Impalas.net banner

21 - 40 of 116 Posts

·
Premium Member
Joined
·
13,142 Posts
When the 700R4 first came out a 305 would break it. GM had a redesign out every production year for the first twelve years it was made. Even the 4L60 that replaced the 700R4 was redesigned within two years of coming out and called a 4L65 because the original design couldn't handle the ever increasing torque of EFI powered 350 SBC in trucks, and the LS-x series of engines in cars with rear wheel drive.

A 383 is an entry level big block under most car company designations such as the Plymouth Road Runner (Beep, Beep). Big blocks require a bigger stronger transmission than small blocks because they make more torque. The 700R4 was rated at only 300 foot pounds of torque. If your engine makes more than that the tranny will need special parts on a rebuild to make it meet the torque load. (bigger input shafts, more gears in the carrier assembly, stronger sun shell, and a strong sprag). None of these aftermarket parts are found in a stock junkyard transmission, so you either have to buy the parts and install them your self or buy a rebuilt tranny based upon torque rating from a competent remanufacter.

I can recommend TCI, because they have a wonderful warranty program, not because they build the strongest transmission with the "best" options (such as gearing or increased clutch holding ability).

It is like saying I want a PowerGlide because all of the top dragsters have one. The Powerglide that are used in Super Comp only share the name with the stock PowerGlide. There isn't a single GM part inside the aftermarket Super Case. Every part has been super sized and machined out of solid billet unobtanium, then cryogenically frozen to near absolute zero or hardened with heat treatments.

Big Dave
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #22
Unobtainium.

LOL.

I was introduced to tranny rebuilds in my diesel truck circles. the 4r100 Ford put behind the 7.3 had major issues with the coast clutch ... it spawned a tranny rebuild industry just for those 99.5-03.5 trucks. The one we used was a guy in Leadville Arkansas. Brian Thompson. He used a TC from a T400 then modified it from there, special sauce or two ... reassembled and that tranny is good forever even behind a chipped/breathing 7.3 powerstroke turbo diesel.

I'm hoping for just over 400 ft/lbs and HP ... so perhaps my 700r4 selection isn't a good one???

Thanks Big Dave
 

·
Registered
Joined
·
404 Posts
Building a 700R4 for your torque and HP numbers would not be that difficult for a competent transmission builder. You can buy a 700R4 from companies newly overhauled that will handle it easily.


https://www.transdepot.net/700R4-St...MI0aKC8ef_2QIV2rrACh1PMAtJEAQYASABEgJao_D_BwE


Only issue I have with going with a 700R4 is the cutting the drive shaft. I think if you go with a 200R4 you can avoid that as it is almost just as long as the Powerglide.
 
  • Like
Reactions: shaark92

·
Premium Member
Joined
·
123 Posts
Discussion Starter #24
The shop says cutting the driveshaft is no problem for them. may even be able to bypass the carrier bearing? My question, not their suggestion. I remember having to replace that carrier bearing. Was a bear for a novice teenager. If I can delete that thing, I will.

Thanks for the reassurance on the overdrive tranny.

I'm wondering, though, if the rear-end ratio of what's probably 3.08 for the powerglide will be good for the 700r4. Gotta do s'more research on that.
 

·
Registered
Joined
·
404 Posts
The shop says cutting the driveshaft is no problem for them. may even be able to bypass the carrier bearing? My question, not their suggestion. I remember having to replace that carrier bearing. Was a bear for a novice teenager. If I can delete that thing, I will.

Thanks for the reassurance on the overdrive tranny.

I'm wondering, though, if the rear-end ratio of what's probably 3.08 for the powerglide will be good for the 700r4. Gotta do s'more research on that.
I wouldn't worry so much about the low gear ratio portion of the system, I would look more into the cruising RPM in overdrive of the engine. If at 65 MPH your down around 1500 RPM you may be out of your engines power range resulting in excessive down shifts and up shifts.


I really want to go with a stick, but after doing my research I can get everything I need to go to a 200R4 for around $2500 new and then everything is a bolt in affair. No drive shaft mods needed. That is going with the stage one kit for 550 HP motors. I will be hard pressed to put an overdrive manual in my car at twice that cost.
 
  • Like
Reactions: shaark92

·
Premium Member
Joined
·
123 Posts
Discussion Starter #26 (Edited)
Also ... will the 700r4 remain "engaged" through a deceleration? IE engine braking?

Wifee had a 97 Tahoe ... so the 4L60e? ... IDK who thought it was a good idea to "coast" below 40 mph, but that (and the lack of driver energy management) caused me to replace brake pads every 20-30K miles! (lots of city driving at that time)

I'd rather the clutches remain engaged like in my F350's "tow mode" and downshift than for the tranny to "let go." Gonna have a reasonably high torque engine. Should be able to use that in both directions of speed change.

Thanks.
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #27 (Edited)
I wouldn't worry so much about the low gear ratio portion of the system, I would look more into the cruising RPM in overdrive of the engine. If at 65 MPH your down around 1500 RPM you may be out of your engines power range resulting in excessive down shifts and up shifts.


I really want to go with a stick, but after doing my research I can get everything I need to go to a 200R4 for around $2500 new and then everything is a bolt in affair. No drive shaft mods needed. That is going with the stage one kit for 550 HP motors. I will be hard pressed to put an overdrive manual in my car at twice that cost.
RIGHT! I don't like downshifts to pull a grade.

Now I'm confused again. (happens a lot! :p ) .... from your transdepot site, the 700r4 500HP rated is about $200 less than the 550HP rated 200r4 ... the crossmember mod for my car is about $160 ... probably a couple hundo for the labor to shorten the drive shaft ... where does $2500 enter???

Also ... the gear ratios for the 700r4 listed on this link you provided (thanks again) show "Gear ratios of the 700R4 are: 3.06, 1.62, 1.00, 0.70, 2.29"

huh? How is Overdrive almost the same ratio as first?

Noted is the 200r4's 4th gear is actually higher than the 700r4's ... first blush, it appears the 700r4 will run a higher RPM than the 200r4 (in high gear)
 

·
Premium Member
Joined
·
13,142 Posts
Also ... will the 700r4 remain "engaged" through a deceleration? IE engine braking?

Wifee had a 97 Tahoe ... so the 4L60e? ... IDK who thought it was a good idea to "coast" below 40 mph, but that (and the lack of driver energy management) caused me to replace brake pads every 20-30K miles! (lots of city driving at that time)

I'd rather the clutches remain engaged like in my F350's "tow mode" and downshift than for the tranny to "let go." Gonna have a reasonably high torque engine. Should be able to use that in both directions of speed change.

Thanks.
The only automatic that could brake an engine was the old style PowerGlide that had a front and a REAR pump. It was the rear pump used to push start the car that caused engine braking. Otherwise the planetary transmission which drives the car, but can not be driven (it will free wheel), that prevents engine braking in all cars with an automatic. The 15% to 17% parasitic drag due to friction will eventually slow the car down, but then again so will sticking your foot out the door.

"Tow Mode" disengages the transmission's ability to lock up the torque converter. This adds to the parasitic drag by adding the the fluid friction of the torque converter to the mechanical friction of all of the rotating parts in the transmission.

The drag of the torque converter is greatest in a stock stall speed tranny and decreases as the stall speed increases in a racing torque convert so there would be less engine braking due to parasitic drag (while loosing more energy to heating the tranny fluid due to slipping when driving).

Big Dave
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #29
Ok. All I know is that the f350 uses engine braking in tow mode and even downshifts as rpm gets near idle. The Tahoe wouldn’t engine brake at less than 40 mph unless Overdrive was locked out. Ditto the 4R100 in the 2000 f350.

In the 2011 f350, the TC locks between 3rd and 4th.

Anyway. Great info. Thanks.
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #30 (Edited)
I found a calculator. If I did it correctly, I can expect 1878 rpm at 70 mph with a overdrive ratio of .7, a 3.08 differential and 235/55r17 tire.

Searched for a power curve which would show a 383 at 1800-2000 RPM .... couldn’t find it but the tamest setup at 3000 was still 360 ft lb.

Since the curve is pretty flat on 383torque, I’m gonna estimate well over 250 ft lbs which should be adequate for cruising.

Am I ate up?

https://www.ringpinion.com/calculators/Calc_RPM.aspx
 

·
Premium Member
Joined
·
13,142 Posts
Very few dyno pulls are made below 2,400 RPM because most engines stall when the water brake is engaged (listen to YouTube videos of dyno runs for the drop in engine RPM when the water brake clutch is engaged). Takes a pretty large displacement big block to test down that low. Most small blocks are tested above 3,200 RPM (small displacement motors are usually class racing engines with a radical cam so they usually start testing at 4,000 RPM).

I have built a lot of motors, and tested most of them on an engine dyno before letting them go to my customers.

Big Dave
 

·
Premium Member
Joined
·
13,142 Posts
It's an automatic. Let the programming (the valve body) figure it out for you automatically.

I have a 6L80 in my truck and I can not tell when it shifts up or down, it is so smooth. Only way I would know would be to put in manual and push the shift button as the tach shift points.

Besides your not likely to even notice with a 383 displacement.

Big Dave
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #34
Guess I'll find out. Thought there might be a precise way, given I'm departing from OEM ...

did that with the 3 speed manual and it was WAY too highly geared with the (3.08) rear end. I could run 80 in 2nd without getting nervous about a tachless overrev.
 

·
Super Moderator
Joined
·
3,455 Posts
If it wasn't so cold here in Ohio still getting some snow, I would go for a test drive and give you some comparative data with definitive RPMs. I have mild 383 with a 5-speed.


Sent from my XT1254 using Tapatalk
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #36
A tech from Blueprint thought the 3.08 would cause the 700r4 to downshift on a grade ... so, I may look for either an other complete rear differential at 3.55 rear end/gear set (pinion/ring?) if I can change the ones in the existing case.

Thanks BA ... look forward to hearing about it. It’ll warm-up long before I have to make a decision on ordering. :)
 

·
Registered
Joined
·
404 Posts
RIGHT! I don't like downshifts to pull a grade.

Now I'm confused again. (happens a lot! :p ) .... from your transdepot site, the 700r4 500HP rated is about $200 less than the 550HP rated 200r4 ... the crossmember mod for my car is about $160 ... probably a couple hundo for the labor to shorten the drive shaft ... where does $2500 enter???
I was looking at the 200R4 Stage 1 complete conversion kit for $1795.
https://www.transdepot.net/2004R-Stage-1-Conversion-Package_p_412.html

This kit includes the odds and ends:
Edelbrock or Holley Linkage, TV Cable, Speedometer, Mount, Dust Cover, Dipstick & Tube, Throttle Bracket, Torque Converter Bolts, Lock Up Wiring Kit, Hayden Cooler, 2 Can Cooler Flush

I have a floor console so I need a special shifter from Shiftworks for a 4 speed console shifter $295
SHIFTWORKS -1963 and Earlier Impala

59-64 Chevy Impala Bowtie Overdrives XMXF59642 Transmission Crossmember 200R $205
https://www.ebay.com/itm/59-64-Chev...2-Transmission-Crossmember-200R-/281987607522

Total $2,295 and then you throw in all the shipping costs and you are probably a little over $2500.00
 
  • Like
Reactions: shaark92

·
Premium Member
Joined
·
123 Posts
Discussion Starter #38
Spent my first dollar on this project ... for the very last item which will be installed ...

An emblem memorializing Pops ... his driver’s license signature on a black Chevy bow tie ... which will be placed just below the impala emblem on the dash.

Emblemart.com
 

·
Premium Member
Joined
·
123 Posts
Discussion Starter #39
OK ... I'm seeing different configurations of a 4 door sedan.

what is the proper names for these different tops? mine has the "slicked-back" style, but I'm seeing a more "conventional"

I was only aware of the two door bubble top and my 4 door sedan.

Thanks.
 

·
Registered
Joined
·
1,033 Posts
There is also the 4-Dr Hardtop which the factory likes to call a "Sport Sedan". We just simply call them 4-Dr HardTops, lol. (No Posts cars)

By the way, I like the Factory Air in your car. Kind of rare for a '61.
 
21 - 40 of 116 Posts
Top