Yes I just had a guy ask about that in a 700R4 with 3.15 gears he said and I was like exactly how fast you plan to go lol. I know in my impala figuring in the 3.08 ratio and tire size it would shift to 4th at 5400 RPM at about 150 mph and it would take alot of HP and torque tp push even a corvette with good areo dynamics at 30 percent overdiven much faster IMO I would rather have part throttle kickdown .if that was the choice.

 

Yes.
140 MPH.
That's the maximum technical speed ( 100 MPH average) for one class of open road racing at the Sandhills Open Road Challenge.
In 3rd, with a 3.73 rear gear and a 26" tire that's 7000 RPM (with a 5% converter slip). That'll never happen with this engine. Overdrive on the other hand is about 5k. Very doable.
And I've done it with a homebuilt 700R4 with little more than the boost valve upgrades, a TransGo 700 2&3 kit and the B4C option. The lockup was disabled via my manual switch. Survived that highway run and it went on to provide many more miles of service but I'm not wanting to risk it again.
Somewhere I've got (or did anyway) in car camera footage for proof (to myself more than anything).
So really, in this new chassis and a new engine, 140 is the target.
115 would be great in the 1/4. That might mean 11's with a decent 60'. The Sandhills race also has 1/2 and 1 mile events. Could I reach 130? Don't know. But overdrive would be nice because it would keep me off the redline.

 

A little further with the above thoughts, even the entry level class (minimal safety equipment) with a maximum tech speed of 120 puts me a little better than 6k in 3rd gear. The 120 technical maximum applies to classes with 80 -90 MPH average speeds.
Again, overdrive would be nice but lockup isn't required. From the sounds of the guys that build these transmissions in this forum, the lockup function is problematic with a great of internal rework needed to make it happen and live.

 

OK. It sounds workable.
I've got a good flat drum, a nice wide band, and a Sonnax 4th super servo. Well, the drum was new until this latest episode. Hope it survived (still waiting). I'm the sure band is smoked but it's pretty much a wear item anyway. The Sonnax Fourth gear super hold servo 77767K would have survived. But the hydraulic modifications (feed hole and accumulator) I haven't confirmed.

So, if can guarantee the above, I can expect similar success I would think.
I don't care if I have for lockup on an open road at WOT. I've always understood that fluid demand side you mention. But no kickdown from 4th at WOT is what I'll need.
Isn't that what the B4C does?

 

In addition to the above comments and questions I've tried to sort through the recommended upgrades and methods and put them in a bullet point format.
How does this look?

 

Just curious what type of engine designed to be raced/abused can't comfortably turn 7000rpm?
Shifting to OD works. It's been done. It can be done again.
It's just usually the better option to avoid it when possible. Typically faster anyway. Takes a decent amount of HP just to turn the planetaries in OD.

 

"Comfortably" is the operative word there.
Is this engine capable of going to 7k? Yes. Been there and done that although that cam made peak HP arguably 500 RPM further up the range.
This new spec will be done by 6500 give or take.
But, that was drag racing.
Having an engine turn 7000 is one thing when it's all done in less than 11 seconds.
It's another thing altogether to do that for half an hour. Yes I'm well aware of the durability tests and all that, but I can't say I care to subject this engine to that kind of torture. It's not like I'm going to pull it out every year for a tear down.

As for the overdrive, your opinion on the power requirements line up with others when asking this same question elsewhere.
It may well be that that part of the racing game will have to be reconsidered. Beyond the engine and transmission capabilities, you also have to start to pay attention to what all that speed for all that time does to the rest of the rotating parts. Diff cooler needed? Special attention to wheel bearings? Not sure but it's a work in progress.

Now, all of that said, having a run at 140 MPH would be a blast. And getting close to 7k in a one mile event is well within reason. But 30 minutes or more kind of makes me a little unsettled.
Just saying.

 

Tear down the engine or tear down the trans.
Your pick
Sustained power through OD will undoubtedly be hard on planets.

Your better all around option here might be a 3.55 gear, and lock the converter in 3rd
That'll get you to 140mph at 6500
It'll run cooler, be better on the trans, and keep the engine in the happy zone if 6500 is were it cries uncle.

 

Well, that is fair comment. And I'd prefer to pick neither again as was my hope last fall before this latest transmission debacle. Fresh engine, relatively fresh transmission and I was supposed to be good to go. I didn't even get to beat on that transmission prior to its meltdown which is even more aggravating.
This is why I ask these questions. It seems almost an unreasonable request to ask that 4L60 to do what I'd like. Maybe the gearing is an option. Or just stick to good old drag racing and maybe a mile event is better suited to the car's platform and my budget.
As for crying uncle at 6500, I'm not sure what others are driving but how many would be comfortable driving at the redline for 30 minutes or more. It puts a new perspective on things.

 

Cries Uncle wasn't meant to be a jab

I'm just saying if you're building a car that's purpose is to drive at 140mph for 30 minutes at a time...you'd better have an engine with a stable enough valve train and oiling system to handle that.
Rocker and spring oilers
Windage control
Stable camshaft profile
Good temperature control
Adequate oil pump
etc etc

I wouldn't crutch the engine's redline stability by putting the stress on the OD of the 4l60e
If you want to put similar effort into geartrain stability, oiling/lube, cooling, and power handling via the band and servo and valve body and pump etc etc
Then it sounds like similar amount of work but behind the flexplate instead of in front of it

 

All very valid points and it brings me back around to OD at WOT to keep revs down.
But, as has been pointed out (via my asking the questions to whose answers I don't particularly want to hear...if that makes sense) that ability, transmission -wise is easier said than done. As it stands at the moment, there's no one I know of locally that I'd trust to do it.
​​​​Further to that, if OD isn't the best idea, I know certainly without further flexplate forward upgrades, that top speed, for any length of time isn't going to happen. 7k in a sprint? Sure. 7k for 20 or 30 miles. No.
So, after having asked around, I have to rethink the project objectives.
Looks like the original plan of a drag and drive car is back front and centre.
It's been an interesting learning curve on the transmission front.

I have to ask though, ask again actually, how did the B4C thing work for the cop cars of the day? I've seen my share of 3rd gen Camaros outfitted for highway patrol duty. Not to mention the Caprices that followed me on more than one occasion (back in the days of my youth). They all had that OD WOT option didn't they?

By the way, thanks for your input.
No jab taken on the crying uncle either!
​​​

 

My family owned a taxi cab company before I was born and as I was growing up
They got ALOT of "9C1" caprice cop cars
Granted they were 4l60e cars, not 700r4 cars but the geartrain/servo functions the same when shifted to 4th WOT
Those 9C1 cars...most were highway patrol cars. So I'll about guarantee they saw WOT 3-4 shifts more than once in their lifetime
And what I can tell you is that the transmission was a wear item. And from what Dad tells me. The highway patrol cars needed planets in a significant higher % than the city cruisers.
Those cars had upgraded coolers and slightly different programming but they weren't bulletproof. I don't know many patrol cars that would rock 140mph for 30 minutes
Even if they did...they came with a 3.08 gear and a 27.5" tire...so they were doing 140 in 3rd more than likely

Having driven a 9C1 for my entire high school life...I can guarantee they'll do 150mph (takes a LONG time to get there)


I digress
Asking the thing to make a WOT shift...fine. In stock form it will do it, it just won't live forever

We can modify servo and Valve Body to do it more reliably and keep the band alive. No problem.

But when you've pointed out that you want to do it for 30 minutes straight...that's a different criteria than any car that ever got these options and it's flat out just going to be tough on parts. You might be able to modify lubrication and keep the geartrain stable and have a shot at it surviving. I could help with those mods if you're dead set on trying it.

I'm just brining up that 140mph for 30 minutes is no small task and if the engine can't survive at 6500 rpm for that duration (a rear gear change would let you get to 140 at 6500 rpm) then maybe the goal isn't matched to the ability of the engine.


If you'd like to shift WOT and let it ride there for a long time under power...give it a shot. We can help on this forum with the hydraulic mods to make the valve body shift, and then we can point out other mods to help the thing live.
Maybe you'll be able to come back to us in 6 months and say *well guys...I did it. And it works great!*

 

I don't mind the digression in the least. Often anecdotal reports provide a lot of insight.
​​​​​​And it often makes for interesting conversation.

A couple of things in my rethinking the project goals.
Regarding 140 MPH: An open road event has that 30 minute WOT deal. My reassessment from the additional facts coming to light transmission-wise, is that it doesn't seem a reasonable prospect.
But 140 MPH in a sprint sounds very doable.
From my list of parts I've already got the TransGo 7-4-V. This gives that functionality regarding WOT in OD I'm looking for.

https://transgo.com/product-details/...4-shift-valve/
​​​​​​
I understand fully it's not an all day every day thing to do. And realistically how many times will I do it? Maybe once, twice. But to do it is a goal.
OD at 140 with 5% slip is 5000 RPM. This new engine is more than capable of staying in one piece for what I figure it would take to get there. It's fully 7k ready, just not for 30 minutes. Something as simple as an engine oil cooler comes to mind. And I'm lacking that.

One thing I mentioned was finding someone capable of doing the work. I'm out of touch with all of my former racing associates. At least for the serious transmission mods needed to make a go of it at an open road race.
But for drag racing and the occasional sprint to 130 or so, I've already done that and I have the collection of parts for a repeat. Like I said, before this last trans ate itself up, it was one of best shifting units I'd owned. Although the times that I went through a full shift sequence (no standing starts though) were very few, it was all that I'd hoped for
Especially the 2-3 which had previously been kind of lacking.
This new guy that I have lined up I think will do just fine. Plus he'll offer at least some level of recourse if it ***** the bed yet again.

Again, thanks as always. Tomorrow will be a touch base day and am hoping to get a verdict on the state of the parts that should have survived.

 

Speaking of anecdotal, I came across these threads regarding the B4C.

From Dana at Pro Built:
You can install two allen plugs in the 4-3 part throttle passages in the plunger sleeve, at a cost of $.17 a piece. Remove the TV linkage setup (2 bolts) and pull plunger sleeve & plunger. Install the two allen & grind off excess with a Dremel to clear the bore & plunger. You will need a GM schematic to show you the 4-3 part throttle holes. Someone on this board might have a picture to show the PT passages. This will eliminate the 4-3 downshift when over 70-80 mph, if you want 3rd gear just grab the lever & pull back.

And this from TransGo:
This 3-4 shift valve kit fits 1982 to 1993 General Motors vehicles equipped with the 700R4, 4L60 automatic transmission. It provides wide open throttle 3-4 upshifts and includes three spring choices to help tailor the shift timing. Maximum line pressure needs to be 175 psi or higher in the D4 range to obtain WOT 3-4 up-shift. Install this kit with the TransGo Reprogramming Kit #700-2&3 and TV boost valve #7-472 to get the needed line pressure.

Putting that together with what's been described in the posts above should give me what I'm looking for.
"Just use with caution" is the caveat here!
​​​​​​

 

The TransGo Part is actually the "3-4 Throttle-Valve and sleeve assembly" for the 3-4 Shift Valve...
All of which make up the 3-4 Shift Valve-Train.

There are more than one way to accomplish the same goal.
(WOT 3-4 Up-Shift).

-1: The B4C TV Plunger Sleeve (Omits Part Throttle "PT" Passages from the Sleeve).
-2: The Sonnax Version of the same Part (Does same thing).
-3: Install Set-Screws in the PT Holes of the Stock TV Plunger Sleeve (Does same thing).
-4: Omit PT/ D3 Check-Ball and Block Separator Plate Hole "H" (Blocks PT Fluid from the TV Plunger Sleeve to the 3-4 Throttle-Valve and Sleeve).
-5: Superior or TransGo 3-4 Throttle-Valve and sleeve assembly (Delays or Blocks PT/ D3 Fluid from acting on the 3-4 Throttle-Valve and Sleeve).

I wanted to make Diagram of this, but I just don't have the Energy Today to do so, or to debate this crap...

 

Doesn't need to be a debate Mr V. It all seems straightforward.
All of the contributors here have served to further my understanding of the 4L60. As such I think I have a pretty good handle on the limitations and along with that, my expectations.
I have (and as yet still undetermined) either one of the TransGo or Sonnax B4C kits. Both look to accomplish the same thing.
As a matter of fact, as I'm thinking about it just now, the 700R4 that was the version before this latest one most certainly has the TransGo part because I made all of those purchases for the upgrades about 15 years ago. I still have that transmission as a usable core should I need it.
Number 3 on the list above is what Dana from PBA posted several years ago. It's actually the quote that I inserted in the post before this one. No needs for his mods though as I have at least two of the manufactured TV assemblies in my stash.
Should I choose too, and I've rethinking the whole deal, go for 140 MPH, it looks that I can make this happen albeit for a short stretch. I can ensure the lockup doesn't engage via my manual switch so I should be OK there.
If not, well, no great loss. Might even be a gain as I might save another transmission from self destruction.

 

A quick question regarding the overall strength of the 4L60 (1992 vintage).What is the estimated TQ handling capacity?
This is in a drag racing application utilizing one of FTI's "hard hit" converters. 4000 stall with 450 lb-ft torque at 4000-4500.
What's the weakest link in the as-built condition according to the build sheet.
​​​​​​Thanks in advance.
@FranksCustomTrans
@MaroonMonsterLS1
@vorteciroc
And anyone else with experience trying to break one of these.

 

Sorry I see the possible parts list etc but not a final did I miss something ?

 

All parts in that list are in play.
The V case was replaced with a K version. The output shaft (originally from a 4x4) has been changed to suit my Camaro.
As for details of the build, there's not a lot I can offer. From the conversation with the new builder, those deeper details such as what you've outlined in your 4L60 mod thread, etc. aren't part of the package. The TransGo 2&3 was, in the builders words, fully utilized for automatic operation.
Red Alto frictions and Kolene steels are used.

FTR, and I've yet to clarify, the original build's demise came about from some issue with the Sonnax input drum reinforcement kit. I'm not sure if the Forward Clutch Piston (Stamped Steel, Moulded Rubber). required with Sonnax input drum reinforcement kit as per Sonnax (?) was actually used. This time around, the builder opted out of using the reinforcement kit.
It was also found the .500" boost valve wasn't used but rather .470". The .500" is installed now.

 

I have seem similar builds hold up solid north of 800rwhp Most depends on how ne addressed leaks in the 3-4 circuit and how aggressive he did the shift kit , its a balancing act .