so i've decided to not " fear the gear" anymore and i'm going to get a 3.90 gear set. I figure its best for my situation more that 3.73's but better milage than 4.10's. so my question is this, i know that gears dont make power, they provide a more efficant use of the power already at hand. so, what kind of speed increase is to gained. for example, say the stock gear my 1/4 time was 13.87 (totally made up!, i've never been to a track) and with 3.90 its now 13.16. is this posibble, I would think gears would make my car faster in that sense. am i correct?

 

That how they work. With 4.10's you should see .5 in the 1/4.So maybe a tad less with 3.90's.

 

seriously i ahd same ordeal and was gona go with 3.90s. jut do the 4.10s like i did. u dont drain gas or anyhitng like u think, infact i think city mpg increased for me.

 

i gained .5 in the 1/4 from gears alone

 

x2 4.10s

 

gained .29 in the 1/4 with 3.73's. in my opinion, dont get 4.10's. even with 3.73's highway noise is a bit much 4 me. at 65mph im at 2700 rpm and it gets old after a while listening to the rumble. if you can take the noise, go 4 4.10's, they make a big difference, if not, id go with .73's or .90's, not as big a difference but still noticable.

 

what tranny is in ur car bcassette, auto or man.? engine? cre8787, if the rpm's are a lil too high for ya, get a diff. muffler, it'll quiet it up a bit. and that's only what, about 800 rpm's higher then stock? sounds like an alright tradeoff considering the advantages of the gears.

 

??? I never said anything about noise or rpms....that was the guy that posted before you said that, but if you must know I have a 5 speed.

 

ok, so i just found out that the xcal2 does not have an end user option of 3.90 gears, it goes from 3.73 to 4.10. so my how do i fix my speedo with out getting a tune? tech support told me a tuner can set up any ratio i want, but i have to have tuner with the software do it, i cant.

 

i dont hear any noise, if you do, get a louder exhaust!

 

What year car are we talking about?

 

03 GT, 5 speed

 

3.90 and 4.10 are so close together that you really should just ditch the 3.90's and go to 4.10. It won't make jack for diff in gas mileage day to day.

 

i am slowly coming to that conclusion.......

 

re-read my post buddy. i addressed you, then i addressed the other guy, by screen name, right after i asked about what engine you had. lol.

 

wo wo wo...buddy..in that tone i take it as if you're calling me **** face. please refrain from that.

 

lol, gotta love the toneless-ness of the internet. nope, not trying to be an ***, just tellin' a fellow forum member to re-read what i posted.

 

Sure they do, I have 3.90s with my SCT XCAL2.

 

wait, is toneless-ness even a word? haha...

 

hmmm...i called their tech support( at sct) and the guy told me its not part of the end user set up.

 

I call BS!!!!!!

You're gettin

 

This is you dude.https://mustangboards.com/mustang-cl...pp-4-10-a.html

 

sry it took so long to reply. i have a 5 speed. i was talking about exhaust noise, not gear noise. Yea i guess its not that bad, too bad ford didnt put a T-56

 

Ford's T56 in the Cobra wouldn't make much of a difference since 6th is .62:1 compared to the 5 speed's .68:1. However, a F-Body/Viper T56 has the .5:1 6th gear which would be very nice but 1st is only 2.66:1 then.

 

the 2.66 first gear works very well with a 3.73 or better yet a 4.10 rear gear. with that combo you end up with a lot more grunt in the 3-6th gears and first gear becomes useful again. remember.. you need to match the gears in the diff to the gears in the trans for best performance in every gear. chebbie really outdid ford on that one.

 

i saw that today, the only thing is i want timken bearings and AM doesn't sell that kit. in fact i called AM and i was told that motive no longer makes a master install kit with timken bearings and i quote "if they say the have timken bearings they are lying" in reference to me metioning another site that sold the kit with timken bearings. so I called motive to find out that yes they do still make a master kit with timken bearings. whats with all the BS lately. first sct now this...