Will haveing 4:11 gears reduce my cars maximun top speed? What are the disadvantages/advantages of 4:11 gears...

 

Yes. A higher number ratio means the car goes slower for a given engine RPM.

Gears multiply the engine torque. A higher number ratio will get the car moving more quickly than lower number ratio gears.

 

The math says it will lower tops speed. In reality though, if your engine doesnt make enough power to 'run out of gear' with what you have now, then 4.11 gears could actually raise it a little bit.

The biggest advantage of going to a shorter gear (shorter = higher number) is that the car will be able to take off harder without actually having the engine make more power.

 

i would go for 3:73. Thats perfect i think not to high or low.

 

what would be a good gear to go with a T-56?

 

depends. car, weight, HP, driving habbits, torque, trans gear ratio. (the t56 had differant ratios), tire size. launch rpm, type of tires


the list goes on and on

 

so the 4:11 will give me slightly better acceleration than the 3.73...but the 3.73 will give me better gas milage and top end speed....is that true?

 

Yes. Basically the lower the number the higher the top speed. I plan on switching to 3.42s or 3.73s instead of my 2.73s. I do not do high speed racing. Just 1/8th mile mostly.

 

With a T56, you can run up to a 4.56 or a 4.88 gear and keep the revs reasonable on the highway, because of the 0.5:1 6th gear ratio.

 

higher number will give you more torque for a given RPM, but also remember that it is only significant in 1st gear when actually racing. Smaller ratio means you will go through gears slower than with higher ratio.

I just made (still working on) a spread sheet where you can enter torque curve, gear ratios and rear end ratio and it calculates hp, speed in each gear and each RPM, torque at the wheels, acceleration of the car, optimal shift points and estimated quarter mile run.

Interesting thing was that with engine I picked at hotrod.com and my gearing, with 4.10's I had 1/4 mile at 10.3 sec, while same numbers but with 2.73's gave me 10.7 sec. The estimate didn't account for a lot of things like exhaust/accesory hp loss, air resistance and gear shifts, but it gives something for comparison (did include 20% drivetrain loss).

With 4.10's by the end of the run you are in 5th gear. With 2.73's by the end you are in 3rd.

btw, with 4.10's at 5k rpm in 6th gear (.5) with my wheel size I would be doing 186 mph, so I don't think top speed is of much concern.

I probably should post that spread sheet on here at some point.

 

Some guys get way to much gear for there engines. 4.10s is to much for most guys on here. 3.73s may be alittle low for a lot of combo's on this website.

I think 3.42's are a good gear. Just depends on how you build your car.

 

are 4:10s and 4:11s almost that same thing?....what is the difference?

 

Mechanically, very very little. Its just a different combo of ring and pinion gears.