SlowerThanYou

You are correct you must take away some weight. How much weight do you have on the arms now?

I would recommend you start with an adjustable launch rpm limiter & adjustable switch clutch lever. Along with clutch tuning/set-up, of course.

Congrats! You have a good start, but there's still a lot of work that needs to be done. You really need to start keeping records for the baseline set-up you have now. Then you need to make changes & notes how they affected the run. I'm going to point out one area to start with & you already hit on it; "lock up weight hit the bike bogged". What change are you going to make to correct that problem?

Are you asking if I'm done with this topic? I gain nothing by sharing this information. If I had to do it all over again. I would do the thread different, but it's beyond my control on an open forum. I haven't got to the friction inspection yet. The main reason is they don't photo well like the steels do. The best I can do is provide written description of what to look for. Hopefully I can get to it this Holiday weekend. I can't answer your question on what springs are stiffer. That's the reason you need a spring pressure tester & the installed hieght of your springs! I'll try & recap the springs I have: Stock, YZF 450, Barnett (light & heavy), EBC, FAST (light & heavy) & probably a couple others I forgot about. It makes no difference to me. I mix, match & modify to get the base pressure I want to use for the conditions. We use the Fast brand/Yamaha 1000 street bike frictions. We have played with 2 or 3 other brands/materials a little. The most important thing to remember is;stay with what gives the best & most consistent results.

X2 on the good place to start! Springs are pretty easy to get. Tuning a clutch set-up is what you put into it. Our tuning process goes in a big circle: carbs, timing, gearing, shift points, porting & dome configuration just to name a few areas. We spend a good amount of time in one area. Then usually find we have to make another change in another area & so on. It just keeps going round & round. LOL!

I agree with Fouled!

http://www.atvdraggers.com/forum//index.php?showtopic=2543

We use a programmable Dyna, but you can use a stock ignition with a Dyna DRL3000. I'll try & post the schematic.

The adjustable is the only way to go. I think we got ours at MTC or Pingle can't remember. There's a certain way to adjust them for best 60'. If they get out of wack they cause all kinds of 60' issues (not good)! This subject will come up later in the lock-up/clutch tuning thread.

Nice try Tricked, but I'm glad someone is trying to take something out of this thread. LOL! This thread was started from a couple other threads that went amuck. Then I provided information where I thought clutch tuning started/originated. The 1st real topic that I brought up was Base/Static Pressure. The 2nd was Arm/Dynamic Weight. The 3rd topic was Maintenance/Inspection of clutch pack. I only covered the steels portion & I need to finish the frictions portion. The #1 & #2 topic are what I consider the most important. When you get to the sweet spot on #1 & #2. The more you have to pay attention to other topics I'm bringing up/discussing. Everything is important because it takes the total clutch combination/set-up for it all to work at maximum efficiency. This is the topic I left off with, Maintanence/Inspection of the clutch frictions!

Thanks for the discussion. Now I have a few questions for you if they apply! I thought I read where you have ran dune drags, sand drags & asphalt drags. I would like to hear your thoughts on the similarities/differences of this topic? Time slips are always nice to add to the discussion. I have posted a few on HQ & can repost to this thread if needed.

We didn't decide/say a 1st gear launch is better than 2nd. This is our data we have. We have over 100 time slips to compare with our competitors. No one has come close to our 60's. We are using what worked for us on asphalt. Plus with our 1-4 override, manual 5 & 6 trans we didn't have much choice for 300'. We have ran low 1.30 60's on both surfaces. We have been mid to low 3.8s in the in the 330' asphalt. We haven't matched them times on 300' sand, but getting close. As for changing tires we have only had time to really run/test 2 sets of paddles & a few runs on a 3rd set. The 1st set of tires netted our best runs 22x11x8 12 paddle Extremes, but we had 3 & 4 gear traction problems. We switched to a 24x12x8 14 paddle Ripper. We lost some 60' & are slowly finding the tune with them, but we solved our 3 & 4 gear traction problems. Picking up 3 mph thru the finish line. The Puerto Ricans borrowed our quad to race & tried the 3rd tire. I'm not sure what the exact tire size was, but can get it. It was like a 26x12x12 14 paddle staggerd Extreme with 1 or 2 layers of kevlar. They went back to the proven Ripper. The gearing is the key for 1st gear, both in the spockets & 1st gear ratio. As for a harder hooking tire, I think the Ripper answers that question. Not sure about what you mean about "if you could get away with less gear so you could use more if the trans gears.....?"

The more wheelspin you have the quicker the arms will lock-up the clutch. Base pressure is still critical. We have a certian way we tune the standard lock-up and it's slightly different from the multi-stage lock-up. Both quads pull a low 1.30 60's. One is a alky 535 cheetah in a custom chassis using a standard lock-up. The other is a race gas 443 cub in a stock chassis using the multi-stage lock-up.

Clutch tuning is really pretty easy! I've said it many times over. The clutch tuning information has been used in many different Motorsports since the 60's & maybe sooner than that. If people don't want to learn it. I'm not going to lose any sleep over it! Some people are getting it.

I haven't talked about air gap for a reason, it will be in the future. The main topics I have brought up so far follow a pattern that I think is the most crictical to clutch tuning. As for your shimming you must describe or better yet show a pic of where you are shimming. One place will affect both the air gap & spring pressure. The other will only affect the spring pressure.

http://www.mcmaster.com/#ceramic-balls/=jwxwim

I wouldn't count out 1st gear launches! With the proper set-up they will out perform the traditional 2nd gear launches.

We have ran the same ceramic ball in our clutch pusher since 2005 with well over 1,000 runs. It's the white one that's is a step down from the grade 5 (black). We have the black one for a back-up, never felt the need to change out the original. LOL! I wouldn't be afraid of using the grade 5s in the slingshot.

I guess I have a lot to learn, LOL!

Most combo's like being described should work the best with small bores. We run Big Bores on a 443 cub and they work excellent for our combo on sand & asphalt.

I used the 1st sentence for the call. There's really now way of telling without out a timing system or data logging. A proper set-up clutch will go at the drop of the clutch lever & be a smooth transistion to lock-up. This will happen very quickly with a standard lock-up 10-20 feet. With a multi-stage it can come in that quickly or be delayed further out.

Someone posted a while ago about using the slingshot. The majority of principles discussed in this thread will apply to the slingshot. The main difference is how the dynamic weight is tuned. IMO it's easier to make changes to the standard lock-up.

We finally got the quad back on asphalt last weekend. The differences showed real quickly, but they were more procedural than actual set-up. The 1st thing I had to adjust for was staging. For most of our asphalt staging we must courtesy stage & with sand it didn't matter. 2nd, was remembering to shift. Asphalt we use all 6 gears with only using 4 for sand. It took a little to get the old mind into the right mindset. For the future racing asphalt/sand we are going to look at simplifying or limiting the differences.

We finally found the limits on the frictions, it happened somewhere around 200 runs. This was discovered last weekend when putting the quad back on asphalt. The clutch frictions have been used on 300' sand for about 125 runs over the past year. The frictions had around 125 runs on asphalt to start with. 250 runs we found broken frictions, decrease in performance & a clutch set-up that was not race able.

Asphalt 330' & Sand 300' similarities/differences. The reasons I went to sand was to find out some answers to the topic. PHunt asked a clutch set-up difference between the 2 surfaces in the lock-up tuning thread. That kind of prompted me to start this thread. Our knowledge/background comes from the asphalt starting in 2005, with somewhere well over 800 runs over 7 years. Our sand experience started in 2009, hill shooting. Late 2010, we finally started 300' sand racing. After a year of racing & over 100 runs, I've made a few observations. I wanted to keep the sand set-up as close as possible to our asphalt set-up. Asphalt we have put down some decent numbers in the 330' so why wouldn't it work for 300'. Here's a few items we found that were the same. 1st gear launch, while most use 2nd in the sand. We found 1st gear works well for both surfaces. Launch RPM using a limiter, we set this between 9,000-10,200 rpm. We have a an RPM that works for the majority of track conditions. Shift points using a shift light, we shift @ 10,000 rpm & it's probably higher by the time we react to the light. It works for us & we really don't change it. Asphalt Gearing, we mainly use a 17/36 (2.12 ratio) with a 20" tire. Sand Gearing, we mainly use a 17/42 (2.47 ratio) with a 24" tire. NOTE: Both gearing set-ups net us around 83 mph in 4th gear for there respective distance. There's tire growth involved with both tires. Clutch, the base pressure is a little higher due to the load differences. Everything else stays the same, like tower springs & arm weights. As for the motor set-up. We use the same carb settings, timing curves, compression & ect. With changes made for air changes & track conditions. Thoughts?