No hijacking at all. I'm just asking questions out of curiosity so I can better understand why people pick the types of torque converters they do. This will be a more useful thread for everyone the more questions are asked and answered.

 

Even better is that you may save yourself a big chunk of money if all that's needed for your DD is a tune rather than the cost and labor of removing the converter, shipping it, downtime, etc

 

I feel the best person to ask these questions is going to be the converter manufacturer. They build the converter and they are supposed t know what it is going to "do". Converter tech can be very tricky because only the little person inside the converter on your car truly knows how it will ultimately behave, and because fluid is involved, its all a bunch of %percentages and efficiency ratios and math math math. Things we might not need to know in order to select the right converter and move on, if I don't want to go into business building my own converters. So, Instead let the expert paint the car this time around, till ur looking to get into that sort of business.


Here is an example of the technical nature of converter lingo:

That is not correct information if the SS converter has at least 800-900 rpm drop on the WOT 2-3 shift it will stay fully coupled up. At that point the converter unlocked will have around 5% slip and that is it the same as a PAS series. The PAS series just couples up quicker which means you don’t need to shift the rpm as high to get the same 800-900 rpm drop you need on a ¼ mile setup. That is why we will tell people it works better with a power adder like spray turbo ProCharger etc.


Dave



To: dave@converter.cc
Subject: Re: Question about ss converter

this is quote:
"SS is an inefficient converter. 15-18% slip uptop (83-85% efficiency). I'd look at the PAS series if you want to spray. They are more efficient uptop (93-95%) and tight for regular driving. The 3800 would work. Same cost as the SS."

Is this true? And I am curious if so, why did you recommend the SS for my daily driver, there must be a good reason.

From thread:
https://ls1tech.com/forums/automatic...ter-stall.html

 

When talking about converter sizes let's think more about the actual surface area that converter would use. Keeping that in mind and understanding how a converter works if you take 2 converters that are different sizes and theoretically set them up to be identical aside the from the size, and put them behind the same power plant, then the smaller converter will stall higher because it has less surface area to use towards working to hold the engine at X stall RPM.

When it comes to interior fin angles the turbine fins generally are not adjusted but it special occasions it is possible. Most fin angle changes take place on the impeller(piece that drives the turbine). Think about you pulling your hand through a pool of water from left to right. a neutral fin angle(finger tips straight down) is a middle of road fin setting. This will still allow the converter to stall at the beginning on the run but it will also stay fairly efficient at speed as well. a negative fin angle(finger tips angled to the left) will stall looser and allow the car to stall higher at the beginning/start of the run but it will not be as efficient on the top end, this is because the fluid "rolls off" off your hand instead of "scooping it and moving the fluid. a positive fin angle(finger tips angled to the right) is going to the exact opposite. Because the fin is getting such a big "scoop" if you will it is directly more fluid and becomes REALLY efficient has the car gains speed. trade off here is it will catch the motor much sooner as well.

Next is the stator: There are so many options for these it is hard to say that one is good for one application or another as it depends on the fin angle you pair it with. For example our "power adder" stator combined with a neutral fin angle makes a great option for a turbo setup that needs to be able to spool but still drive fairly nice on the street. This same converter with a slightly negative fin angle makes a very nice N/A higher stall(3600-4000) converter that still has nice street driving manners. Switch gears over to the stator we use in our N/A low stall daily driver style converters(2600-2800) and you've also got a good roots/screw blower setup converter that can capitalize on the blowers instant torque.

Hope this helps shed some light on what goes on when choosing the right converter. Bottom line is the fin angle, converter size, and stator all have to work together to make the converter work and they all have to be weighed equally when deciding what converter is best.

-Dalton

As always if you guys have any questions feel free to give me a call here at the shop or shoot me a PM or email!

 

Dalton, thank you for the very detailed, well written and information information.