. Every clutch is a little different in what it likes, but .035 is a very good base. Once it gets to .055 or more (from the discs wearing) its time to rebuild.

Spring Heights:

The springs on the clutch are what adjust the engagement RPM. Counter clockwise decreases RPM engagement...clockwise increases. Clutchs will vary on how many RPM is changed per 1 turn, as well as the thickness of the spring and the amount on the lever, but below are some "target" engagement RPM's to shoot for depending upon engine:

Flathead: 3800-4000
Animal: 3700-3900
Clone: 3600-3800
Predator: 2600-2800

Again, these are just starting points, not absolutes. Consult a clutch builder or your manufacturer for more specifics on RPM, springs, and weight.

Below is a very simple procedure to maintain your clutch week to week:

-Remove the clutch from the engine, as well as the end snap ring and basket. NEVER use water on any clutch components.
-Visually inspect for wear (ex. crack in the drive hub, bent/stuck levers, basket wear, driver wear, etc)
-Wipe off any excess dirt/grease
-Spray clutch with brake cleaner in between the discs to remove any dirt/oils/etc. Blow dry with compressed air
-Repeat the same process for the basket. The basket should have very little, if any "grey" dust/dirt under the basket. If it is covered in black, you are using too much grease on the bearings
-Remove the needle bearing from the driver and the flat bearing on the drive hub, spray with brake clean and blow with compressed air
-LIGHTLY use a thin coat of grease to cover the needle bearing for the driver, and the flat bearing on the drive hub. LIGHTLY dab a little bit of TriFlo or WD40 after grease is applied, and rotate the bearings to work it in. Wipe off any excess
-Re-assemble

Utilize a set of feeler gauges to check the air gap for wear, and you can use either a dial indicator OR a spring height gauge to check the spring height. Make sure springs are all the same...variable heights will cause uneven lock up and wear.

Again....this is all a very basic tutorial and guide for the beginner. It is always helpful to have your clutch built by a reputable builder (shameless plug) to make sure you have a good base to start with and that you arent trying to polish a turd.
Click to expand...
 
racinnut15xm said:
Thanks guys I don't have a 4ft level but I've got some steel tubing I will give that a go.
Click to expand...

steel tubing would be shaky fluorescent light tube is going to be perfectly straight .
ok steel tube or round ;is going to take some finesse . you will need to have a good visual of what you want .
IE: parallel or toed out closer in the front then the rear . alternatively you could use a shim this still requires good visual or lots of shims .
a dri-wall square would be a good option , 4' level has more uses . so a good investment.
scribing the tire's and using a tape is about as simple as it gets. this method is fine albeit it does not address the squaring of the rr and rft.
doing this with the level then measuring the toe out on the lft frt. imho will result in the least error and best option.
 
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There are a lot of Kart shops that will have everything you need to setup your kart. And will be happy to help you. For small fee they will set everything you need set. If you don't have the equipment. Or local engine builder often offer other services. Talk to to the vendors at the track.
Or other races that you meet there.
 
4ft levels are cheap, now I don't fully trust a cheap mass produced level for my job, but for setting toe it will be ok.
 
racinnut15xm said:
how about some tips on drum clutches? I feel like most beginners are going to start on a drum before dropping coin on the disc style.
Click to expand...

Unfortunately we don't do any shoe clutch racing, and since I don't like giving advice on something that I don't do, I can't be of any help when it comes to shoe clutches.
 
JPMKarting said:
Unfortunately we don't do any shoe clutch racing, and since I don't like giving advice on something that I don't do, I can't be of any help when it comes to shoe clutches.
Click to expand...

No worries. Carlson gave me a lot of good advice in another thread. I would say it could be copied and pasted here by an Admin.
 
Quick gearing question. Just started racing last year and only had a tac for the last 3 races. Never really understood the ins and outs of it. How could someone best describe the relationship between RPMs you're running and gearing? Is the goal to stay as close to the max RPM of the motor (AKRA unrestricted in my case)? How much RPM drop in the corners is too much? When to make an adjustment based off of what the tac is reading and what adjustment? thanks
 
UMAX#10 said:
Quick gearing question. Just started racing last year and only had a tac for the last 3 races. Never really understood the ins and outs of it. How could someone best describe the relationship between RPMs you're running and gearing? Is the goal to stay as close to the max RPM of the motor (AKRA unrestricted in my case)? How much RPM drop in the corners is too much? When to make an adjustment based off of what the tac is reading and what adjustment? thanks
Click to expand...

RPM range is going to be based upon the engine build, and RPM drop will be dictated by track layout. I know most clone builders like the peak RPM to be in 6600-6800 range.

Are you wide open around the track, or are you lifting a lot?
 
JPMKarting said:
RPM range is going to be based upon the engine build, and RPM drop will be dictated by track layout. I know most clone builders like the peak RPM to be in 6600-6800 range.

Are you wide open around the track, or are you lifting a lot?
Click to expand...

Wide open. It is a small 1/8 or 1/9 or so track, but carries momentum through corners. Usually only see the AKRA guys lift and instantly go right back to it on entry of corner, if they lift at all.
 
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