Hey guys,
been messing around on desktop dyno and their drag simulator program for awhile and have been a little confused with the results im seeing. Peak HP for my 340 is rated at 417 at 6000 and 402lb-ft torque at 4500. With this combination in a stock geared 4 speed manual, typical track conditions, optimal wheelspin with a 28x 11 inch tire, in an abody mopar (duster) with 4:11 gears im getting a time of 13.168 at 114.6mph launching at 2500 rpm and shifting at 6300 rpm. this is a number im very happy with but heres where the confusion for me comes in...
when screwing around with the rear end gear ratio, I actually noticed that i would get quicker et's by going with a higher gear (lower numerical ratio)...for example, if I change to a 3.23 gear ratio im getting an e/t of about 12.83 at 115.5 mph... This is what im having trouble understanding....I understand that the higher numerical ratios would give me better acceleration, but i thought that would equate to a faster et (especially with the tire size im running) overall as compared to a ratio such as 3.23...My car will be a 95% street driven car, but i want to perform well on the quarter mile as well...I have been told that 3.91 is the highest numerical ratio i should run for a street/strip car without ruining mileage, but from the numbers im getting, im wondering if it would be better to just stick with the 3.23's i have right now...
so i guess what im asking is a couple of things...first, what explains this change in et's as i go from a higher numerical ratio to a lower numerical ratio? What gear will give me more fun on the street (mainly city driving, with some highway on occasion)- the higher ratios like 3.91, 4.10 or the lower ones like 3.55 or 3.23? I dont mind sacrificing some of my et to having quicker acceleration, but if im not going to notice much of a difference from going from 3.23 to something like 3.91 or 4.10 on the street, then maybe i should consider keeping what i have?:dontknow:
feel free to educate me guys...id really like to understand all this:read2:
thanks
Matthew
been messing around on desktop dyno and their drag simulator program for awhile and have been a little confused with the results im seeing. Peak HP for my 340 is rated at 417 at 6000 and 402lb-ft torque at 4500. With this combination in a stock geared 4 speed manual, typical track conditions, optimal wheelspin with a 28x 11 inch tire, in an abody mopar (duster) with 4:11 gears im getting a time of 13.168 at 114.6mph launching at 2500 rpm and shifting at 6300 rpm. this is a number im very happy with but heres where the confusion for me comes in...
when screwing around with the rear end gear ratio, I actually noticed that i would get quicker et's by going with a higher gear (lower numerical ratio)...for example, if I change to a 3.23 gear ratio im getting an e/t of about 12.83 at 115.5 mph... This is what im having trouble understanding....I understand that the higher numerical ratios would give me better acceleration, but i thought that would equate to a faster et (especially with the tire size im running) overall as compared to a ratio such as 3.23...My car will be a 95% street driven car, but i want to perform well on the quarter mile as well...I have been told that 3.91 is the highest numerical ratio i should run for a street/strip car without ruining mileage, but from the numbers im getting, im wondering if it would be better to just stick with the 3.23's i have right now...
so i guess what im asking is a couple of things...first, what explains this change in et's as i go from a higher numerical ratio to a lower numerical ratio? What gear will give me more fun on the street (mainly city driving, with some highway on occasion)- the higher ratios like 3.91, 4.10 or the lower ones like 3.55 or 3.23? I dont mind sacrificing some of my et to having quicker acceleration, but if im not going to notice much of a difference from going from 3.23 to something like 3.91 or 4.10 on the street, then maybe i should consider keeping what i have?:dontknow:
feel free to educate me guys...id really like to understand all this:read2:
thanks
Matthew
