Meant to say steel MASS*

Agree wholeheartedly.

 

With the modifications that have been suggested for making the 3-4 clutch pack live. You should be okay with eight if you do these modifications. I have found, that the more surface area you have, the input torque is transmitted evenly, the cooler the clutches will run.

 

The force would be more distributed among more friction plates, yes.

But the heat also has to be then distributed into more steel.
I find that the density of the steels is a greater factor than the surface area of the steels.

There are diminishing returns in either direction (more or less steels and frictions).

The High-Energy linings are like sponges compared to many traditional paper frictions.
This and a Kolene steel work very nicely with the conditions of the 3-4 clutch.
I rarely use Kolene... but I do here as well as turbulator kolene steels for the intermediate clutch in the THM400 and 4L80E.

I do not build many units with OEM input-drums anymore, but I would use 8 frictions here.
The Sonnax drum, I use 9...
I do not see any need for more frictions, even with 1,000+ HP.
And the 4L79 drum is another story completely.

I see the need for better cooling of the clutch.
A sufficient amount of steel to dissipate the heat, and...
the need for more lube oil to get in and get out of the clutch pack.

I actually spend a significant amount of time adding and/ or enlarging lube oil holes to aid in cooling.
On these transmissions for example; improving lube oil in and out of the 3-4 clutch and forward sprag, go a long way when power starts to get up there.

In a THM400 or 4L80E the intermediate sprag, and direct clutch also get this treatment.
With a trans-brake, the forward clutch does as well... simply adding lube holes in the forward hub, makes a big difference.

 

"I contacted a local performance transmission ship and said he was not impressed with the 3-4 clutch setup from the PBA Pro Street kit."

If he looked at the rest of the kit, he might learn something. It is just not the clutch count here. It is the matching of the other components that contribute to making this setup work. I have well over 750 of these clutch packs out there. And they have worked out very well. One of the reasons the thinner steels work here, is the input drum being made of aluminum. Aluminum absorbs and dissipates heat very well. If it was made of steel, then I would agree that the thinner steels most likely would not work. I got this idea of using the thinner steels for more capacity in this type of transmission (700R4 & 4L60E) back in 1995 from Gil Younger (now deceased) owner of TransGo.

Note. I have never had a comeback, or a customer wanting to go, with an 8 clutch setup, due to the 9 clutch setup failing.

 

Dana,

your combinations have most definitely proven that they work.


The less informed will often doubt what they do not know.
Sadly that is the way of the world.

 

well after hearing all the positive feedback I know I can definitely put confidence in your product, I will definitely be getting your kit after a bit of saving and going with a different installer. I just have to find one willing to put in aftermarket products.

 

What is the max power these 4L65E's can handle reliably when rebuilt properly?
I will be running one behind a 700hp NA engine.
It was rebuilt to max spec about 6 years ago and when serviced last year I was told it still looks like brand new inside.
I'm hoping it will be reliable with this new engine.
This is a very interesting thread.

 

The THM700-R4 and 4L60E/ 65E/ 70E/ 75E is not a cost effective solution, when built for higher power than the 700 - 800 HP range.
Not many builders can or will reliably build these transmissions past this power level.

I do build these THM700-R4, 4L60E/ 65E/ 70E/ 75E, and THM200-4R transmissions reliably in the 1,200 Hp range...
They are just too expensive compared to a 4L80E rated for the same power level.

Even the 4L80E units that I build for the 1,800 HP level is less expensive than the 1,200 HP level 4L60E, Etc...

I consider it to be a bad investment; and I tell all my customers that.
The most common reason I build one of these transmissions instead of a 4L80E...
Would be to build a THM200-4R for a Buick GN.

I have been experimenting with some 3,000+ HP "Drag-Week" style race cars running one of my 4L80E units...
But a THM400 with a Gear-Vendors Over-Drive unit is a better solution at that power level.
The 4L80E One-way roller clutch in the over-drive section becomes a problem... I retrofit a larger sprag into the transmission for the higher power units.