SlowerThanYou

Detonation & that plug is showing pieces of piston on it also.

It can be put on the tires, but you will pick-up everything in the pits. For street racing we put it in a small squirt bottle and put a little across the front of the tires. A small burnout will apply it.

We run a 17 tooth lightened/drilled front sprocket. It has over 200 runs on asphalt & over 100 runs on sand. It hasn't broken yet.

This post is getting ahead in the subject of clutch tuning. Actually I should have put before the inspection & maintenance portion. Here's a Dyna DRL 3000 diagram for setting up a launch limiter. I've never used this set-up before, but know many that have. Our's is a built in feature of our Dyna ignition. I forgot you need a switch clutch lever to trigger the limiter. Hint, get the adjustable switch one. I does make a difference if you adjust it right. More on this later.

Here's a Dyna DRL 3000 diagram for setting up a launch limiter. I've never used this set-up before, but know many that have. Our's is a built in feature of our Dyna ignition. I forgot you need a switch clutch lever to trigger the limiter. Hint, get the adjustable switch one. I does make a difference if you adjust it right.

OK

We have the launch limiter feature on our Dyna ignition. If you are running a stock ignition you can add on a dyna launch limiter. I can find you the part # & instructions depending on what you are running. As for your clutch slip. You provide the installed hieght of your springs ( I can walk, talk & picture you through it), LOL! Then provide your springs & I can baseline your primary pressure. Then provide you with a recommended base pressure. Or, if you want to in the off season send your set-up to me & I'll baseline line/set-up the recommended tune up free of charge. You pay the shipping/parts.

While I don't race on 500' dirt with Knobbie tires. I do have some things in common with Brad's situation. We have a 7mm cub on C14 race gas, no additives or nitrous. While most of our set-up knowledge is 1/4 mile asphalt. We have also had good success with 330' street legal drags, 300' sand & sand hill shooting. We have used our clutch tuning experience in all them situations. The 330' street drags are our worst traction nightmare. It helps equalize different motor sizes, bigger isn't always better! Anyway, by watching a few of 332's videos. He has a traction nightmare to deal with. Will the clutch tuning totally solve the problem; no, but it will help lower the ET. Brad & I have discussed some basic clutch tuning recently. I'm pretty sure we could lower his ET with a few basic adjustments. I would like to see a launch rpm limiter added also.

We have never broken a fiber or steel, but had cracks start on the steels. As for clutch chatter, I prefer to fix the problem with the primary weight or arm weight. It can also be fixed with tire pressure, launch rpm change and wheelie bar hieght to name a few. It's good to know your fix for the problem. I agree & use heat cycled steels with proper inspection/conditioning. Inspection & maintenance among other things leads to a good running race vehicle. The majority of maintenance problems can be solved at home & not at the track (preventive maintenance). We race other forms of motorsports & use what worked there for our quads. It's not just about the clutch, it applies to the overall race vehicle set-up!

Neutral down trans

Getting into the inspection phase of the steels. The steel on the left has plenty of heat in it, but is still usable with inpection & conditioning. As you can see I did a little bit of conditioning at the top. This plate will be used after being measured, inspected for cracks & conditioned to a certain roughness. This plate shows the heat we used to have in our clutch pack, more than what we want! The plate on the right is getting close to what we want. This is accomplished with modifications within the clutch assembly, using synthetics, coatings & different materials. Our most recent changes have our steels coming out with no color showing after 30-40 runs. These are our aluminum plates that are cryo'd & hard coated. The one on the left has 10-20 runs on it, basically broken in. The right plate has around 150 runs on it. I still think I can get another 100 passes out of the right plate.

Between this post & your PMs I have a few ideas on your situation. I really need more information to better pin point the problem, but I'll work with what info I have. It sure sounds like you are slipping the clutch down track. I weighed a bolt/nut & got 8.7 grams, but they all weigh different. It would help if we had your weight #s. The best way to test this is with your track mph #s. What's your mph with only the 3 bolts & nuts? I'm thinking you should be running mid-high 90s for mph? I think you already have your problem figured out, not enough arm weight. Do not put on too much wieght, there's a fine balancing act going on with the set-up.

Ours, 443 Cub on race gas HP unknown. 535 builder's shop bike, I'm sure more than mine.

4th

When we ran the dunes flats/hill our best gearing combo for 1st gear launches was a 16/41. That was with a 72 RO 14 paddle hauler. Our bike was set-up a little different than now. Same motor/frame, the swingarm was a +8 from the current +14. I was 220-230 lbs then. We gauged our performance off a name builder's shop bike (535 Cheetah on alky). The first time running against that shop bike we beat it 3 out of 3 times by 1 - 1 1/2 bike lengths. Next time out against the same bike we lost 3 out of 3 races by the same margin we had beat them by. The only change we had made between them races was a rear sprocket change. We had went to a 40 on the rear from the 41.

Correct, with a bar. We also ran this motor & stock chassis on the dunes. It was set-up a little different, but we still used the 1st gear launch.

60' timers is the ideal way to dial in the set-up. 1st gear can work very well for heavy rider's, putting on a 165 lb rider slows the combo down. We are going to try a 2nd gear launch with a different trans. We run a 7mm cub on race gas, stock frame, +14 arm, 14 paddle rippers 75" RO, 17/41 gearing (39 & 40 works well also), 2.86 primary with a +210 lb rider. I ran a 3.99 3rd pass out with a 1.364 60'. I've been faster in both incriments. It runs well on the top end also, I've been 80 mph & a 185 lb. rider went 82 mph in 300'.

Trying to get caught up on the clutch pack side of lock out/lock-up tuning side. While this is probably the boring side of clutch tuining, like everything else in the total quad set-up it all plays important factors. While there are different things that play a factor. These things are what I find important in the clutch pack; Break-in, inspection & maintenance. I'll start with clutch break-in. While I don't consider it a necesstity, I still do it for consistency reasons. We follow what works for Top Fuel Dragsters/funny cars. We apply the brakes & slide the clutch to the point of almost killing the motor. We do this 2 -3 times then let the clutch cool overnight. We consider the clutch ready to race after this procedure. I'll cover inspection of the clutch pack, hopefully in the near future.

Good to see a couple newbees getting their feet wet with asphalt drag racing. Maybe Tedder can chime in on the stock stroke stuff. He knows how to get it done with a cub & stock cylinder with the stock stroke. I'm sure I can help out also, when I have time.

Like mentioned in this thread, the trans ratio spread is not ideal for 1-2 shift. You tend to have a greater rpm loss usually around 1,000 rpm less than all the other gears. We use a gearing calculator to help with the set-up. Using our shift rpm, trans ratio, primary ratio, final gearing & tire hieght. Using a 10,000 rpm shift point the calculator predicts the motor pulls down to 7,300 on the 1-2 shift. All the other shifts range between 8,200 - 8,300 rpm. One of the key areas needed to make 1st gear launches work is the clutch set-up. The above scenerio for the 1-2 rpm drop is changed to the clutch rpm slip (higher than 7,300 rpm). There area a few other areas you need to change also, but not totally necessary. We change our 1st gear trans ratio & it actually makes the 1-2 spread worse, but our other quad does just as well with the stock trans ratio.

Most prefer 2nd gear starts, but we make do with with 1st gear launches for sand drag/hillshooting. We have a 1-4 tranny that primarily is used on asphalt. It has worked very well on sand pulling 1.3 60's with a 210 lb. rider. We have changed a few things to make it work. We made the 1st gear launches work on two different quads/rider's with the same results. I would like to try 2nd gear starts, but don't have the right trans for it yet.

X2, but need more info! Tire diameter, primary ratio, transmission & bike/rider weight.

Not really a secret, but there's not enough information. The lock-up tuning thread in this section starts to cover your question. The clutch set-up needs to have a baseline to work from. The most critical being primary pressure in lbs. & arm weight in grams. Other things play a factor too.

I just wanted to provide a visual reference. I happened to have the matching time slip for that series of photos.

Here's what a .291 light vs. .033 light with .000 being perfect. I remember having 3 bikes on him early in the run. The quad in the left lane was a bigger bike & a lot faster. He caught me around 250'. Scroll down a couple rows. http://gallery.competitionplus.com/main.php?g2_itemId=961651&g2_page=5