Gearing question

[FASTDARTCHESTER]

Anyone,

When I had the dart at the track a few weeks ago, it was topping out at 6800 rpm about 200 feet before the traps.

I am using a 4.56:1 final gear and the car weighs in just under 3000 lbs. I plan on lightening it to around 2700 lbs this year.

There was quite a bit of spin off the line with the Quicktime pros (even after heating them) and it seemed like when it hit top end it just hovered there at 6800 for the last 200 ft.

Will changing to a 4.10 help/hurt the overall time? Seems like it may help in the traction and ET dept.

Once again, the combo is a 318/904.

Thanks

TD

[Kevin Garceau]

Ya never know could help. But with the smaller engine it may need the rpms. Big Blocks if built right with the CORRECT convertor usually do better with less gear.

In your case if its petering out before the end, you really dont have much of a choice but to change them, or change, heads, carb, and or cam.

[FASTDARTCHESTER]

Hey Kevin,

Well it ran a 12.16@112. It really pulled hard too; getting a lot of tire spin off the line. I think it will easily run 11.50's with the traction problem solved.

It just seemed wrong to let it hang there at 6800. It proved out the combo though.

TD

[goldfevr]

I'm not sure what size of tire you are using but you can always reduce top-end rpm with a taller tire.

Jeff

[John Kunkel]

goldfevr is on the right track, a taller tire will help the tire spin and the topping out.

[FASTDARTCHESTER]

Unfotunately, i'm kinda stuck with the tires because:

I still use the stock 5 on 4 axles with 14" cragar SS rims. The biggest tire i could find was the Hoosier Quicktime Pro cheater slick, which is 26x 9.50-14LT and they were like 180 bux/pc mounted. Also, they are brand new.

That's the only reason I looked at gearing. Also, I didnt really wanna tub the car.

It's the good 'ol economical approach..how long it will last I dont know.

BTW, I am really happy with the performance of my 904. They can really be built to work!!!

TD

[shawnronan]

A change to 4.10 will give you another 12MPH top end. 3.91 will give you another 18MPH. If you stay with those tires, 3.91 would be a good choice.

[FASTDARTCHESTER]

hey shawn,

what do you think the 4.10's will do to my ET? I thought due to the fact that it's just sitting there topped out for the last 200 or so feet that it's wasted time????

TD

[shawnronan]

That sounds right to me, why hang out for 200 feet when you could be accelerating! I still think that 3.91 is the right choice for your set-up.

[dwc43]

Originally posted by FASTDARTCHESTER
Unfotunately, i'm kinda stuck with the tires because:

I still use the stock 5 on 4 axles with 14" cragar SS rims. The biggest tire i could find was the Hoosier Quicktime Pro cheater slick, which is 26x 9.50-14LT and they were like 180 bux/pc mounted. Also, they are brand new.

That's the only reason I looked at gearing. Also, I didnt really wanna tub the car.

It's the good 'ol economical approach..how long it will last I dont know.

BTW, I am really happy with the performance of my 904. They can really be built to work!!!

TD

All you need is the proper tire to gain traction and more top end speed with less rpm. You also dont need to tub the car to use a taller tire. Only do that to use wider tires. You should be able to get 27 to 29 inch tires for your 14 inch rims easily. Tha'ts what you will need nd you'll go faster that way keeping hte gear you already have. Besides new gears will cost you more than a new set of tires and requires a lot more work to install gears than tires.