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Discussion Starter #1
Since I am just getting back into cars and the prior high perf were all 4 speed, someone gave me a new phrase to become familiar with.

This is not a drag car, instead I want reliability, performance with street manors.
It has a 7004R with station wagon gears (probably 2.##) and 26 inch rear tires.

We will be replacing the starter and flexplate (with ring gear).
We were discussing whether or not to change the TC.
Up popped the phrase: "Torque Converter Efficiency".

Now, this isn't TC stall values. It is more about the hydraulic efficiencies of the converter. Apparently that can change how much torque gets to the rear wheels.

It was suggested that I look at Performance Industries.

Any of you running their products for street use?

Thoughts?
 

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Some companies do offer a , tight convertor , such as in the dirt track racing applications, see my avatar,:nanawrench: www.daymotorsports.com

They have a excellent counter staff, very friendly folks. :texas:
 

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would that be as in gas mileage Efficiency [less slippage]
or performance Efficiency [more slippage or torq multiplication]?

with a 700r4 and lockup torqconverter you can have both, right??

The key characteristic of a torque converter is its ability to multiply torque when there is a substantial difference between input and output rotational speed, thus providing the equivalent of a reduction gear. Some of these devices are also equipped with a temporary locking mechanism which rigidly binds the engine to the transmission when their speeds are nearly equal, to avoid slippage and a resulting loss of efficiency.
http://en.wikipedia.org/wiki/Torque_converter


:texas:
 

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Discussion Starter #5 (Edited)
JJ
with a 700r4 and lockup torqconverter you can have both, right??

That's kind of where I am looking at this. I don't want to give away power.
The person helping me has found ways to balance guiding me as we go forward. He has learned how to say "Not quite for what you want" when I make some statements. He doesn't knock what is in the car, yet his word for the current torque converter were like "not an efficient one".

With this heavy 3,800 lb vehicle, recapturing lost torque when going from stop, could help it get under way more efficiently.

I thought the current TC had lock up, yet I see no evidence of that. So for my needs a lock up TC would be best. Every trip around here is Fwy or PCH (55 mph). Even though the rear end keeps RPM at 65 on flat land to under 2,000 RPM, it would be easier on trans temp if TC locked.
 

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IMO the 2.## gear needs to go to help any convertor.
 

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Discussion Starter #7
Thanks Ralph, That may be a change further down the improvement path.
The starter and ring gear are not in good shape, so they moved up the priority list.
 

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I understand priorities. The problem is if you get a custom convertor for your combo with 2.## gears it will not work the same (better or worse) when you go to a 3.42-3.73.
If you tell them your planning on changing gears later down the road and they build it for that, it won't work correctly with the 2.## gears, and may damage the convertor.

Back to MO, I would put the flex plate and starter in and wait on the convertor until gears are changed.
 

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I understand priorities. The problem is if you get a custom convertor for your combo with 2.## gears it will not work the same (better or worse) when you go to a 3.42-3.73.
If you tell them your planning on changing gears later down the road and they build it for that, it won't work correctly with the 2.## gears, and may damage the convertor.

Back to MO, I would put the flex plate and starter in and wait on the convertor until gears are changed.
Ralph is on point here. Rear end gears are also a multiplier of torque and need to work together with the torque convertor, as well as the engine's intended RPM range. Your guy should know that as well and suggest waiting until you decide on a gear change. New gear ratio will affect the efficiency of the new torque convertor, and maybe not to your advantage.
 

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Discussion Starter #10 (Edited)
Thanks guys.

One of the reasons for getting the car, was to have areas to learn that would help retrain the brain. I think it is helping (with help of you guys and others). Justin understands this too. He threw the torque converter efficiency out there knowing I would look into it. Get me thinking about it now, so we can have better conversations as we get closer. He understands by now, I would find out the rear end ratio, rear tire diameter, trans type (gears) and engine torque range all play into that decision.

The typical standard rear end was 3.08 for the small block 1970 El Camino. There was a 2.73 available for economy, and that may be what is installed. Nothing fancy back there on mine. Ten bolts, grease and oil, no sway bar (one up front), no lower rear control arms, no air shocks, no air bags, replaced shocks.

But it now has brakes!!!
 

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You can look at torque converters, gear ratios,and other statistics for hours.Drag racers are looking for hundreths of a second. What are you looking to find and how many thousands of dollars are you willing to spend to get it?
 

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Discussion Starter #12 (Edited)
Some companies do offer a , tight convertor , such as in the dirt track racing applications, see my avatar,:nanawrench: www.daymotorsports.com

They have a excellent counter staff, very friendly folks. :texas:
Thank you Marcus
I had visited their site before.
I did get to this "introduction video" from one of their suppliers: TCI.
https://www.youtube.com/watch?v=29-9LRtkGTM

And... For those who like me found a way to forget even the basics of torque converters
Eric the Car Guy intro to TC
https://www.youtube.com/watch?v=pTfipsejqS0
 

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Discussion Starter #13 (Edited)
You can look at torque converters, gear ratios,and other statistics for hours.Drag racers are looking for hundreths of a second. What are you looking to find and how many thousands of dollars are you willing to spend to get it?
Hopefully my original post implied that tenths of a second do not matter for this application. The goals are stated as reliability, without wasting everyday efficiency of performance.

As for having thousands to spend...... Could you have me confused with someone else?
 

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Thanks guys.

One of the reasons for getting the car, was to have areas to learn that would help retrain the brain. I think it is helping (with help of you guys and others). Justin understands this too. He threw the torque converter efficiency out there knowing I would look into it. Get me thinking about it now, so we can have better conversations as we get closer. He understands by now, I would find out the rear end ratio, rear tire diameter, trans type (gears) and engine torque range all play into that decision.

The typical standard rear end was 3.08 for the small block 1970 El Camino. There was a 2.73 available for economy, and that may be what is installed. Nothing fancy back there on mine. Ten bolts, grease and oil, no sway bar (one up front), no lower rear control arms, no air shocks, no air bags, replaced shocks.

But it now has brakes!!!
Brakes are a good thing sometimes. Retaining the brain is also a good thing, this place makes me think more than before. I only come here to help and I hate seeing people spend money twice for one result.
GM and all other auto makers found out that under powered engines and super hi gears was burning more fuel around town than it was saving on the highway. So the automatic overdrive was born. They were never intended to be coupled with super hi gears, although they tried in the early '80,s.....
 

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Discussion Starter #15 (Edited)
Thank you Ralph.
I have had the car for a year now. It is a bit odd with how it was set up when I got it. Some things are now improved and I appreciate the help you guys provide. PO did not have it long and only put very limited miles on it. They thought it had a TH400 3 speed. At least now the 700r4 is now working and the TV cable is set correctly. It shifts smoother and knows how to find 4th.

I agree on not spending twice. Once is expensive enough, yet if a TC would help, then the labor was not much different from R & R of the ring gear.
I will keep learning, and hear and appreciate your advice on just fixing the starter & ring gear in the next phase.

A rear end gear change, adds the decisions of whether to stay 10 bolt, and what changes to the suspension. That will need to be balanced financially as I go forward.

I need to be fair to the fellow helping me. I asked "Do we need to do anything else when we change the ring gear?" "Was the rear main seal leaking?" Actually it is OK, it is the trans pan gasket that is leaking. That gasket replacement may get added with the ring gear project. "Is the torque converter OK?" So the suggestion was to look at different torque converters so that I understand them better. Not necessarily a recommendation that we need to upgrade.
 

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IF it's a street driven car don't go too nuts with the stall speed. Yeah it'll roast the tires if the rest of the engine/drivetrain is matched to its specs but it'll be bloody awful just cruising around town.

Been there, done that, paid the tow truck driver...:eek3:
 

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Discussion Starter #17
Thanks Guys for the advice. We did not change my TC.

We did change the flexplate and put a Powermaster mini PMGR starter on to stop the grinding.

We made a couple other changes for reliability, including larger starter cable, starter heat shield (blanket), an additional trans cooler and larger cooler lines to help protect the 7004r.

TCC is now locking up, yet may need to be adjusted a little more.
On the way home, we were at 1500-1800 RPM at about 60 MPH (speedo is way off and read 75-80 - low priority).

Oh.... I was clearly wrong in a post above. The rear end does have the original upper and lower control arms. Not sure of the rear end ratio yet, but it is definitely for cruising at 70 and above.
 
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