OK I am looking to change gears in my car, It has 331s right now. I am planning on supercharging in the future and want to keep that in mind. I am not a drag racer, just want to make sure I have the power cook the occasional rice!!! And to add to the fun factor!!!
Gear choice varies but the general feeling seems to be 3.73's for forced induction cars and 4.10's for naturally aspirated.
I did 4.30s early on and then went to a supercharger about a year later. I am still happy with gears but I don't drive on the freeway too often. Most of my driving is around town. I have no trouble smoking the rice burning crowd but I don't get many challenges.
I agree with these guys on the FI and 3.73's, but keep in mind you can always go with a taller rear tire to help compensate for that higher 4.10 gear.
You'll probably be ok with 3.73's, but probably happier with 4.10s. As stated above, if 4.10's feel like too much after supercharging, then you can just throw on a 28" tire and that'll take your ratio down to about 3.90. There are plenty of guys running around with 4.10's and a supercharger. If you go with 3.73, you might wonder "what if I went with 4.10's". Few people go with 4.10's and wonder "maybe I should've went with 3.73's".
probably, probably? There's plenty of guys running around with 3.31's, 3.55's etc - that's no indication that it's necessarily "optimum". Let's be honest - whatever gears you go with you'll wonder "what if I'd gone with the next size higher or lower". I still have the 3.31's and after watching the trends carefully on here and other forums I stand by my statement that 3.73's for FI are the most recommended by guys that are FI. I've ordered the 3.73's.
I went with 4.10's last week from 3.31's and at 70 I was at 1800 with the 3.31's and with 2200 with the 4.10's...I haven't driven the car alot but so far i'm happy with my decision. I also got 26.5 mpg on the way home too. but 29.6 on the way there.
Was anything else different on the drives (tailwind to high headwind or something). I want some gears, but a 3 mpg hit is a lot, that could convince me to get 3.73. Dan
Minus being on the throttle alittle more, the driving conditions were pretty much the same. I ran it up to 80 a couple times just to see where I would be rpm wise and it was at 2500 incase you were curious. i'm going to do gas mileage again next week from home to work and back since before it averaged 27-29 and I'll report back if you'd like.
If you're wondering what it'll feel like, go test drive a new bullit mustang at your dealership. They come equiped with 3.73s
I was considering the 4.10's, but 3mpg? That's gonna suck when I decide to return home from Ga...3mpg adds up on a 2200mile drive... I'm standing by for more samples and reviews...
4.10's and a supercharger on my '07 GT automatic. Wouldn't have it any other way. Fuel economy before the supercharger, but with the 4.10's, was about 25-26 mpg on the highway at 60-65 mph. That's better than the EPA estimate of 23 mpg highway for my car. With the supercharger I get about 23-24 mpg on the highway at 60-65 mph. At 70-75 mph, the fuel economy drops to about 19-20 mpg. 4.10's work great with turbo or centrifugal blowers (I have a Vortech V2 centrifugal blower). 3.73's would be my pick if I had gone with a twin screw or roots style blower. Gears are a torque multiplier, so you don't need as much multiplication when you have the instant low rpm boost of the twin screw or roots.
3.5 I have 3.55 gears. My RPM's at 70 MPH are about 2200, with a 5-speed stick. I rev about 1800 at 60mph...but the speed limit is 70 so that means I drive 80mph.....so I tach 2500RPM's and get no where near 25+ mpg. How some of these guys get 25+ miles a gallon and tach so low with 4.10's, I don't know. I don't do that well with 3.5's....who drives at a conservative pace? I'm lucky if I get 20 mpg. I know that with the 3.55 I can basically drive the car from 30 to 105, tached out, in 3rd gear...makes for a nice pull onto an on ramp
I'm debating on the 3.73's vs. 4.10's w/ thicker tires... Looking to go saleen/roushcharger (goal of around 400, maybe up to 460 when I'm finally finished), long tubes, coast driveshaft, not sure of cams, yet, and Roush 3 Suspension. I've currently got 17's on it, and debated a thicker tire, but don't want to rub after the stage 3 kit's drop. However, it might be nice to have a thicker tire for a softer ride. Car is looking to be a DD/WW at both drag (mostly for fun, just for kicks) and AutoX/Track time (which is more the style of enthusiasm I'm into). The car is mostly going to be in town, but I prefer to save a little gas mileage as I do occasionally make the hour or two drive from San Diego up to LA just for the weekend. Thoughts?
OK, 3.79 or 4.10 Drag racing then u want 4.10 or even 4.30+ Daily driving then you want 3.79 or 4.10, given those are the only choices u offered. Depends on how you drive daily. Obviously, the 4.10's will turn more RPM and burn more gas. But, they will be quicker off the line and slower at the top than 3.79. From what I have seen 4.10 gears will gain .2 to .3 seconds in the 1/4 mile. Which is huge. Is that worth 2 to 3 miles a gallon to you? I think 3.79 is a good balance between economy and performance but others will swear by 4.10's.... You have to decide between economy and performance.
