just played with some setups in a gear calculator.

the 4.11 in an otherwise stock 9 gearbox adds adds 11mph to 4th gear and 17mph to 5th gear. that is a huge jump.

putting an 8 third in a 9 box with that straight cut 4th makes for a nice looking gear chart tho.

 

Andy - how soon would you be organizing this group buy?

 

yup. and depending on the track a JDM 5th might be nice, but we have a few tracks in the Midwest where the JDM5th would be too short.

Well, we could get something together now. I'm just a little nervous having several people buy these without any actual first hand experience. My first event wont be for another 4-5 months.

 

Semi-related 4.11 data.
I went to a local half mile event and ran my car with the 4.11.
It went 149.7 at 8500ish in 4th. This was on a 25" tire. 235/45/17.

Normally 7000 in 4th is 120 mph with a evo 8 trans with 4.11 gearing in my car.

 

This thread is about road racing, not drag racing, and although you got a nice result , you did not offer a baseline on 4:53 stock FD to compare and understand if this was beneficial to you? Nor is thir indicative of roadracing performance.
Can you please tell us if did the 1/2 mil on stock FD -and same setup otherwise, what were the results?

 

Check out pg.2 post 29. That was my 4.53 to 4.11 test. I was just adding some more real world data. I posted the above 1/2 mile data to show how much longer the gears are if you are willing to rev the engine out. 7000 is 120 mph, 8000 is 140mph on a 235-45-17.
The 4.11 gearset will be slower on the stock turbo. I've also run the car in the 1/4 mile at the same power with the 4.53/4.11 and the taller final drive slowed the car from 12.4@113 to 13.0@ 107.

I feel that the 4.11 was good for the 1/2 mile since I didn't have to shift into 5th at my current power level. For track days/ street driving I think the stock evo 8 gearing/final drive is the way to go for 2.0 engines. An evo 9 5th gear or JDM 5th would be a nice addition if you had the trans apart.

 

Unless you are saving significant time by taking out a shift, the 4.11 is going to be slower than the 4.53 due to wtq loss. Every gear will require 9.25% more torque at the flywheel to get the same torque at the wheels. Since there is also a mph shift for a given rpm in each gear, you also need to make that higher torque at a lower rpm to get the same acceleration at each mph.

If someone was feeling ambitious, they could take their dyno plot and work out how much they are loosing with the gear change.

 

unless you are making some serious power, I really don't think taller gears will help much. the only gear that really needs help is 4th.