ImUrOBGYN wrote:I have an 03 GT on the stock aluminum 16's. I can land in lift on every single shift. The 1st to 2nd is, of course, the trickiest but can be done with the proper combination of hand speed and rev matching. With a low inertia flywheel and a high revving motor, momentum is HUGE. If you can launch the car into lift and hold through all gears you'll be shocked just how much faster the car will be, to both your "(removed)" times and actual times at a track.
This is the single, biggest reason why I refuse to run a larger diameter wheel than what's on there. Even though it would look better aesthetically, it would effectively lower the final drive making it even harder to land in lift between shifts.
First: Final drive and tire size have absolutely nothing
to do with RPM change from one gear to the next. The only thing that affects the relative drop is the difference between the two gear ratios. For example, 1st gear is 3.17 and 2nd gear is 2.05. If you shift from 1st to 2nd instantaneously at 10000 RPM, your new RPM is 10000*2.05/3.17 = 6469 RPM. If you put a 15" tall tire and a 10:1 final drive on the car and shift at 10000 RPM from 1st to 2nd instantaneously you still end up at 6469 RPM.
Second: It is physically impossible to land every shift in lift on a stock motor. Depending on who you ask, stock rev limit is between 8200 and 8400. Let's assume it's 8400 to give your claim a fighting chance. Let's also assume that you are so skilled that you can shift instantaneously without losing any speed whatsoever and you can do that instant shift precisely at the rev limit. Your 03 lift engagement point is 6200 RPM. Your gear ratios are 3.17, 2.05, 1.48, 1.17, 0.92, and 0.73 for 1st through 6th.
A perfect 8400 RPM shift from 1st to 2nd lands you at 8400*2.05/3.17 = 5432 RPM. That's nearly 800 RPM short of staying in lift - and in reality you will not shift at exactly 8400 nor will you lose zero speed in the process.
A perfect 2nd to 3rd shift lands you at 8400*1.48/2.05 = 6064 RPM. Again short of staying in lift...
3-4, 4-5, and 5-6 all land at 66xx RPM with perfect redline shifts. Those are the only possible times you can stay in lift after shifting - all at highly illegal speeds.
What does it take to actually stay in lift during shifts at legal speeds (1-2 and 2-3 shifts)? Aftermarket beefed up valvesprings and a piggyback or standalone engine management system. By increasing the rev limit to 9000 and decreasing the lift point to 5800 it becomes theoretically possible to stay in lift after all shifts. A 9000 RPM shift into 2nd lands you at 5820 RPM, just into your newly lowered lift zone. (2-3 lands you at 6498, well into lift)