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 (http://www.protorque.com/store/index.php?main_page=product_info&cPath=6_9&products_id=10)
Non-Lock up listed in link HERE (http://www.protorque.com/store/index.php?main_page=product_info&cPath=6_9&products_id=12)

[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/CamDetails.aspx?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/CamDetails.aspx?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? :eek: 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:box2:

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.

[Steve Chryssos]

Right then, baby's asleep. More on efficiency:
At a red light with foot on brake, the engine is spinning, but the trans is not. Difference in rpm is about a thousand. Converters are designed to be inefficient at idle--otherwise the car would surge. So the earlier question about a 2000 stall converter combined with a big cam? Not advisable as it might cause surging.
Other extreme: The top end of a 1/4 mile run should see engine rpm and transmission input shaft rpm at about equal--not quite, but close. Pro Torque has more than a few savvy drag race customers with data logging capability showing 96, 97, or even 98 percent efficiency and that's without lock-up! These days, if a drag car is showing 85% at the top end, the chosen converter is too loose.
The difference in percentage is known as slippage. 85% efficiency is 15% slippage.
What about in between? As your street car accelerates away from an intersection, the output side (turbine) lags in rpm behind the input side (impeller). As load decreases by way of inertia, the two elements (input and output) approach the same speed. So load is inversely proportional to efficiency. And it can be said that a tighter converter is more efficient than a loose converter, all other variables being equal.

So that 2500 stall converter doesn't suddenly come alive at 2500 rpm. It has efficiency while accelerating from, say, 1200, 1500, 1800 rpm to 2500 rpm. Efficiency is present and increasing as the vehicle accelerates because load is decreasing. How much efficiency is present at a given rpm might vary from one converter manufacturer to the next. Good companies maintain a wide range of impeller/turbine/stator combinations and utilize more costly but more efficient CFD designed late model cores.

And of course, efficiency can be maximized when a converter is locked up where a mechanical clutch locks both sides of the converter together.

But there are circumstances during the acceleration phase where lock up is not desirable. It's called torque multiplication.

[critter]

So, locking up the converter in a drag racing application or in a spirited driving situation seems like a bad idea. We not only strain the clutches in the converter but we also deny the possible benefit of torque multiplication under high load situations?

[Steve Chryssos]

Like everything else in a hydraulic coupling, the answer is not cut and dry. But you stated the key word: Load. Lock up is most desirable when load is low. And as stated above, load is lowest when efficiency is peaking.
Torque multiplication occurs whenever engine speed exceeds transmission input speed. The engine side of the torque converter is called the impeller. The transmission side of the torque converter is called the turbine. So whenever the impeller is spinning faster than the turbine, torque multiplication can occur. A greater differential means greater multiplication. A torque converter has three elements: Impeller, turbine and stator. Fluid returning from the turbine is passed thru the stator which changes the fluid flow's direction and sends it back to the impeller. That returning fluid is added to the fluid coming from the impeller. That fluid plus scenario is torque multiplication. It provides an advantage when compared to a mechanical clutch. Torque can be multiplied 1.8-2.5 times.

So now the optimists might think "Great! I'll run a 5500 stall converter to create lots of speed differential between the engine and trans. That'll give me crazy torque multiplication" An the pessimists are thinking "Wait a minute! In an earlier post that dude just told me that speed differential is slippage, so I want a 1500 stall converter--and I want it locked up as early as possible."

We're using fluid to couple the engine and trans. And where there is fluid, there is the potential for turbulence. Turbulence disrupts that vortex loop of fluid in the converter. And where there's turbulence there is slippage without torque multiplication.

So there is a juggling act between stall, efficiency, torque multiplication and finally, lock up.

-At a stop light we want low efficiency, so that the car doesn't move or stall. Slippage is desirable.
-When the light turns green, we want low efficiency off idle so that the car doesn't stall. Again slippage is desirable.
-As we accelerate at part throttle, we want efficiency to increase as rapidly as possible but with as little sacrifice to torque multiplication as possible. Load decreases as vehicle speed increases.
-When we stomp on the throttle from a roll, we want torque multiplication.
-When we drive banzai at a steady 140 mph, we want efficiency. Lock up is very useful here because overdrive causes a negative speed differential. The trans (and converter turbine) is turning faster than the engine and converter (impeller).
-Same holds true at a 70 mph highway cruise, plus we want the added benefit of fuel economy. (at 140mph you have other things to worry about)
-When we decelerate for a turn on the road course, we want and can use lock up here to keep engine and trans coupled.
-When we power out of that turn, we want torque multiplication. And there's no need for rev matching. A fluid coupling takes care of that.
-When we stage at the drags, we want stall. Engine turning at stall rpm with trans at zero rpm.
-Upon launch, we want torque multiplication. High Load.
-Top end--thru the lights, we want efficiency. Low Load. Lock up at the drags is useful only if data logging confirms that it's usage is not negating torque multiplication.

Whew!

[BRIAN]

Torque converters are one of those black magic deals to me. I think the most important decision is to go straight to the manufacturer and buy the best converter you can afford. Do not buy from a retailer.
There are several co's that offer a free re-stall of the converter if you feel it is off or change your combo. i know it sucks to pull out a converter but it suck even more to pay $800 more while you are doing it.
I think the problem is the lack of 99% of the Co's ability to test effeciency or dyno their product before delivery. Most are using factory numbers and applying them loosely to their product. Some just mix and match OEM parts to obtain a stall rating and others mfg their own parts and are willing to show you the difference. This might work on track only cars but in a street car that is cycling in and out of OD it doesn't work.

Then there is the problem with one or 2 Co's actually building just about every converter out there are selling them under different names. So before you say one is better than the other you might want to check who is actually building them. Don't want to pay $400 for a $139 converter.

I have used Precision Industries and can say the converter was like bolting in a NOS kit compared to another well known Co's product. They asked tons of questions and got it right. Not cheap at about $800 but the car was an animal when I smashed it and drove like a stocker.

[Steve Chryssos]

I guess I'm a retailer, so I should take offense to that. Fortunately, I'm also a paid employee of Pro Torque. Our companies are closely affiliated, so I'm cool with that. Fill out a comprehensive torque converter analysis form HERE (http://www.protorque.com/freeanalysis.html) and the design process starts at my desk.


I think the problem is the lack of 99% of the Co's ability to test effeciency or dyno their product before delivery.

There's only one aftermarket company devoting R&D time to pro-touring cars--CFD, dyno and track. That's us. The rest are focused on drag cars and new car/truck upgrades. Our R&D can be seen
HERE:
https://www.pro-touring.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=18874&g2_serialNumber=1
and HERE:
https://www.pro-touring.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=18532&g2_serialNumber=1
and HERE:
https://www.pro-touring.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=18820&g2_serialNumber=1
and HERE (This one's a 700R4):
https://www.pro-touring.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=18898&g2_serialNumber=1
and HERE:
https://static1.pt-content.com/images/noimg.gif
oh, and HERE:
https://www.pro-touring.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11194&g2_serialNumber=1

The only other company investing any time in thsi stuff is Bowler transmissions.
As for mixing and matching parts, ALL torque converter manufacturers rely on "cores". Junkyard torque converters supply turbine and impellers. They are simply too complex for the aftermarket too produce. A significant amount of finish work is invested in these cores. Stators are the only critical parts that can be custom made within the scope of the aftermarket's CNC manufacturing capabilities and CFD design. And even then, many OE stators can be used as they are simply defined by the number of blades, angle and shape of blades, and open area. Again, finish work, kinda like porting and polishing a cylinder head, separates the best from the rest. Mixing and matching IS the name of the game. The only new turbine and impeller components are for 8" drag race powerglide converters based on near obsolete but desirable sixties and early seventies compacts. Obviously these turbines and impellers are irrelevant to our needs.
The difference is that cheapie converters use available cores from 40 plus years of manufacture. Stuff that was designed with slide rules. the supply side economics of 40 year availability make them cheap. Advanced manufacturers, including PI, use late model cores that are expensive but worthwhile due to their advanced CFD design. Since they are pulling from a supply side that is only 10 to 15 years old. Unfortunately, most of these converters are still out there driving around. Lower availability means that these newer cores cost significantly more. But, matched correctly, they yield that part throttle efficiency with wide open throttle torque multiplication plus an expensive price tag that you have experienced.

PI rocks. Pro Torque and PI are closely allied friendly competitors.

[Steve Chryssos]

So before you say one is better than the other you might want to check who is actually building them. Don't want to pay $400 for a $139 converter.


A few companies are buying off-shore converters. Not as many as you think. Most converter companies have two sides their business: An OE rebuild side that supplies local transmission shops and a High Performance side. The same holds true for trans shops. Very few shops are exclusive to high performance work. They make a living off of daily driver rebuilt work. Unfortunately, some transmission shops will order up a basic rebuild intended to fix a disabled Blazer (maybe as cheap as $70) and then pawn it off as a high performance piece. The converter manufacturer has no way of knowing that the trans shop did a bait and switch. As far as the converter shop knew the rebuilt converter was destined to sit in front of a rebuilt trans. If that's a concern, buy straight from the converter manufacturer and hand deliver it to your trans shop.

[Steve Chryssos]

Here's an exploded view of a MuscleDrive converter. Prices start at around $659 for a 9.5" Most of the goodies are inside the welded case, but there are still ways to tell if you are getting a serious piece. For that much money or more, your converter will have a billet front cover with integral mounting lugs shown at far left. On the other end, an anti-balloon plate has been welded into the center of the impeller cover--around the splines. The anti-balloon plate makes the surface relatively flat. The pump cover itself is a new replacement piece. The splines are billet and the machine welding is flawless. Machine welding is pretty commonplace though. The billet front cover and anti-balloon plate should be confirmed.
https://static1.pt-content.com/images/noimg.gif

In contrast, the budget converter below has a stamped front cover with welded on lugs (on bottom). The dished area on top around the splines means that there is no anti-balloon plate. There's nothing necessarily wrong with budget converters. The good ones still have important internal features like furnace brazed fins and good bearings. Just know what you are getting and make sure it matches your engine's load requirements. From the outside looking in, this appears to be a $350 piece.
https://static1.pt-content.com/images/noimg.gif

[BRIAN]

Steve believe it or not no insult meant to you or PT. My experience with a certain converter Co was more as you explained a problem with a tranny shop that escalated into a bigger problem than it should have. Then again Co's chose their retailers and maybe should chose a little wiser.

Few converter Co's are willing to show and explain their internals. You know as well as I do before you actually made the leap to the other side converters were a hard choice. You have to have complete confidence in the Co that they are delivering what they claim. Your R&D looks impressive and money would be well spent with your set ups. Great info and next automatic built car I will give you a ring as i think others should.

Hard to get buyers to understand the difference between a custom built unit and a Summit special. There is a magazine article???

[critter]

Heh. I was in that traffic jam on Hot Rod Power Tour in 2007 along with you guys. That is where that one image came from, correct?

So can I take this in another direction?

I've never rebuilt a transmission. I've done my own motors and restored cars but have never taken on an auto. I have a 1987 core 700 r4. Would it be possible for me to build it myself without a great deal of fear and trepidation or should I put all the stuff in a box and find a reputable local builder to trust? FYI, I make about 420hp and 500+ ft. lbs. of torque.

[6'9"Witha69]

Heh. I was in that traffic jam on Hot Rod Power Tour in 2007 along with you guys. That is where that one image came from, correct?

So can I take this in another direction?

I've never rebuilt a transmission. I've done my own motors and restored cars but have never taken on an auto. I have a 1987 core 700 r4. Would it be possible for me to build it myself without a great deal of fear and trepidation or should I put all the stuff in a box and find a reputable local builder to trust? FYI, I make about 420hp and 500+ ft. lbs. of torque.At that level, find a good builder.

[Steve Chryssos]

Steve believe it or not no insult meant to you or PT. My experience with a certain converter Co was more as you explained a problem with a tranny shop that escalated into a bigger problem than it should have. Then again Co's chose their retailers and maybe should chose a little wiser.

Few converter Co's are willing to show and explain their internals. You know as well as I do before you actually made the leap to the other side converters were a hard choice. You have to have complete confidence in the Co that they are delivering what they claim. Your R&D looks impressive and money would be well spent with your set ups. Great info and next automatic built car I will give you a ring as i think others should.

Hard to get buyers to understand the difference between a custom built unit and a Summit special. There is a magazine article???

Thanks. Take a drive out when the roads are free of salt and I'll let you drive these things. Function will not be very different that your PI unit. The application is just more comprehensive. Computer control allows us to do more with these converters.
I think I can write such an article and do it in plain english as above. Being highly technical and potentially critical, it might be a tough sell to our industry's advertorial oriented publishers. If that's the case I'll just upload it to twistmachine.com.

[Steve Chryssos]

Heh. I was in that traffic jam on Hot Rod Power Tour in 2007 along with you guys. That is where that one image came from, correct?

So can I take this in another direction?

I've never rebuilt a transmission. I've done my own motors and restored cars but have never taken on an auto. I have a 1987 core 700 r4. Would it be possible for me to build it myself without a great deal of fear and trepidation or should I put all the stuff in a box and find a reputable local builder to trust? FYI, I make about 420hp and 500+ ft. lbs. of torque.

That pic was sent to us by one of our good friends and customers. Bob Bertelson. Out of necessity, he replaced his big brand name, mass produced transmission and converter with an RR system based around a Bowler engine brake trans and MuscleDrive torque converter.
I sincerely believe that transmission building is best left to professionals. It's an art form. Hard parts are readily available. It's not so hard to make the puzzle pieces fit together, but a true builder has a sixth sense regarding blueprinting and calibration. That's the part that can't be listed in an ad or quantified with an attractive price tag.

[Steelrat]

Wow, starting this inquiry into the 700R4 for my Nova has been an education. I appreciate all the info/advice. I am a big supporter of doing business local when I can. The tranny will be built by a local guy. I was pointed to this local company for a TQ convertor by the builder. http://www.tcsproducts.com/index.html


Advice from you has put me at about a 2500 stall, so I am thinking this is the TQ convertor for me. http://www.tcsproducts.com/details.html?id=533 or should it be this one http://www.tcsproducts.com/details.html?id=534

Cheers,
Shaun