Okay, I am lost when trying to purchase a converter and need some expert help. Basically, my engine is a mild 350 with Accel High Flow TPI and a built 700R4 with shift kit.

My rear gear is a 3.23

My cam:

Lingenfelter 74216 Camshaft L98, LT1, LT4 1987 - 96 TPI - Hyd Roller 213/219.493/.502 HR112

The cam manufacturer reccomends a 2,600 - 2,800 stall which sounds high.

AFR 180 heads


Thanks for your help!

 

That's not a bad little engine built there. Very nice. I am NOT a converter guru, but yes, that does sound a little high. Traditionally, yes, you do pick the converter based on the cam. I guess it all depends on what you plan to do with the car. If its a Saturday night special that you will be racing a lot, then sure, throw the higher stall converter in. If its a street car that will see only a little bit of racing, then you should probably go with a lower stall. Stock is around 1800-2000, mild upgrades are 2000-2200, so I if you are building a street car, then I guess 2400 would sound about right? I know there is more info on this around. Hopefully someone else will chime in. Also, are you going to keep the lockup function or not? Removing it will cut 10lbs or so off your rotating weight, but no more cruising down the highway at idle. I've driven a mild stall (around 2200) in a mild vehicle with no lockup, its kinda fun, engine definitely spins up faster, but not so good on gas on the highway.

 

Thanks for the help! It is mainly going to be a street car with very little strip time. I agree with you, I think the 2400 is reasonable. I just could not believe Lingenfelter reccomended a 2,600 - 2,800 stall. I thoughy maybe I had something wrong but you confirmed my thoughts.

I plan to keep the lockup function just because it will mainly be a street car.

Thanks again for your help! It is much appreciated.

 

One is it a daily driver? or weekend warrior? And how do you drive? conservative? moderate? moderately aggressive? or aggressively? With the information you have given, the above questions will help out on the final decision. Let me know? Dana

 

It is mainly going to be a weekend warrior. I plan to do some long drives on the weekends mainly. It will see very little strip time. I may take it out of few times after it is broken in just to see what it will do.

Well, I most likely drive this car pretty moderately with some occasional aggresssion. I woudl say 70% moderate, and 30% aggressive.

 

You want the converter to be in the motors power band. You cant just say I think X is to high so I'm going with Y. If they say your gonna start making power 2600-2800 then you need to get a converter that starts in that rpm range. And having the low gears in the car isnt going to help either.You will need to get a taller gear also.

 

Do you have any reccomendations? I would prefer to buy another cam over changing out the rear end gear. I guess another option is jsut to get a converter at the bottom, so maybe a 2,500 - 2,600 stall. What does that do the the overall drivability and performance? If TPI is only going to make power to 5,000, should I get a cam with peak power at lower RPM and therefore get a lower (closer to stock) stall speed?

 

I'am saying all this for optimal performance. You can use the 3.23 gear but your not going to get all the performance out of the car.And just beause a converter says its a 2600 stall dosent mean thats what it will do behind your motor. That depends on how much power and torque you motor will be putting out.My car has a 3000 stall in it and its a street car and I have no problems on the street.

 

Based upon calculations by my engine builder, I will be around 350 HP and 420 torque. Not sure if that helps and is of course a calculation and not actual. I just hate to change the rear end gear. If I do, what gear would be best?

 

84 z28 is right, there are a lot of things to take into account when you actually go about selecting a specific converter. There are a variety of ways to measure stall speed, and it all depends on what you are doing which one makes sense. TPI makes torque, TONS of it, but it makes it low down, not up high. I believe someone said it was the best truck engine GM put in a sports car, which I think it pretty accurate. So you need to pick heads/cam/trans and rear gears to go along with that low-end grunt.

If you cam spec says a stall of 2600-2800 stall, when does the cam run out of steam? 6500? What are you going to do with power up there? Not much I would guess, especially with an automatic. You went with the convervative heads, the 180's rather than the 190's, so that's good, but again, its more about low power. The big heads make the difference in the higher rpm's, where you will probably not be. (At least that's how I interpret what I've read)

It sounds like you are building a street car that you can drive very often, so the conservative rear gears are fine, you'll still make enough power to break the tires loose at will, you just won't have the best hole-shot.

I think you should check the operating range on that cam, and then put in a call to TCI or some other tech line and talk to them. Also, you should do some online research about converters. I seem to recall there being a few different ways to measure stall, and they all mean different things, hence why 84 z28 is driving a 3000 stall converter on the street happily.

Here, read this:

http://www.carcraft.com/techarticles...ter/index.html

should help you out. Remember, Google is your friend!!

Conversely, you could just PM Dana the transmission guy (Pro Built Automatics)...I'm sure he can give you some quick answers as well.

 

Thanks everyone, I truly appreciate the help. I called TCI yesterday, gave them my specs, and he reccomended a 2,400 - 2,500 stall converter based upon my rear gear, transission, and cam. That still sounds high but I am by no means and expert and definitely not qualified to challenge a professional. I will probably get one more opinion before I make my purchase.

 

Trust me thats not a high stall. You will be happy with it and it will make the car alot more responsive when you jump on it. Are you getting a lock up or non lock up ?

 

I am probably going to stay with lock-up just because it will spend some time on the expressway. Overall, I jsut want a fun street car that is QUICK 0-80. I will take it to the track a few times but then jsut have fun with it.

Is there an advantage to getting a non-lock up?