BC Torque Converter/ 3500 or 3200?

97woodward · Mar 8, 2008

Hey everyone, after a ton of reading an research I have decided to purchase a Torque Converter and Valve body kit from BC Automotive. The only thing I am going back and forth on is what stall to choose.

My car is an automatic with 87k on it. It just had FFRP 4.10s put in. I have a transGO kit that Im taking out as well as a trans cooler thats too small Im replacing with something much larger. I use this car as my daily driver. I ownly have 1 car and this is it, so I dont want to spend about a $1000 after buying and installing it on something that is a bit to extreme for day to day driving. Dont get me wrong i want this car to wake the hell up but not at the expense of losing a ton of mpg and effecting the ride negatively. So what would be the best idea?

Im kind of imagining this like the 3.73 , 4.10 situation. Where once someone gets the 3.73's they generally wish they would of went with the 4.10s. So I just wanted to get some advice on this. Any help is appreciated. Thanks!

Brian95SVT · Mar 8, 2008

i'm goin with a 3500 stall

i know a guy with an LT1 body with an LS1 swap in it and he has a 4000 stall and it's his DD
so

i think a 3500 stall will be good enough for me

i'm puttin 4.10s in soon

Jrgunn5150 · Mar 8, 2008

3500, I know it sounds like alot, but you will love it.

97woodward · Mar 9, 2008

so how exactly will the ride be? I know its kind of difficult to describe over a computer but does it really effect acceleration ? Im noticing with my 4.10s that on the highway it seems to lose that great pull, i know that my pi intake and cams will help but will the 3500 stall play a part in improving that? Thanks for the responses

Jrgunn5150 · Mar 9, 2008

It effect's acceleration in a huge way, mostly from a standing start though. The engine will be able to rev easier, and quicker (not really accurate, but that's the feeling), you will be able to blip the throttle in gear.

As for the freeway, the valvebody and PI cam's and intake will bring that back.

97woodward · Mar 9, 2008

yeah when this is all said and done I will have spent the same amount if not more than a supercharger just getting the car where i want it. But i think this is a better route, I wouldnt of been able to get my 4.10s, suspension upgrades, FULL tune-up, Tires, PI intake kit,PI cams, and my transmission kit and cooler. The car just would of been a poor running GT with a supercharger.

Thats the way Ive always thought about, when people say save that money for a blower. If your a college student (like my self) or have a strict income than that basically means you are going to skimp out on regular maintenance. My Full Tune Up ran me around $700 when I finished everything. Thanks for the replys!

justinschmidt1 · Mar 9, 2008

97woodward said:
yeah when this is all said and done I will have spent the same amount if not more than a supercharger just getting the car where i want it. But i think this is a better route, I wouldnt of been able to get my 4.10s, suspension upgrades, FULL tune-up, Tires, PI intake kit,PI cams, and my transmission kit and cooler. The car just would of been a poor running GT with a supercharger.

Thats the way Ive always thought about, when people say save that money for a blower. If your a college student (like my self) or have a strict income than that basically means you are going to skimp out on regular maintenance. My Full Tune Up ran me around $700 when I finished everything. Thanks for the replys!

post some after opinions when you get it...you got any 1/4 mile times now?

97woodward · Mar 9, 2008

Yeah I will, I dont ever take it to the track, but I may during the summer, Ill keep you posted.

justinschmidt1 · Mar 9, 2008

97woodward said:
Yeah I will, I dont ever take it to the track, but I may during the summer, Ill keep you posted.

Im kind of second guessing the whole blower thing.....if the thing blows im gonna be so screwed

97stanger · Mar 9, 2008

Instead of guessing what stall you think you should get why not call Darrin, im 100% positive he would tell you what stall you would need. Just tell him yourset and what your plans are for the car.

voidfinger · Mar 9, 2008

Blown speaks the truth ... but i would say anywhere around 3400/3500 stall... since your getting the pi cams and intake.

Johnny Langton · Mar 10, 2008

For a stock cams/intake modular-you really need a 3500 converter. I run a 4000 converter in my car,and it really needs to be a bit more,but that's about as loose as you can get a 245mm converter. I also drive my car all the time,and it's not bad at all on the street-it's actually quite fun to snap the throttle and fry the tires on command when the converter flashes up to stall speed.
JL

voidfinger · Mar 10, 2008

JL didn't you say that for a npi you need around 3200? but for the pi you need 3500? Just wondering B/c he has the pi stuff minus the heads then 3500 should be it.

Johnny Langton · Mar 10, 2008

voidfinger said:
JL didn't you say that for a npi you need around 3200? but for the pi you need 3500? Just wondering B/c he has the pi stuff minus the heads then 3500 should be it.

A stock NPI engine will stall a converter at say...3200 rpms. Switch out to the PI intake and cams, and you'll see around 3500 with the same converter. Stall speed is strictly based on input torque. My 4000 converter would be 5000+ with a S/C on my car.
JL

voidfinger · Mar 11, 2008

ahhh sweet, so you could just buy a 3200 for a stock npi and then as you mod the stall will go up to what you need. thats pretty cool

Brian95SVT · Mar 11, 2008

i didn't know that.... that sounds sweet though ahah
i guess i will be set with my 3500 that i planned on getting ahahh

Jrgunn5150 · Mar 11, 2008

It will go up to an extent, depending on the torque input on the shaft like JL said, but it won't stay optimum for the motor once you go far enough.

I mean a built motor will stall a stock converter higher, but it's still not optimum, so don't think that it will adjust itself to your combo or something.

Johnny Langton · Mar 11, 2008

voidfinger said:
ahhh sweet, so you could just buy a 3200 for a stock npi and then as you mod the stall will go up to what you need. thats pretty cool

Stall speed is setup based on input torque-so if the converter is setup to stall at 3200 on 270ft-lbs,then it'll stall higher with 290-300 ft-lbs.
JL

Brian95SVT · Mar 11, 2008

so will a 3500 be enough for once I get blown (hahah) and all?
or will i have to step it up again?

Johnny Langton · Mar 11, 2008

J.R. said:
It will go up to an extent, depending on the torque input on the shaft like JL said, but it won't stay optimum for the motor once you go far enough.

I mean a built motor will stall a stock converter higher, but it's still not optimum, so don't think that it will adjust itself to your combo or something.

Exactly...if you add cams to it-then it could very well stall lower than it did with a stock engine,and make the car SLOWER.
You need to setup stall speed based on the peak torque of the engine. All the old-timer crap about stalling lower than peak torque is just that-CRAP.
JL