Upgrade 5AT torque converter/stall? Possible?
Joined: Apr 2007
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From: Tulsa, OK
Upgrade 5AT torque converter/stall? Possible?
My friend has an ls1 camaro with a 3800 stall, he says it's the best upgrade for any auto. his car hauls ***. I did a quick search and didnt turn up lots of info on this.
Is this something available for our cars? If so, who sells them and what is recommended for a bolt on VQDE? Anyone know what the stock TQ converter is set at?
Thanks for any helpful info.
Is this something available for our cars? If so, who sells them and what is recommended for a bolt on VQDE? Anyone know what the stock TQ converter is set at?
Thanks for any helpful info.
I think the stock converter is set between 2400-2600 stall (I could be wrong). RCdash is selling his 3600 stall GTM converter.
I had mine modded by edge racing in ca. I think Edge Racing, GTM and Pro Torque are the only ones that mod our converters.
I heard a high stall one takes some getting used to on our car especially if it's your DD.
I had mine modded by edge racing in ca. I think Edge Racing, GTM and Pro Torque are the only ones that mod our converters.
I heard a high stall one takes some getting used to on our car especially if it's your DD.
As DSSkyline mentioned, Edge Racing (builds for GTM I believe) and ProTorque are the two shops that have lots of experience with our TC.
The stock stall according to the FSM is 2600-2900 but Andre at Edge told me no way, that is only with cavitation. His words - didn't ask for explanation. He said true stall is around 2200. Anyway, I thought my GTM TC was going to be 3200 but what I didn't know is that that depends on the input torque going through it. The more engine torque, the higher the stall. So with 400 ft lbs, I was stalling around 3600-3800. At stock tq levels, it may really be 3200. It is for sale - all internals are upgraded from the lock up clutch to the fins, stator, etc. Will be in Marketplace by Sun.
I moved back down to a 3000 stall converter rated at 400 ft lbs torque. All generate lots of heats, so a trans cooler is highly recommended.
The stock stall according to the FSM is 2600-2900 but Andre at Edge told me no way, that is only with cavitation. His words - didn't ask for explanation. He said true stall is around 2200. Anyway, I thought my GTM TC was going to be 3200 but what I didn't know is that that depends on the input torque going through it. The more engine torque, the higher the stall. So with 400 ft lbs, I was stalling around 3600-3800. At stock tq levels, it may really be 3200. It is for sale - all internals are upgraded from the lock up clutch to the fins, stator, etc. Will be in Marketplace by Sun.
I moved back down to a 3000 stall converter rated at 400 ft lbs torque. All generate lots of heats, so a trans cooler is highly recommended.
A TC is simply a torque multiplication device. The higher the stall speed, the greater the torque multiplication. It's much like launching a manual tranny at a higher rpm. Instead of a direct connection to the tranny, the auto uses a fluid connection. In simple terms, the TC operates like two fans. Visualize two fans facing each other. One is on and the other off. The one on is connected to the motor. The other is connected to the drivetrain. As you raise the rpm, the on fan starts going faster and faster and the off fan starts to spin. Instead of air being the medium, tranny fluid is. Before long, the off fan is moving as fast as the on fan. That's the stall speed. Aftermarket TCs can typically increase torque multiplication by 2.5 to 3 times. That means launch torque could be well over 800ft/lbs on the initial hit (this isn't sustained though). Having a well matched TC can really give an auto a HUGE advantage on launch. Huge. The other advantage is the auto launch doesn't shock the drivetrain remotely as bad as that of a manual because you can preload the drivetrain by braking stalling. This removes driveline shock.
The downsides to an aftermarket TC include:
1) laggy around town driving because the TC has more slippage before the drivetrain connects.
2) high tranny temps because of more slippage. An additional tranny cooler is needed. Contrary to belief on this forum, the 5AT has a stock tranny cooler, but it's not up to the task of cooling fluid from an aftermarket TC.
The reason aftermarket TCs haven't caught on here is because of expense (product and install) and the fact that to most people, TCs are voodoo.
If you want to take full advantage of an NA 5AT, you need the following:
1) Aftermarket TC (around 3000-3200rpms)
2) Gears 3.7s
3) Cams
4) Rods, valvesprings, oil pump
5) Cosworth intake manifold
6) Longtube headers
7) Tuning
That would be an absolute killer 1st gen sedan and easily a low low 13 second ride. It would reliably rev to 7500rpms while making power to that point.
that setup would cost a good $8-10K...and I bet you'd be in the high 12's
it would be a great setup
it would be a great setup
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I have the GTM upgraded tranny which consists of the Edge racing TC and not sure who did the VB but mine is holding 550ft trq for over 50,000 miles so far.
Mine did not cost anywhere near 8-10k
Mine did not cost anywhere near 8-10k
Now regarding the other posts, take everyone's advice on these forums with a grain of salt (including mine of course)
. GTM isn't smoking crack as DaveB reports. And it wasn't GTM that said the stock stall is 2200. It was Andre at Edge Racing, a man that has designed torque converters for quite some time by all reports. He also said that the stall may be higher with cavitation, something I did not ask him about because he finds it an undesirable design characteristic and removes it from all of his upgraded converters. Once you start researching into torque converters you realize that there are different ways of measuring stall, hence some of the variability associated with assignment of a single number. Further the actual stall (however you decide you're going to measure it) is a function of the input torque. The higher the engine torque the higher the TC stall, for the same exact converter with the same physical characteristics. So what does this mean in daily driving? A 3600 rpm stall converter at 300 wtq will stall much lower at only part throttle. It's not as though the car doesn't start moving until rpms hit 3600.It is true that a higher stall converter feels less "direct" than a lower stall converter, but a higher stall converter also has less of that "bog" when you get on it. There are some trade offs. The biggest one is heat and you will want an aftermarket transmission cooler. That said here is the breakdown for upgrading a TC:
Upgrade your TC to a higher stall and strengthen internals to handle higher torque - $400 - $600 (I think you can get a used core for $200 if you don't want to modify yours)
Transmission cooler - $80-$100 ($220 for the one with the fan)
Cooler install - $100 (you can do this on your own if you've got basic tools).
TC install - $500 (requires dropping the transmission - this is a quote from an Infiniti dealer. Forged Performance charges about the same)
ATF Fluid - 10 qts ($80; expensive fluid!).
In terms of performance gains, a torque converter upgrade is one of the best bangs for the buck as it helps the car the most in the launch which is a key component of a good 1/4 mile result.
Gears, VB, TC - are the big 3 I would do while NA. If you think you might go FI, I would skip the gears, but the VB and TC would continue to serve you well.
Good luck.
Last edited by rcdash; Mar 1, 2009 at 11:02 PM.
The 8-10k is still way off to properly implement a TC, which is the topic of THIS thread.
My response was to what you can do to the NA 5AT TC and VB so that is what I did, anyone who spends 8-10k on just upgrading a 5AT tranny is out of their mind, especially when people have done and tested this and have shown it can handle XX amount of power.
Just because I am FI does not change what can be done to the tranny.
I also have an oil and tranny cooler to stave off heat.
Just because I am FI does not change what can be done to the tranny.
I also have an oil and tranny cooler to stave off heat.
My response was to what you can do to the NA 5AT TC and VB so that is what I did, anyone who spends 8-10k on just upgrading a 5AT tranny is out of their mind, especially when people have done and tested this and have shown it can handle XX amount of power.
Just because I am FI does not change what can be done to the tranny.
I also have an oil and tranny cooler to stave off heat.
Just because I am FI does not change what can be done to the tranny.
I also have an oil and tranny cooler to stave off heat.
Speaking of cams, that is what's next on my list..lol


