I find it interesting that CFM chose to use the 4.10 gears for their car. Seeing they went through the trap at about 125mph, they would definitely be in 5th gear. Looking at 3.73's, and 3.51's, they would have also had to shift into 5th. Only 3.31's probably would have allowed them to stay in 4th. Would the longer gears of 3.31's not be worth the tradeoff of that extra shift? And also, since they had to go into 5th anyways with the other gear options, would 4.10's definitely had given them the best time perhaps? And I also wonder if the same would hold true for the MT.

http://www.topspeed.com/cars/car-new...-ar131327.html

 

Gotta use 4.10s and a good stall to get that sucker into the powerband quickly. Since it's a centrifugal sc it takes a while to build peak boost.
Obviously they know what they are doing, and their car is setup really well. Common it's a single power adder at only 14psi 10 sec v6. Heck they get that 60 ft down a little more it'll go mid-low 10s as is.

 

Agreed. No bottom end torque to get it moving. Impressive anyways.

 

Ahh right...good points on those. I'm sure that staying in the power band more than offsets the extra shift. Now just trying to figure out which gears for my car. My local track is an 1/8th track and I have a manual. To complicate things, it's not even a full 1/8th. It's slightly shorter...uggh. So I don't really want to get gears based on that odd configuration. But it is where I spend most of my time....uggh.

These engines sure are impressive too. You hear frequently about the Coyote engines and failures, but I've yet to hear of one single failure of these engines under normal conditions, let alone power adding. And eve with power adding, the only case I know of anyone blowing them up was by literally pushing the engine as far as they can go well over 600hp. So it seems you can boost these engines to 500hp pretty safely and reliably without strengthening internals from what I've read so far.

 

American Muscle uses 3.73's and a 3500 stall in their ProCharged car with 28" tall tires.

The "extra" shift is inconsequential though on these cars since they are both automatics, not as big of a deal as a manual.

 

That is true too. It's interesting they chose that ratio too. My wheels are about 27.5". A 10 second car goes through the trap at my track at about 90mph which would be right at the redline in third with 3.73's. So it would be cutting it close. I'm a good shifter and can powershift with minimal loss, but it's still not like a an AT with a converter. Hmm...decisions, decisions. I just wish my track was a bit longer because it really throws a wrench into the equation.

 

Just get some short drag tires like a 315/35/17 which is 25.7" tall, will have you shifting at 85-86 mph and trapping about 5500 at 90 in 4th.

 

Good call. That's probably a direction I'll end up going.

 

Here's a great calculator for seeing what different gears and tire sizes will do.

http://www.f-body.org/gears/

 

Thanks a lot. That's a great calculator. Very very helpful.