4.10 gears...not what I expected.

[KILLSHOTS]

Picked up the car yesterday after having the stock 3.45 changed to 4.10 Danas. It appears that I am a victim of my own inflated expectations. After hearing the accolades and reading on this forum a post from a guy who literally said he practically had to "relearn to drive the car" after getting 4.10s, I guess I expected the car to take flight or something. Hmmm, not quite. Yeah, I can tell a small difference but I'd be willing to bet the car is no quicker to a stopwatch, which is kind of a bitter pill to swallow when I just spent $1500 to get "18% more torque to the rear wheels at all engine RPM", according to Marc.

Driving the 2 ratios back to back, I don't feel any 18% torque difference. Not even close. And yes, I did confirm that the stock 3.45s came out of the car. I can say this for sure: if your car is stock or near stock and you're thinking about new gears, DO NOT do anything less than 4.10s. You'd be flushing money down the toilet. Just my 2 cents.

[Locobob]

I'm of the opinion that gears shouldn't be looked at as a power adder but rather as a tuning tool to get what you want out of the car. You really only get the extra torque in first gear (provided you have enough tire to hook it up), after that you are just changing shift points.

[mike100]

Obviously gears don't change the torque at the flywheel or affect the power of the engine at all, but what it does do is get you to the sweet spot a little sooner which would be more obvious during acceleration timing, quarter mile runs etc.

6th gear may actually be useful uphill no as well.

[KILLSHOTS]

Originally Posted by mike100

Obviously gears don't change the torque at the flywheel or affect the power of the engine at all, but what it does do is get you to the sweet spot a little sooner which would be more obvious during acceleration timing, quarter mile runs etc.

6th gear may actually be useful uphill no as well.

Marc says, "18% more torque to the wheels. All of the time!" Of course, gears don't change flywheel HP but gears, by definition, multiply torque and more gear is supposed to provide more torque at the end of the equation. Surprisingly, my car is not even any more tail-happy than before. Extremely disappointing for what's talked about as the "best upgrade ever."

[Locobob]

Originally Posted by KILLSHOTS

Marc says, "18% more torque to the wheels. All of the time!" Of course, gears don't change flywheel HP but gears, by definition, multiply torque and more gear is supposed to provide more torque at the end of the equation. Surprisingly, my car is not even any more tail-happy than before. Extremely disappointing for what's talked about as the "best upgrade ever."

Gear to gear at any rpm yes more torque with the 4.10's but.... speed in gears is now different and at certain vehicle speeds the 3.45 car is going to be in a lower gear than the 4.10 car therefore the 3.45 will effectively have more torque in certain speed ranges. Numerically taller gears will not make every car faster in every circumstance, gears should be chosen based on the cars power output, traction, intended purpose and driving style.

[PhillipsLT5]

Would of been nice to see before/after dyno sheets
I still think you made a good move and only will compliment the rest of your future mods
You should now be at aprox 2200RPM @ 75MPH

[rhipsher]

Killshot you will feel more of a difference installing a Fidanza flywheel than gears. A light weight flywheel doesn't ad hp either but less rotating mass on the crank is very noticeable. RPM's rise very quickly.

[Bearly Flying]

With stock 3:45' I can spin the tires at will in first gear/ I cannot see how 4:10's would benefit me, it would only light up 2nd gear.

[Dynomite]

Originally Posted by KILLSHOTS

"18% more torque to the rear wheels at all engine RPM", according to Marc.

Just my 2 cents.

That is a correct statement by Marc. At any specific engine rpm when compared to before and after differential gear change your wheel rpm has gone down and your wheel Torque has gone up (Same wheel Horsepower after drive train losses). This compares to the same engine horsepower output at any given engine RPM (flywheel horsepower) before and after differential gear change.

Now the reason you might not "feel it" is because you have altered your shift points when comparing before and after shift points at specific vehicle speeds. You now have a useful 4th, 5th and 6th gear. When before you could top out the quarter mile in 3rd gear.

Oh...and I can spin my tires in 1st, 2nd, and 3rd gears

See Tech Info - LT5 Horsepower and Torque Calculations

I happen to like stock rear end ratios as I can get that 28mpg cruising in sixth at 70 mph

Originally Posted by rhipsher

Killshot you will feel more of a difference installing a Fidanza flywheel than gears. A light weight flywheel doesn't ad hp either but less rotating mass on the crank is very noticeable. RPM's rise very quickly.

See rotating mass discussion and effects on Horsepower Tech Info - L98 Frisbee Horsepower

Hi rhipsher

[KILLSHOTS]

Originally Posted by Dynomite

That is a correct statement by Marc. At any specific engine rpm when compared to before and after differential gear change your wheel rpm has gone down and your wheel Torque has gone up (Same wheel Horsepower after drive train losses). This compares to the same engine horsepower output at any given engine RPM (flywheel horsepower) before and after differential gear change.

Now the reason you might not "feel it" is because you have altered your shift points when comparing before and after shift points at specific vehicle speeds. You now have a useful 4th, 5th and 6th gear. When before you could top out the quarter mile in 3rd gear.

Oh...and I can spin my tires in 1st, 2nd, and 3rd gears

See Tech Info - LT5 Horsepower and Torque Calculations

I happen to like stock rear end ratios as I can get that 28mpg cruising in sixth at 70 mph



See rotating mass discussion and effects on Horsepower Tech Info - L98 Frisbee Horsepower

Hi rhipsher

Oh no, don't get me wrong: I do NOT doubt Marc. I fully understand the physics of his claim and I know it to be true. My issue is with the EFFECT of the "upgrade". So much was made of it by many that I think I just expected too much. However, going by just the numbers, I think you can understand why I expected a pretty drastic difference. I figured my car (Marc's chip, open exhaust) with stock gears was getting roughly 340 lb/ft of torque to the rear wheels at peak. Multiply that 1.18 and I'm over 400 lb/ft at peak. On paper, that is a DRASTIC difference in twist and I expected a big SOTP effect that I did not realize.