700R4 Build, tough enough?

[Steelrat]

Here is a list of parts tranny guys are quoting to use for a 700R4 build to stand behind my 70 Nova -

Current car specs-
Engine is a .040 over balanced 400 small block
Block is decked and drilled for steam holes
Scat 9000 crank
Scat forged 4130 5.700" Rods, ARP 8740 Bolts
Mahle pistons 10:44 compression
Competition valve train
Crane gold full roller rockers
Competition Cam 284xe.
AFR 210 Fully CNC Heads.
Hogged out RPM Air Gap Manifold
Custom 950 Pro Series Carb
3:77 gears
Dyno'd at 488 HP 504 TQ @ motor
I have a stock console shifter

What do you tranny pros think? Good parts, good build for the following?:

All frictions (except 3/4 clutch pack) will be Red Eagle coupled with Kolene Steels.
-3/4 Clutch Pack will be High Energy Frictions. (The Red Eagle/Kolene Clutch Pack consists of Frictions & Steels that are too thin which overheats & burns up). -Harden Input Shaft with Reinforcement Sleeve (will accept up to 600 ft lbs of Torque).
-Welded SunGear Shell to SunGear (OEM is weakest part of the 700R4)
-High Energy 2/4 Band.
-.500 Boost Valve
-.279 Reverse Boost Valve
-Transmission will be set up so that you will NOT require any wiring to operate the Torque Converter Lock-up.
-1/2 and 3/4 Corvette Servo assembly. This provides the greatest Clamping available for the Band in both 2nd and 4th Gear.
-B&M Street & Strip Shift Kit which will allow you to shift both Manually and
Automatically.
-All the Brackets, Clamps, Cables, and Linkage necessary to operate your Trans properly and fit in your car Professionally.



Converter suggestions??

Thank you.

[MarkB]

I do not want to sound like I am knocking anyone, everyone has their own modifications and success rates with 700-R4 transmissions. To me this is a pretty short list of items that is being installed into a 700-R4 that is going to be able to handle 504 ft lbs of torque. I would ask for a detailed list, to be safe. What I see listed is what is typical upgrades up to about 375 ft lbs of torque. But there may be many more items installed that has not been listed. If the builder has a good reputation and success rate, then trust him and move forward.
Do yourself a favor and ask if the input shaft has been pressed out of the original drum to be heat treated, if so has it been leak tested while hot, how did they seal the factory press fit (spline area). We have been burned by a few after market drums with heat treated input shafts and cryogenic drums with the steel sleeve. So we know from experience, after a few comebacks you learn.
As I said earlier, this combination may work well for them and if the builder & you both feel comfortable then go for it.

As for a recommended stall, I would need to know your cam spec and what your primary use would be. If you are asking what brand, there are several good ones to choose from: ProTorque, Precision, TCS, Coan or Champ.
If you have any additional questions feel free to ask.
Thanks,
Mark

[Steve Chryssos]

I'm with Mark. When shopping for a trans, you should expect to see a parts list that is at least as comprehensive as the engine spec sheet that you have provided in your post. Most people take the time to shop for the right con rods, the right crank, etc. But when it comes to transmissions, it's "how much $$$ and what is rated torque capacity?" So you are on the right track by questioning transmission spec content. Smart companies like Bowler list components and blueprinting/calibration services. They also tend to charge more money and UNDER rate their transmissions. So put some time into your research and call for or five shops before pulling the trigger. After calling around, you will get a good chuckle from the wide range of responses.

As for a converter recommendation, you are running a very similar combination to my car. Same engine, gear ratios, etc. I have more cam than your 284 in the form of a crower hydraulic roller and I'm running the 700's electronic cousin--a 4L60E.

I run a ProTorque 10" 2500 rpm stall converter--even with my larger cam. I auto-x and road race as well as the occasional run at the drags. Your application appears to be geared more towards Street/Strip. I'm feeling about 70% street and 30% strip. If that's the case, a 2700 rpm stall converter will be perfect if I have properly guessed at your intended usage.

At 500 Ft-Lbs input torque, I strongly recommend running Pro Torque's ProDrive series (aka my MuscleDrive Series). Based on your description above, I'm not quite sure if you'll be using lock up capability. Listed below are links to both lock up and non-lock up.
Lock up version listed in link HERE
Non-Lock up listed in link HERE

[ProTorque]

Hey steve and Mark,

I am new to the site but I saw the post and figured I would introduce myself


Thanks for the vote of confidence,

I am glad to be grouped with the likes of Precision and Coan. They are reputable brands.

I am sure we can help you if you need a converter

Joe@ProTorque

[Steelrat]

Thank you for the input, some great advice and follow up questions to the builder. I will continue to do my homework.

Steve - 90% street 10% strip
My cam - http://www.compcams.com/Cam_Specs/Ca...?csid=136&sb=0
Description says -2800+ stall ,yet I am reading some threads on this site that 2200 - 2400 may be a better stall convertor to have for street. ?

[Steelrat]

Do yourself a favor and ask if the input shaft has been pressed out of the original drum to be heat treated, if so has it been leak tested while hot, how did they seal the factory press fit (spline area). We have been burned by a few after market drums with heat treated input shafts and cryogenic drums with the steel sleeve. So we know from experience, after a few comebacks you learn.
Mark

Talked to the builder, he obtained the Input Drum with Harden Shaft from TCS Performance Products.
It is part of the "Torque Delivery Kit" which includes a Harden Low/Rev. Sprag Race and a Torrington Bearing.
The Harden Input Drum is capable of handling up to 700 ft lbs of torque (twice the OEM strength).
It also has the Sonnax Reinforcement Sleeve pressed into the Drum where the Aluminum Splines are.

Does that make sense?

[MarkB]

I would use caution with this drum setup, this kit is made by a company called TD. I would ask them if they are now leak checking this setup with the parts warm. We put the drums in our parts washer at 180 degrees 75% of them would leak around the input shaft. Like mentioned earlier, we had several kick our butts due to this issue and it took us awhile to determine why we kept having multiple 3-4 clutch failures. We have not used these kits for about 5 - 6 months now. The company is well aware of the problem and was going to address the issue, I just have not hear if it has been resolved.

[Steve Chryssos]

Thank you for the input, some great advice and follow up questions to the builder. I will continue to do my homework.

Steve - 90% street 10% strip
My cam - http://www.compcams.com/Cam_Specs/Ca...?csid=136&sb=0
Description says -2800+ stall ,yet I am reading some threads on this site that 2200 - 2400 may be a better stall convertor to have for street. ?

At 90% street I would tune your stall to 2500 rpm. Don't worry about that being too "loose". Our converters are highly efficient, so throttle response from 2000-2500 will be excellent. But when you stomp on the throttle, she'll scream!

[Steelrat]

Thanks.
Another question

Any of you running a 2500 stall or higher have any issues when highway driving with 700R4 with 3:77's or close to that ratio?
If the stall is higher than the rpm needed to maintain say 60 MPH and if 4th gear locks at 2,500, and your overdrive is cruise speed of 2,300 rpm, any issues with slippage or heat in the tq converter, or the clutch packs needing to slip. Damage?

What if I ran a 2000 - 2200 converter - pros cons?
Also, pros cons on lock up vs non lock up convertor in Overdrive?

[6'9"Witha69]

Lock up is lock up, irrespective of stall or flash rpm. You could be @ 1800 in lockup and it will be @ 1800 locked up 1:1.

I highly recommend lockup converters for street use. Hell even for a dual purpose car.

[critter]

So where and why do you use non-lockup?

[6'9"Witha69]

So where and why do you use non-lockup?

Unnecessary additional rotating mass for drag purpose cars. When all you do is blast through gears then hit the brakes there is no real need. If you cruise higher than stall you won't need it either.

[Steve Chryssos]

Okay, let's go thru this. Go take a vitamin or something before proceeding:

The aftermarket has spent the last 40 years hyper-simplifying torque converter science into one term: Stall Speed. This approach has worked reasonably well for standing start to wide open throttle drag cars, but it kinda screwed the rest of us. And after 40 years, this gross oversimplification is so ingrained and so misunderstood, that people still fight the science. So let's try to fix things by breaking torque converter selection into three terms--not one. I'm still oversimplifying, so please--rocket scientists--don't shoot me. When we're done, I'll apply my explanation to the 700R4 equipped Nova. Here are the three terms that we will focus on:

1) Stall RPM
2) Torque Multiplication
3) Coupling Efficiency

1) Stall RPM: Absolute Stall is defined as the engine rpm at which the converter absorbs 100% of the energy supplied by the engine RATHER than transferring that energy to the transmission. Physics tells us that the engine's energy must go somewhere. It is transferred to heat rather than moving the vehicle. Absolute stall speed is determined with the output side (i.e. wheels) locked and peak input torque applied. And since peak torque occurs at a certain rpm, stall is defined as a given rpm

So torque goes into the converter thereby spinning the impeller. But the output side is locked. Picture an axle or transmission output shaft bolted to the ground or in the real world--a trans brake.

That is stall speed. It is highly useful for a drag car, on the trans brake and on the mat waiting at a christmas tree. At peak input torque, all of the engine's energy is transferred to heat rather than moving the car--absorption. Relative stall speed is what you buy. Converter manufacturers choose a stall speed that is somewhat south of peak torque.

But as long as we have throttles rather than on/off switches, input torque is variable, right? That same drag car at 50% throttle angle is sending less input torque to the converter. Stall speed is, likewise, variable. So a torque converter designed for 450FtLbs of input torque at 2500 rpm will stall at a different rpm when only 225 FtLbs of input torque is applied, with the drive side locked. And street cars rarely launch with the drive side locked and peak input torque applied.

There is a huge misconception that pure slippage occurs before stated stall speed. Loose street converters are the result of poorly applied science--not science itself.

So now, for the purpose of our pro-touring cars, we will unlock the drive side. Unlocking the drive side (the real world) relegates stall speed to a secondary tuning parameter as well as a tool for comparison.

You guys wanna stop there and take a break? Q&A?

[Steve Chryssos]

You guys okay? If it helps, in the next lesson we will unlock the drive wheels. Up to this point, I just want you to understand what is happening with the drive side locked. ALL (or virtually all) power is absorbed by the fluid.

Here: Stall speed revenge: You find out that your buddy is bangin your girlfriend. And you find out AFter you give him your spare converter and trans AND help him install it! What a guy. As revenge, you sneak into his garage while he's at work, roll the car forward against the concrete wall, chock the front wheels (for safety), engage the line lock and bring the car up to maximum allowable rpm. Without the concrete wall, the car would try to move, yielding an inaccurate stall speed on the low side.
At first everything is fine. But after a few minutes at stall speed, all of the fluid in the transmission and converter goes thru a phase change. Trans Temps increase astronomically. Energy that should have been used to move the car (perform WORK) is absorbed by the fluid. Instead, the trans, converter and fluid are barbecued. The rpm that all of this occurred is pretty close to stall speed.

When you're done, roll the car back to it's original spot, and close the door behind you. That's Stall Speed revenge.

[6'9"Witha69]

I wouldn't take it out on the car

Good explanations Steve, as always.

[critter]

So if you are above the real stall speed during cruising would in not be as efficient at that point as it would be if the clutches in the converter are locked up? I know the answer is negative because the reason for lockup converters was to increase efficiency and allow higher MPG, correct?

[6'9"Witha69]

So if you are above the real stall speed during cruising would in not be as efficient at that point as it would be if the clutches in the converter are locked up? I know the answer is negative because the reason for lockup converters was to increase efficiency and allow higher MPG, correct?

The thing is the fluid is no longer doing the work, the internal clutch is. Less heat is generated adding longevity to the trans. Particularly in the case of the 700, heat is the greatest killer of all installs (most commonly from poor/incorrect TV adjustment).I had my old TH350 up to near 300* temps before and it still ran fine. Get a 700 up that high for more than a minute and it is toast.

[Steve Chryssos]

So if you are above the real stall speed during cruising would in not be as efficient at that point as it would be if the clutches in the converter are locked up? I know the answer is negative because the reason for lockup converters was to increase efficiency and allow higher MPG, correct?

Ah, well the point of bringing up the locked output scenario is to show that stall rpm is variable in the real world. Less input torque means less stall for a given vehicle and circumstances (load). So a converter rated to stall at 2500 rpm peak will stall lower at part throttle when input torque is far less. That drag car, on the other hand strives to always be at WOT, so stall rpm is neat and tidy. The rest of us need to factor in part throttle.

And we haven't talked about torque multiplication yet. But I'm outta time.

[critter]

LOL. You can't tell a guy with a 462ci Pontiac motor much he doesn't know already about the "advertised" stall VS the "real world" stall. I make over 500 ft. lbs. of torque so you have to have a converter builder who understands the application to get one that's even close. Kris at Continental seems to have a pretty good handel on the Pontiac torque factor. My 3000 stall Continental is very tight on the street and still flashes to right at 3000 coming off the line at the drag strip.

I did appreciate the expanation of the torque revenge. I never considered that. ;)

[Steve Chryssos]

Yeah, it's tuff. Like I said: 40 years of cramming a complex subject into one tidy value. Two actually--diameter and stall rpm.

Okay here's an easy one:

Coupling efficiency: Efficiency is said to be lowest when engine rpm and transmission input shaft rpm are furthest apart. Therefore efficiency is highest when engine rpm and transmission input rpm are at the same rpm. Chew on that.