Pick a convertor

[will]

I have a new engine which I will be installing as the weather turns colder. It's 595 hp. I have an automatic with 3.91 gears in a 68 Charger, it has the Chrysler 166k torque convertor. I already know I'm going to have to get a new driveshaft at this horsepower level, this car will be driven on the street, fitech efi. My question is, what stall would be the best for the street, or is the 166k I have suitable for the tire roasting mayhem that will take place in the spring? I have the transmission already for this, it's the tried and true 727, bolt in sprag, hemi clutch packs, fresh.

[BSB67]

what cam, intake, carb, compression ratio and exhaust

[will]

I don't know, the cam is a custom grind. Fitech meanstreet efi, shorty type headman elite headers. I'm going to change those eventually to tti's. Right now the exhaust is 2.5 inch, I know i'm going to have to go to the 3". As far as compression, I'll guess 11:1, that's the height of 93 octane.

[c00nhunterjoe]

Guessing is the worst thing you can do. It will end up with the wrong converter and you will hate it. Do you at least have the dyno sheet so we can see the exact torque curve? That would make it an educated guess.
   If you have no info then i suggest installing what you already have and drive it. See if it is too loose or too tight for your preference and then make the change.

[BSB67]

   If you have no info then i suggest installing what you already have and drive it. See if it is too loose or too tight for your preference and then make the change.

This

[will]

I'll make a phone call tomorrow to see what the compression and torque curve is. The intake is an edelbrock rpm.

[c00nhunterjoe]

I'll make a phone call tomorrow to see what the compression and torque curve is. The intake is an edelbrock rpm.

Get the actual piston part number, head gasket thickness, and if any milling was done on the block or heads.

[will]

The heads are brand new trickflows, the torque peak was 647@3200rpm. I will call them in the morning to find out the particulars. I can't wait for this thing, it's gonna be a monster!

[c00nhunterjoe]

What was the torque from 2200 to 2500

[will]

Here we go, these are the numbers I have:
speed    Torque   HP
3700      627        433.9
3800      626        452.6
3900      629        467.2
4000      632        481
4100      634        494.1
4200      634        507
4300      632        518
4400      629        527
4500      626        536
4600      622        545
4700      616        552
4800       608       556
4900       600       560
5000      591        562
5100      584        567
5200      580        574
5300      574        579
5400      567        583
5500      557        583
5600      546        582
5700      535        581

The numbers increased a little bit for pump gas. This is on the shop carb, I will be using fuel injection. I wish I had the numbers for lower rpm, but this is what they sent. I will ask for the lower set tomorrow.

[c00nhunterjoe]

Reason i asked is because that is where converter companies get their advertised "stall speed" from. The torque at that rpm determines what rpm the converter will flash at. Based on the rest of the curve, its probably still well over 500 ft lbs. I would say leave the stock converter in it and try it. It will probably flash in the 2500 range easily with that much torque

[will]

Great, I don't feel like spending more money, although I understand the speed:$$$$. Need some recovery time for the next step.

[c00nhunterjoe]

Isnt the 166k a lockup converter for the newer model transmissions?

[will]

I bought that thing at Carlisle like 8 years ago. It's working, I may be wrong on the number, but that's what mancini told me when I bought it. The box with the numbers on it is long gone. Maybe I can do a brake check to see where it breaks loose this weekend. that will be on the 383 that's still in there.

[c00nhunterjoe]

Stall speed on the 383 vs the motor you posted will be 700 rpm different minimum i bet.... but will give you an idea.

[Nacho-RT74]

Isnt the 166k a lockup converter for the newer model transmissions?

I don't know what it is really the K factor, but, here is the MP Chart

[will]

Thanks Nacho, as always an encyclopedia of information. I guess I'll go for a hammer ride and see what the stall is.

[c00nhunterjoe]

So based on that chart i will go with my origonal estimate of 3000-3500 behind that much torque

[Nacho-RT74]

I have a 166K and a 175K, but can't compare them easilly, since I used the 166K with the stock 400 crank, so I welded the counterweights. The 175K is running on back of the now stroked 400 with 440 crank, forged... 282hdp crower cam, over 10:1 CR

[firefighter3931]

The 166k Converter is going to be too tight for that engine combination, INMHO 

You can try it but don't be surprised if you can't get the motor to idle properly. A tight converter will pull the engine down and make it difficult to tune at idle. You definitely need something that is a bit "looser" to make it enjoyable to drive. 

If it were mine....I'd be looking at a "tight" 9.5in street/strip converter from PTC or Dynamic. I had a 9.5in unit from Dynamic in my car with the old 446 combo that made 535hp/540tq and it was fantastic. It drove just like a stock converter off idle and flashed to 4000 on a WOT blast from a dead stop. Just driving around normally you would have never known that there was a high stall converter in the car. 



Ron

[Nacho-RT74]

Ron... a MP convertor wouldn't increase the stall rate anyway on an engine with more torque ?

although dunno how much could change the iddle "tightening"