Is there a way I can increase the top speed on a stock 1966 Mustang with a 289 engine and C4 automatic transmission? I want my car to be able to go 70 mph at lower RPM's. For exapmle now my car does 2650 RPM's at 70 mph. I want to be able to go 70mph at lower RPM's such as 2300 RPM. Is this possible to do without any major modifications?
2007-02-12 14:44:46 · 9 answers · asked by gmv20002000 1 in Cars & Transportation ➔ Car Makes ➔ Ford
Do you want higher top speed or better gas mileage? you can't have both. It takes hp to go faster, you can't pull a taller gear without it. You will be giving up one for the other. :(
2007-02-13 06:52:10 · answer #1 · answered by ClassicMustang 7 · 0⤊ 0⤋
If you change rear end gears or tire hight you'll lose take off power.The best thing to do is (and I love C4 trannys) Is swap the C4 for an AOD.It has a lower first gear ratio than the C4 so you gain take off power but with the overdrive you have less RPM at highway speeds and better fuel milage.There is little diference in lenghts so you'll have to shorten the drive shaft,do a little modifing to your crossmember and hook up the TV cable to the carb. and get a shifter for the AOD.
2007-02-12 22:51:37 · answer #2 · answered by Anthony 2 · 0⤊ 0⤋
The easiest way is bigger diameter rear tires. IF you can fit, say, 235/70/15 tires with a 29" diameter, from the standard 14" tire, your revolutions per mile would decrease, the same effect as adding an overdrive transmission or changing the gear ratio out to a higher numerical ratio.
If I were you, I would spend the money to change out to an AOD transmission. See the 2nd Link for changing tires - it's easier!
Phoenix is THE best. Tell em Jimmy from Granbury sent ya
2007-02-12 14:54:25 · answer #3 · answered by Anonymous · 1⤊ 0⤋
Taller tires would be the cheapest way. You might also consider a change to a numerically lower rear gear. The downside maybe slower launch times. Find out what gear ratio you have now and go from there.
2007-02-12 15:44:35 · answer #4 · answered by m k 5 · 0⤊ 0⤋
I often wonder if a person such as yourself really has any business owning a classic car. I believe your best off to sell the 66' and buy a 06' it would seem that's what you really want.
2007-02-12 20:54:32 · answer #5 · answered by Dr Phil 5 · 0⤊ 0⤋
yes and it's very easy. You need a different rear end gear. (technical term: ring and pinion gear) you're probably geared at 3.73, or 3.10 where as if you had a higher gear (lower numbered) your engine wont have to work as hard to sustain that speed. You can pick them up at most all auto parts stores. Good luck.
2007-02-12 16:00:00 · answer #6 · answered by svtmuscle2003 1 · 0⤊ 0⤋
your rear end carrier probably has a 3.08 ratio change to a 2.73 ratio or put out big bucks and buy a richmond 5 or 6 speed tranny.
2007-02-13 02:02:01 · answer #7 · answered by I race cars 4 · 0⤊ 0⤋
change the rear end ratio to a lower numeric value.
2007-02-12 14:49:20 · answer #8 · answered by Fordman 7 · 1⤊ 0⤋
try upgrading the headers....thats usually fairly cheap. And if all else fails try tinkering with the carburator <----spelled that wrong
anyway my dad and i used to work on his old 66 mustang untill he totaled it......>.<
2007-02-12 14:49:08 · answer #9 · answered by Anonymous · 0⤊ 1⤋