enginehp and rwhp
#1
enginehp and rwhp
if a 350 is putting out 400 at the motor, with a 700r4,and a B&M holeshot 2400, what kind of rwp will be had with 3:73's? what kind of difference if you make the gears smaller to 3:23s? what ways can you increase rwhp?
#2
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Car: seeking '90.5-'92 'bird hardtop
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Re: enginehp and rwhp
If you have 400 HP at the crankshaft, even with the alternator, water pump and power steering pump, you can figure on a 700R-4 and 7.625" axle together eating about 22% of that, which is 312 rwhp. Your converter will reduce that, it's looser than stock. Other things to do to increase rwhp include synthetic lube in the rear axle, choosing a shift kit that does not increase the line pressure inside the 700R-4, choosing a tighter torque converter, running an electric water pump, and increasing the engine power.
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Car: 1987 Iroc-Z28
Engine: 305 TPI
Transmission: 700r4
Axle/Gears: G92 3.23, G80, J65 disc
Re: enginehp and rwhp
you lose about 20% of your flywheel horsepower through an Automatic, and about 15% through a Stick. But some things can slightly decrease that loss.
#4
Re: enginehp and rwhp
does having a high flow pump or an alternator amp above 120 does that decrease your power even more? Atilla, what do you mean a tighter torque converter?
Last edited by Floorman279; 06-02-2009 at 08:56 AM. Reason: none
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Re: enginehp and rwhp
your cam is what determines what stall speed you can use. Also, your 2400 stall is in a 12" shell. Get a 2400 stall that uses a 10" shell, and it will be tighter above 2400 rpm.
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#8
Re: enginehp and rwhp
what do you mean by a tighter torque converter? also does having a high flow pump or an alternator amp above 120 does that decrease your power even more?
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Re: enginehp and rwhp
When cruising on the highway, going fast enough to be above the rpm the converter stalls to, if the converter isn't a lockup type, or if it is a lockup converter that isn't locked, a tight converter only slips about 50 rpm. A loose converter can slip as little as 200 rpm or as much as 1200 rpm. For example, I had a B7M TorkMaster 2000 in a '78 Camaro with a 305/TH350/3.08:1 combo, on the highway the tach was reading 2450 rpm at 60 mph, while my calculator said I would be at 2400 if that trans and converter had had a lockup feature like later automatics do. That was a tight converter. Another example, at the opposite end of the spectrum. I had a '95 Z28 with LT1/4L60E/2.73:1 combo. Running 65 mph with the converter locked gave me 1600 rpm It was a B&M TorkMaster 2400, and I installed a toggle switch in the dash to disable the lockup on command. The first time I flipped it, my rpm went to 2800, and the trans did not downshift.
this isn't the extent of what all I've tried, not by a long shot, but it seems to be the least I can share to best illustrate the point.
this isn't the extent of what all I've tried, not by a long shot, but it seems to be the least I can share to best illustrate the point.
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Re: enginehp and rwhp
I thought of another way to illustrate looseness or tightness. My '95 Z with the stock converter did 54 mph in first gear, at 6200 rpm. With the B&M, it was reaching 6200 at 46 mph.
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