Stopsign32v

iTrader: (1)

The car will be mainly a daily warrior against those pesky 5.0s But keep in mind it will be a 4000lb car. The cam I will be using will need a 3200+ stall but I want to go for broke.

I doubt it will ever see the track but if it does I'd like a 1.5 60' on slicks.

With that said I'm torn between a 3600 stall and a 4000 stall. I was told by FTI that the 3600 would be much better on the street and the 4000 will feel a lot like a truck pulling a trailer at lights. I'm also up in the air about Yank, Circle D, or FTI. I'm sure all make good converters. I also thought about the 3800 for a nice middle but I'm also wondering if it would be better skipping the 3800 and just going with a 3600 or 4000. Opinions on this is appreciated. FTI also said since the car is so heavy it makes the 4000 feel that much worse on the street.

Oh yea, and it will have 3.45 gears in the rear

NEstyle

iTrader: (1)

What trans?

Stopsign32v

iTrader: (1)

6l80e

vorteciroc

Have you taken a look at Neal Chance Racing Converters?

The majority of my high powered customer's vehicles end up with a torque converter from Neal Chance... Unless they are being frugal.

FTICONVERTERS

iTrader: (3)

Don't forget while i said it would have that mushy trailer like feel under light peddle, the 4000 hard hit would be an animal out of the hole at the track. A lot of the users here are the guys i was telling you about that like to daily driving the 4000+ stall converters.

-Dalton

Stopsign32v

iTrader: (1)

It was good talking to you Dalton. I've gotten more advice like yours than the 4000. The cam maker said the 3600 would be perfect so it's pretty much a sealed deal at this point.

NEstyle

iTrader: (1)

I have a 4000 pound car street car with a 6L80e and 3.45 gears which is pretty much the same combo as you. The converter is a 3600 which is more like a 3800 at that weight according to Circle D, and I wish I had more converter. I would go with a 4000 at least depending on the cam.

vorteciroc

Out of curiosity... Have either of you had your vehicle on a chassis dyno and compared the results with different torque converters/ different stall speeds?

NEstyle

iTrader: (1)

I have not. What could be learned from that information?

vorteciroc

To try and make a very simple explanation...

Depending on where in the RPM range your engine is making peak power to the tires (lets say 500.00 HP @6,000 RPM with a stall speed of 2,500 RPM)
You may be loosing power to the tires from an increased stall speed (lets say 4,000 RPM) due to less coupling of the torque-converter above stall speed.
Lets think of this like a clutch slipping and refer to the lack of torque-converter coupling as "slipping" (even though that is not the case).

With the 4,000 RPM torque-converter compared to using the 2,500 RPM unit, there will be more slipping @6,000 RPM and less power to the tires.
Lets say now with the 4,000 RPM stall speed, the peak power is now 450.00 HP to the tires @6,000 RPM.
The lower stall speed torque-converter would be slipping less @6,000 RPM, getting more power to the tires.

Now if the engine was making peak power @7,500 RPM instead of 6,000 RPM.
The 4,000 RPM stall speed unit would not be slipping as much at 7,500 RPM and would get the 500.00 HP to the tires back again.

Again, this is not exactly correct in several ways... however this is the most simplistic way I could express how HP would change between torque-converter of different stall speeds for a given engine.

MaroonMonsterLS1

I'm glad you said it before anyone else had to...

Torque multiplication wasn't even mentioned. That's huge when selecting a converter

And your description of coupling isn't very accurate.
You can have a 12" 4000 stall converter and a 9" 4000 stall converter and they will behave TOTALLY differently
same with a 3600

so you could have a 9" 4000 that couples better than a 12" 3600
Comparing converters on stall speed alone really isn't a fair comparison.

When buying a converter, you need to look at the diameter, STR, and the stall. Then pay attention to slip on the big end, shift extension, etc

Tramminc

Found this info'

https://www.converter.cc/YANK_FAQ_s/45.htm

vorteciroc

I totally agree :-)

I did not wish to cause more confusion when some people here were not even aware that coupling percentage after stall speed was "a THING".
It seems people believe that once the torque-converter stall speed is reached, then the transmission is just completely attached to the engine.

As you said the torque multiplication ratio/ STR and diameter are BIG factors in how the unit operates.

Finkledbody

Greetings stopsign. I aint as smart of some of these folks but I have experience with two.

Back in 2009 I drove a bolt on (full exhaust / lid) 344hp Z28 Camaro that had a Yank PT4000 stall in it. Some time has passed since then but I remember the 4k stall was ridiculously loose. I made a thread back then asking https://ls1tech.com/forums/general-l...you-allow.html - When I drove it, I would have to rev the motor to at least 2500rpm just to make the thing move. Really, if you wanted to keep up with stop and go traffic, it would have to be revved to 2800-3000RPM which made me look like a ******* mad man at every traffic stop.

I just bought a H/C/I 02 Z28 that has the Yank SS3600 stall. Its much more tame. I can rev it to 2000k and have plenty of get up and go to keep up with traffic.

Hope this helps!

MaroonMonsterLS1

That doesn't help at all
Different transmission
different power level
different converter altogether

As I've said before...you can have a 12" converter drive like hell and have the same stall as a 9.5" that drives like a dream

Call and talk to the people that build them...give them as much info as possible...get 3 or 4 recommendations from different companies and take your pick.
If they're all recommending a 258mm core converter in the 3600-4000 stall range...then there ya go
If one recommends a 12" 3600 stall and one recommends a 245mm 4000 stall...then you have more of a choice to make.

If fti has already made you a recommendation...I don't see them steering you wrong. I've had nothing but great luck dealing with FTI. Great guys and very knowledgeable

5.7stroker

iTrader: (36)

All I did was call André at Egde and he set me up with the converter I needed after giving him the details he asked for.

vorteciroc

When shopping for a torque-conveter...

You guys can ask:

-what type of core the converter is based on.
-what the diameter is.
-what the torque multiplication ratio is.
-what the stall speed range should be with your engine specs (primarily your torque curve is what is going to dictate this).
-is the unit a lock-up converter, what type of clutch is used, is the clutch intended for full throttle use.
-is the torque-converter intended for use with a trans-brake.
-is the converter intended for use with a power adder.
-what does the assembly process consist of (IE Heli-Arc welded fins, billet front cover, anti-ballon plate, ETC).
-what is the maximum power suggested for the unit (adding more HP later may cause the torque-converter characteristics to drastically change and possibly over power the unit).
-Lastly I'd like to make sure the manufacturer/ supplier services the unit in-house (usually a place like this will carry many stators of varying fin angle for a stall speed change during a cut and clean.