4.10's vs 3.73's

Discussion in 'SN95 4.6L Mustang Tech' started by 04gtdrop, Jul 13, 2005.

  1. 5spd GT

    5spd GT "the 5.0 owns all"
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    The reason why people ask these questions because it has to do with THEIR CAR not someone else that wanted to know what gear ratio they should have a few days earlier. I would never make a engine/tranny related decision based on someone's goals.

    If you don't want to answer and just complain...how about don't answer.

    Not everyone's goals are exactly the same. I like new/refreshed info about MY car and not someone elses...

    Just think about it...
     
    #41
  2. jimfitzgerald

    jimfitzgerald New Member

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    That may be valid for some mods and/or combinations. The gear question is asked over and over and there is NO NEW INFORMATION to share. Everything that can be said has been said over and over. That's why they have a search function on this website.
     
    #42
  3. 5spd GT

    5spd GT "the 5.0 owns all"
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    They have a search function on many websites.

    I like personal info on my car. I don't want to "search" thru 10's or 100's of possible threads to look for the info that I want.

    Do they drive it 90/10 (street/strip)? 70/30? 50/50? Stop and go more than some? Trap the same? different? Other mods? concerned about gas mileage? engine wear? wear and tear? etc...etc...etc.

    Do you really want to search thru all the potential answering threads or do you want someone to post their specific goals and wants for their cars?

    "Just think about it"...

    I want personal answers to questions about my personal car...not someone's that is a bit different. It is all about efficiency in the post...plus the search has it's down falls with their min. and max letter characters.
     
    #43
  4. 04gtdrop

    04gtdrop New Member

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    well i just wanna say thanks guys, i have been back and forth on this all weekend. but since fri was payday i had to get them. i went with the 3.73's only becuase i plan on putting a 50-75 shot of NOS on her. i just want a little more power ya know? so i think 4.10's with NOS would be TOO much. so 3.73's it is, plus i do a decent amount of freeway driving. i guess if i get bored maybe later i'll get the 4.10's, but for now i think 3.73's are good. i'm not sure why anyone would bother with 3.55's??? hmm well i just want 2 say thanks for all the input.....

    ohhh i went to that mustang/ford show on sat and it was SWEET ! ! ! i got about 47 pics from my cell phone. not the best, but hey... i would love to share them with you guys, but i cant even get a pic of my own car up let alone the others like the TWO new ford GT's that made it out....
     
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  5. skullmaster427

    skullmaster427 New Member

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    hey thanx to all u guys ...merc123 that was the kind information i wanted it made me stick with the 3.73 ... i think highway distance and rpm r the 2 things... and 5spd gt thanx for the support i think people should only asnwer only if they want to ... no body have to help no one unless they want to.. anyways thanx to u all
     
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  6. tony laq

    tony laq New Member

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    i dont know if this will help you...i just got 3.73's on thursday..i picked them for a few reasons..
    1. it's a daily driver..never gonna see the track.
    2 i'm gonna be doing ALOT of highway driving
    3 i drive alot in snow
    4 EVERYONE i asked outside of message boards said that for what i want with my car 410's would prob be a bit too much gear.
    5 i really dont race..stoplight to stoplight once in a great while- thats it.


    im really happy with them...it woke the car up without being excessive. i can see where 4.10's would be cool once in a while ( for me ) but the 3.73's are perfect in my opinion. others swear by 4.10's which is cool. im happy with mine and thats what really counts...get what YOU want.

    tony
     
    #46
  7. jstreet0204

    jstreet0204 Active Member

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    Opinions differ, but I drive 30 miles one way to work everyday, and make several long interstate trips a year with 4:10's and I dont' feel like it is overkill at all. Gas mileage before the supercharger was around 24, now it's about 21, so no big deal there either.:nice:
     
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  8. 03ghoststang

    03ghoststang Well-Known Member

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    I didn't want to start a thread but i have an automatic with 3.73's i was wondering if i go supercahrged and swap to 4.10's if that'll be overkill for the stock block? I'll appreciate any reply's thanks :shrug:
     
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  9. Give Me TP

    Give Me TP New Member

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    On several 2,500+ mile road trips and a daily 45 mile round-trip commute to work, I like the results after changing from 3.55s to 4.10s. Do not hit 3000 rpm in fifth gear until 90 mph, and that's perfectly allright in my opinion.
     
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  10. jimfitzgerald

    jimfitzgerald New Member

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    It's got nothing to do with your block. The issue with the stock block is you don't want to make more than 400 rwhp without forged internals. As far as gears, you might as well keep the 3.73's now that you have them. With the automatic, you probably should have gone with 4.10's to start with.
     
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  11. shiftless

    shiftless New Member

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    I have an 02 5 speed GT with 4.30s, and I love them. I do a lot of highway driving at 70-80 MPH, and I am absolutely satisfied with these 4.30s. They are awesome. My car rips out of the hole like a bat out of hell, and tops out at redline in 5th (~ 162 MPH, or probably around 155 if accounting for tire growth and tach inaccuracy). I may have lost 1-2 MPG, which I could easily get back by not driving like a maniac. But I can't do that, because my car is so much fun to drive now. DON'T FEAR THE GEAR. Jesus Christ, what else is left to be said on this subject?
     
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  12. 03ghoststang

    03ghoststang Well-Known Member

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    thanks, i was just asking because i always keep hearing that i have to strenghten my internals if i go supercharged and with 4.10 the engine will rev a lot quicker but thanks anyway :nice: but i was more than likely going to stick with the 3.73's i have thanks again
     
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  13. jimfitzgerald

    jimfitzgerald New Member

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    Sorry, but 162 mph with 4.30's and 26 inch tires would be 9100 rpm. 155 mph would be 8700 rpm.
     
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  14. skullmaster427

    skullmaster427 New Member

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    hey**** Give Me TP*** thats not so bad 3k at 90mph i can live with that but the information i have here http://www.03sbgt.com/gear_ratios.html shows 3372. rpm at 90mph now what kind tranny do u have? should be the same as mine correct?..now i dont think the link its correct with my car... the other day i did 150mph + at 4th gear until the rev cut off kicked in witch should be what 6.200 rpm if i'am right kind getting confused with this gear thing man.. dont wanna get 4.10s change it and then 2 weeks later will be getting nother set :shrug:

    my car its bone stock on mechanical... only got a pair of flows 40s ,stock rims and tires and plan on keeping that way just the gear and some home made cold air from the hood scoop ...its my d d cant do much on it..

    thanx guys...
     
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  15. Give Me TP

    Give Me TP New Member

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    A Tremec 3650 5-speed is in my '03, what year is your car?
     
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  16. Dingleweed

    Dingleweed New Member

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    For those of you that are trying to decide what gears to get, and what difference it makes in the actual torque applied to your back tires... try this out for size.

    So, I have been doing a little homework trying to figure out if I want to get 4.10s or 4.30s. One thing that I did to help me decide was to graph the actual torque to the wheels (dyno WTQ x gear ratio x diff. gear ratio) for a variety of different gears versus my car's speed.

    For the dyno WTQ numbers I used this graph that I found for a stock 1999 Cobra (since I haven't dynoed my car...yet):
    [​IMG]
    (I forget where I found this, but it seems kind of typical, and my car is sort of near stock... for now... :cool: )

    I then mapped out the torque curve and input the data into a data processing program that I use. Once the data was acquired, I calculated the torque to the wheels (after gears, and differential ratios). For speed I used the info for the stock 245/45R17 tires.

    Here's the chart for 3.90 differential gears:
    [​IMG]

    and for 4.10 gears...
    [​IMG]

    and for 4.30 gears...
    [​IMG]

    and for 4.56 gears...
    [​IMG]

    Since actual torque to the wheels is directly proportional to your acceleration, just think of the vertical axis as the kick in the pants that you feel for that gear at that particular speed. :D

    As you can see, from a roll in second gear (say on the 4.10 graph) from anywhere between 20 and 50 mph, you have an extra 500 or so ft-lbs of torque to the back wheels! So, for 4.10 gears, second gear pretty much feels like second gear with 3.27s with a 100 or so shot of nitrous!

    These graphs and data are rather useful for other things; for instance, thrust (forward force) is your torque to the wheels divided my the radius of your back tire. Since the stock 245/45R17 tires are close to a foot in radius (12.84") you can approximately think of the vertical axes as the forward thrust of your car. Then divide that number by your car's weight and you have your forward thrust in g's. (Of course this is all assuming that you don't break traction...) Also, where you see the curves for a given set of gears cross is your optimal shift point for maximum acceleration and 1/4 mile times.

    My conclusions:
    After playing around with the numbers, I am definitely going with 4.30 gears! With sticky tires, first gear will launch you out of the hole like a freaked out cat on carpet. Then for regular city driving on street tires, second and thrid gear would make it feel like I've got another 100 to 130 ft-lbs of torque to pin me back in the seat for sh1ts and giggles!

    I had the "fun" of analyzing this data for my own info and gear decision, but I thought the info and graphs might be useful for the rest of the community.

    Enjoy... :nice:
     
    #56
  17. 04gtdrop

    04gtdrop New Member

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  18. BaconBits

    BaconBits New Member

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    EXECELENT post! And for all of you thinking about gas mileage, look at it this way. There are simple and easy ways to ensure you maintain and even get BETTER gas mileage from your gears. First: Under drive pulleys. The name speaks for itself, at the upper RPM's you reduce the drag on your motor, and thus it’s more efficient. Second: Aluminum driveshaft. Reducing the weight on your drivetrain puts more power to the wheels and makes your engine more EFFICIENT. Look at gears like a 10 speed bicycle. Ever try to accelerate from top gear? You better have Hulk strength to get anywhere. But switch it to a lower gear and you are off and running without using all that much force. A car is no different. To MAINTIAN a speed (highway driving) you are going to use less petal (gas) to maintain the same speed as you would with a lesser gear. Get on your bike and see what I mean.
    As far as power adders go, I’ve read threads on www.svtperformance.com where guys are running well over 600whp and 4.30 gears. Hell some of them are doing 4.56's. That is with a ROOTS blower. You are ALWAYS going to have "traction issues" no matter what gear you have if you have more than 200whp. There is more to driving than putting your foot to the floor and hoping for the best. For those who say you can't do gears with a power adder, don't know how to drive. Simple as that. In the latest MMFF there are 2 valve GT's Running 12.03 1/4 miles with "only" 298whp. All of the top cars had 4.30 gears.
     
    #58
  19. jimfitzgerald

    jimfitzgerald New Member

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    If you're into 1/4 mile drag racing, the gear decision is pretty simple to me. You basically want the gear that puts you close to your rev limiter at your trap mph. The following is a link to an on-line calculator that I use...

    http://www.turbofast.com.au/Drag.html
     
    #59
  20. skullmaster427

    skullmaster427 New Member

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    01 gt 5 spd :nice:
     
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