My best time out of two visits to the track was a 2.2 60' foot, 14.4 @ 98 mph. All i have is a flowmaster muffler and 4.11's. Im really contimplating on switching to 3.42's. First off at around 60 mph on the highway with the 400le im at 2500ish rpms. And when i stomp on it the downshift lands me at 4500 or so rpms and quickly goes to redline (AKA SCARES THE CRAP OUT OF ME lol). Second, when i raced at the track, with these gears it feels like they dont allow the car to shift correctly, I mean that it really goes to redline and stays there for a while, before it shifts. What rpm would i be at going through the traps at 98 mph, with the 4.11's.
Because of all of this i really am leaning towards going with 3.42's, what rpms would i be at 60 mph? Because i do alot of highway driving. And what should my quarter mile time look like with a new cat back, and K&N Fipk intake? The car has 110k(ish) miles on it.
Thanks for any information possible guys, i appreciate it, as always.

 

You would get a lot better gas milage with the 3.42s but they wont make you any faster unless the improve your traction alot. They make really great n2o gears cause the hit of the n2o usually breaks tracion with steeper gears. I dont mind my 4.10s but they did suck on long trips and if i break the rear i will probably be going with 3.73s or 342s. in a better rear.

 

Thanks for the insight James.

 

A new PCM program will get it shifting right with those 4.11s.

 

How much of difference in rpms is there when cruising with 3.42's @ 60 mph compared to 4.10's, 4.11's ? I only go to the track maybe once every 1-2 months if that, so the gears kind of kill my pocket since i live in nyc.

 

anyone with a 3.42 rear , please help

 

I went from 3.23's to 3.73's and had a problem with the shift timing not getting it in the next gear without hitting the limiter. As fireman suggested, I solved all the shift problems with programming via LT1_Edit. Or a mail order tune from somewhere like madz28.com can also work as long as they know what gear ratio you have.
And the MPG thing will be a little better with 3.42's, but you won't be as quick. And with a 2.2 / 14.4, there may be another problem rather than gears.
I'm no matmatician, but I have a log file of my 13.21 1/4mi time that shows my trap RPM @ 5425. That's in 3rd {1-1 ratio} gear with the 3.73's and a long way from the stock 5805 RPM limit.
I had a Flowmaster 80 series before installing the 3" Hooker catback. I could feel an improvement after the install, and the Flowmaster is not well known for good flow characteristics. And the K&N is good for a couple of ponies too.
Hope that helps.