Locking or Non-Locking Converter?

91CaliTBIRD

Registered User
My 91 SC is getting a trans. rebuild with a 2200 stall, and a shift kit. The other mods are 10% overdrive pulley, removed air silencer and good exuast. Should i put a locking converter on the transmission like it came with or put on a non-locking converter?
Thanks
 
Depends what you want to do with it. If it's your daily driver, probably best to stick with the lockup. A non-lockup will cost you mileage, generate more heat, and isn't so great if you do a lot of freeway cruising. But it will help you accelerate faster, since you get torque multiplication in every gear. Also changes the feel of the car pretty significantly. I have a 9.5" non-lockup (2500 stall) and I'm still not sure whether I like it better than a lockup or not...
 
small diameter non lockup converters cost you gas mileage. I have actually seen improvements with a 2200 stall 12inch converter unlocked.
Alan
 
SilverCasket said:
I've got a non-lockup. I like the lock-up better.

Anthony
Actually, Anthony you have Tranny problems. :D
I have a 2500 non lock up and love it. I drove the car from Phila, PA to Norwalk getting 24mpg driving at 80+mph. I do not see too much difference in gas mileage from my stock converter to a non lock up.
The difference in mileage will come from how efficient the converter is made.
My converter runs a little hotter than stock, but nothing I am getting concerned about.
Ken
 
Ken, I built that converter and it's not your typical 10 inch converter. That is the most efficient 10 inch converter I know of. I have redesigned the unit and it will be back in production soon. The front cover on your unit takes forever and a day to make so I designed it with a 1 piece plate instead. The new design will have more ballooning prevention and is only about 4 oz heavier. I ended up with a total weight just under 26 lbs. Supercoupe performance will be offering those units in the next couple months. There might be a left over old style design I will sell when my work is completed.
Alan
 
Anybody know what the stall speed is on an AOD converter

What the stall speed on a stock AOD converter?

Me personally Id go with a Lockup unless you plan on making some serious HP
 
Iam getting one of his converters non lockup at 2700. Lets go drag racing. I have a transcooler now and a 2200 rpm. converter with no heat problems that I am aware of. I like the nonlock up a lot more. I dont do much highway driving however.
 
Well Randy I still want to be able to drive it back and forth to the track and up to the local spots for fun. My goal for spring is to get into the 12 second bracket and still be somewhat streetable 500-600 more rpms. will get me offf the line like gang busters. Besides that the 10 inch converter will be a few lbs. lighter so the engine should wind up quicker. I want to see what it is revving thru the traps and may even go with a 4:10 gear if the engine will handle it. I have a few other plans too if I have the money to do them. :)
 
Thanks you gentlemen, i am assuming so far i went with the right choise of a locking converter. I am picking up the SC this morning and i cant wait to test it all out. I also had the trans guy put a tran. cooler on it and fill it with nothing but "Lucas Trans fluid". I think now i am good.
Thanks
 
Randy N Connie said:
If your only going to drag race.Wouldnt It be better to get a stall
of 3000 to 3500 RPMs ?

Randy

not with a SC motor IMO when the most you get the most ft/lb at 2600rpm :)
 
I forgot the exact number. But isent there a thumb rule.

example
That you run your stall 800 to 500 RPM below your peak
hp.For drag racing.

Maybe somone would know the thumb rule numbers off
the top of there head.For the proper stall when drag
racing.

Thanks Randy
 
Randy N Connie said:
I forgot the exact number. But isent there a thumb rule.

example
That you run your stall 800 to 500 RPM below your peak
hp.For drag racing.

Maybe somone would know the thumb rule numbers off
the top of there head.For the proper stall when drag
racing.

Thanks Randy

Randy,

I always thought the rule of thumb was to use a stall setting that is 200-300 rpm below your peak torque.

David
 
Randy N Connie said:
David N, thanks for the numbers.I just thought somone would want
to know what to buy if building for racing.

Thanks Randy

Randy,

Sorry I didn't know there was a difference. Are you saying that for a racing converter the stall setting should be based on peak HP instead of torque ?

David
 
David N.
I am only bringing up that there is a rule of thumb for torque convertor
stall if you want to go full time drag racing.

I didnt know the exact numbers to compair to a dyno sheet to arrive
at the proper stall.For purchase of convertor.

I just thought some would want to know this info.Like TIM.As it is a
one of the cheaper ways to get a lower et when building a car to
go drag racing.

Just tring to encourage more posts.

Thanks Randy
 
Last edited:
Randy N Connie said:
David N.
I am only bringing up that there is a rule of thumb for torque convertor
stall if you want to go full time drag racing.

I didnt know the exact numbers to compair to a dyno sheet to arrive
at the proper stall.For purchase of convertor.

I just thought some would want to know this info.Like TIM.As it is a
one of the cheaper ways to get a lower et when building a car to
go drag racing.

Just tring to encourage more posts.

Thanks Randy

Randy,

I think you are missunderstanding my response. I'm not arguing with you...I'm asking you about how you think a converter should be stalled on an SC similar to mine for drag racing, to get the most bang for the buck. I'm trying to learn from your past experince, not debate the matter.

After hearing how high Kevin's stall is set and seeing how well the car performs on the track, I'm eager to learn more about converters.

David
 
David N. I don't know anything about torque convertors.

The only experiance I have would be with ways to slip a clutch.
Or the set up of a multi stage slipper head clutch,with air lock.

If I was building a drag car I would only use sintered iron
clutch plates with steel plates.With air shifting.

This is the only setup I now how to work with.

I was never allowed to use computor controlled any thing except ignition.
But was allowed fact finding data.We did not go by torque or hp. numbers
to set up the clutch slippage.We went by engine rpm,clutch basket speed,
or rearwheel speed,with ground speed,and of course tire smoke .

There are tire dynos for motorcycles ,But you will be hard pressed to strap
a bike with 750 to 1000 hp on a dyno to get some good numbers .There are
a couple engine dynos around setup to handle what I used to do.

I am not arguing either,just tring to get you or somone to responded with
some good numbers.I didn't have them.

But I do know about slipping the drive-line power (clutch or torque convertor) To keep the engine in its power band ,& getting maximun traction,to go with track conditions.

I am under the impression that with a torque convertor you will not have
a option of adjusting stall or lockup of a turbo blade convertor.TO match
the weather or track conditions.Unless you have a electric controlled
lockup of convertor.So convertors are set at a ballpark number to perform
on the strip.I guess what I am saying is a multi slipper clutch is better
for adjustments for max traction.

On stall or slippage you want this to get to your peak torque window
with at the same time producing maximun traction.So the best stall or slippage is to match your torque.But this setting would be a ballpark
stall number.Not perfect for all track conditions.

But with a torque convertor you cannot adjust the slippage force to
the driveline.To match tire speed to track surface speed.To tune for
max traction on a given race date.

I don't see Kevin L's. torque to be to high.Since it is a drag only car.
It looked to me that Kevin L. and Cory M. both have around 3500
stall convertors.But I bet both would like to be able to control the
force of the stall or slippage, and lock-up.

The problem is that most people want a strip & street car that turn
a world class time.Well this isnt going to happin.Performance parts
made for both worlds.Are Not adjustable enough to be at a perfect performance level.

To be on the fastest SCCoA list.I would drop the number 2 on my torque
convertor numbers and start with a 3.This is why you buy a trailor to go
racing.Its not to haul your car home because it may break down.But also
to haul your car to the track,because its to hot to drive to the track.

David, I am not sure,I am not from the auto world, but if you would
installed a 7 or 8 inch lentech with a 3500 stall.I would think you
could maybe take another .500 off your time slip.But you would
need to mount a full size radiator on your SC to keep you transmission
fluild cool.If you still want to drive your SC to work.

You have every thing needed to go a lot faster than you are.You got
kirt K,Chris W.to help swap out your convertor for a smaller ,& higher
stall,a trailor,and an extra car to drive to work.It would be nice if one
high stall convertor could be swaped back and forth between your two
Super Coupes.

Randy
 
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