Transmission Tuning Tutorial
01-28-2007, 05:57 PM
#16
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Join Date: Aug 2006
Location: Longview, TX
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120 max line pressure has been on that tranny for a little over 35,000 miles with what I would call a 75% from maxed out trans-go shift-kit, and 10,000 of those miles are with a new converter.
Fluid has been clear and untainted that entire time, no leaks, no metal shavings.
Fluid has been clear and untainted that entire time, no leaks, no metal shavings.
02-25-2007, 08:49 PM
#18
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Join Date: Mar 2004
Location: PA
Posts: 146
I have a question. In the up/down shift point tables is there an easy way to change them or do you have to change one at a time? If I put 20 at 0 tps and 70 at 100 tps how would I fill in the rest? Some need to be changed by 3, some 5 and so on. I can't just add or subtract one certain number or percent. Thanks, Ray
02-25-2007, 08:52 PM
#19
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Location: Seattle area
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I use Tunercat's stuff, but I suspect the other editors work similarly. What I do is cut-n-paste to and from Excel to make it easier to edit the values. You can also select the whole table, or a portion of it, and scale/modify the values by right clicking and selecting from the list.
02-26-2007, 08:58 AM
#20
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Join Date: Mar 2004
Location: PA
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I use Tunercat's stuff, but I suspect the other editors work similarly. What I do is cut-n-paste to and from Excel to make it easier to edit the values. You can also select the whole table, or a portion of it, and scale/modify the values by right clicking and selecting from the list.
02-27-2007, 01:05 PM
#22
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Join Date: Mar 2004
Location: PA
Posts: 146
I think this is one of the best threads I have found yet on tunning for shift points. With that being said I want to try and tune my own shift points useing this information.
Here's what I have so far. I went to the caculator on this site and figured out what my speed was supposed to be at a given rpm in a given gear. Now, my max rpm is 6200 do to my mods.
Constant tables: fuel cut off speed=255
fuel resume speed=253
fuel cut off 1st-6th=6510
fuel resume1st-6th=6397
low PRNDL upshift speed threshold=255
low PRNDL downshift speed threshold=255
max line pressure=120
kickdown mode enable tps threshold=89.8
kickdown mode disable tps treshold=85.2
OK, thats it for the constants. On to the other tables. Now when I bring up the normal/performance/cruise mode up/down shift points for the 1st to 2nd I take 41 and enter it in the max because that is what I got from my calculations and 11 for the min and how do I go about filling in the rest? I'm not sure I understand. Let me know how I am doing. I am stoping here till I get some feed back from you guy's. Thanks, Ray
Here's what I have so far. I went to the caculator on this site and figured out what my speed was supposed to be at a given rpm in a given gear. Now, my max rpm is 6200 do to my mods.
Constant tables: fuel cut off speed=255
fuel resume speed=253
fuel cut off 1st-6th=6510
fuel resume1st-6th=6397
low PRNDL upshift speed threshold=255
low PRNDL downshift speed threshold=255
max line pressure=120
kickdown mode enable tps threshold=89.8
kickdown mode disable tps treshold=85.2
OK, thats it for the constants. On to the other tables. Now when I bring up the normal/performance/cruise mode up/down shift points for the 1st to 2nd I take 41 and enter it in the max because that is what I got from my calculations and 11 for the min and how do I go about filling in the rest? I'm not sure I understand. Let me know how I am doing. I am stoping here till I get some feed back from you guy's. Thanks, Ray
02-27-2007, 01:41 PM
#23
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Join Date: Oct 2006
Location: Seattle area
Posts: 477
Filling in the rest is best accomplished by starting with a factory table and tweaking it by driving the car. I actually started from the performance shift table from a F-body, copied it over to the normal shift table and worked from that. The performance shift profile was more like what I wanted.
Of course, you're running a non-stock gear ratio. You will need to scale the stock values appropriately. In the past, I started by figuring out how much to scale by dividing the old ratio by the new ratio. For example, which i upgraded from factory 3.08 gears in my Impala to 3.73: 3.08 / 3.73 = 0.82573726541554959785522788203753. OK, we don't need THAT much precision, let's trim it down to .826.
Now, if the first line in your original shift table is:
11 19 29 11 11 27
...you would multiple each value by 0.826, which, when rounded off, gives you:
9 16 24 9 9 22
Do this for every value in the table. You can easily do this with Tunercat by selecting the whole table, right clicking, select 'Scale', then enter .826.
No guarantees this will get you exactly what you want, but its a great place to start. Drive and tune, drive and tune. I think I went through about 15 program iterations to dial in my Impala transmission *exactly* the way I wanted it.
I'd like to hear from other experts on this, but I am not sure increasing the max line pressure to 120 psi actually does anything. I'm going to start a new thread about this though.
Of course, you're running a non-stock gear ratio. You will need to scale the stock values appropriately. In the past, I started by figuring out how much to scale by dividing the old ratio by the new ratio. For example, which i upgraded from factory 3.08 gears in my Impala to 3.73: 3.08 / 3.73 = 0.82573726541554959785522788203753. OK, we don't need THAT much precision, let's trim it down to .826.
Now, if the first line in your original shift table is:
11 19 29 11 11 27
...you would multiple each value by 0.826, which, when rounded off, gives you:
9 16 24 9 9 22
Do this for every value in the table. You can easily do this with Tunercat by selecting the whole table, right clicking, select 'Scale', then enter .826.
No guarantees this will get you exactly what you want, but its a great place to start. Drive and tune, drive and tune. I think I went through about 15 program iterations to dial in my Impala transmission *exactly* the way I wanted it.
I'd like to hear from other experts on this, but I am not sure increasing the max line pressure to 120 psi actually does anything. I'm going to start a new thread about this though.
02-27-2007, 01:55 PM
#24
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Join Date: Aug 2006
Location: Longview, TX
Posts: 199
I can help a little with max line pressure... adjusting that alone will not do anything, but if you watch datamaster on a run with it maxed and with it not you can see a difference.
You will also need to adjust the main tables that control your line pressures so that it actually achieves those numbers.
Since those tables had already been changed and I didn't want to mess with them, I set my max line pressure back to 90 and took it for a spin, once the tranny had heated up I did some 30%,50%,75% and WOT 1st to 2nd's and noted how firm the shifts were.
There was a significant and noticeable difference from when it was at maximum of 120psi vs 90psi, and datamaster log for the transmission showed that it went to those pressures during the runs.
Bear in mind I also have a trans-go shift kit which has been modded to about 75% of its potential, so that may effect it, but the bottom line is the greater line pressure in the main constants table when it was achieved by the other tables in the actual shift made for a much faster, much stiffer shift.
vgeglia, any chance you can get back to me on the email regarding my A/F tuning questions?
You will also need to adjust the main tables that control your line pressures so that it actually achieves those numbers.
Since those tables had already been changed and I didn't want to mess with them, I set my max line pressure back to 90 and took it for a spin, once the tranny had heated up I did some 30%,50%,75% and WOT 1st to 2nd's and noted how firm the shifts were.
There was a significant and noticeable difference from when it was at maximum of 120psi vs 90psi, and datamaster log for the transmission showed that it went to those pressures during the runs.
Bear in mind I also have a trans-go shift kit which has been modded to about 75% of its potential, so that may effect it, but the bottom line is the greater line pressure in the main constants table when it was achieved by the other tables in the actual shift made for a much faster, much stiffer shift.
vgeglia, any chance you can get back to me on the email regarding my A/F tuning questions?
Last edited by aifilaw; 02-27-2007 at 01:57 PM. Reason: fixed mispellings
02-28-2007, 09:26 AM
#25
Registered User
Join Date: Mar 2004
Location: PA
Posts: 146
Filling in the rest is best accomplished by starting with a factory table and tweaking it by driving the car. I actually started from the performance shift table from a F-body, copied it over to the normal shift table and worked from that. The performance shift profile was more like what I wanted.
Of course, you're running a non-stock gear ratio. You will need to scale the stock values appropriately. In the past, I started by figuring out how much to scale by dividing the old ratio by the new ratio. For example, which i upgraded from factory 3.08 gears in my Impala to 3.73: 3.08 / 3.73 = 0.82573726541554959785522788203753. OK, we don't need THAT much precision, let's trim it down to .826.
Now, if the first line in your original shift table is:
11 19 29 11 11 27
...you would multiple each value by 0.826, which, when rounded off, gives you:
9 16 24 9 9 22
Do this for every value in the table. You can easily do this with Tunercat by selecting the whole table, right clicking, select 'Scale', then enter .826.
No guarantees this will get you exactly what you want, but its a great place to start. Drive and tune, drive and tune. I think I went through about 15 program iterations to dial in my Impala transmission *exactly* the way I wanted it.
I'd like to hear from other experts on this, but I am not sure increasing the max line pressure to 120 psi actually does anything. I'm going to start a new thread about this though.
Of course, you're running a non-stock gear ratio. You will need to scale the stock values appropriately. In the past, I started by figuring out how much to scale by dividing the old ratio by the new ratio. For example, which i upgraded from factory 3.08 gears in my Impala to 3.73: 3.08 / 3.73 = 0.82573726541554959785522788203753. OK, we don't need THAT much precision, let's trim it down to .826.
Now, if the first line in your original shift table is:
11 19 29 11 11 27
...you would multiple each value by 0.826, which, when rounded off, gives you:
9 16 24 9 9 22
Do this for every value in the table. You can easily do this with Tunercat by selecting the whole table, right clicking, select 'Scale', then enter .826.
No guarantees this will get you exactly what you want, but its a great place to start. Drive and tune, drive and tune. I think I went through about 15 program iterations to dial in my Impala transmission *exactly* the way I wanted it.
I'd like to hear from other experts on this, but I am not sure increasing the max line pressure to 120 psi actually does anything. I'm going to start a new thread about this though.
02-28-2007, 09:44 AM
#26
Registered User
Join Date: Mar 2004
Location: PA
Posts: 146
I can help a little with max line pressure... adjusting that alone will not do anything, but if you watch datamaster on a run with it maxed and with it not you can see a difference.
You will also need to adjust the main tables that control your line pressures so that it actually achieves those numbers.
Since those tables had already been changed and I didn't want to mess with them, I set my max line pressure back to 90 and took it for a spin, once the tranny had heated up I did some 30%,50%,75% and WOT 1st to 2nd's and noted how firm the shifts were.
There was a significant and noticeable difference from when it was at maximum of 120psi vs 90psi, and datamaster log for the transmission showed that it went to those pressures during the runs.
Bear in mind I also have a trans-go shift kit which has been modded to about 75% of its potential, so that may effect it, but the bottom line is the greater line pressure in the main constants table when it was achieved by the other tables in the actual shift made for a much faster, much stiffer shift.
vgeglia, any chance you can get back to me on the email regarding my A/F tuning questions?
You will also need to adjust the main tables that control your line pressures so that it actually achieves those numbers.
Since those tables had already been changed and I didn't want to mess with them, I set my max line pressure back to 90 and took it for a spin, once the tranny had heated up I did some 30%,50%,75% and WOT 1st to 2nd's and noted how firm the shifts were.
There was a significant and noticeable difference from when it was at maximum of 120psi vs 90psi, and datamaster log for the transmission showed that it went to those pressures during the runs.
Bear in mind I also have a trans-go shift kit which has been modded to about 75% of its potential, so that may effect it, but the bottom line is the greater line pressure in the main constants table when it was achieved by the other tables in the actual shift made for a much faster, much stiffer shift.
vgeglia, any chance you can get back to me on the email regarding my A/F tuning questions?
How is your Transgo shift kit? I have heard that they are much better than B&M and am thinking about putting one in. Is there alot ti the Transgo?
02-28-2007, 10:09 AM
#27
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Thread Starter
Join Date: Aug 2006
Location: Longview, TX
Posts: 199
The reason to take the stock ratio's and plug in your lower and upper limits and scale based on the stock is because you are used to driving stock...therefore chances are this is what you will like to drive. You can go hog-wild on the tables if your fancy is to have the vehicle shift from 1->2 at 20mph regardless of throttle and RPM, et cetera.
02-28-2007, 10:11 AM
#28
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Join Date: Aug 2006
Location: Longview, TX
Posts: 199
I have a B&M shift kit in mine and I have played with the max line pressure a little bit and didn't notice a difference but I also didn't log any info.
How is your Transgo shift kit? I have heard that they are much better than B&M and am thinking about putting one in. Is there alot ti the Transgo?
How is your Transgo shift kit? I have heard that they are much better than B&M and am thinking about putting one in. Is there alot ti the Transgo?
If you notice the posts in the tranny section about shift kits, you'll see a large trend towards most people thinking they are the best thing since sliced bread. I agree with that.
It will come with install instructions, you can can tune the same shift kit to shift harder or softer by drilling out holes in the plate. It's a little more work, but the instructions are quite good and the end-result is well-worth it in my opinion.
02-28-2007, 10:39 AM
#29
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Join Date: Mar 2004
Location: PA
Posts: 146
I had a more noticeable difference, but like I said, I have a bored out shift kit and new torque converter.
If you notice the posts in the tranny section about shift kits, you'll see a large trend towards most people thinking they are the best thing since sliced bread. I agree with that.
It will come with install instructions, you can can tune the same shift kit to shift harder or softer by drilling out holes in the plate. It's a little more work, but the instructions are quite good and the end-result is well-worth it in my opinion.
If you notice the posts in the tranny section about shift kits, you'll see a large trend towards most people thinking they are the best thing since sliced bread. I agree with that.
It will come with install instructions, you can can tune the same shift kit to shift harder or softer by drilling out holes in the plate. It's a little more work, but the instructions are quite good and the end-result is well-worth it in my opinion.
I just hope that I can install it with the same plate I used for the B&M.
02-28-2007, 10:41 AM
#30
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Join Date: Oct 2006
Location: Seattle area
Posts: 477
A word of caution about line pressure and shift kits.
Chevy High Performance published a tech article (http://www.chevyhiperformance.com/te...ertrain_module) about custom PCM tuning and they consulted with the owner of PCMFORLESS.COM on the subject. The article wrote that increasing line pressure on transmissions with shift kits and/or other modifications that increased the line pressure mechanically can result in blown seals and other broken transmission internals due to excessive line pressure.
At least one custom transmission builder's warranty policy stated the warranty would be void if the PCM's line pressure tables were not stock and there was a component failure.
Of course, the only expertise I have in the 4L60E is breaking them with my heavy right foot. Lol.
Chevy High Performance published a tech article (http://www.chevyhiperformance.com/te...ertrain_module) about custom PCM tuning and they consulted with the owner of PCMFORLESS.COM on the subject. The article wrote that increasing line pressure on transmissions with shift kits and/or other modifications that increased the line pressure mechanically can result in blown seals and other broken transmission internals due to excessive line pressure.
At least one custom transmission builder's warranty policy stated the warranty would be void if the PCM's line pressure tables were not stock and there was a component failure.
Of course, the only expertise I have in the 4L60E is breaking them with my heavy right foot. Lol.
