What stall speed would you pick?

[davepl]

I'm using a built 200-4R for my otherwise-stock build so that I have overdrive; I also have 4.88s in the rear, which become 3.08s in overdrive.

I made the bad choice of leaving a performance converter, maybe 2800 stall, from the last car I used the trans in. Since the trans comes from an '87 Grand National, I had two options for stock replacements:

a) The 3.8L Turbo converter, 9", 2000rpm stall
b) The 5.0L V8 converter, 10", 1400 stall

I went with option B, but the shop has spooked me a little saying it might want to push through intersections. My cam is quite mild, almost stock (214/218 @ 50), and I'm hoping it will idle at 600 or so in drive.

I guess it's a little late now, but which do you think would be closest to the stock TH400 converter stall speed?

Thanks
Dave

[hugger6933]

The 1400 would be closer to the stock stall speed I don't think you have to worry about the truck Pushing. Just remember the converter is gonna act a little different behind the big block than it would a small block so I would add another couple hundred to the advertised stall

[hamjet]

What Hugger said 1400 will work fine. I had 2 choices with my 2004-r ( 1600 or 2000) I went with the 1600, almost stock cam. it works great..

[davepl]

Originally Posted by hamjet

What Hugger said 1400 will work fine. I had 2 choices with my 2004-r ( 1600 or 2000) I went with the 1600, almost stock cam. it works great..

Were those the two stock stall speeds listed, or what forced those choices on you? At RockAuto I could only find the 1400 and 2000; it's not a perfect science rating the stall speed though.

[davepl]

Thanks! I imagine my 402 makes a little more torque than the Buick 307, so the flash stall will be a lot higher too.

[picklito]

I'm doing a similar build: 200-4R behind a stock 402. I'll be interested to hear what you think of the lower stall. When will you have it running?

[hamjet]

I bought a reconditioned trans. with converter off ebay from a trans place in florida, the one I bought was supposedly rated for 400 HP (basicly a stock build with heavy duty parts, and stock converter. the other choice was one with heavier duty parts, higher shift points, 500 HP, and the higher stall speed converter. since its for daily driving and never beating it I was afraid to go to the higher stall, higher shift points. I don't know for sure, but if I'm doing 50 mph, does the higher stall converters mean it will be slipping more at that speed? Maybe not, but didn't want overkill for a stock setup.. unless you have a real lopey cam, the 402 with 4.88 gears will leave the line like a bear.http://www.ebay.com/itm/2004R-200R4-...3D181711575750 The price is lower now than when I bought one.

[picklito]

That's a good price. I guess you wouldn't recommend it if you weren't happy with the performance?

[hamjet]

Originally Posted by picklito

That's a good price. I guess you wouldn't recommend it if you weren't happy with the performance?

I'm not really recomending it, just letting davepl see the one I bought. I have had good luck with it but as I say, I don't abuse it with my weak little W engine. I just wanted to get away from 2500+ rpms at cruzing speeds on a budget.

[davepl]

Well, the way they work is that engine RPM causes the fluid to be thrown to the outside of of the converter, where slip is "prevented". When the fluid is more towards the inside of the converter, it can slip.

At low RPM, there's not much centrifugal force, and it can slip. By the time you're on the highway, you're probably turning 1500RPM anyway, and that's enough to keep the fluid outboard and the converter coupled well.

With a 3000rpm stall converter, though, you'd still be getting a lot of slip on the highway probably.

Key point to keep in mind is that it's the rotational speed of the converter, not the vehicle speed. Since it's bolted to the back of the engine, its dependent on engine RPM. You'd get less slip in 2nd than 3rd at the same road speed.

[hugger6933]

One thing for people to know and this thread may be a good place to look if doing a search IF YOU HAVE A HIGHER THAN STOCK STALL SPEED, YOU NEED A GOOD EXTERNAL TRANS COOLER!! This is more important the higher than stock stall you go as the higher stall will build more heat and that will kill your trans. Jim