Torque cut module for face plated and dog engagement gear sets
03-19-2011, 02:09 PM
#1
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Torque cut module for face plated and dog engagement gear sets We have been doing some development work over the winter on a version of our LNC 2-step module to provide a momentary torque cut on the gear change for use with face plated, pro-cut, dog engagement and other similar gears sets in order to allow you to do a full throttle, no clutch shift.
On these transmissions you want a momentary torque cut to allow the transmission to get out of one gear and into the next. Many racing and aftermarket engine management systems have provisions for this (Motec, Bigstuff3, Bosch Motorsports etc.) so we wanted to have the same capability with the OEM GM controllers.
We are now at the in-vehicle testing stage and have been doing the testing on our 2010 LS9 Camaro SS. This vehicle weighs over 4100 lbs and currently makes over 1200 rwhp hp with both stages of nitrous (I can post a link to more details of the vehicle build if people are interested).
Here is a link to video of our latest testing on the chassis dynamometer:
http://www.youtube.com/watch?v=Fcb-JS4HAuM
The first run shown in the video is before we had all of the settings working properly and the shift didn't take place properly. You can see the misfire event under the car when it happened (exhaust exists under the vehicle). The second and third pulls show clean 3-4 WOT clutchless shifts at around 7200 rpm under full power. The mass air flow (MAF) signal barely drops during the shift (YES - we are still running MAF at this power level).
We are testing in vehicle simulation mode so the Mustang dynamometer is simulating the weight of the vehicle and the aerodynamic load so it should be fairly similar to what we will see at the track.
Our next round of testing will be at the track.
We are also sending a few of these out to specific customers for additional in vehicle testing. We hope to be able to release the product to the public soon after we get more in vehicle testing completed, hopefully in the next month or so.
The product will retain the one stage of 2-step. The other set of adjustments is for the level of load to be considered a shift initiation and the amount of time the torque cut is be applied.
We are using a load cell in the shifter to determine that a shift is in progress. The load cell is powered by the 5 volt regulated output from our torque cut module. The load cell output is 2.5 volts +/_ 2 volts with no load being 2.5 volts and then up to +4.5 volts when loaded by pushing forward on the shifter and then down to 0.5 volts when the shifter is pulled back.
If you have feedback on features you would like to see or any other constructive comments, we are interested in hearing from you.
Attached are pictures of the load cell shifter and of the label on the torque cut module showing the activation input voltage change levels and the torque cut time interval.
On these transmissions you want a momentary torque cut to allow the transmission to get out of one gear and into the next. Many racing and aftermarket engine management systems have provisions for this (Motec, Bigstuff3, Bosch Motorsports etc.) so we wanted to have the same capability with the OEM GM controllers.
We are now at the in-vehicle testing stage and have been doing the testing on our 2010 LS9 Camaro SS. This vehicle weighs over 4100 lbs and currently makes over 1200 rwhp hp with both stages of nitrous (I can post a link to more details of the vehicle build if people are interested).
Here is a link to video of our latest testing on the chassis dynamometer:
http://www.youtube.com/watch?v=Fcb-JS4HAuM
The first run shown in the video is before we had all of the settings working properly and the shift didn't take place properly. You can see the misfire event under the car when it happened (exhaust exists under the vehicle). The second and third pulls show clean 3-4 WOT clutchless shifts at around 7200 rpm under full power. The mass air flow (MAF) signal barely drops during the shift (YES - we are still running MAF at this power level).
We are testing in vehicle simulation mode so the Mustang dynamometer is simulating the weight of the vehicle and the aerodynamic load so it should be fairly similar to what we will see at the track.
Our next round of testing will be at the track.
We are also sending a few of these out to specific customers for additional in vehicle testing. We hope to be able to release the product to the public soon after we get more in vehicle testing completed, hopefully in the next month or so.
The product will retain the one stage of 2-step. The other set of adjustments is for the level of load to be considered a shift initiation and the amount of time the torque cut is be applied.
We are using a load cell in the shifter to determine that a shift is in progress. The load cell is powered by the 5 volt regulated output from our torque cut module. The load cell output is 2.5 volts +/_ 2 volts with no load being 2.5 volts and then up to +4.5 volts when loaded by pushing forward on the shifter and then down to 0.5 volts when the shifter is pulled back.
If you have feedback on features you would like to see or any other constructive comments, we are interested in hearing from you.
Attached are pictures of the load cell shifter and of the label on the torque cut module showing the activation input voltage change levels and the torque cut time interval.
03-20-2011, 11:00 AM
#5
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Thread Starter
Target price The target price is for the LNC-TC1 is to be under $300. That will not include the shifter load cell (or the transmission).
03-20-2011, 11:04 AM
#6
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03-20-2011, 01:07 PM
#7
Liberty modified the gears and sliders and Morris Motorsports(former sponsor) assembled the trans. I was thinking about sending in my LNC-003 to have it updated with the new logic you guys come out with, but I might just wait till this comes out. Would you say using the torque cut and no clutch is about as hard on the trans as no cut and using the clutch?
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03-22-2011, 09:55 AM
#9
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Lnc-tc1 I don't really have enough test data/torn down transmissions to tell you for sure but I would guess that torque cut is going to be harder on the transmission unless you run a fairly long torque cut. We are trying to run the torque cut for as short as possible and still be able to make the shift. We expect some transmission service interval will be needed (especially at our hp and vehicle weight level).
The LNC-003 won't be able to be updated to the LNC-TC1. The LNC-TC1 needs inputs that don't exist on the LNC-003. We might be able to convert existing LNC-002's but I have to see if that makes sense from a cost/time standpoint.
The LNC-003 won't be able to be updated to the LNC-TC1. The LNC-TC1 needs inputs that don't exist on the LNC-003. We might be able to convert existing LNC-002's but I have to see if that makes sense from a cost/time standpoint.
Liberty modified the gears and sliders and Morris Motorsports(former sponsor) assembled the trans. I was thinking about sending in my LNC-003 to have it updated with the new logic you guys come out with, but I might just wait till this comes out. Would you say using the torque cut and no clutch is about as hard on the trans as no cut and using the clutch?
03-22-2011, 10:17 AM
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Those without straight cut would probably benefit from a long torque cut. Really wouldn't slow the car but would be easy on the gearset. Im picky about my shifter and I know that loadcell would be pricey and its not my style.
03-22-2011, 01:55 PM
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Yea the shifter is way to ricer looking as Im old school stick and white ball type. If Im not mistaken I have seen load cell shifters from $300 to over 1k. I applaud Ligenfelter for their continued development of LS based high quality products.
04-02-2011, 06:24 PM
#15
04-18-2011, 10:38 AM
#18
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Testing I will post some acceleration/data acquisition data from our testing at Muncie and then our testing at the Camaro5 event in Arizona.
At 800 rwhp the system is working very well. At 1250 rwhp/1300+ rwlb-ft we are having trouble getting the transmission out of gear. We tried disabling the nitrous just before the shift but that didn't work (probably due to the time lag in the nitrous flow and the engine acceleration rate). We are making too much torque to get the transmission to disengage.
We have to do some more testing to see if it is time lag/acceleration rate related. In 1st gear we are accelerating at roughly 3600 rpm/sec.
At 800 rwhp the system is working very well. At 1250 rwhp/1300+ rwlb-ft we are having trouble getting the transmission out of gear. We tried disabling the nitrous just before the shift but that didn't work (probably due to the time lag in the nitrous flow and the engine acceleration rate). We are making too much torque to get the transmission to disengage.
We have to do some more testing to see if it is time lag/acceleration rate related. In 1st gear we are accelerating at roughly 3600 rpm/sec.