That’s probably not loose enough for what I need.

 

3,000 RPM could be fine...

Honestly the way in which a torque-converter performs/ operates comes down to personal preference.
A given vehicle and power-train does not use a "One-size fits all" mathematical equation.

The characteristics of the torque-converter can be altered with in a range to the drivers liking.
If you have any friends that have made torque-converter upgrades...
I would kindly ask them if you could test-drive their vehicles; to try and get the feel of some different converter configurations.

FTI is going to give you a recommendation.
Part of that will be dictated by the estimated average torque production and RPM.
Some people like a unit that will have an even higher stall-speed then that RPM (Good for track only).
And some will go in the other direction, with a lower stall-speed (Can be better if regularly used in stop and go traffic).

 

Thanks for that explanation. And I understand all of that. But it seems like a lot of people who went somewhere between 2800-3200 always wish that they would have gone looser (for whatever reason). I understand that cam specs, rear end gears, etc play into stall speed selection too. Riding in/driving a car with something similar is good advice.

 

Post in your local LS1tech forum (midwestern members forum in the regional section) and ask if there's anyone near you that you could drive out and go for a ride with them.

Most likely you wont be able to tell much of a difference at all between a 3600 and a 4000 because they're going to be so radically different than anything you're used to. And even a experienced person wouldn't be able to tell a whole lot of difference. Some, but nothing major.

 

Thanks for the advice guys. I'll see what I can figure out.

 

Excellent!
And if there is anything that you are uncertain about... I would call FTI and ask them questions.
They are honestly great people over there!

Even if you just wanted a knowledge dump of information, on how a torque-converter operates/ how they can be changed for a given application... Call FTI.
Dalton has his own explanations/ language, that I find extremely understandable to the 1st time DIY builder/ uneducated.

Let me give you an example of what can happen, when going to another Torque-Converter/ Transmission business:

-I had a customer vehicle here for a trans. and converter. It was a 1966 Buick Skylark/ Gran Sport with a 462" BBB (Big Block Buick)
-The vehicle got a rebuild THM400 transmission from me and I needed to have a converter built.
-The Engine produced just over 700 HP/ 700 Ft/Lbs... but being a Buick engine; peak HP was at about 4,900 to 5,000 RPM.
-I told the converter company what I had... and what I think I would like... Lets call the company "Nonpro Torque".
-They sent me the converter... I installed and tested it.
-The stall speed was about 1,000 to 1,500 RPM higher than I wanted (the slipping near 5,000 RPM where peak HP occurs, was terrible)
-This completely killed the performance of the engine.
-I called and told them what had transpired... the salesmen said he was baffled and did not understand what happened

In trying not to make this story any longer than it is...

-I asked him how he came to spec the converter for me.
-Eventually he told me, that part of the math came from a model based on a Big Block Chevy engine (average HP/ Torque and the curve through the RPM).
-I was so angry to hear this... that I actually berated the poor man over the phone... and he didn't understand why I was angry, nor why there was a difference using a Buick engine.

Sorry... The point of my ramblings, were to say that:

-Doing the research first on your own, is imperative.
-Choosing a business/ company that is familiar with the products you are using is a necessity... they must be able to further your research!
-Lastly, when it comes down to it... you need to make sure that everything is correct once installed... NO one else is going to do it for you.

Call FTI... They're good!

 

You should talk to yank. There is something wrong with the converter you have, they might help you out with a rebuild/ replacement.
FWIW I have the ss3600 and love it. Hardly notice the difference from stock until you get into it.

 

Vorteciroc i know what you mean. I appreciate you taking the time to help out a rook.

 

The SS3600 seems to be a very popular converter.

 

I would go with a 3600 or 3800 stall speed. I see a crazy amount of slip in the videos, there is definitely something way wrong. I think you will be very happy with the performance of your combination once you get the trans and converter working like they should.

I've got a very similar combination(228/232 112lsa cam, 3.42 gears, fast 92mm, ported 243 heads, 26in tall tire) and initially went with a FTI 3200. The converter worked great but just didn't keep the engine in it's power band...I drove it several years always wishing I had gone with a higher stall speed. So I sent it back to FTI and had it adjusted to a 3800 last winter. The car drives just as well with the 3800 stall speed and keeps the engine in it's power band much better. I haven't had a chance to make it back to the track to see how much quicker the car is but it's a noticeable difference according to the butt dyno for sure. I would say the only disadvantages of a higher stall speed is it generates more heat and lowers the gas mileage. I installed a bigger trans cooler with a fan to help with the heat, my car is mainly street driven and maybe raced 1-2 times a year. When I do drive it it tends to be in a lot of stop and go traffic so the bigger trans cooler and fan give me some peace of mind in those conditions. Hope this info helps.

You really can't go wrong with FTI or Yank, both are great companies with proven products. Good luck with the wife!

 

Great firsthand account! I put a trans cooler in when I swapped out the converter and it's mounted in front of the a/c condenser on the passenger side.

 

During 2-3 shift (typically just normal driving) I can feel a "thump" sometimes. It kind of feels like the trans hits the trans tunnel or something. Is this the trans slipping between the two gears or do I maybe have a bad trans mount?

 

If you have the stock trans mount it's likely toast. I went through 3 of them, tried a poly mount, didn't like the nvh that produced so ended up getting a t/a relocation cross member.

 

I'm not familiar with the acronym nvh.

 

Dumb question, but fluid level was checked right? It almost drives like its low on fluid.

My fti 3800 drives great with 3.73's. To accelerate like you are in the first video Im at like 1900rpm-2100. But stalls are not created equally.

The hard shift into 3rd may be the computer boosting line pressure because its seeing slippage in the converter/trans. It probably happens after a few miles of driving right?

 

Yeah I just checked the fluid in it the other day and it was full.

It does seem to do the 2-3 more once it’s warmed up.