Torque Converter selection

[Evil Red Demon]

The time has come to have my 4L60e transmission rebuilt with all the fun parts. Fortuinatly (or unfortunately) I have to select the torque converter to put into the build. It was recommended by my builder that Yank, Circle D, and Precision Industry were the leading TC companies. But I'm open to suggestion on other brands if someone has a reccomendation.

Currently the car sits in near stock trim as far as power goes. No internal engine work has been done but I do have the SLP CAI with a tune from Texas Speed. I do not yet have headers (coming very soon) but I do have a dynomax catback. Rear end is an auburn 3-series with 3.42 Richmond gears tied to the soon-to-be-modded trans with an aluminum 1 piece driveshaft. The rest of my mods are all suspension: LCA's with relocation brackets, panhard bar, tunnel mounted torque arm, KYB shocks, Strano springs, almost all poly bushings, 15" race star wheels wrapped in Hoosier drag radials, 8" wide in back, 4" up front.

Future plans do include heads, cam, and fuel injector work from ZZP in the next 2 years. So I'd like to set up my transmission to play nice with the stock set up now and the mildly modified setup of the future so I don't have to back track once the engine is done. Either way, my goal is to get it down to or as close as possible to high 13's in the 1/4 mile. I think that's as far as my budget and time allotment will take me before my son gets into Jr dragsters and I'll have to devote more time to his car than mine. Also, i feel its worth mentioning that consistency is going to be key for this build as all we do is bracket racing.

That might be info overload but I want to provide all the parameters I'm working with. Any thoughts and ideas are greatly appreciated!

[ssms5411]

I went with a TCI 3500 stall, can't say if i like it or not, haven't driven the Camaro that much, just got it broken in. Will let you know how it goes, still need to do some tunning on it. Hptuners should be on your list also, if you don't already have it.

[Evil Red Demon]

Cool, TCI wasn't on my list yet but I'll check them out. As far as good ol' HP Tuners, I do not have it simply because it terrifies me. I'm not sure I would fully understand everything I'm looking at since I don't have a real in-depth automotive background and I would be afraid to really screw something up. I don't know what your background is but would you mind telling me how your experience was and what you use it for mostly?

[ssms5411]

Sure, they have writeups on Hptubers explains it pretty good, I've used it since 2002 i think when i got it. Also on hptuners it explains it, when you click on what you want to change it will tell you what functions your in, plus they have beginner and advanced so you choose what you want to look at. Since your modding and plan on continue to mod it would be a worthy investment.

[ssms5411]

Almost forgot, they also have Hptuners forums that you can ask questions and their pretty damm smart. But if you go that route youll need a nice wideband. If your doing heads cam and injectors and a stall your going to need some tunning.Those mods there would put you in the 13s.

[Evil Red Demon]

Cool man, thanks. Like I mentioned, I ruled out getting it a few years ago since I was concerned about messing something up. But maybe its time to take another look at it and give it a shot!

[LETZRIDE]

Are you planning on staying Naturally aspirated or Forced induction?

If you plan on staying naturally aspirated do you have an idea of the Cam you want to put in is?

You'll want to match the stall to the cam / build you intend to put together. A forced induction setup will want less of a stall than an NA setup

[Evil Red Demon]

It'll stay N/A since it's just a bracket car, no need to complicate things further. I would imagine that I will go with something like the ZZP GT2 cam when the time comes.

[LETZRIDE]

I would go with something like the TCI and their 3500 stall if you want to stay somewhat conservative (I had a custom 3200 stall by them and always wish I went more) or if I personally had to redo my build all over again I would go with a 4000 stall if staying N/A. I have a 3600 stall in my LS1 now and again, wish I went with the 4200 instead as this one is even a little tighter than my old 3200 one.

Back in the day I bought my Stall off of Abbott Racing Heads website

[ssms5411]

Thats where I ordered mine from Abbott Racing, although they charged me alittle bit more then whats on their web page.

[Evil Red Demon]

So if I were to go 4,000 vs. 3,200 is there any chance of it running out of power at the top end of the 1/4 mile with the 3.73's in the back. Just curious since starting at 4,000 would seemingly run me into 2nd (and the rest of the gears) much quicker and I don't want to get to the 1/8th and have it fall flat on it's face.

[LETZRIDE]

You have it backwards with your question so let me try and clarify and turn it around for you.

What you mean to ask in your question is will you run out of gear in the top end of the 1/4 mile with the stall and 3.73 gears in the back. The answer is no - You do not want to go into 4th gear at WOT as that is your overdrive gear. What determines if you run out of gear (i.e peg redline beyond what your motor is capable of) is not the stall but rather your gears. With 3.73 and the stock rev limiter you won't top 3rd gear out until 117mph. Once you get the cam in and supporting valvetrain you'll likely be able to push your limiter up to 6400-6500rpm meaning you won't top 3rd gear out until about 130mph. You won't hit 130mph in the 1/4 unless you are a 10 second car.

By having the bigger stall what will happen is it will cause you to stay at 4000 or higher RPM at all times when full throttle as opposed to falling out of your powerband. When I had my 3200 stall and I was at full throttle my car would roll between 5000rpm to my redline then back to 5000rpm to redline all through my gears. Without a stall you'll find when you go full throttle you fall back to 3500rpm or so on each shift having to climb back into your power band. The part that allows this in a stall converter is known as the "shift extension"

When spinning that high your limiting factor on power becomes your cam/heads/engine as a whole and how much air it can take in. More air + more fuel = more power

[Evil Red Demon]

See, that's why I come to you guys for this kind of stuff! Thank you so much for the explanation, that makes perfect sense. Just curious, what is the powerband on the 3.8? Since all I use it for anymore is bracket racing and it gets trailered to the track, I'm beginning to lean towards the 4000