The point of gearing is to keep the car in its powerband. All the drag cars I have built were geared to cross the line at or near it's peak horsepower rpm in a 1:1 gear. If the vehicle is only crossing the line in 4th you are all loosing time and speed.

My car is rated at 280HP @ 6200rpm. If we are crossing the line even 3/4 of the way through 4th this is only roughly 4500rpm. 3.90's would at least raise this closer to the HP peak in 4th or maybe even 3500-4000 in 5th.

 

You have an 06' with a raised limiter!!

 

You are near redline in fourth gear, what like 6000 rpms?

Hmm...that would mean that you're trapping 109-110mph. If you have a stock tranny, stock wheels and tires, it just doesn't make any sense. Either your tachometer is broken or there's something you didn't tell us.

PS: Unless you consider top of fourth gear to be 4000rpms and up then I understand, but really you shouldn't be too much past 5000rpms when you cross the line. At near stock power levels that is.

 

Then again maybe not.

 

Well this is the drag racing forum. I though that an example would be appropriate.

 

Well this is the drag racing forum. I though that an example would be appropriate.

 

kleefton, not trying to sound like a jerk, but I really dont think Davidv needs any drivng/racing advice. He should be the one answering questions for you.