gmmusclecarman

iTrader: (20)

Im aware that coasting in neutral wastes gas because it uses fuel to keep the engine going however how does reving up the engine to match the rpms of the lower gear save gas? And how does downshifting and rev matching help slow the car down? If you were downshifting without rev matching and using the slower speed of the engine to slow the car down I could see how this would help slow down the car.

blackls1ta00

iTrader: (27)

i downshift most of the time also,i dont see what the problem is.it also helps save your wear on your brakes, but rev matching each gear wud be wasting gas i know i do it too slow down, but i didnt build a car with 500hp to save gas,i hope you get it figured out bro.

therobman

iTrader: (39)

hmm whats cheaper engine clutch and trans wear or brake wear. i downshift all the time like the noise

Fry_

I'd much rather replace 10 sets of brake pads that even one transmission. Although I do down shift to 4th when coming into town and let the engine pull the car down to 35. But for stop signs/lights I just kick it into neuteral and use the brakes.

Arctic2002ss

I agree that our cars seem somewhat lacking in compression braking, unless you are in the upper RPMs. I do get that affect on the road coarse with more revs but under "normal" driving not so much so. I think the computer is slow to drop the revs or something.

SSCamaro99_3

iTrader: (1)

He is maintaining that using the highest possible gear (maintaining the lowest possible rpm) is statistically insignificant from rolling to a stop in neutral. Not shifting to each gear in the transmission as one slows. In absolute terms there is no way that these cars rolling in neutral at an 850 rpm idle will consume more gas than leaving it in gear up until the stop at lets say 1500 rpm. Statistically insignificant, yes, in absolutes, no.

If you enjoy downshifting to a stop great, I just roll to stop lights in neutral, look around for trouble (if I need to grab a gear), and save the wear and tear on the clutch/trans/engine. It not like its the 1960's and these cars have 4 wheel drum brakes and the engine braking aids in stopping. The disc brakes will out stop the engine any day.

In addition this yahoo that wrote the article states that in a steady state turn a car without its driveline engaged will be more unsafe than one with it engaged. Like to see his proof on that.

blackls1ta00

iTrader: (27)

yeah i see your point but if you have a built t56 you shudnt have any worrys,i have a stage 2 tick rebuild and it can take alot more than what i throw at it,and i can downshift at any rpm.

blackls1ta00

iTrader: (27)

ive had these bauer rotors and hawk pads front and rear on for about 2 years of summer driving and havent had them even half way worn down yet.i do creep up too stop signs and lights and put in neutral at times.

67SS&99SS

iTrader: (7)

The reason the car feels like it doesn't slow down as much now by downshifting as it did when the stock engine was in it, is because of dynamic compression. Dynamic compression is compression of the engine when it is actually running. The larger than stock camshaft in your LS2 actually bleeds off more compression than the stock camshaft that was in your other engine. Thus you have less compression braking available with the new engine.

Personally, I would put it in neutral and use the brakes to stop. Your wearing the back side of the gears when it isn't necessary, thus accelerating the wear on the gears and reducing the service life of the transmission. Brakes are cheap. Trans rebuilds aren't.

RAMPANT

iTrader: (17)

Recalling back to when I had a H/C set up. There was also one other contributer to a lack of compression braking. I found the tuners needed to make the rpm higher than with stock on the downshifts so it would not stall. Not sure what the setting was but it holds the rpm up a little more when you down shift. I had them adjust it down, but it was a fine line.

When you get to a stop does it seem to idle high for a split second?

For those going on about heel and toe down shifts, if done right it is easier on the transmission. I can down shift without a clutch that way. That alone tells me it is easier on the transmission. Not the without a clutch part! :-)

SSCamaro99_3

iTrader: (1)

I agree with you completely if you are out having some fun, or road racing the car. We are disagreeing with him about using the tranmission to slow the car approaching every red light, or for some percieved gas mileage advantage from a Poplar Science article.