Triple Disc VS Single Disc TC

[curatchko]

Well I have to pop in here a moment.



A TC is not supported by the Flexplate. The TC pilots in the back of the crank just like 99. 9 percent of TC's out there.



So, it wouldn't matter what the weight of the converter is.



Just another . 02 worth, or maybe . 03.



Chris

 

[Snow man]

Chris,the TC pilots in the flex plate,Not the crank shaft. John,i asked you to go to PM if you want to go further.

 

[BillGotthelf]

Fleahead-as you can tell people are rabid about there tansmissions. You made a good choice with Suncoast as you would have with many others. Each company turns out a good product and has reasons for their designs.

 

[MCummings]

When I was doing research to fix some broken parts in my trans, I talked to a couple people, and guess what,, There is no need to really worry about the Torque Converter Lockup clutch. Why? At any given time, 3rd gear is 30% weaker, or, will only hold 70% of what TC is capable of holding. So, Yea, you've got a TCC capable of holding 2,000 Ft/Lbs,, that's great, 3rd gear is going to let go at 1,400 Ft/Lbs. So,, when you engage your TCC, if you are in 3rd gear,, the slippage you feel for a split second probably isn't the TCC,,, it's probly 3rd gear. I know I'm slipping 3rd gear in my truck right at lock-up,, otherwise,, something would break, becuase my tires aren't chirping, and the RPM doesn't fall ASAP.



To drop ~800 RPM going into lockup with 75+PSI boost, something has to give.



You HAVE to fix internal leaking. You might have 100PSI line pressure at your test port, but by the time your fluid gets to your servo's, you may only have 75PSI, or less.



If you could, picture a garden hose that has a plug with a pressure gauge at the end. Imagine you have only 10PSI at your faucet. The stock Dodge transmission is like this water hose, but imagine a couple 1/8" holes being punched at several different places. (that's how it really is) Now, with all the holes (internal leaking) the pressure at the end of the water hose definatly isn't going to be 10PSI, not even by the most optomistic calculations. (the pressure at the end of the hose is what pressure your servo's would see)

What happens when you put more pressure on the hose, directly from the faucet (increased line pressure)? Say, you have a 100% increase pressure at your faucet (20PSI), but you might see a 50% increase at the end of your hose (servo's). If you fix the leaks in the hose,, you get more efficient use of the pressure, and you don't have your faucet running near the pressure needed as before you fixed the leaks.



Clear as mud?



If you fix the leaks,, you can run the same pressure as before, but will greatly increase the apply force of ALL parts in the trans.



Does that make sense?



Merrick Cummings Jr

 

[Edward]

Someone has said that my opinion is not of any use because I do not know transmissions. Well I chuckle at that overly simplistic statement and point out that I do not need transmission experience to know which is best; I just need to listen to the sources that know the best or set the standards that define the best. All anyone needs to know is the company that has the best reputation for quality and look at what it is doing. The company that I am referring to has a reputation for quality that is world renown. They got their reputation the old fashioned way by years of building a product that is second to none in quality. This company has the engineering staff and testing facilities to test all the transmission and torque converter concepts out there and then establish which one is actually the best. They could have chosen the concept of increasing the percent of fluid coupling to decrease the load on the lock up clutch and then take the steps necessary to deal with the extra heat this concept generates. Or they could use the multiple lock-up disk concept. Again the company I am referring to will only accept proven technology, no second-class stuff allowed. Who is this company and what concept did they choose?

The company is Mercedes Benz, and they chose to use the multiple lock-up clutch torque converter concept for their new 7G - Tronic transmission. Hopefully the release of this new state of the art seven-speed transmission will put an end to the transmission wars. It should also give us Dodge Cummins owners hope that we will soon have a transmission that exceeds the capabilities of the six speed Allison used in the Chevrolets.

In my opinion it is past time to move on. All of us should tell those who want to continue the argument that they can now take it up with Mercedes Benz. They have the engineering staff, which is abundantly more qualified than any transmission builder, installer or automatic transmission owner. In my opinion anyone who still wishes to argue the point should simply take it up with Mercedes Benz.



Edward



PS

Here is a link on this new transmission. Some of the photos clearly show the multiple lock-up clutch torque converter. There are other articles on this transmission try doing a search on Google or your favorite search engine type in 7G-Tronic.



http://www.germancarfans.com/photos.cfm/photoid/3030903.001/mercedes-benz/1

 

[Jamie Attridge]

May as well post since this is dead anyways. Edward as always finds a way to insert his brand bash in a political way good show Edward. May I ask you this though sure the Mercedez can use the TCC that is because it has the computer to control the 3 disks. As you have argued many times before about trans Im sure you will have something smart to day about this.



Here is a quote about triple disk TCC's on the cummins with nothing computerized to enable the triple disk.



http://www.dieseltrans.com/phpBB/viewtopic.php?t=197

 

[LSMITH]

The 7G is apples and oranges. The 7G has a 6" convertor. The 7G will not be going in a diesel. There is NO ROOM to get the surface area needed for a single disk, it will be a full order of magnitude smaller than our TC yet it will be trying to hold 300 HP or more. The TC in our trucks has PLENTY of area, the guys with 700+HP have proven that beyond a shadow of a doubt.



BTW, fluid coupling does not in any way, shape, or form take load off the lockup clutch. Anyone that knows anything about TC's would know that. It is a physical impossibility.



BTW, Mercedes has made some of the finest torque convertors ever seen over the years for the diesel applications, with welded steel fluid formed stators that are simply beautiful. The fluid coupling is something to behold, they are TIGHT yet have good multiplication. As someone that has worked on Mercedes for years and possesses the experience to comment on it I can tell you that they are VERY much like the DTT 518 convertor in design theory, overall performance characteristics and basic construction. They were doing it in the late 70's and got it right.

 

[Piston Slapper]

Flex Plate Breakage

Never really thought about this...



"The triple disc tc's and all billet covered TCs break flexplates quite frequently. This is a fact,it can be proven if you took an honest poll ... "?





Just replaced the Flex PLate in my dad's. It's about 350-375 Hp, Only transmission mod is a "Purple TC", which was added before we bought the truck. That thing is heavy too. It has a definite surge of power at lockup. Drastic change in RPM. Everybody thinks it's cool... . I just look at it like why want it "pull" like that all the time? Look at how much power we was loosing...

 

[Straight6Jeff]

I may be way off course here, but the "hanging weight of the torque converter seems to be only part of the weight issue. Wouldn't the other be inertia? The rapid drop in RPM during shifts would seem to produce shearing forces. If I wrong on this, I will shut up. Aw hell, I'll shut up anyway and go back to my NV 5600 that clashes in every gear.

 

[MCummings]

Originally posted by Edward

They could have chosen the concept of increasing the percent of fluid coupling to decrease the load on the lock up clutch and then take the steps necessary to deal with the extra heat this concept generates.



Or they could use the multiple lock-up disk concept.

Wow,, I don't know how you came up with that.



How do you explain 260* in the pan after some hard running in the sand? I'm sure if I would have locked it up I would eliminate the heat,, but, any time the tires would have stopped spinning it would have stalled the engine, or broken something. Locking up in 2nd gear isn't always the best idea either.



I think if the TC was tighter,, there would not have been the "shearing" of the ATF in the TC. A tighter TC would eliminate the large RPM drop when locking up the TC, and would eliminate the heat created when locking up, would decrease the large RPM drop going into lockup, and would decrease shearing of the fluid using alot of HP out of lock-up.



Once the TCC is locked,, there is no difference between one disc, or three discs. Locked is locked, Fluid coupling makes no difference when in lock up. Now,, an 800RPM Drop, vs. a 200RPM drop locking up, definatly would decrease the load on the TCC. (200RPM being easier on the TCC)



A tighter converter runs hotter while stopped,, because the fluid is really being whipped around, while a loose TC doesn't generate much heat while stopped because the fluid isn't being whipped around as hard,, while, a Loose TC generates alot more heat trying to use alot of HP.

I can't explain that one technically, but That's how it works.



Merrick Cummings Jr

 

[pwr2tow]

If I'am not mistaken I think www.suncoastconverters.com makes both. Why not call them and get their opinion, at least from someone who makes both you would get an unbiased answer.



1-800-868-0053

 

[Snow man]

Mcummings, My DTT 91 tc drops about 350-400 RPM into lockup,with the nitrous on,at about 650+hp. If you are dropping 800RPM,you are seriously pulling right through the TC. You musthave a stock TC or a milled stock stator. You are right about 3rd gear being weaker than the TC,the entire trans is only as strong as the weakest link.

Piston slapper, you found out why the flexplates break,that TC is way to heavy for that thin plate.

 

[Walleye mike]

I dont know what others warrenty is but Goerend Bro's triple disk is warrentyed for life. So I just dont worry about it!

 

[MCummings]

Who will warrenty 3rd gear?



Why worry about the TCC, if it can't slip? 3rd will slip first.



Picture yourself driving 65MPH, and you floor it, and you see the RPM rise,, and you don't really speed up,, you think, uh-oh, my TCC is slipping, so you take it to a shop, and nope,, the TCC isn't slipping,, it's 3rd gear. That might put you in an odd situation.



Merrick Cummings Jr

 

[pwr2tow]

As for fluid coupleing, just about every transmission company, if not all of them, uses fluid coupleing multiplication in the products they produce these days, to use that as a selling point is only trying to blind side the green horns that don't know any better or the lazy ones that do not do their home work.

 

[pwr2tow]

Whats this crap about third gear being weaker than the TC. On a modified TC maybe but not on a stock TC.



If that is what your meaning then you might as well go down the whole gamit because anytime you beef up one component the next one becomes the week point, so where does it all end, might as well just get a complete upgraded transmission, Oh I forgot it still would be the week point because some company will invent something more we need

 

[fox]

This thread was started by the question " what are the benefits/ differences between a single disc verses a triple disc clutch".



If third gear clutch is the weak point of a trans in stock form when in lock-up adding 2 more discs doesn't improve anything.

By buying a redesigned/improved fluid coupling converter helps the feel of the drivability but the weak point is still the 3rd gear clutch.



Adding weight to the converter and locking it up at low RPM is possible what is breaking the flex plate.

With CORRECT fluid coupling you will find that there is no need to lock it up.

I put a mystery switch in mine last year and used it in ever day driveing until this spring when I put in the tight fluid cuopling converter. (And many other up-grades . ) Now I don't need it.

Exception to this is that I lock it out of lock-up in town driving because of the Dodge engineered 3rd to 4th lock-up shift disaster. I also put in the billet shafts to make sure that I don't have to R + R it for many years.

I cannot see any benefit to running thru the gears and shifting locked now.

Now back to the 3rd gear being weaker--- it has less clutch area-- when stock, than the converter clutch. And it has pressure feeds to it that leak in stock form.



So If you need to open it up do it once and do it right fix the leaks and causes of failure.

 

[pwr2tow]

So what is the difference between a single disc and triple disc converter again, it seemed to get lost in the fluid coupleing stuff again. Transmission builder of today use better fluid coupleing in there converters so the fluid coupleing point is mute.



Yah, someone will come on and say it is how they are designed, well there isn't a whole lot between them anymore, some, not a whole lot, they all do the same thing and for someone to say they don't is pure bull excrement.



I have never heard of anyone pulling through third gear locked in normal driveing situations, or towing, or just plain romping on the throttle, In race situations maybe, yes.



You guys talk about race situations with upwards of 700+ Hp, well hell just about every manufacturer has those kind of numbers. Most general consumer will never go over 350 Hp so when you talk about things keep it in perspective and inform them if they do this or that, this is what you need.



There are manufacturers building TC's that will hold unlimited Hp and backing them up with three and more years of warranty.



It also floors me the statements that are prompted by whay some manufacturer told them, or a vendor selling type 9 product, or just the proud owner of a new product, it does non of any good to listen to this kind of hype.



Ultamitlay it is the buyer that has to decide, do your home work well and read through the reteric. Ask question of every manufacturer from every manufacturer and why theirs is better than the next manufacturer. Don't be shy, don't be ashamed, for god sakes people it's your money that your spending not the manufacturers.



I will get off my soap box now and start liveing again.

 

[MCummings]

Originally posted by ronsram1999

You guys talk about race situations with upwards of 700+ Hp, well hell just about every manufacturer has those kind of numbers. Most general consumer will never go over 350 Hp so when you talk about things keep it in perspective and inform them if they do this or that, this is what you need.

Well, Darn.

I'm out. If you are at 350RWHP,, 95% of the transmission vendors out there will do what you need. I guess I loose perspective that not everybody has 500-600RWHP.



Merrick Cummings Jr

 

[KLockliear]

Originally posted by ronsram1999

You guys talk about race situations with upwards of 700+ Hp, well hell just about every manufacturer has those kind of numbers. Most general consumer will never go over 350 Hp so when you talk about things keep it in perspective and inform them if they do this or that, this is what you need.

Heh, guess it depends on who you talk to. My general consumer is 400-450+ hp.