Anyone tried a gear change?

[christians87]

I like the idea of the lower gear and od at the top of the quarter. Seems like it would offer better performance to take advantage of all the gear ratios the transmission offers instead of three. Mr. Spool how was the car on the highway. How many revs were you turning at 70mph and what not?

 

[bison]

I like the idea of the lower gear and od at the top of the quarter. Seems like it would offer better performance to take advantage of all the gear ratios the transmission offers instead of three.

It will e.t. slower than a properly setup car using 3 gears. A 33% drop on the 3-4 shift. think about it. Ideally if you had the power you would take gear out of 1st and 2nd and close the ratios up so that you have a lower % drop on ratio change then gear the rear to get you through the quarter without running out of gear. Adding gear is going in the wrong direction unless you are tubbing the car and running 30+" tires.

 

[Mr.Spool]

bison that is one way of approaching things and it is a proven way,however a friend of mine years ago ran 5.13 in the rear using all 4 gears for a completed 1/4 mile on a 28 inch tall slick no tub high 9 low 10 sec buick on a 70mm turbo, race gas combo, another proven method just a different approach.in my case, on the 4.10 rear 28 inch tire,od was a very brief experience as my 49 turbo would only muster 120mph on pump gas alky,and 125mph with a wet shot.it's not like the speedo stops when the car hits od

 

[harris48cars]

If memory serves me correctly, 3.73 gears with a 28" tire equates to a 3.45 final ratio. The advantage in this combo is that you are adding traction by virtue of the larger diameter of the 28" tall tire. Basically the same ratio as stock, just more rubber on the road per revolution. I've run this combo on many GN's. I always liked it.
Gary

 

[wbrophy]

3.42/26" tall tire or 3.73/28" tall tire: that is the question?

Old skool math question:

One turn of a 28" tall tire will get you down the road further than one turn of a 26" tall tire, so which car will get to the end of the 1/4 quicker/faster all things being equal and have better traction too?

PS: back in the old days a 28" tire did not make a stock geared car go faster till it was an 11 second car.