I have an all motor 221/160 EK hatch and presently do 12.7 in the 1/4 mile. I use a B16B tranny with the Mfactory 4.785fd, and race with 22x8x15 MT slicks. I have a problem where I have to shift 1/2/3 gears fast after launching and then have to ride out fourth for about half the track crossing the 1/4 mile at 9100 rpms. I want to know if switching back to a 4.4fd or going to a 23" slick will evenly distribute my gears and help take the strain off 4th while staying within my powerband.
Here is a run from last night. Listen to the shift points http://www.youtube.com/watch?v=v8axAzFlKsU

 

Well, what rpm's do you want at the finish line? Less, more? Get a longer 3rd gear. When you map out the gear chart what does it show?

 

Here's a question..
When your coming off the line, are you spinning?? If you are, are you allow yourself to bounce the rev limiter and gain traction before shifting to the next gear? OR are you just shifting as soon as you hit redline.. because from the video, it seems your just shifting as soon as you reach redline..

I've not been to the track on slicks yet, and i spin a fair amount through my first,2nd and 3rd.. and coming off the line, I'm usually bouncing 1st gear about 5 times before i actually shift, because i can feel the car gain traction and catch.. i'm launching at 5800rpms right now, off a 2 step and catching 1.9 60's on 205's...street tires. i'm upgrading to a 215 and i'm running a 4.9FD and i'm shifting at 9500rpms. I'm finishing the quarter around 9000rpms in 4th gear almost shifting to 5th..I have no idea what my trap is, I haven't been to a test and tune night to see my times.. but i am beating cars that trap 108+ by at least a car.. so..ya.

 

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I would like to cross the line in 4th at about 8500-8600rpms. I have a 4.4fd and also MF shorter 3/4/5 gearset, put down.

 

Crossing in 4th gear right at redline sounds pretty ideal to me...No wasted shifts. Taking full advantage of your redline...
How bad are you spinning and in what gears?

Going with bigger slicks should help with wheelspin, but effectively make ratios taller which might act against you.

 

here is a better vid of my car. Listen to the revs and shift points. http://www.youtube.com/watch?v...=user

 

what are your 60fts on the 22s ?

I would stay with the 4.7 and switch to 23s . . Has always worked well for me

 

my 60ft's are inconsistant also. My best was 1.712 and the very next race I got a 2.1 60ft.

 

In that last video you just posted it doesn't sound like your not spinning much at all. It looks like you didn't ride out second gear long enough because it sounds like the car bogged in 3rd gear. I'm more of a autox guy, but what are you lauching at off the line? tire pressure?

 

Try changing the tires first. Easier than the gearing changes.

 

What's your current 1/2/3/4/5/fd setup, and what sort of rev limit and trap are you aiming for? I'll put it through the calculator and see what your best options are

 

1.695/1.296/1.000

 

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Actually, I don't have in the gearset right now, because that would be to radical for my setup as I don't want to shift 5th. I have in standard B16B gears with MF 4.785 FD. My revlimiter is 9200, but I want to be at about 8500-8600 at the end of the 1/4. I am aiming for 108-110 traps.