shift extension problem w/new yank TC
07-04-2008, 09:16 PM
#1
shift extension problem w/new yank TC SS3600 shift extension is supossed to be around 4900rpm, mine is falling to about 4200-4300 after the 1-2 and 2-3 shifts during WOT. RPMs look like they hang at 48-4900 briefly then drop rpm to 4250. Shifting out of first at almost 6200 and out of second at around 6100. I have HPTuners and can make adjustments I just dont know WTF to adjust.
or
is this converter NFG?
or
is this converter NFG?
07-04-2008, 10:04 PM
#2
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Who told you that a bolton ls1 shifting at 6100 rpm is going to have an extension of 4900 with the SS3600?
My stroker LT1 makes 460 SAE rwhp locked through a 12 bolt and with the SS3600 converter shifting at 6750ish would drop down to 4990 rpm on the 2-3 and 4900 on the 1-2. They are a very efficient converter and stay hyd locked at lower rpm's,. Maybe not the greatest for cammed cars but work very well for most. I had mine restalled to SS4000 and I'm alot happier. On a hot day about a month ago my times did not change but .04 from first run to the last.
Also, do you have your shift crap turned off...I'm assuming you do or you would feel it nose over on the shifts....
My stroker LT1 makes 460 SAE rwhp locked through a 12 bolt and with the SS3600 converter shifting at 6750ish would drop down to 4990 rpm on the 2-3 and 4900 on the 1-2. They are a very efficient converter and stay hyd locked at lower rpm's,. Maybe not the greatest for cammed cars but work very well for most. I had mine restalled to SS4000 and I'm alot happier. On a hot day about a month ago my times did not change but .04 from first run to the last.
Also, do you have your shift crap turned off...I'm assuming you do or you would feel it nose over on the shifts....
Last edited by jimbob; 07-04-2008 at 10:10 PM.
07-04-2008, 10:56 PM
#3
torque management is all off. Dave at Yank told me it would have the ~4900rpm shift extension. Looking at the log I notice the TCC mode is --3-- , have no clue what that means but it didnt do that before I put in the yank. The rpms do hesitate at 4800 or so, but then drop down.
07-05-2008, 01:10 AM
#4
I noticed the same thing logging my runs with the SS3600. Shift extension is identical to what it was with my TCI 3000. 4200-4300 1-2, 4500 2-3.
My theory is that "shift extension" is not what it's often made out to be ... I think there are some physical limitations in converter design that keep it within a certain range at a given power level.
My theory is that "shift extension" is not what it's often made out to be ... I think there are some physical limitations in converter design that keep it within a certain range at a given power level.
07-05-2008, 01:50 AM
#5
I had a fuddle 3600 and my shift extension with that was 4800 rpm, I'm really hoping the Yank can match that cuz if not I wasted money. I'll try changing shift times and pressures, maybe even shift points. Hopefully someone with knowledge on this will chime in.
07-05-2008, 04:01 AM
#6
The SS3600 will likely have 4300-4500 SE if it's a basically stock LS1 or with just a few bolt-ons. A heavier car or higher HP/TQ set up will bump the SE up a bit.
You might try just raising the shift points by a couple 100 rpm and see if the SE follows. I bet with 6500 rpm shifts points, it'll all come together for you.
Good luck!
You might try just raising the shift points by a couple 100 rpm and see if the SE follows. I bet with 6500 rpm shifts points, it'll all come together for you.
Good luck!
07-05-2008, 09:49 AM
#7
The SS3600 will likely have 4300-4500 SE if it's a basically stock LS1 or with just a few bolt-ons. A heavier car or higher HP/TQ set up will bump the SE up a bit.
You might try just raising the shift points by a couple 100 rpm and see if the SE follows. I bet with 6500 rpm shifts points, it'll all come together for you.
Good luck!
You might try just raising the shift points by a couple 100 rpm and see if the SE follows. I bet with 6500 rpm shifts points, it'll all come together for you.
Good luck!
is it safe to shift a stock internal LS1 at 6500 rpm?
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07-05-2008, 10:02 AM
#8
"Safe" is an interesting term. The only way to be safe is to not mod your car. LOL
As far as the tranny is concerned, I think 6500 RPM shift point is still in the "Safe" range. It has been widely discussed that RPM is a big killer of the 4L60E. So the higher you spin it, the more unsafe it becomes. But it will make you faster
Chris
As far as the tranny is concerned, I think 6500 RPM shift point is still in the "Safe" range. It has been widely discussed that RPM is a big killer of the 4L60E. So the higher you spin it, the more unsafe it becomes. But it will make you faster
Chris
07-05-2008, 10:39 AM
#9
how about, will a stock internal LS1 be able to handle shifting at 6500rpm? I have a 30,000gvw cooler and the trans temps dont get over 180*, I wasn't very worried about the trans until you said that but now I'm wondering about it.
07-05-2008, 07:02 PM
#10
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you have about the same mods as i do. My fuddle 3,800 has a se of 5k-5,100 or so rpm per sift. A stock ls1 like yours with thoes mods wont handle spinning 6,500 rpm, you will definately get valve float and cause all kinds of other damage not to mention your probably so far out of the motors power band. Did you ever have the car dynoed. My car starts droping power right around 5,800 rpm which is why stock shift points are around 6k. Currently i have mine set to shift @6,200 rpm with the rev limiter set around 6,300 rpm. You also need to check the mph per shift table and see what its set to shift at. The computer needs to see that the mph is meet and the rpm is meet to make the shift.
07-05-2008, 07:35 PM
#11
Where are you located?
Yeah one persons idea of safe is going to different than the next guys. The stock bottom end isn't going to have an issue with 6500 rpm shifts, but if you have stock springs, it ain't gonna like it.
Something isn't adding up if you really do have a 2000 rpm drop between shifts.
Yeah one persons idea of safe is going to different than the next guys. The stock bottom end isn't going to have an issue with 6500 rpm shifts, but if you have stock springs, it ain't gonna like it.
Something isn't adding up if you really do have a 2000 rpm drop between shifts.
07-05-2008, 09:08 PM
#12
I'm in central california, fresno.
I logged a run this moring, 1-2 shift @ just over 6200rpm dropped to 4550rpm. Looking at the log file I noticed a few things. On the graph I notice the rpms stop/hesitate at 4900rpm and wheel speed goes up to 60 then drops to 51mph and at the same time the rpms drop to 4559. Also during all this the TCC slip goes negative, about 400 rpm or so. I can upload the log data/tune if it would help any, I'm using HPTuners.
I logged a run this moring, 1-2 shift @ just over 6200rpm dropped to 4550rpm. Looking at the log file I noticed a few things. On the graph I notice the rpms stop/hesitate at 4900rpm and wheel speed goes up to 60 then drops to 51mph and at the same time the rpms drop to 4559. Also during all this the TCC slip goes negative, about 400 rpm or so. I can upload the log data/tune if it would help any, I'm using HPTuners.
07-05-2008, 09:43 PM
#13
Car has not been on a dyno for awhile. Last time is was on a dyno the only mods were Lid, ported throttle body, LM1, and the EGR tube inside the intake cut off. The car made 335tq and 330rwhp. Shift points and rpm are good, the car is shifting, and shifting well. I'm currently adding shift pressure to those tables and adjusting desired shift time, which I may need to just zero out those tables if I'm reading things correctly.
you have about the same mods as i do. My fuddle 3,800 has a se of 5k-5,100 or so rpm per sift. A stock ls1 like yours with thoes mods wont handle spinning 6,500 rpm, you will definately get valve float and cause all kinds of other damage not to mention your probably so far out of the motors power band. Did you ever have the car dynoed. My car starts droping power right around 5,800 rpm which is why stock shift points are around 6k. Currently i have mine set to shift @6,200 rpm with the rev limiter set around 6,300 rpm. You also need to check the mph per shift table and see what its set to shift at. The computer needs to see that the mph is meet and the rpm is meet to make the shift.
07-05-2008, 11:04 PM
#14
Car has not been on a dyno for awhile. Last time is was on a dyno the only mods were Lid, ported throttle body, LM1, and the EGR tube inside the intake cut off. The car made 335tq and 330rwhp. Shift points and rpm are good, the car is shifting, and shifting well. I'm currently adding shift pressure to those tables and adjusting desired shift time, which I may need to just zero out those tables if I'm reading things correctly.
Its strongly suggested that you do not raise shift presure tables above stock we already set the MAX psi at 225-230 which is as much as it should ever be
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07-05-2008, 11:29 PM
#16
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what does your mph table look like. As for what i can tell you have the shift rpm table set at 6,200 which is fine. As said before you really don't want to mess with the pressures too much as things internally have been done to the trans already to improve fluid flow as well as pressure. Wish i had my hp tuners program already so i could take a look at what you got. Let me know the mph table you have for up shifting and down shifting.