What is it like driving a stalled auto?
11-29-2017, 07:30 PM
#22
1. Without forced induction, you usually get about half of a random stock engine's capability.
2. The max output possible is based on the compressor, not the engine.
i.e. if I want to know how much power a combo makes, I can tell it's max output without looking at the engine, all I have to do is look at the turbo.
In this way, a vehicle with no engine, lets pretend it only has a trans and turbo on it. I can still call this a "1000 horsepower car" even though there is no engine installed, it is still "1000 horsepower capable" because of the turbo. Likewise if the turbo only supports 300 I can call it a 300 horsepower car.
What I can't do, is upgrade the engine fully/any (head/cam/intake) and get even 1 more horsepower out of it, not without changing the turbo.
Once you see its all about the size of the air compressor, you stop looking inside the engine for power. I can make the same 500 horsepower using a 2.0L or 5.0L engine as long as my compressor flows 500 horsepower.
So if I have a 600 horsepower turbo on the car, I can install any 4.8, 5.3, 6.0, LS size V8 engine and make 600 horsepower. It wouldn't matter if there are any upgrades/etc... The only thing that can happen is I can exceed the limitation of one of the OEM parts. For example valve springs probably won't live past a certain point and they would need an upgrade. The trick for budget enthusiasts is finding an engine where all or most of the OEM parts come "prepped" to hit that 200% or beyond output number. A couple that come to mind are the LS of course, and the 2jz-gte, 4g63, sr20det, RB25/6, Those seem the most popular and all of them have OEM capacity more or less for around double output figures, or beyond. For example I have seen OEM 2jz-gte from 2004 Aristo produce 550ft*lbs of torque at 3000rpm and over 800rwhp on the OEM internals. Those things are only 3.0L but again- we aren't looking at the engine.
11-30-2017, 02:03 PM
#25
A bigger stall slips below its stall speed and slips worse if it's a looser stall or less if it's tighter. So a 4000 is looser than a 3600. But you can design a 4000 that feels "tight" and performs closer to a looser 3600. The stall speed is simply determined by the stall size, stator design, and number of fins and their angle.
So, for example, a stator designed for nitrous or a blower will feel tighter than one designed for NA performance. So two 3600s could feel different because of how they slip. But are rated to 3600 because that's where you can foot brake the stall to before the car lurches forward. So that's why it's important to look at the stall speed, the STR, and the overall efficiency of a converter for how you intend to use it.
However, back to my original analogy of the 3600s. Both are slipping until they get to about 3600. So they are generating heat. Also, your throttle input is sort of wasted, because the car doesn't accelerate like it does when locked up or with a manual. Instead, with a loud exhaust, you just hear RPMs rise without much forward acceleration. The tighter the stall, the less of this you have.
But once you hit your stall speed, the converter couples and you begin getting torque multiplication. The car then accelerates like a slingshot until it essentially arrives to a 1:1 multiplication somewhere above 6k. Give it a lot of throttle input at first, and it flashes to its stall speed quickly, and you blow the tires off and accelerate like crazy.
Then you have shift extension. Once you shift, let's say 6700, and it drops back to 5900 on the 1-2, you have a pretty good stall matched to the combo, keeping you in your powerband. Again, you're riding sort of the "slingshot" coupling ability of the converter, so you're getting a lot of torque multiplication at the start of the next gear as the car catches up to the engine. But if the stall falls back to say 5400... it's too tight, and you need to loosen it up. Which could make drivability less than ideal.
So a converter is about balancing drivability and performance. More rear gear helps a looser stall driver tighter and it also helps with shift extension. Because again, the converter is multiplying torque a lot and is pushing engine RPMs up and waiting on the rear gear and tires to catch up. So having more gear, speeds that process up and also gives the car more mechanical advantage.
At lockup... they drive exactly like stock.
I've been driving a loose 4000 stall for 3 years. With a 3.23 and then a 3.73. The 3.73 made it nicer around town and helped a little with shift extension. I see usually 2500-3000 to keep up with traffic. But if I give it a little more throttle and jump up to 4k, I leave the traffic behind. And anything over 4k and the car is gone. But I was seeing 5600 shift extensions on a 7000 shift point on my 2-3 shift. So the converter was actually too tight for my combination and needed to be loosened. But it would drive worse because of it.
So, I decided to go with a much tighter 3600 triple disk next. It's designed for a blower, which is next on my list of things to do. But it'll be interesting to see where the shift extension is with this combo. I expect to see probably 5200 on the shift... so obviously, it'll slow down a lot. But add boost back in and I expect it to be 6300-6400 or so.
So, for example, a stator designed for nitrous or a blower will feel tighter than one designed for NA performance. So two 3600s could feel different because of how they slip. But are rated to 3600 because that's where you can foot brake the stall to before the car lurches forward. So that's why it's important to look at the stall speed, the STR, and the overall efficiency of a converter for how you intend to use it.
However, back to my original analogy of the 3600s. Both are slipping until they get to about 3600. So they are generating heat. Also, your throttle input is sort of wasted, because the car doesn't accelerate like it does when locked up or with a manual. Instead, with a loud exhaust, you just hear RPMs rise without much forward acceleration. The tighter the stall, the less of this you have.
But once you hit your stall speed, the converter couples and you begin getting torque multiplication. The car then accelerates like a slingshot until it essentially arrives to a 1:1 multiplication somewhere above 6k. Give it a lot of throttle input at first, and it flashes to its stall speed quickly, and you blow the tires off and accelerate like crazy.
Then you have shift extension. Once you shift, let's say 6700, and it drops back to 5900 on the 1-2, you have a pretty good stall matched to the combo, keeping you in your powerband. Again, you're riding sort of the "slingshot" coupling ability of the converter, so you're getting a lot of torque multiplication at the start of the next gear as the car catches up to the engine. But if the stall falls back to say 5400... it's too tight, and you need to loosen it up. Which could make drivability less than ideal.
So a converter is about balancing drivability and performance. More rear gear helps a looser stall driver tighter and it also helps with shift extension. Because again, the converter is multiplying torque a lot and is pushing engine RPMs up and waiting on the rear gear and tires to catch up. So having more gear, speeds that process up and also gives the car more mechanical advantage.
At lockup... they drive exactly like stock.
I've been driving a loose 4000 stall for 3 years. With a 3.23 and then a 3.73. The 3.73 made it nicer around town and helped a little with shift extension. I see usually 2500-3000 to keep up with traffic. But if I give it a little more throttle and jump up to 4k, I leave the traffic behind. And anything over 4k and the car is gone. But I was seeing 5600 shift extensions on a 7000 shift point on my 2-3 shift. So the converter was actually too tight for my combination and needed to be loosened. But it would drive worse because of it.
So, I decided to go with a much tighter 3600 triple disk next. It's designed for a blower, which is next on my list of things to do. But it'll be interesting to see where the shift extension is with this combo. I expect to see probably 5200 on the shift... so obviously, it'll slow down a lot. But add boost back in and I expect it to be 6300-6400 or so.
Last edited by JakeFusion; 11-30-2017 at 02:09 PM.
11-30-2017, 02:35 PM
#26
Actually, he's right. You know less than I thought you did. Looking at only the turbo for a power goal is asinine. There's this thing called efficiency. A turbo that makes 600hp on a honda at 40psi will struggle to make that same power on a 427 c.i. motor due to efficiency and back pressure.
11-30-2017, 04:26 PM
#29
A bigger stall slips below its stall speed and slips worse if it's a looser stall or less if it's tighter. So a 4000 is looser than a 3600. But you can design a 4000 that feels "tight" and performs closer to a looser 3600. The stall speed is simply determined by the stall size, stator design, and number of fins and their angle.
So, for example, a stator designed for nitrous or a blower will feel tighter than one designed for NA performance. So two 3600s could feel different because of how they slip. But are rated to 3600 because that's where you can foot brake the stall to before the car lurches forward. So that's why it's important to look at the stall speed, the STR, and the overall efficiency of a converter for how you intend to use it.
However, back to my original analogy of the 3600s. Both are slipping until they get to about 3600. So they are generating heat. Also, your throttle input is sort of wasted, because the car doesn't accelerate like it does when locked up or with a manual. Instead, with a loud exhaust, you just hear RPMs rise without much forward acceleration. The tighter the stall, the less of this you have.
But once you hit your stall speed, the converter couples and you begin getting torque multiplication. The car then accelerates like a slingshot until it essentially arrives to a 1:1 multiplication somewhere above 6k. Give it a lot of throttle input at first, and it flashes to its stall speed quickly, and you blow the tires off and accelerate like crazy.
Then you have shift extension. Once you shift, let's say 6700, and it drops back to 5900 on the 1-2, you have a pretty good stall matched to the combo, keeping you in your powerband. Again, you're riding sort of the "slingshot" coupling ability of the converter, so you're getting a lot of torque multiplication at the start of the next gear as the car catches up to the engine. But if the stall falls back to say 5400... it's too tight, and you need to loosen it up. Which could make drivability less than ideal.
So a converter is about balancing drivability and performance. More rear gear helps a looser stall driver tighter and it also helps with shift extension. Because again, the converter is multiplying torque a lot and is pushing engine RPMs up and waiting on the rear gear and tires to catch up. So having more gear, speeds that process up and also gives the car more mechanical advantage.
At lockup... they drive exactly like stock.
I've been driving a loose 4000 stall for 3 years. With a 3.23 and then a 3.73. The 3.73 made it nicer around town and helped a little with shift extension. I see usually 2500-3000 to keep up with traffic. But if I give it a little more throttle and jump up to 4k, I leave the traffic behind. And anything over 4k and the car is gone. But I was seeing 5600 shift extensions on a 7000 shift point on my 2-3 shift. So the converter was actually too tight for my combination and needed to be loosened. But it would drive worse because of it.
So, I decided to go with a much tighter 3600 triple disk next. It's designed for a blower, which is next on my list of things to do. But it'll be interesting to see where the shift extension is with this combo. I expect to see probably 5200 on the shift... so obviously, it'll slow down a lot. But add boost back in and I expect it to be 6300-6400 or so.
So, for example, a stator designed for nitrous or a blower will feel tighter than one designed for NA performance. So two 3600s could feel different because of how they slip. But are rated to 3600 because that's where you can foot brake the stall to before the car lurches forward. So that's why it's important to look at the stall speed, the STR, and the overall efficiency of a converter for how you intend to use it.
However, back to my original analogy of the 3600s. Both are slipping until they get to about 3600. So they are generating heat. Also, your throttle input is sort of wasted, because the car doesn't accelerate like it does when locked up or with a manual. Instead, with a loud exhaust, you just hear RPMs rise without much forward acceleration. The tighter the stall, the less of this you have.
But once you hit your stall speed, the converter couples and you begin getting torque multiplication. The car then accelerates like a slingshot until it essentially arrives to a 1:1 multiplication somewhere above 6k. Give it a lot of throttle input at first, and it flashes to its stall speed quickly, and you blow the tires off and accelerate like crazy.
Then you have shift extension. Once you shift, let's say 6700, and it drops back to 5900 on the 1-2, you have a pretty good stall matched to the combo, keeping you in your powerband. Again, you're riding sort of the "slingshot" coupling ability of the converter, so you're getting a lot of torque multiplication at the start of the next gear as the car catches up to the engine. But if the stall falls back to say 5400... it's too tight, and you need to loosen it up. Which could make drivability less than ideal.
So a converter is about balancing drivability and performance. More rear gear helps a looser stall driver tighter and it also helps with shift extension. Because again, the converter is multiplying torque a lot and is pushing engine RPMs up and waiting on the rear gear and tires to catch up. So having more gear, speeds that process up and also gives the car more mechanical advantage.
At lockup... they drive exactly like stock.
I've been driving a loose 4000 stall for 3 years. With a 3.23 and then a 3.73. The 3.73 made it nicer around town and helped a little with shift extension. I see usually 2500-3000 to keep up with traffic. But if I give it a little more throttle and jump up to 4k, I leave the traffic behind. And anything over 4k and the car is gone. But I was seeing 5600 shift extensions on a 7000 shift point on my 2-3 shift. So the converter was actually too tight for my combination and needed to be loosened. But it would drive worse because of it.
So, I decided to go with a much tighter 3600 triple disk next. It's designed for a blower, which is next on my list of things to do. But it'll be interesting to see where the shift extension is with this combo. I expect to see probably 5200 on the shift... so obviously, it'll slow down a lot. But add boost back in and I expect it to be 6300-6400 or so.
11-30-2017, 06:11 PM
#33
I need to make a better video. But that shows it more or less. I fixed the rattle (exhaust on the DSL loop) and put a quieter muffler in there (still loud), but you can see how it needs revs to move.
And yes, with a loud exhaust and a cop next to you, you try to ease into it. But then you don't really accelerate.
Everyone who says a high stall is such a fun experience, doesn't know what fun is. It's only fun when you're on it. Any other time, it's pretty much stupid. And I've tried to do as much as I can to make this car less extreme over the last 3 years... less cam, less stall, less exhaust. And it's not any slower. But it's more fun to drive.
If you want to go fast, get a tight stall and turbo the car. Everything else is a waste of money.
And yes, with a loud exhaust and a cop next to you, you try to ease into it. But then you don't really accelerate.
Everyone who says a high stall is such a fun experience, doesn't know what fun is. It's only fun when you're on it. Any other time, it's pretty much stupid. And I've tried to do as much as I can to make this car less extreme over the last 3 years... less cam, less stall, less exhaust. And it's not any slower. But it's more fun to drive.
If you want to go fast, get a tight stall and turbo the car. Everything else is a waste of money.
11-30-2017, 08:05 PM
#35
11 Second Club
I need to make a better video. But that shows it more or less. I fixed the rattle (exhaust on the DSL loop) and put a quieter muffler in there (still loud), but you can see how it needs revs to move.
And yes, with a loud exhaust and a cop next to you, you try to ease into it. But then you don't really accelerate.
Everyone who says a high stall is such a fun experience, doesn't know what fun is. It's only fun when you're on it. Any other time, it's pretty much stupid. And I've tried to do as much as I can to make this car less extreme over the last 3 years... less cam, less stall, less exhaust. And it's not any slower. But it's more fun to drive.
If you want to go fast, get a tight stall and turbo the car. Everything else is a waste of money.
And yes, with a loud exhaust and a cop next to you, you try to ease into it. But then you don't really accelerate.
Everyone who says a high stall is such a fun experience, doesn't know what fun is. It's only fun when you're on it. Any other time, it's pretty much stupid. And I've tried to do as much as I can to make this car less extreme over the last 3 years... less cam, less stall, less exhaust. And it's not any slower. But it's more fun to drive.
If you want to go fast, get a tight stall and turbo the car. Everything else is a waste of money.
Back to the original question. A stalled auto will drive different one person to the next. A little less stall and more gear is always the answer when in doubt. I wouldn't go less than a 3600 stall ever with a 4L60e tho.
12-01-2017, 08:07 AM
#36
I have to disagree with a good bit of this. I have SS3600/3:73 combo with Kooks true duals too. I would call my car very fun and easy to drive under summer daily conditions. It upshifts at 1800-1900rpm just driving around town but I have stock cam. Jake has a cam with 5.5degrees of overlap, 4000 stall, and same gear. All these things add up and can make or break the drive-ability of your ride.
Back to the original question. A stalled auto will drive different one person to the next. A little less stall and more gear is always the answer when in doubt. I wouldn't go less than a 3600 stall ever with a 4L60e tho.
Back to the original question. A stalled auto will drive different one person to the next. A little less stall and more gear is always the answer when in doubt. I wouldn't go less than a 3600 stall ever with a 4L60e tho.
12-01-2017, 08:13 AM
#37
This brings up another question, although I probably wont run into this much - but in rain or wet weather, driving under the stall RPM should technically be easier due to less power actually making it to the wheels but if the converter flashes while you're on wet pavement then I guess that could lead to trouble couldnt it?
12-01-2017, 08:33 AM
#38
TECH Junkie
This brings up another question, although I probably wont run into this much - but in rain or wet weather, driving under the stall RPM should technically be easier due to less power actually making it to the wheels but if the converter flashes while you're on wet pavement then I guess that could lead to trouble couldnt it?
