build a 200-4R for 1,000 HP
- Thread starter LSJM1
- Start date
Just got home from work. Sorry i missed a lot of fun. Don i have a question. Have you proven that the output twisting is a result of a ratio change? Not theories about how shift timing or the increased speed of clutch apply under positive power could possibly twist a shaft. Id be willing to bet (havent proven it myself, nor do i care to) that the twisting occurs in 1st gear when the trans brake is released and torque is sent through the drivetrain and there is little to no tire slip and likewise the different clutches that are applied (including holding roller clutches). That is the time when the output shaft will see the highest loading from the torque multiplication of the converter and the first gear ratio if traction is good. We see the most rear axle failure at this time. A 2-1 kickdown could also shock the output hard and potentially twist the shaft. Btw the clutch surface area, heat transfer rate, and amount of input torque will limit the heat soak capacity of any clutch pack that applies or tries to apply under power. You should post your proof of twisting based on ratio change then we can actually debate proven information.
240 to 250 is by no means extraordinary.how in the world can a slipping clutch absorb energy from the power transmitted to the output shaft.we all know if the clutch slips it delays the power transfer to the shaft and shows up in the form of excessive engine rpm.tell us something we dont know.any time you alter the shift timing ,overlap or accumulation in changes shift feel.your confusing the fact that there are 2 things happening at once and are ,before any of these transmissions made it into a passenger car the things you looking into were already figured out.these are basic principles of operation and in no way shape of form pointing to a broken output shaft.the shaft breaks because it is overloaded and underengineered.just like the input,forwad drum and od planet assembly.of course too firm a shift could cause enough shift shock to break a 4wd 700 output shaft,BUT THE CLUTCH IS NOT SLIPPING.
Any tortional spike loading of the output shaft will contribute to the eventual failure of the part. I hope I didn't state that I thought the high clutch was the only reason for the output shaft failures. I didn't mean for anyone to think that. My main reason for all this writeup is, why keep developing more parts if the high/rev clutch is going to continue being a weak link? Someone may develop an output shaft that will handle 1,000hp, but you can't convince me that the high/rev clutch can go there, so why bother?
refer to post #61
I don't think I ever discouraged anyone from making parts to upgrade the 200-4R. I do definitely think at this point in time the direct clutch is what needs to be upgraded. In fact, you can be witness to me telling Chris, "Make a direct clutch for the 200-4R that can handle the next level before anything else."
I still think that a 200-4R that can handle 1,000hp is a pipe dream, but hey, go for it. As long as people are willing to support the effort with their wallet, I see no reason to stop. I can't wait to see a 200-4R do mid 8s.
Refer to posts #9, #10, #11, #26, #39, #40.
So, if anyone is still interested.
What is limiting the heat soak capacity of the high/rev clutch pack?
The line pressure is not the problem. It is a symptom of the problem.
GNBRETT
Pelennor Fields
- Joined
- Feb 8, 2004
Would the coating of internal transmission parts do anything to reduce the transfer of heat friction inside the tranny? Like from ceramic coatings, teflon coatings, thermal coatings solutions with Calico Coatings
I know it's used for bearings, headers, etc... commonly but do people utilize it in their transmissions?
I dont know, im just asking?
I know it's used for bearings, headers, etc... commonly but do people utilize it in their transmissions?
I dont know, im just asking?
You have to think of the job that the direct clutch does as similar to what a standard transmission clutch or your braking system has to do. It has to take motion energy and stop it. In doing so, heat is created. That heat must be dissipated quickly enough so that the friction plates are not overheated.
How do we increase the heat soaking ability of this clutch pack? Think about this question in the terms of what is normally done to increase standard transmission clutch or braking capacity. What is the first thing that comes to mind when you want more braking power?
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
Increase the surface area or more pressure on the surface area. Or both.
You are correct.
Let's look at these two options.
More pressure. What if you're already at the point of using extraordinarily high pressures to keep the clutch alive? Do you keep going higher? When do you say, 'OK. That's enough pressure. We need to do something else.'?
More surface area. This is by far the preferred choice at this point for the 200-4R high/rev clutch. This is where peoples attention needs to be focused.
But, will increased friction surface area alone do the trick? Or do we also need more material that can increase the heat soaking ability of the overall clutch pack? Thicker steel plates? Thicker friction plates?
On the subject of increasing frictional surface area in clutch packs in an automatic transmission, that is generally done by increasing the number of friction and steel plates. Due to the limited room that's available with most clutch pack designs, there comes a point where you have to make the steel plates and the friction plates thinner inorder to be able to stake them all into the same height dimension. What does that do to your heat soaking capacity? You're increasing friction area, the area that will be generating heat, but you're decreasing the mass that will be needed to absorb heat. You're concentrating more heat generation into the same limited space.
Looking at a similar problem with braking systems, when you want to increase braking ability, you increase the diameter of the rotor and the thickness. The diameter gives you more surface area for larger brake pads to act upon, and the diameter and the thickness gives you more mass of the component that will be acting as a heat sink in very hard braking situations. The principles are really very similar between the brakes and a clutch in an automatic transmission.
Has anyone ever seen a racer try to save rotating mass by going with small diameter and thin brake rotors? I've seen them where the rotors were horribly overheated, blued, and hard spotted. Seemed a little unsafe to me, but to some, that time slip is all that matters.
Back to the transmission. So. What in the 200-4R is the main limiting factor in being able to increase the high/rev clutch pack size of the 200-4R?
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
You run out of room to install more friction/steel discs?
my 10 clutch hi drum offers 40 percent more frictions surface area,with thick steels.The custom top pressure plate is used in conjunction with the stocker.it is .250 thick .this is an additional heat synch that puts apply heat into the drum outer edge ,not the stamping like the stocker does.the billet aluminum piston has a solid bottom not a wire ring.this improves heat synch on apply and keeps the clutch pack from deflecting during apply.i am very confident with the new 3.2 mod and plate that we have defiantely extended the clutch pack life.when you see the drum youll see how I did it.thanks to gm for making the direct hub on the forward drum a lot longer than was needed for the 6 clutches.
I know absolutely nil when it comes to automatic transmissions, so this will be a wild stab in the dark, but the case itself?
For someone who knows nothing about automatic transmissions, you've made a dang good guess.
Ultimately, it is the size of the case that will dictate how much room you have to install upgraded clutch drums that will allow larger OD clutch plates. The high/rev clutch return spring package limits how far you can decrease the ID of the clutch plates in an effort to gain more friction surface area.
So what is there to do? Here are some ideas.
A custom high/rev drum with a shallower piston cavity so that the clutch plates can be stacked deeper into the drum, maybe allowing one more friction and steel plate using the present thin frictions and steels that are available.
A thinner apply piston, with a larger OD for more hydraulic apply area.
Bringing the pressure plate snap ring groove to the most upper location possible without interfering with the forward drum. Maybe allowing another friction and steel plate using the present thin frictions and steels that are available.
Design the high/rev drum to take advantage of any space that is available between the front of the drum and the drum support. Locating the apply piston in the drum even further forward to leave more room for extended clutch pack capacity.
Design a new piston return spring that will allow a decrease to the ID of the friction and steel plates. Increasing clutch surface area. This will require custom steel plates and friction plates, and also a modification of the high/rev clutch hub mounted on the front of the forward clutch drum.
Stretch the OD of the drum to the limits of what the case will bare. This will require a larger OD band which will give us more friction surface area for the band. It will also increase the OD of the clutch pack pocket, allowing an increase in friction and steel plate ODs. Increasing friction surface area.
To the layman what I'm saying is, stretching the overall height, ID and OD of the clutch pack to the limits of all the space that is presently available using a custom high/rev drum. This, in my opinion, should be a priority project for any further development of the 200-4R.
Now. What should be done first is an analysis of just how much more friction surface area we will be able to get out of this mod. Will the cost of the development be worth the reward?
Chris. How much more friction area can we get from this?
What are the ID and OD dimensions of the friction plates? The material only.
That's 40 percent more area than a stock 6 pack. We're trying to get to 1,000hp here! The state of the art now is a 9 pack. A 10 pack is an increase of 11 percent. Given that the 9 pack is being stretched to the limit of its capacity and the limited stock piston apply surface area, we're going to need much more than 11 percent. We need to think larger here. Larger drum, larger piston, larger plates, more plates.
YOU are not listening.THE CURRENT 9 PACKS ARE USING 9 THIN STEELS AND A TRIMMED DOWN PRESSURE PLATE.THE STOCK TYPE 6.I AM USING 10 STOCK THICKNESS STEELS. THERE IS NO COMPARISON BETWEEN THE THIN AND THICK.THE THIN DOESNT WORK.WHY DONT YOU UNDERSTAND THAT?IT IS 66.666664 PERCENT MORE FRICTION MATERIAL.ITS VERY EASY TO CALCULATE. STOP WITH THE CLAMPING PSI.THERE IS PLENTLY THE DRUM IS IN NO WAY AS HEAVY AS A 400.440 DRUM EMPTY WITH SPRAG IS 10 LBS AND THE 2004R 5.3.WHY WOULD WE MAKE A BIGGER DRUM BEFORE MAXIMIZING THE STOCKER?WE WILL GET 1 IN BISONS CAR AND FIND OUT WHAT THE DEAL IS .JOHN CRAWFORD CALL ME I HAVE A BUNCH OF NEW PARTS FOR YOU TO TEST,NO CHARGE.
IMHO, ultimately mass of the drum/components play/s a significant role in "how much" heat a particular part can take without overstressing components.
Take front brake rotors for example..... the diameter as something to do with the potential stopping power... or available foot lbs of torque absorbtion one can absorb.... but the mass acts much like a capacitor in an electric circuit.... absorbing the heat.... preventing the permanent deformation... warping.... heat checking.... etc....
IMHO the same theory applies to internal transmission components. This is why the thick steels "work"... and the thin steel "don't work" as Chris states. It has everything to do with mass.
I'm not suggesting that we should make everyhting as heavy as possible.... but that components that fail due to heat... will live longer if they have more mass.
Keep it coming... I enjoy tech school..... it is very interesting.
Take front brake rotors for example..... the diameter as something to do with the potential stopping power... or available foot lbs of torque absorbtion one can absorb.... but the mass acts much like a capacitor in an electric circuit.... absorbing the heat.... preventing the permanent deformation... warping.... heat checking.... etc....
IMHO the same theory applies to internal transmission components. This is why the thick steels "work"... and the thin steel "don't work" as Chris states. It has everything to do with mass.
I'm not suggesting that we should make everyhting as heavy as possible.... but that components that fail due to heat... will live longer if they have more mass.
Keep it coming... I enjoy tech school..... it is very interesting.
