DCT in a Vette.
10-01-2013, 05:05 PM
#21
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Sequential would be boss.
However, I have heard more than once that they will never be in a production car, because one always has to be able to go from drive to neutral, which in a sequential isnīt possible.
Not sure if thatīs driven by some yahoo at the OEMs or government mandate...
Had a long discussion about this with guys that did the T850.
However, I have heard more than once that they will never be in a production car, because one always has to be able to go from drive to neutral, which in a sequential isnīt possible.
Not sure if thatīs driven by some yahoo at the OEMs or government mandate...
Had a long discussion about this with guys that did the T850.
10-01-2013, 05:26 PM
#22
Team Owner
Brother! What does a SLS cost? What does it weigh? How fast is it around the RIng? Do you think GM will build an 8000 rpm production engine? How high do you think the C7Rs engine will rev.?
Do you honestly think GM is going to build a transaxle like this?
What does this arrangement do to the CG, both longitudinally and vertically? Where do you put the golf clubs? Draw all the shafts with your crayons just for your own amusement. Check the angles of the side shafts. Plan and side view.
Or like this Ferrari FF. I'd would not admit to anybody that I was on this FF drive train design team if I were. I'd be ashamed.
They are both crap solutions and engineering nightmares.
Now, if you were talking sequential, I'd be with you.
Note how compact this is. Note were the single clutch is. Note the position of the gearbox in front of the rear axle. This is a thing of beauty, simplicity, lightness and strength.
Do you know that you can purchase this type of gearbox for your C7 right now? Today? There are some sequentials in Corvette street cars already.
Do you know that the LT1 requires a big flywheel/clutch or a torque converter bolted directly to the end of the crankshaft and they can't be remote? Do you know it can't rev up or down too fast therefore the gearbox does not need to change that fast as a F458 does.
Lastly, for this post anyway, GM will have a very light and strong A8 that will fit into Cadillacs and Vettes pretty soon.
Corvette does not have a transaxle which requires a single casing. This is engineering cost saving geneous which is the mark of GM.
I would like the M7, the A7 and for the hyper Vette, the sequential.
Or, just the sequential with a dry clutch or a torque converter. QED.
Do you honestly think GM is going to build a transaxle like this?
What does this arrangement do to the CG, both longitudinally and vertically? Where do you put the golf clubs? Draw all the shafts with your crayons just for your own amusement. Check the angles of the side shafts. Plan and side view.
Or like this Ferrari FF. I'd would not admit to anybody that I was on this FF drive train design team if I were. I'd be ashamed.
They are both crap solutions and engineering nightmares.
Now, if you were talking sequential, I'd be with you.
Note how compact this is. Note were the single clutch is. Note the position of the gearbox in front of the rear axle. This is a thing of beauty, simplicity, lightness and strength.
Do you know that you can purchase this type of gearbox for your C7 right now? Today? There are some sequentials in Corvette street cars already.
Do you know that the LT1 requires a big flywheel/clutch or a torque converter bolted directly to the end of the crankshaft and they can't be remote? Do you know it can't rev up or down too fast therefore the gearbox does not need to change that fast as a F458 does.
Lastly, for this post anyway, GM will have a very light and strong A8 that will fit into Cadillacs and Vettes pretty soon.
Corvette does not have a transaxle which requires a single casing. This is engineering cost saving geneous which is the mark of GM.
I would like the M7, the A7 and for the hyper Vette, the sequential.
Or, just the sequential with a dry clutch or a torque converter. QED.
Last edited by JoesC5; 10-01-2013 at 05:31 PM.
10-01-2013, 09:30 PM
#23
Safety Car
Thread Starter
Guilty as charged. My bad. Had looked beyond the end of my nose, in this case, the end of the torque tube, I would have found the TC.
The front mounted damper tuning requires a load on the other side of the crankshaft. That was my focus which was at the tip of my nose.
One must always be aware of global factors in any engineering endeavour. I notice you focused on a mute point. It's funny how one accuses others of things that they are guilty of themselves.
I have done work on vibration dampers involving Suburu and Porsche engines in aircraft applications and I knew this was a design consideration.
Anyway, what about the rest of my post? How bout the LFA gearbox? Like?
Since you are being picky, you mention that the 901 gains 46 pounds with the PDK. The cars that have the clutches directly behind the engine have an advantage, don't you think?
The Corvette requires substantial friction surfaces for the two clutch packs in a remote location. You actually compare the two designs, mmmm. The Corvette has a bigger engine also. The gain will be at least twice the weight that you have stated and that is just for the clutch packs. Take a look at the DCT pictures again. What a disaster. That is one heavy mother, complex and expensive and of dubious reliability. How many track days do you think you will get out of that baby?
What does the SLS and the Ferrari cost again?
You also compare the weight of the 6L80 to the TR 6060. If you looked beyond your nose, you know I was talking about the next generation of auto transmissions and torque converters which weigh about the same as the M7.
I understand. It happens to me also.
The DCT in a Vette will weigh more than the ZF A8 and will place the CG out of envelope, vertically as well as longitudinally. What, pray tell, would be the consequences of that?
Keep the engine and transmission between the axles I say.
Fast shifts come with consequences and design factors have to be increased. A torque converter can absorb these loads and with some clever mapping to the staged gear shifts, there need not be any interruption of torque and maybe some multiplication. Check out autos at the drag strip. Watch them lurch during shifts.
There are Mercedes cars with ZF autos that rev beyond 6500. We have moved on. Please keep up. Like the LS engines, the LT1 will not be happy over 7gs and the race car, even less.
The front mounted damper tuning requires a load on the other side of the crankshaft. That was my focus which was at the tip of my nose.
One must always be aware of global factors in any engineering endeavour. I notice you focused on a mute point. It's funny how one accuses others of things that they are guilty of themselves.
I have done work on vibration dampers involving Suburu and Porsche engines in aircraft applications and I knew this was a design consideration.
Anyway, what about the rest of my post? How bout the LFA gearbox? Like?
Since you are being picky, you mention that the 901 gains 46 pounds with the PDK. The cars that have the clutches directly behind the engine have an advantage, don't you think?
The Corvette requires substantial friction surfaces for the two clutch packs in a remote location. You actually compare the two designs, mmmm. The Corvette has a bigger engine also. The gain will be at least twice the weight that you have stated and that is just for the clutch packs. Take a look at the DCT pictures again. What a disaster. That is one heavy mother, complex and expensive and of dubious reliability. How many track days do you think you will get out of that baby?
What does the SLS and the Ferrari cost again?
You also compare the weight of the 6L80 to the TR 6060. If you looked beyond your nose, you know I was talking about the next generation of auto transmissions and torque converters which weigh about the same as the M7.
I understand. It happens to me also.
The DCT in a Vette will weigh more than the ZF A8 and will place the CG out of envelope, vertically as well as longitudinally. What, pray tell, would be the consequences of that?
Keep the engine and transmission between the axles I say.
Fast shifts come with consequences and design factors have to be increased. A torque converter can absorb these loads and with some clever mapping to the staged gear shifts, there need not be any interruption of torque and maybe some multiplication. Check out autos at the drag strip. Watch them lurch during shifts.
There are Mercedes cars with ZF autos that rev beyond 6500. We have moved on. Please keep up. Like the LS engines, the LT1 will not be happy over 7gs and the race car, even less.
Last edited by Shaka; 10-01-2013 at 09:39 PM.
10-01-2013, 09:37 PM
#24
The Consigliere
Member Since: May 2006
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10-01-2013, 10:43 PM
#25
Race Director
Guilty as charged. My bad. Had looked beyond the end of my nose, in this case, the end of the torque tube, I would have found the TC.
The front mounted damper tuning requires a load on the other side of the crankshaft. That was my focus which was at the tip of my nose.
One must always be aware of global factors in any engineering endeavour. I notice you focused on a mute point. It's funny how one accuses others of things that they are guilty of themselves.
I have done work on vibration dampers involving Suburu and Porsche engines in aircraft applications and I knew this was a design consideration.
Anyway, what about the rest of my post? How bout the LFA gearbox? Like?
Since you are being picky, you mention that the 901 gains 46 pounds with the PDK. The cars that have the clutches directly behind the engine have an advantage, don't you think?
The Corvette requires substantial friction surfaces for the two clutch packs in a remote location. You actually compare the two designs, mmmm. The Corvette has a bigger engine also. The gain will be at least twice the weight that you have stated and that is just for the clutch packs. Take a look at the DCT pictures again. What a disaster. That is one heavy mother, complex and expensive and of dubious reliability. How many track days do you think you will get out of that baby?
What does the SLS and the Ferrari cost again?
You also compare the weight of the 6L80 to the TR 6060. If you looked beyond your nose, you know I was talking about the next generation of auto transmissions and torque converters which weigh about the same as the M7.
I understand. It happens to me also.
The DCT in a Vette will weigh more than the ZF A8 and will place the CG out of envelope, vertically as well as longitudinally. What, pray tell, would be the consequences of that?
Keep the engine and transmission between the axles I say.
Fast shifts come with consequences and design factors have to be increased. A torque converter can absorb these loads and with some clever mapping to the staged gear shifts, there need not be any interruption of torque and maybe some multiplication. Check out autos at the drag strip. Watch them lurch during shifts.
There are Mercedes cars with ZF autos that rev beyond 6500. We have moved on. Please keep up. Like the LS engines, the LT1 will not be happy over 7gs and the race car, even less.
The front mounted damper tuning requires a load on the other side of the crankshaft. That was my focus which was at the tip of my nose.
One must always be aware of global factors in any engineering endeavour. I notice you focused on a mute point. It's funny how one accuses others of things that they are guilty of themselves.
I have done work on vibration dampers involving Suburu and Porsche engines in aircraft applications and I knew this was a design consideration.
Anyway, what about the rest of my post? How bout the LFA gearbox? Like?
Since you are being picky, you mention that the 901 gains 46 pounds with the PDK. The cars that have the clutches directly behind the engine have an advantage, don't you think?
The Corvette requires substantial friction surfaces for the two clutch packs in a remote location. You actually compare the two designs, mmmm. The Corvette has a bigger engine also. The gain will be at least twice the weight that you have stated and that is just for the clutch packs. Take a look at the DCT pictures again. What a disaster. That is one heavy mother, complex and expensive and of dubious reliability. How many track days do you think you will get out of that baby?
What does the SLS and the Ferrari cost again?
You also compare the weight of the 6L80 to the TR 6060. If you looked beyond your nose, you know I was talking about the next generation of auto transmissions and torque converters which weigh about the same as the M7.
I understand. It happens to me also.
The DCT in a Vette will weigh more than the ZF A8 and will place the CG out of envelope, vertically as well as longitudinally. What, pray tell, would be the consequences of that?
Keep the engine and transmission between the axles I say.
Fast shifts come with consequences and design factors have to be increased. A torque converter can absorb these loads and with some clever mapping to the staged gear shifts, there need not be any interruption of torque and maybe some multiplication. Check out autos at the drag strip. Watch them lurch during shifts.
There are Mercedes cars with ZF autos that rev beyond 6500. We have moved on. Please keep up. Like the LS engines, the LT1 will not be happy over 7gs and the race car, even less.
10-02-2013, 03:03 AM
#26
The Porsche 911 Carrera 4s has both a 7 speed manual and a 7 speed PDK transmission available.
Curb weight with the manual is 3186 pounds and the curb weight of the7 speed PDK is 3230 Pounds, An increase of 46 pounds over the 7 speed manual.
A 6L80 Corvette transmission weighs ~122-125 pounds more than the TR6060 transmission.
Looks to me that a PDK(DCT) transmission in a Corvette would weigh less than an automatic transmission, shift as fast, if not faster, and the car would weigh less.
GM has said that the auto transmission was not capable of handling engine RPM's over 6,500, not high lateral g's on the track. It would seem to me that both of those restrictions would be a hindrance in designing high performance sports car.
Curb weight with the manual is 3186 pounds and the curb weight of the7 speed PDK is 3230 Pounds, An increase of 46 pounds over the 7 speed manual.
A 6L80 Corvette transmission weighs ~122-125 pounds more than the TR6060 transmission.
Looks to me that a PDK(DCT) transmission in a Corvette would weigh less than an automatic transmission, shift as fast, if not faster, and the car would weigh less.
GM has said that the auto transmission was not capable of handling engine RPM's over 6,500, not high lateral g's on the track. It would seem to me that both of those restrictions would be a hindrance in designing high performance sports car.
Also, there are many 6L80s in Z06s where the LS7 redlines at 7000 RPM...clearly 6500 RPM is not a limitation. And it's never been said a 6L80 isn't capable of high g road course work.
10-02-2013, 08:35 AM
#27
Safety Car
Thread Starter
The Corvette 6L80 weighs 229 lbs while the TR6060 weighs 121 lbs (according to Tremec) for a difference of 108 lbs. The 6L80 weight includes the torque converter, however the TR6060 weight doesn't include the clutch/flywheel, the clutch pedal/linkage, or the clutch hydraulics. The clutch/flywheel alone is about 60 lbs bringing the difference to only 48 lbs which is about the difference between the Porsche 7M and PDK. Looks like the DCT would come in close to the 6L80.
Also, there are many 6L80s in Z06s where the LS7 redlines at 7000 RPM...clearly 6500 RPM is not a limitation. And it's never been said a 6L80 isn't capable of high g road course work.
Also, there are many 6L80s in Z06s where the LS7 redlines at 7000 RPM...clearly 6500 RPM is not a limitation. And it's never been said a 6L80 isn't capable of high g road course work.
The 6L80 does have oil pick up problems when the car has wings and slicks and there can be slippage in high G turns. Tadge mentioned it but I don't know what has been done on the Z51 to address this. I expect a real cool A8 in the C7 soon. It may first appear in the high performance C7, the one with the big brakes.
10-02-2013, 08:49 AM
#28
Yeah, he presents his material in a political manor. Though accurate, it is highly selective and disingenuous. Engineering is all encompassing and you simply can'r be 'dishonest'. Natural law is the truth, and nothing but the truth.
The 6L80 does have oil pick up problems when the car has wings and slicks and there can be slippage in high G turns. Tadge mentioned it but I don't know what has been done on the Z51 to address this. I expect a real cool A8 in the C7 soon. It may first appear in the high performance C7, the one with the big brakes.
The 6L80 does have oil pick up problems when the car has wings and slicks and there can be slippage in high G turns. Tadge mentioned it but I don't know what has been done on the Z51 to address this. I expect a real cool A8 in the C7 soon. It may first appear in the high performance C7, the one with the big brakes.
10-02-2013, 11:47 AM
#30
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Assuming shifting issues (shifts when the driver wants it to not when it wants to) can be resolved the real problem with using a torque convertor based auto on a road course is heat from the torque convertor. I have a friend with a supercharged C5. The car was basically setup for drag racing with a high stall convertor but he has progressed into road courses since they are a lot more fun. He trashed the tranny two times before the builder told him the torque convertor was generating too much heat. Too resolve that my friend used his tuning software to keep the TCC locked up even when shifting. That has reduced the transmission over heating issues since the convertor isn't generating as much heat and made the transmission predictable from a shift standpoint.
Bill
Bill
10-02-2013, 05:54 PM
#32
10-02-2013, 06:40 PM
#33
Safety Car
Thread Starter
Sequential would be boss.
However, I have heard more than once that they will never be in a production car, because one always has to be able to go from drive to neutral, which in a sequential isnīt possible.
Not sure if thatīs driven by some yahoo at the OEMs or government mandate...
Had a long discussion about this with guys that did the T850.
However, I have heard more than once that they will never be in a production car, because one always has to be able to go from drive to neutral, which in a sequential isnīt possible.
Not sure if thatīs driven by some yahoo at the OEMs or government mandate...
Had a long discussion about this with guys that did the T850.
Last edited by Shaka; 10-02-2013 at 06:43 PM.
10-02-2013, 07:13 PM
#36
Safety Car
Thread Starter
The clutch and the actual shift is fly by wire. Like F1 cars, this is easily made automatic.
The are street going C5 and 6 driving around the USA with padel shift sequentials. The LFA is the most refined for street and I would love to see something like that for the super Vette.
10-02-2013, 07:18 PM
#37
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I know what you are talking about, I just always wanted a car with a fully manual, all mechanical sequential gear box.
That would just be the best thing since ... ever.
To me anyway.
Only plug and play application I know is for Nissan 6 cylinder cars though and the ones I like aren't legal to import yet. Give it a few more years and I might add one to the collection
That would just be the best thing since ... ever.
To me anyway.
Only plug and play application I know is for Nissan 6 cylinder cars though and the ones I like aren't legal to import yet. Give it a few more years and I might add one to the collection
10-02-2013, 07:35 PM
#38
Safety Car
Thread Starter
I know what you are talking about, I just always wanted a car with a fully manual, all mechanical sequential gear box.
That would just be the best thing since ... ever.
To me anyway.
Only plug and play application I know is for Nissan 6 cylinder cars though and the ones I like aren't legal to import yet. Give it a few more years and I might add one to the collection
That would just be the best thing since ... ever.
To me anyway.
Only plug and play application I know is for Nissan 6 cylinder cars though and the ones I like aren't legal to import yet. Give it a few more years and I might add one to the collection
10-02-2013, 07:57 PM
#39
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LOL.
Yeah... NO.
You can get the trans for the Nissan for 5k and the car for 15... so, if I ever get one, it's probably going to be that route. Plus, that way it's a proper shifter without the cables.
Not hating on the C5/6/7s, but let's face it, nothing beats a linkage for shift feel.
Yeah... NO.
You can get the trans for the Nissan for 5k and the car for 15... so, if I ever get one, it's probably going to be that route. Plus, that way it's a proper shifter without the cables.
Not hating on the C5/6/7s, but let's face it, nothing beats a linkage for shift feel.
