[FAPhoenix]

I once read that a TH400 absorbs 20% of your engines power, if this is true about how much does a 7004R absorb?

TIA

Tyler

[FAPhoenix]

I once read that a TH400 absorbs 20% of your engines power, if this is true about how much does a 7004R absorb?

TIA

Tyler

[TTS]

Less!

[ascreemer68]

700 - 4 = 696. 696 divide by auburn rear = burnouts. i dont know what that meanz, so dont ask.

http://www.stefanjames.com/goat.htm

[72 LeMans]

696+4=700+r=700r+4=700r4 Dont ask either!

1968 GTO-455, Muncie M-21, Limited Slip, Being Painted Turquoise Blue With White Royal Bobcat Stripes
1972 GTO-455, Ram Air IV Cam, 6X Heads, Headers, Performer Intake, Q-Jet, Th400, 3.55's. Cardinal Red
1966 LeMans-Aquiring soon. Want to add 389/3x2's, 4-speed, GTO hood, and Burgendy paint.
Heart Of Illinois GTO's Member

[RPM]

[72 LeMans]

Actually, I heard (key word heard here) that a 700r4 is basically a Th400 with an overdrive. So as for parasitic loss, I would say it would be similiar, but mainly in how you build the transmission will be the key.

I havent experimented with the GM overdrives-700r4 & 200r4s but I'd like to down the road for a nice street car.

1968 GTO-455, Muncie M-21, Limited Slip, Being Painted Turquoise Blue With White Royal Bobcat Stripes
1972 GTO-455, Ram Air IV Cam, 6X Heads, Headers, Performer Intake, Q-Jet, Th400, 3.55's. Cardinal Red
1966 LeMans-Aquiring soon. Want to add 389/3x2's, 4-speed, GTO hood, and Burgendy paint.
Heart Of Illinois GTO's Member

[spamburger17]

what about t350s??

[TTS]

A 700R-4 and a 400 have nothing in common other than they both have aluminum cases and are both GM products.

[b-man]

No way does any transmission absorb any certain percentage of an engine's power. If that was true a 500 HP engine would lose 100 HP through a TH400, not even close. The TH400 takes at the most about 38 HP to drive it at highway speeds, the TH350 takes about 30 and the 2-speed Powerglide takes close to 20.

The 700R4 is closely related to the TH350, not the TH400 so the power to drive it would be similar to the TH350.

The only people who should be truly concerned with a few HP difference in parasitic losses through the tranny are class racers who need every ounce of power to be competitive. These racers favor the TH350 and TH200 since they don't use much power. These race-built trannys usually cost a LOT of dough with all of the special lightweight parts used to cut HP losses.

Just use whatever trans has the proper gearing, fits your car and is the most durable or the best compromise between these three things. The TH400 is by far the most durable for the least amount of $$, no way would I give up strength and reliability in my performance car to save a few HP that won't even be noticed anyway.

[FAPhoenix]

Thanks :-)

Tyler

[Half-Inch Stud]

None of the above.

A factory 12.5" convetered TH400 took about 38 HP in the neighborhood of 6000RPM.

While cruising the highway. I bet the alleged 38 HP was converted to heat....my solo remote trans cooler ain't no 38HP*748Watt/HP)= 28KiloWatt heat exchanger.

Rather, I'd park it at 2000Watt maximum heat rejection....for a 30C thermal rise.

HIS

"tbdET/1xxMPH/1.xx 60foot/28"/3.54:1/10"/469 #48/Flat HYD/DualQ-Jets/Offyl/3xx0Lbs
11.00/123MPH/1.50 60foot/29.5"/4.10:1/10"/469 #48/FlatHYD/DualQuad/Wenzler/3250Lbs
12.00/112MPH/1.61 60foot/26"/3.31:1/10"/469 #48/FlatHYD/Q-Jet/Torker/3650Lbs
12.70/103MPH/1.71 60foot/28"/4.10:1/12"/469 #48/FlatHYD/Q-Jet/Torker/3950Lbs"

[Half-Inch Stud]

So,

We're talking Inertial load now. Like rotating mass that is forced to rotate faster and faster yet.

The factory 12.5" convertered TH400 inertial load is indeed very high. It would take a 10second car in the neighborhood of 38HP to spin that cast iron mass from 2000RPM to 6500RPM.

a 10" convertered TH400 would be about half the inertial mass.

yet these inertial loads are less than the 12Bolt Posi rear with rims&tires.

These inertial loads are not parasitic loads. Easily seen as energy storage like a fylwheel, while cruising.

BUTT, to your point, the Powerglide is the least transmission, then the Manual transmissions (not including flywheel) inertial load, TH350, TH400.

All out compete for fastest ET will cause a fella to consider a flyweight driveline inertia.

HIS

"tbdET/1xxMPH/1.xx 60foot/28"/3.54:1/10"/469 #48/Flat HYD/DualQ-Jets/Offyl/3xx0Lbs
11.00/123MPH/1.50 60foot/29.5"/4.10:1/10"/469 #48/FlatHYD/DualQuad/Wenzler/3250Lbs
12.00/112MPH/1.61 60foot/26"/3.31:1/10"/469 #48/FlatHYD/Q-Jet/Torker/3650Lbs
12.70/103MPH/1.71 60foot/28"/4.10:1/12"/469 #48/FlatHYD/Q-Jet/Torker/3950Lbs"

[Half-Inch Stud]

I've always wanted to couple a 1HP electric Drill to the TH400 with converter, while on the floor, coolingline with a U-turn, and see how fast the elec motor could get it going.

Aside from the Drill topping out at 670RPM, I'd then try a 1650RPM household motor...like from my air compressor.

From there, a 34250RPM electric motor.

and so on.

noway would 38HP be the load at 6000RPM cruise, steady RPM..

"tbdET/1xxMPH/1.xx 60foot/28"/3.54:1/10"/469 #48/Flat HYD/DualQ-Jets/Offyl/3xx0Lbs
11.00/123MPH/1.50 60foot/29.5"/4.10:1/10"/469 #48/FlatHYD/DualQuad/Wenzler/3250Lbs
12.00/112MPH/1.61 60foot/26"/3.31:1/10"/469 #48/FlatHYD/Q-Jet/Torker/3650Lbs
12.70/103MPH/1.71 60foot/28"/4.10:1/12"/469 #48/FlatHYD/Q-Jet/Torker/3950Lbs"