Stall selection based on peak torqe?
05-13-2014, 06:43 AM
#1
Stall selection based on peak torqe? I'm trying to select a stall that would make the most sense by where the power is at in the car's rpm range. I want to use the power effectively and not just toss a monster stall in the car.
I read in various places stall selection should be 500-700rpm below the car's torque peak. Is that really the magic behind proper selection? (flame suit is on for the high stall guys) lol
Now if that's the general rule to go by looking at my dyno chart it looks like peak torque is around 4700rpm. So stall should be 4000-4200rpm. Any thoughts on that?
What about shift extension? Is there any thoughts on where a shift extension should be to effectively use the power according to the graph?
I read in various places stall selection should be 500-700rpm below the car's torque peak. Is that really the magic behind proper selection? (flame suit is on for the high stall guys) lol
Now if that's the general rule to go by looking at my dyno chart it looks like peak torque is around 4700rpm. So stall should be 4000-4200rpm. Any thoughts on that?
What about shift extension? Is there any thoughts on where a shift extension should be to effectively use the power according to the graph?
Last edited by senicalj4579; 05-13-2014 at 06:55 AM.
05-13-2014, 07:30 AM
#2
My shift extension with the SS4000 is around 5600-5700 rpms!
Get your Yank restalled to a SS4000 and knock me out of the 25th spot from the https://ls1tech.com/forums/drag-raci...ck-ci-h-c.html!
Not only will your ET drop, your mph "may" go up as well (keeps it up there in powerband)!
Get your Yank restalled to a SS4000 and knock me out of the 25th spot from the https://ls1tech.com/forums/drag-raci...ck-ci-h-c.html!
Not only will your ET drop, your mph "may" go up as well (keeps it up there in powerband)!
05-13-2014, 07:52 AM
#4
My shift extension with the SS4000 is around 5600-5700 rpms!
Get your Yank restalled to a SS4000 and knock me out of the 25th spot from the https://ls1tech.com/forums/drag-raci...ck-ci-h-c.html!
Not only will your ET drop, your mph "may" go up as well (keeps it up there in powerband)!
Get your Yank restalled to a SS4000 and knock me out of the 25th spot from the https://ls1tech.com/forums/drag-raci...ck-ci-h-c.html!
Not only will your ET drop, your mph "may" go up as well (keeps it up there in powerband)!
Yes my car being at 10.9 currently is being denied top 25 thanks to you! LOL!
05-13-2014, 08:06 AM
#6
The 2E you're looking at has shift extensions well into the 6000s depending on your max RPM.... It only drops 800 RPM and will have 5% slip or less at the top. Super efficient with a lot of shift extension. The 3E is even bigger. Talk to Chris about which would maximize your ET.
05-13-2014, 08:08 AM
#7
I don't have a graph, but my tuner logged the rpm drop, along with looking at the gauge. Yes! The SS4000 will wake it up, along with 1.4 60s (traction permitting). Not if you get it restalled. You can thank me later. 
My cars torque goes down hill after 4700-4800rpm so wouldn't I need a converter with an extension that falls just below the torque peak?
Yes my car being at 10.9 currently is being denied top 25 thanks to you! LOL!
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05-13-2014, 08:09 AM
#8
FormerVendor
It really just depends lol. Some combos like the fastest average torque (lets say a combo that doesn't just completely fall off after peak torque). Some are fastest shifting at peak hp and getting your typical 1200-1500 rpm drop. And yet some are just as fast with only a 600 rpm drop (not as common, but I have seen it). Also other factors are rear gear, which trans, car weight, etc. A stock LS1 in front of a glide in a rail car won't want the same converter as a stock LS1 in an Fbody with a 4L60E.
05-13-2014, 08:11 AM
#9
The 2E you're looking at has shift extensions well into the 6000s depending on your max RPM.... It only drops 800 RPM and will have 5% slip or less at the top. Super efficient with a lot of shift extension. The 3E is even bigger. Talk to Chris about which would maximize your ET.
I think I have it narrowed down to 1e vs 2e. 6k extension?
05-13-2014, 08:16 AM
#10
Normally you want your stall speed as close to peak torque as possible, but these ls motors seem to come in so high your kind of stuck having to be a bit lower to keep them efficient up top, as far as shift drop you also want to keep them fairly loose so you can use the hp because you have alot more hp then torque. I normally aim for stall speed to be 2500 rpm below the peak hp and drop 1000 rpm on the shifts with a setup like yours. I would recommend a ss4000
05-13-2014, 08:38 AM
#11
It really just depends lol. Some combos like the fastest average torque (lets say a combo that doesn't just completely fall off after peak torque). Some are fastest shifting at peak hp and getting your typical 1200-1500 rpm drop. And yet some are just as fast with only a 600 rpm drop (not as common, but I have seen it). Also other factors are rear gear, which trans, car weight, etc. A stock LS1 in front of a glide in a rail car won't want the same converter as a stock LS1 in an Fbody with a 4L60E.
Normally you want your stall speed as close to peak torque as possible, but these ls motors seem to come in so high your kind of stuck having to be a bit lower to keep them efficient up top, as far as shift drop you also want to keep them fairly loose so you can use the hp because you have alot more hp then torque. I normally aim for stall speed to be 2500 rpm below the peak hp and drop 1000 rpm on the shifts with a setup like yours. I would recommend a ss4000
05-13-2014, 09:37 AM
#12
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You wont get a 6k extension with a 6500 shift, lets make that clear. As you get into a more aggressive stall, you combo should match.....directly related to this discussion: shift rpm. Where are you planning to shift at now that your transmission will be able to take it?? That's an important question in my book. I'll quote Yank when I say - I'm shifting at 6400, "then the SS series is probably what you want." Well, what about the PT series..."you want more rpm for it, high 6ks and up for shift rpm." So I stuck with the SS at that point. Next time I will go more aggressive.
05-13-2014, 09:43 AM
#13
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2 things, 1. if you can spring the extra dough, and 2. if you can tolerate a little less streetability, my official recommendation is a PT4k. Since the SS3600 didn't appear to bother you, I think you will get used to a PT series quickly. Have you seen some of the driving videos with the PT series, that thing is wicked.
Check these out:
https://ls1tech.com/forums/multimedi...uge-shots.html
Check these out:
https://ls1tech.com/forums/multimedi...uge-shots.html
05-13-2014, 10:05 AM
#14
You wont get a 6k extension with a 6500 shift, lets make that clear. As you get into a more aggressive stall, you combo should match.....directly related to this discussion: shift rpm. Where are you planning to shift at now that your transmission will be able to take it?? That's an important question in my book. I'll quote Yank when I say - I'm shifting at 6400, "then the SS series is probably what you want." Well, what about the PT series..."you want more rpm for it, high 6ks and up for shift rpm." So I stuck with the SS at that point. Next time I will go more aggressive.
unless the tuner sees it will benefit to change that IDK. Yeah I guess that is important info that I don't have a lot of my fault.
2 things, 1. if you can spring the extra dough, and 2. if you can tolerate a little less streetability, my official recommendation is a PT4k. Since the SS3600 didn't appear to bother you, I think you will get used to a PT series quickly. Have you seen some of the driving videos with the PT series, that thing is wicked.
Check these out:
https://ls1tech.com/forums/multimedi...uge-shots.html
Check these out:
https://ls1tech.com/forums/multimedi...uge-shots.html
05-13-2014, 12:32 PM
#15
If you spin to 6800 (which you should) then you'l get 6k shift extension out of the 2E.
It's essentially a PT 4000 with less STR.
I wanted something that would absolutely fly on the street. Frum roll and from a dig with drag radials. It hits slightly less hard, but is more consistent and more efficient. So it won't blow drags off, allowing you to hook up consistently and fly.
One other thing: due to the plastic intake harmonic resonance, all LS1s essentially peak at 4800 on torque. If you have an IVC of 48 or higher with lots of overlap, you can "double-hump" the curve and cause a second peak torque of around 5500. In which case, a 4000 is too small. Your cam isn't that big. So a 4000 is right. Under the second set of circumstances, you'd need a 4800/5000 stall. And a redline of 7400 or so.
It's essentially a PT 4000 with less STR.
I wanted something that would absolutely fly on the street. Frum roll and from a dig with drag radials. It hits slightly less hard, but is more consistent and more efficient. So it won't blow drags off, allowing you to hook up consistently and fly.
One other thing: due to the plastic intake harmonic resonance, all LS1s essentially peak at 4800 on torque. If you have an IVC of 48 or higher with lots of overlap, you can "double-hump" the curve and cause a second peak torque of around 5500. In which case, a 4000 is too small. Your cam isn't that big. So a 4000 is right. Under the second set of circumstances, you'd need a 4800/5000 stall. And a redline of 7400 or so.