3.73 vs 4.10 estimated 1/4 mile ET

Discussion in 'SN95 4.6L Mustang Tech' started by Side0ut, Feb 14, 2004.

  1. Ok, I have just spent several hours searching this forum, google and whatever else I could find in order to make up my mind on 3.73 or 4.10 gears. This is what I have found out using the gear/rpm calculator at corralnet.

    3.73 gears @ 70mph is about 2300rpms
    4.10 gears @ 70mph is about 2500rpms

    To me that is not alot of difference for 5th gear highway driving. What I have not been able to find is how much faster a car without adding anything other than 3.73 or 4.10 gears will be in the 1/4 mile. I am trying to fill in the following equation in theory of course for my car.

    3.27 gears is about 14.0 ET
    3.73 gears is about ??.? ET
    4.10 gears is about ??.? ET

    If I had an idea about how much faster I could go in the 1/4 mile then I could see how much it would be worth it to me to rev higher on the highway.

    My other concern is that I am having trouble with wheel spin and 3.27 gears, how much of a problem am I going to have with 3.73 and 4.10. Heck, in reality, I could be slower in the 1/4 mile.

    Thanks in advance,

  2. gear

    My automatic ran 3000 at 70mph with 4.10s. Long trips were out.

    I put the 3.27s back in because the car wouldn't shift out of first with nitrous,along with a few other problems, like the car shifting into overdrive at the 1/4 mile trap. Slicks are a must at the track with 4.10s.

    I did gain .2 tenths in the 1/4 with the 4.10 gears.

    I like the way the car is now with the stock gears; and the bottle when I need it !!!
  3. this will prob. not help @ all, but this is my experience with my 01 gt 5 spd. everyone i talked to, (except most everyone on stangnet) said get 3.73's. so i got 4.10's. guy who installed it, told me "its your car, but i'd go with 3.73's, 4.10's are for the strip mostly." so i said, yeah, well here they are, put em in. he did. i love them. first gear is steep, think of your first gear now, now imagine it being double that steep. however, think of your car in 5th now. now imagine it pulling like 3rd in 5th. thats the new 5th. the other gears don't seem as drastic as 1st & 5th to me, so we'll ignore them. i have driven a buddy's 2000 5 spd with 3.73's & i really can't say there's a HUGE difference between the feel of his and mine. i have raced him several times & by the time i hit 3rd, he is always losing; is it his driving? is it his car?? (our mods are almost identical, except for exhaust) don't know. so maybe it's the gear?? or maybe not? either way, u will be much happier than with the stock gears, they make the car twice as much fun to drive and ten times more fun to race. just my 2 pennies.
  4. If youre planning on staying n/a, then anything less than 4.10 gears is going to be a waste in terms of max performance. I have an automatic 01 GT which I will be putting 4.30 gears into in the near future. Trust me, it isnt too much gear. The only way I would go with anything less than 4.10's in a auto is if either your seriously concerned about gas mileage or your going boosted. If either of these is the case, then 3.73's would be good for you.

    00GTconv, It sounds to me like you needed a dyno to get your shifts correct between the gears and the nitrous. Without proper programming, the electronic autos can have a problem with shifts after gear changes. Especially with nitrous.
  5. Thanks for the repies. So it is possible that I could get .2 secs faster with 4.10 gears. I wonder if the 3.73 gears will only get me .1 sec faster. I have a 5 speed so I can shift to the next gear whenever I want. I guess it would be cool to find out who changed their gears with no other mods and then took their car to the track. How much of an improvement did you see with the gear that you selected whether it be 3.73, 3.90, 4.10, etc?


  6. Another quick question that may make me look completely stupid.

    In the quarter mile, what gear would the Mustang (Manual trans) with 4.10's be in? What about the 3.73's?

  7. with 4.10's you will have to make 1 last shift into 4th right before the 1/4 ends.
  8. I just shift into 4th at the end of the 1/4 mile with 3.27 gears. Both 3.73 gears and 4.10 gears should be in 4th gear unless they are going faster than 110 - 115 at the end. I am curious to see how much each gear ratio will lower my ET in the 1/4 mile. That is of course with minimal tire spin. Can I get away with 3.73 gears and stock tires or will they spin as badly as 4.10?


  9. Does Any body Know what rpms your pulling cruisin on the highway at 85,90 mph with 410 gears compared to 373,s. I have a 2003 GT and I travel about 40 miles on the highway two and from work and I was curious About gas usage compared to performance gained. My gears are currently stock. :(
  10. From my post here:


    I took the opportunity to do some calculations in Excel to give some real numbers. These are based on a P245/45ZR17 tire with 809 revs/mile and the TR-3650 gear ratios of 1:1 (4th) and 0.67:1 (5th). YMMV.

    4th gear engine RPM (3.27/3.73/4.10) @ MPH
    50 - 2204/2514/2764
    60 - 2645/3017/3317
    70 - 3086/3520/3869
    80 - 3527/4023/4422
    90 - 3968/4526/4975
    100 - 4409/5029/5528
    110 - 4849/5532/6080*
    120 - 5290/6035*/6634*

    5th gear engine RPM (3.27/3.73/4.10) @ MPH
    50 - 1477/1684/1851
    60 - 1772/2021/2222
    70 - 2067/2358/2592
    80 - 2363/2695/2963
    90 - 2658/3032/3333
    100 - 2954/3369/3703
    110 - 3249/3706/4074
    120 - 3544/4043/4444

    * - at or past redline
  11. Thank you For that info :nice:
  12. I am running 295/35/18 sticky tires on 10.5" wide wheels. Wheel/tire combo weigh 61lbs. in the rear. I also have 6800rpm to work with (cobra), which also effects performance and usability of gears on my Mustang. Keep this in mind for my post below:

    With my '97 Cobra, I am at about 2550rpm in 5th gear with my 4.10's on the highway. First gear being unusable is a myth, at least for me. I either hook up with little/no wheelspin, or my rear end will break loose. But First gear is far from unusable. It feels like my car gained 50hp, but every single gear is still very usable. 5th gear feels about the same, it feels like the stock 3.27's + 25hp. I am used to how my gears feel now. I feel I need more HP to compliment my gearing now, my car needs an extra kick.

    What does the GT redline at? I think, at least for the Cobra, 4.10's combined with a nice assortment of bolt ons makes for a very sweet street car. If I was keeping my Cobra stock (no power mods), I would go with 4.30's, but I want the HP to back up the gears.

    The addition of gears for me has made for a much more exciting car. I still find myself letting the revvs eek up to around 4000 in 2-4th gears before I punch it, because its still the nature of my car, but it pulls a lot stronger.

    The only beef I have is that 3rd gear is for the most part useless on the highway. In fact, if I downshift into 3rd at anything over ~73mph, my clutch slips and I don't go anywhere. That's about the only downside to having gears, if you want to call it that.

    Anyways, from my experiences, 4.10s + bolt ons makes for a streetable rocket.
  13. Doesn't anyone else have what the increase would be in the 1/4 mile with 3.73 vs 4.10 gears?


  14. If youre looking for a clear cut answer as to what the difference in 1/4 mile times is going to be between any two gears, youre just not going to find it. All you will find is peoples individual experiences which will very due to track experience, traction, launching techniques, etc.

    I DEFINATELY assume you can gain more than .2 tenths with 4.10 gears as opposed to stock 3.27's. I even think you can gain at LEAST that much with 3.73's. Ive seen some people knock off as much as .8 tenths in the 1/4 mile by switching to 4.10 gears over stock 3.27's. It all depends as I stated before on launching techniques, traction, experience, etc.

  15. Agree completely.
  16. my car is a fast street tired car, and i have 4.10s-thats a good example...
  17. I have had both the 3.73 and the 4.10 in my
    2001 gt 5 speed. With both gears, you have
    to shift into 4th near the end of the quarter.
    I personally feel that the difference in times
    is nominal, but from experience, I could say
    that the 4.10 feels like it pulls much stronger
    with no effects really in fuel economy over the
    3.73 ratio.
  18. WHY are you grabbing 4th? You're getting less than 100mph in the 1/4 but your TR-3650 tranny and 3.27 gears will go over 106 mph before hitting the limiter in 3rd gear. I've posted this before but this link should help everyone understand the 2001-1/2 to present 5spd tranny a little better.



  19. Actually since posting this thread and hearing everyone else, I started wondering why I was shifting to 4th also. I wonder if that is why I can't get into the 13's because I am taking time to shift to 4th before I end. I am sure that is costing me a little bit of time. I think next time I go to the track, I will hold 3rd until redline (6000 rmp). See what that does to help me out.

    As far as gears, I like the idea of 4.10's but I guess I fear the gear a little. I really have just 2 fears.

    1. Revving the car to high making trips at 80 - 85 mph...
    2. Spinning tires alot worse than I do now in 1st gear on wet or dry

  20. High revs with gears at cruising speeds arent that bad on gas mileage or in terms of stress on the motor. Remember, theese are not wide open throttle rpms. Their cruising rpms and they're very relaxed rpms compared to in town rpms.

    As for traction, you will need at least a set of good drag radials for proper traction with 4.10's. Actually, for best results you should ALWAYS use at least drag radials(slicks prefered) for best times. Traction in the rain wont be much of a problem either. People get this idea that with 4.10 gears you'll be chriping tires at the slight touch of the throttle pedal. That just isnt the case. Gears are very easy to manage. Just dont floor it when in the rain and you'll be fine.