Supercharged Mustang GT best gear ratio?

Discussion in 'Mustang Chit Chat' started by JG-1, Apr 20, 2019.

  1. JG-1

    JG-1 forum member

    So I’m running 4.10s on my car right now. The car originally had 3.55s when it was NA. With that ratio, the car didn’t pull hard enough for me. I went to 4.10s and thought it was great.

    With the car being supercharged now, it’s making 801/650 at the wheel on E85. When I go WOT I shred the tires. I really have to be gentle on the throttle when driving around town. It’s still a ton of fun, but I’d like to take a little of this gearing away. First gear is completely unusable. I use second gear as if it were first. I was going to get taller tires to take away some of this gear, but ended up getting the same height tires as I have now, just in drag radial form.

    What do you guys recommend? I know it’s personal preference, but I think the car would be faster with taller gearing.
  2. fdjizm

    fdjizm Drag Queen

    3.31’s would be good for that amount of power.
    redsnake likes this.
  3. stkjock

    stkjock ---- Madmin ---- Staff Member Administrator Super Moderator S197 Team Member

    3.73s and a 28" tire works well on my set up at similar power, however, I have a TR6060 of course
  4. Candy10

    Candy10 forum member

    I thought 4.10s would be awesome! But at the strip, I launch in second gear and still light em up (Nitto NT05R 305/45). I’m sure a dedicated drag tire would make it better. And i only make 490/420 at the wheels

    All that said, it really depends on the tire you’re using around town. That’s a lot of power, I’d try the 3.31 idea
  5. 06JET

    06JET forum member

    I'm running 3.55's but at your HP 3.31"s may be a better choice for you. Just remember that when you go to that gear ratio and some sticky tires you will put a lot more pressure on your clutch.
  6. Gabe

    Gabe Whippled Coyote

    I'd vote for going back to the 3.55's

    Is that 801 rwhp on a stock '12 bottom-end???
  7. JG-1

    JG-1 forum member

    Yes for now. I’m getting a new shortblock by the end of the year. The Aluminator.
  8. JG-1

    JG-1 forum member

    I think the 3.31 would work well, I’m scared to take that jump though. I’m worried I may hate it. I may love it, idk. It’s not cheap to swap gears.
  9. 07 Boss

    07 Boss forum member

    Control throttle input, driver mod. Yeah you can make your car slower as to not light the tires up so easily but you're gonna be slower than your potential. Maximize traction through tires and suspension and then learn how to drive it. If you only know how to put the pedal all the way to the floor you're never going to reach optimum performance. Launching a high horsepower car takes skill and it's not learned overnight. Practice, practice, practice. Learn how to harness the power as opposed to slowing the car down. Learn the limits of your car and ride that edge between planting your tires and blowing them off. Don't fear the gear.
  10. konablue11gt

    konablue11gt forum member

    3:31 work very well with supercharged applications its a proven combo on many cars out there
    Candy10 likes this.
  11. 06redgt

    06redgt forum member

    Double adjustable shocks help a lot....set the compression so you get enough squat then set the rebound high so the rear end stays down and it will keep the weight planted on the rear tires. Keep the 4:10's and figure out what works. You probably need a 28" tire though so you can go through the traps in 4th gear.
  12. 1950StangJump$

    1950StangJump$ forum member

    Interesting thread, as I will end up in a similar boat eventually.

    I have 4.10s now with a T56 Magnum (2.97 first) and 450RWHP. It is perfect for a street car . . . might could even go up a size in tire for more traction.

    Once I forge the engine and turn up the boost, I am looking for 700 at the wheels. I couldn't decide whether I would need to go to 3.31s or 3.55s, so I will be following this thread.

    With 800 at the wheels, OP, I can't imagine how 4.10s feel. I suspect 3.31s at that power level is a no-brainer.
  13. Sactown

    Sactown Sactown

    I would buy some better/taller tires before switching out the gears, if you do switch IMO 3.73 with the taller tire would be a good fit
    06redgt likes this.
  14. RedMosesSC

    RedMosesSC Senior Member

    3:55 came in my Supercharged Saleen, its like a great balance. 275-40-20
  15. Grabber Blue 5.0

    Grabber Blue 5.0 forum member

    3.31's work well with the MT82 and F/I.
  16. booster19

    booster19 Junior Member

    Following! This is an interesting thread for me I don't mean to highjack your thread but I am currently trying to figure out what size wheels to buy for my 06 with Magnuson Supercharger. The car is currently sitting in the shop waiting it's turn for a tune up and a list of modifications and I didn't even think about the rear end sizing. I know my set up won't be pulling anywhere near those numbers if I'm lucky she'll be around 410-20rwhp. I am having issues with the engine cutting power at around 4400rpm maybe a spark knock code still to figure out. But anywhoo I'll gain any information shared here so looking forward to all the input on the subject!
  17. jdlatil

    jdlatil Twin Srew Driver

    If you are still running TR3650 the lowest gear radio
    I would run is 3.73 with a 28” tall tire. First gear ratio in your transmission is 3.38, very low.

    I’m currently running 4.10 gears on my KB 3.2 at 18-20 lb boost, 700+ rwhp. I’m running 28” tires but have Magnum T56 with 2.97 first gear ratio. I love this combination for street fun an occasional strip. Able to launch on street on two step slipping clutch slightly, without spinning very much or not at all.

    You should be about same gear ratio in first with 3.73 gears. I think you will be disappointed if you go below 3.55 gear. Would not do 3.31 gears.
    Mustang dog and 06redgt like this.
  18. 06 T-RED S/C GT

    06 T-RED S/C GT forum member

    I went from 4:10's with 285/40/18" tires = 27" dia back to the stock 3:55 gear ratio. IMHO a 27" tire just isn't tall enough to keep planted on the pavement when running FI with a 4:10 gear ratio which is just plain overkill. As mentioned, either go with 3:73's with 28" inch tires max or 3:55's with the stock 27" tire height. I also recommend not to go below 3:55 gear ratio, as I agree that you would more than likely be disappointed if you went with 3:31 gears :shrug:
    Last edited: Apr 28, 2019
  19. JG-1

    JG-1 forum member

    I had 3.55s in here stock. I should have kept them.
  20. 1950StangJump$

    1950StangJump$ forum member

    I've got the OEM 3.55s that came out of mine with less than 22k miles. If you want them, I'll sell for cheap. Zero problems with them.