hammerjammer

Recently I read an article in an automotive magazine where dodge,ford and Gm,where tested head to head in 2500 ,auto,diesels. The dodge actually beat them by a fraction in the quarter mile,but all three turned about 82 mph,in the high 16's,the dodge had superior 60 to 0 stopping times. The dodge and Gm,were close in the hill climb towing,the ford had the fastest hill climb whle towing.by a significant mph., The tester pointed out that the ford was designed to produce max horsepower at high rpm,which made it tow better uphill at max rpm,the downside to the ford was weak-low-end grunt.the dodge and gm truck were equiped with the new 610ft;lbs engines and the ford the 6.0. This particular test showed that there is very little difference in perfrormance between the three brands.They did not talk about durability or reliability., or fuel economy.

cumminsdriver635

Yeah, but i bet for the towing part they were using automatics too. The 4spd dodge auto cant really put the power to the ground like the other two 5 spd auto trucks can. Hook all 3 of them up to about 20k lbs with 6 spds in them. Cant keep them in the high rpm's when you have to manually shift, and when you have that heavy of a load; low end torque is everything. That would show who the daddy of towing/pulling would be, and that is the cummins . They always compare automatics, and dodge has always been lacking in the auto department. Compare them with 6 spds, and about 20k lbs, and see which one pulls the best.

Eric

hammerjammer

yep. that would be an interesting test.The one I referenced was all done with 2500/250 automatics.

kingofdodge7131

what is this automatic stall? is it lock up?

cumminsdriver635

The stall as best I can figure is where the converters really start putting power to the ground. Thats kind of why you need a low stall converter for a diesel. It is not lockup.

Eric

Mcmopar

Stall is a tough one to describe, but in drive with your foot on the brake, floor it, the max RPM is the stall speed. It will go up as you build more power. It is a function of the stator and the fluid coupling in the convertor. The lockup is an electronically controlled "lockup" of the clutch in the convertor. Not a very good description, but I tried.

mr T

automatic stall??? well u got the turbine and the pump those are the two halves of ur torque converter....they act independently somewhat....the pump starts to spin as the engine rpms go up(pumps connected to the engine u can say) and then the pump starts to make the turbine spin (connected to ur tranny) when they're both spinning at the same speed and there is equal fluid pressure on both sides or whatever then u have stall....thats the best transfer of engine power unless locked up with the clutch

so when a powerpoke motor makes its torque at 2000 or 2200 or whatever they have and their srall is at 2400 thats pretty good....but if we have a peak at 1500 rpm and we stall at 2200 then we're wasting time revving unnecessarily to transfer the power

mr T

im still learnign though and the one thing im having trouble understanding is why stall goes up when the truck's under load...seems very counterproductive to me...i dont see any benefits to it it increases the slippage ..heats up the fluid.....someone tutor me here

kingofdodge7131

are they made to do that? Otherwise it would seem like it should. The load would make the turbine turn slower. Oh well atleast now i get it

mr T

the stock trannies i noticed work awesome at full throttle shifts hard and the tach drops wuite a bit between shifts but only at WOT u can feel it pull or "grab" quite a bit when it hits 2100 or so rpm but u cant be WOT it all the time...... i know guys on here will argue that