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Lock Out/Lock-Up Tuning


SlowerThanYou

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  • 1 month later...

OK, once in a while I use subjects from PMs I get about clutch tuning. While I don't give specifics in PMs or in this thread I will point you in the right direction.

 

What do you do if the engine sounds like a centrifugal clutch going down the track or can't hear or feel the shifts. 

 

The base pressure in this situation is low enough to cause slip & that's the start of process. Now, you have to stop the slip. IMO, there's no reason to have clutch slip past the 60' & in most cases it should be locked before that. There are exceptions to every rule.

 

Back to the problem & how to start fixing it. The basic answer is to start adding weight to the arms, but how much weight do you add? This is where you start with your baseline. Say in this situation we have 10g of weight on each arm. The important thing is to pick a weight you want to add in grams & keep it in your records. Lets say 1g per arm & go run your set-up. The ideal situation would be it fixed the down track slippage. In this case probably not.

 

Back to the clutch being locked up by the 60'. If it's still slipping the rest of your run. You are way off on your arm weights. Now, lets say your clutch locks at 50' out. Then has slip down track in 4th & 5th gear. That indicates you are closer on your arm weights & may only need a small amount of weight.

 

Don't get hung up on the numbers of base pressure & grams. You need them, but the important area is to make changes from them numbers, evaluated the data & determine if the change(s) help/hurt your run.

 

 

 

 

 

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I've seen this a few times at the track from other bikes. People might not be talking about the clutch but I bet they are reading it cause I see more bikes at tracks on one side with the clutch cover off. Thanks again Brian for all you have posted on here.

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  • 1 month later...
  • 4 weeks later...

People might not be talking about the clutch but I bet they are reading it cause I see more bikes at tracks on one side with the clutch cover off. Thanks again Brian for all you have posted on here.

 

You are right about people reading about it, but not talking about it.

 

I want to thank-you for sharing your experience with clutch tuning or learning. If I remember right your 60's started in the 1.5 range. Then you worked your way down into the 1.4 range & continued all the way down to low 1.30s. Great Job!

 

When this thread evolved into the mid to later stages. I was hoping to hear more discussion/feedback from people reading & hopefully learning from it. Phunt stepped up to the plate & I appreciate that. 

 

Where this thread goes is really up to the reader's at this point. You get what you put into it & I have already said too much! :shootself:

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  • 2 weeks later...

Bryan is back.. Yes listen to Bryan he might be grumpy be (but) he is very knowledgeable. He helped me over the last two years. My 60' want from a 1.7 to 1.39 with the help from Byran. Also my best et to date is a 6.1 at 109 all thanks to bryan and a mutual friend . I had 10" wide tires I sold to get 8" picked up a tenth just form tires. So again listen to him and Tedder. Jmo

 

Here's another example of a member on BHQ using clutch tuning. The clutch didn't contribute to all of the gains, but it still played an important factor. The 60' would be better, but the member has a 2-5 trans & is manually shifting the 1-2 shift.

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Any thoughts on how to gauge the load or strain a clutch is seeing? Like a way to actually strain gauge a clutch? I see the big ol top fuel cars have wires out of the clutch to the data logging box. So how can you physically monitor slip. So far I can use RPM and Throttle position to sort of gauge what's going on. Just wondered if there is a more precise way to data log.

 

Side note, when I asked the fellas in the NHRA pits exactley what it is that they monitor and what sensors they use one guy came forward and basically said

"Clutch RPM, Input Shaft RPM, Output Shaft RPM, LOTS of temps. I can't tell ya what we use to monitor or what we do with the info..."

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Any thoughts on how to gauge the load or strain a clutch is seeing? Like a way to actually strain gauge a clutch? I see the big ol top fuel cars have wires out of the clutch to the data logging box. So how can you physically monitor slip. So far I can use RPM and Throttle position to sort of gauge what's going on. Just wondered if there is a more precise way to data log.

 

Side note, when I asked the fellas in the NHRA pits exactley what it is that they monitor and what sensors they use one guy came forward and basically said

"Clutch RPM, Input Shaft RPM, Output Shaft RPM, LOTS of temps. I can't tell ya what we use to monitor or what we do with the info..."

 

Not really, LOL! We did find out a little information by mistake on a couple of dyno runs!

 

I'm old school when it comes to data logging, but it works well. Tedder is a little bit more advanced in his data logging. Hit him up, he may or may not share his information.

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  • 2 weeks later...

It was asked in a different thread, so I'll put it here. If my response makes any one angry, I'm sorry and fuck you. I'm bored and got the time to babble.

 

 

"m671054, on 13 Aug 2014 - 10:21 PM, said:

As for the clutch frictions we primarily use Yamaha fzr 1000 fibers. We have played with Barnett kevlar and want to try carbon fiber frictions some time soon.

 

As for the steels, we use different types of materials, treatments & coatings. We have a pretty detailed maintenance & inspection program for the clutch frictions & plates."

 

 

 

I have a set of those carbon fiber clutches from Barnett. I got them from STY. He sent them out and told me to kick the shit out of them and so far I like them ALOT!

 

As far as weird things done to my clutch, there is lots of Cryo treated parts. The hub, basket, plates, springs, driveline unit. Mostly for strength and wear resistance. The springs the drag guys wouldn't notice, but for something you ride a ton you will notice. It seems to keep them consistant under longer races. Cryo really helps the plates with warpage as well which is the big thing for me.

 

Prep and maintainence, well I guess in dummy terms that means, fighting the glaze. Nothing worse then seeing guys glaze clutches with nearly all the friction material still in tact and wanna throw them out because they think it's junk. (Tip, the heat/oil work hardens this stuff) some guys simply hit their frictions plates with a scotch Brite or roloc on an air grinder. Kinda works, but I think it leaves an Un even surface in some points which causes some issues.

Me personally I use a piece of 400 grit on glass or my machinist granite block and figure 8 the frictions just till I get fresh uniform surface. Tip: don't use your hand as pushing with five fingers creates five points of pressure which leads to Un even surface. I lay a round chunk of steel over the friction and hold it from the side and move it. You need to be hitting everythig with a micrometer before and after. My steels, I've come up with an idea that seems to work really well. I used to do them like the frictions but took time and I don't like making them thinner. So I came up with a chemical solution. Acid etching. Dunk and scotch Brite and they are good as new. Damn near Zero material removal. There's other stuff, but that's the basics of it in my bike.

Edited by trickedcarbine
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Good info.... wat are your 60' times?

I have never looked at. 60' times as I'm not running a drag bike. I am running an oval bike with a lot of slip for the turns and hole shot. This thing gets out of the hole well! Plus my bike is on a -2 arm so I'll never get this thing in the famed 1.3x range. I'd bet on a good dial and if I keep the front end sort of down, maybe 1.6 ish.
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