Torque Converter Question
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 35
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From: Honolulu Hawaii
Torque Converter Question
Got my new crate 350/408 for my 76 today. I have a 3600 that I want to put in for when I get back to the mainland to take to the strip. However, the speedway here in Hawaii is no longer operating. So, if I put the 3600 in this week, it will really limit my driving to almost none. What happens if I leave the 1800 that it is there now and put the new motor in? Will I be sitting at stop lights in neutral to keep the car idling? Would I have to baby it if I'm driving it normal? As it is, I only put about 40 miles a month on it and expect that to stay the norm until I go back to the mainland. Any ideas?
Le Mans Master
Joined: Jul 2006
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From: charlotte north carolina
i believe that the stall speed on your 1800 converter would allow the engine to run up to that rpm without forcing power thru to the trans. so unless your idle will be above 1800, you should be ok.
why not wait until you get to the mainland and change the engine and converter at the same time?
why not wait until you get to the mainland and change the engine and converter at the same time?
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I drove around for a year with my 3800 stall probably 5000 miles when I blew it's lockup clutches on my 700R4. Then again last year i blew the lockup clutchess in my 3500 stall behind my 427 small block 600 hp and i drove it around till i yanked it out and installed a 5 speed.
It's not a big deal if you have a quality converter
It's not a big deal if you have a quality converter
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
it all depends on how tight the 1800 is........i had to replace mine and several guys around here have high stalls like what you are talking about ....i have a 2500 stall and it works well
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 35
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From: Honolulu Hawaii
Originally Posted by jnb5101
i believe that the stall speed on your 1800 converter would allow the engine to run up to that rpm without forcing power thru to the trans. so unless your idle will be above 1800, you should be ok.
why not wait until you get to the mainland and change the engine and converter at the same time?
why not wait until you get to the mainland and change the engine and converter at the same time?
Because I'm a spoiled kid. Couldn't wait the 12 months to upgrade the HP from the stock motor it had. Just couldn't wait...
Now, the motor is sitting at my mechanics waiting on me to bring the car in. Think I'll stick with the 1800, drive my 40 miles a month keeping the battery and such fresh. When I get back to the mainland, I'll pull the motor and redo the tranny and put the 3600 on. Thanks guys. I appreciate the info!
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
I would put the 3600 in it now and be done with it. As long as you have a good tranny cooler, its not going to hurt a thing driving with a loose converter aside from your gas card bill. 
I used to drive a 78 Trans am with a pont 406", I had a 3200 converter and only a 3.42 gear, in that 3700lb car behind a torquey pontiac motor, THAT sucker was loose. I drove that car like that for 5 years. Old turd would run 12.0s@only 108mph...hahaha
Sure would leave good. It was my daily driver but that was back when gas was a $1.20 a gal,
Good times, good times.
I used to drive a 78 Trans am with a pont 406", I had a 3200 converter and only a 3.42 gear, in that 3700lb car behind a torquey pontiac motor, THAT sucker was loose. I drove that car like that for 5 years. Old turd would run 12.0s@only 108mph...hahaha
Sure would leave good. It was my daily driver but that was back when gas was a $1.20 a gal,
Good times, good times.
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 35
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From: Honolulu Hawaii
Originally Posted by ajrothm
I would put the 3600 in it now and be done with it. As long as you have a good tranny cooler, its not going to hurt a thing driving with a loose converter aside from your gas card bill.
I used to drive a 78 Trans am with a pont 406", I had a 3200 converter and only a 3.42 gear, in that 3700lb car behind a torquey pontiac motor, THAT sucker was loose. I drove that car like that for 5 years. Old turd would run 12.0s@only 108mph...hahaha
Sure would leave good. It was my daily driver but that was back when gas was a $1.20 a gal,
Good times, good times.
I used to drive a 78 Trans am with a pont 406", I had a 3200 converter and only a 3.42 gear, in that 3700lb car behind a torquey pontiac motor, THAT sucker was loose. I drove that car like that for 5 years. Old turd would run 12.0s@only 108mph...hahaha
Sure would leave good. It was my daily driver but that was back when gas was a $1.20 a gal,
Good times, good times.
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Melting Slicks
Joined: Jul 2002
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From: Deltona (son of Deland and DAYTONA) FL
an 1800 stall for my 383 was WAY too tight, and yes I had to sit at stoplights in neutral.
It would flash to almost 2200 behind my 383 because it put out over 500 ft/lbs of tq. But if I tried to power-brake, it would transfer enough power to the rear wheels at 1300 rpm to either start smoking them or push the car with the front wheels locked, depending on the surface.
A 3500 stall should be ideal. It will only flash that high if you nail the throttle from a standstill. You will probably start rolling once the throttle reaches 1000-1200 rpm if increased gradually.
It would flash to almost 2200 behind my 383 because it put out over 500 ft/lbs of tq. But if I tried to power-brake, it would transfer enough power to the rear wheels at 1300 rpm to either start smoking them or push the car with the front wheels locked, depending on the surface.
A 3500 stall should be ideal. It will only flash that high if you nail the throttle from a standstill. You will probably start rolling once the throttle reaches 1000-1200 rpm if increased gradually.
Thread Starter
Intermediate
Joined: Nov 2006
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From: Honolulu Hawaii
So, if I put the 3600 in, I will be able to drive it normally? Not having to rev up to 3500+ rpms just to get the vehicle rolling? That's what I'm concerned with. Although I do not drive this car very often, it would be nice to drive through Waikiki every now and then. I wouldn't want to drive it, though, if I had to maintain high RPM's the whole time.
My motor puts out 400 ft lbs torque. Will I experience the same issues at stop signs/lights? Or, will I be able to sit on the brake and still keep it running?
Next week is go time for me. Mechanic has motor, I have my hooker super comp headers, and I have the 3600 stall converter and am ready to get this thing done. But, once I make that decision to put this in or not, it'll not be cost effective to change my mind afterward. So, any suggestions offerred are greatly received.
My motor puts out 400 ft lbs torque. Will I experience the same issues at stop signs/lights? Or, will I be able to sit on the brake and still keep it running?
Next week is go time for me. Mechanic has motor, I have my hooker super comp headers, and I have the 3600 stall converter and am ready to get this thing done. But, once I make that decision to put this in or not, it'll not be cost effective to change my mind afterward. So, any suggestions offerred are greatly received.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Originally Posted by gkull
I drove around for a year with my 3800 stall probably 5000 miles when I blew it's lockup clutches on my 700R4. Then again last year i blew the lockup clutchess in my 3500 stall behind my 427 small block 600 hp and i drove it around till i yanked it out and installed a 5 speed.
It's not a big deal if you have a quality converter
It's not a big deal if you have a quality converter
On the other hand I Mistakenly trusted a local shop when they rebuilt my tranny behind my 440 dodge Charger. They installed some cheap 3000 stall converter and it always ran down the road at 3000 rpm unless of course I went faster down the freeway.
I'd also say to anybody that has a 1800 stall that puts such a load on the motor that it dies at a stop light unless you put it in "N" You got what you paid for! I had a special 1200 rpm stall made for a full manual tranny for racing and out on the streets. It worked really nice. It was much cheaper than going to a clutch/flywheel fed TH400
Le Mans Master
Joined: May 2006
Posts: 9,993
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From: League City Tx
Robtam, just because its a 3500 stall, that doesn't mean that it runs at 3500 rpms all the time. You will still be cruising around town at 40 mph at like 1800-2200 rpms(depending on your gears) like a normal stock converter. YES it is looser then stock and you will have to apply more throttle to get the car to move initially but its not like you think its going to be. Your car will still be very driveable. It will slip some and yes your highway rpms MAY be a few hundred higher if your normal cruise rpm is right in the low-middle range of the stall speed.
A stall speed rating is more of an average between how much you can foot brake the converter and the flash rpm. For instance, with a 3500 stall, you might only be able to foot brake up to 2500-2700 rpms behind a decent 383, but that converter may FLASH to around 3800-4000 rpms. I have found the advertised stall speed is kind of an average of the two.
Just stick the 3600 in there, put on a GOOD tranny cooler and drive that sucker, you will really enjoy driving it on the street, they are a lot of fun if you have good sticky tires.
A stall speed rating is more of an average between how much you can foot brake the converter and the flash rpm. For instance, with a 3500 stall, you might only be able to foot brake up to 2500-2700 rpms behind a decent 383, but that converter may FLASH to around 3800-4000 rpms. I have found the advertised stall speed is kind of an average of the two.
Just stick the 3600 in there, put on a GOOD tranny cooler and drive that sucker, you will really enjoy driving it on the street, they are a lot of fun if you have good sticky tires.
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 35
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From: Honolulu Hawaii
Originally Posted by ajrothm
Robtam, just because its a 3500 stall, that doesn't mean that it runs at 3500 rpms all the time. You will still be cruising around town at 40 mph at like 1800-2200 rpms(depending on your gears) like a normal stock converter. YES it is looser then stock and you will have to apply more throttle to get the car to move initially but its not like you think its going to be. Your car will still be very driveable. It will slip some and yes your highway rpms MAY be a few hundred higher if your normal cruise rpm is right in the low-middle range of the stall speed.
A stall speed rating is more of an average between how much you can foot brake the converter and the flash rpm. For instance, with a 3500 stall, you might only be able to foot brake up to 2500-2700 rpms behind a decent 383, but that converter may FLASH to around 3800-4000 rpms. I have found the advertised stall speed is kind of an average of the two.
Just stick the 3600 in there, put on a GOOD tranny cooler and drive that sucker, you will really enjoy driving it on the street, they are a lot of fun if you have good sticky tires.
A stall speed rating is more of an average between how much you can foot brake the converter and the flash rpm. For instance, with a 3500 stall, you might only be able to foot brake up to 2500-2700 rpms behind a decent 383, but that converter may FLASH to around 3800-4000 rpms. I have found the advertised stall speed is kind of an average of the two.
Just stick the 3600 in there, put on a GOOD tranny cooler and drive that sucker, you will really enjoy driving it on the street, they are a lot of fun if you have good sticky tires.
Thanks! Your reply explains my concerns exactly. Many thanks.