Anyone with 4.10 Gears?

[BlackenedSVT]

Im contemplating putting rear end gears in my 04 Cobra. The stock 3.55s are nice, but i want something more for my daily driver + summer time track car. I dont really want to try tackling the gear install myself, i learned its a pain when i did them in my 02 GT, so i'll have my friend whos a Ford master tech install them for me. I'd like to keep them FRPP gears since that what my friend prefers installing (motives can be a pain to install, and i dont need him charging me more for the hassle).

Soooo

Ford only seems to have 3.73 gears or 4.10 gears. IDEALLY I'd like to get 3.90 gears for the cobra....but ford doesn't make those. And im thinking going from 3.55s to a 3.73 gear would be more of a waste of money, since its really not that much of a difference.

Any of you guys have 4.10 gears in your daily driver cobras? How about any of you track guys?

I personally think 4.10s might be a bit of overkill...but badass at the same time :rockon: LOL

Keep in mind it is my daily driver car, and i go to the track about 5x over the summers. Lets hear some input Thanks guys :beer:


Is an IRS rear end gear install harder or the same as doing one on a live axel?

 

[GodStang]

I have 4.10s and hate them. Zero Traction even with Mickey Thompons.

 

[BlackenedSVT]

jesus christ! 14.3 @ 96? was that with your cobra and 4.10s?

I have 0 traction too, but thats because i went from a GT to a cobra and took her to the track 1 month after i bought her lol. Best i could muster was a 12.9@117mph on 18" street tires...but i also have 483rwhp...so its obvious i was spinning 1st through 3rd down the track.

why do you hate them? do u daily drive your car?

 

[V3NOM3S]

I have 410's in my Cobra. It depends what mod's you have but I like the 410's just fine also you control traction with your right foot. I'd probably be happier with 390's though.

 

[RCMPSVT]

I love mine but depends what u do with the car. I love the Tq but I dont see the track alot with my car

 

[speeddemon2000]

I have got 4.10s with my KB 2.2 at 20psi. In the summer time traction is ok with 315/35/17 MT drag radials. On street tries traction is a joke. I can start of in second and still spin the tires to 60+. In the winter time forget it. I will spin the tires even in 3rd gear. 1st and 2nd are a joke. Overall I like the gear. It defiantly adds some vibration at higher speeds, 100+. Really thogh the 3:55 are a good overall gear so really think hard before going to a 4.10. If you like to cruise at 90 on the highway 4.10s are not the way to go stick with the 3.55. If you a weekend warior and only like quick burst and you run MT drag radials all the time you will like these gears.

 

[SVT_4_me]

i can't imagine having 4.10's, even at my power level... doesn't seem like it would even be worth it at all. :shrug:

 

[SicStang03]

I too have thought about gears. I wanted 3.73 but figured that would be a waste too... I will just stick with the 3.55... 4.10 are way to steep IMO

 

[03MUSCLE]

way to much gear for stock suspension.

 

[BlackenedSVT]

Hmmm ok anyone here swapped from 3.55 stockers to 3.73s then??? hows THAT difference?

 

[GodStang]

jesus christ! 14.3 @ 96? was that with your cobra and 4.10s?

I have 0 traction too, but thats because i went from a GT to a cobra and took her to the track 1 month after i bought her lol. Best i could muster was a 12.9@117mph on 18" street tires...but i also have 483rwhp...so its obvious i was spinning 1st through 3rd down the track.

why do you hate them? do u daily drive your car?

No the 14.3 @ 96 is with my stock Stang GT.

 

[SoCalHarley]

I have 3.73's but with a T-56 with 2.97 first gear.... my 1st gear is 1% steeper than your tranny with 4.10's, 2nd is 5% steeper and 3rd is the same so my setup would be close to yours with 4.10's. Our HP/TQ numbers are similar as well.... As many have stated 1st with street tires even my Toyo 295's spin instantly but 2nd with some skill will hook up if you don't flat foot the accelerator. 3rd is great and 4th pulls well. Your 4th would be 9% steeper which would be really strong. 75mph in 6th would be 2500 rpm's, 4th at 6500 rpms would be 123mph . I think the issue is 1st gear which really is not useable with any boost on street tires.... it is fun but I would bet from a dig a taller gear would produce much better results and be more useable.... after that at least for me is good.

 

[RCMPSVT]

I picked up 2/10th's in the 1/4mile with my 410's

 

[9746Cobra]

I really enjoy my 4.10's on my DD '03. I could never go back to the 3.55's.

I could see 3.90's though. The motive brand should be fine.

I have a stock pulley though. If your running just a pulley and don't plan to do more and it's a DD I'd say get 3.90's or 4.10's.

If your running well over 450hp and you don't take your car to the track or don't use sticky tires stick with the 3.55's.

75mph in 6th gives me 2500rpm. Gas mileage has not changed.

Clutch engagement in 1st gear is really nice! It's actually what I like most about it. I hated slipping the clutch so much to get going in day to day driving with the 3.55's

Be aware the more gear the more likely you'll get some vibration. I have a very slight amount around 80-90mph but it's no big deal. It's been worth it.

Expect to pay for about 5 hours of labor to change your gears. (@500) If your somewhat handy you can drop the "pumpkin" yourself and just bring that to the guy doing the gear install. Then he should charge about two hours. @$200. Just some rough numbers though.

9746C

 

[96 chris]

Go for 3.73's
You will notice a difference, It will just seem a little peppier

 

[BlackenedSVT]

the vibration you guys are referring to sounds like a drive shaft inbalance which isn't uncommon with rear end gear changes. try getting the drive shaft balanced and it should go away for good.

Thanks for the advice. I'll consider some after market 3.90s

 

[Almo]

I have 4.10s and hate them. Zero Traction even with Mickey Thompons.

Off topic a bit but have you tried Hoosier DRs?

 

[particleman]

I'm at 515rwhp in my 03 w/ 4.10s,sra, nitto 315 555rs. My car has seen the interstate twice since I've owned it, I wouldn't recommend this gearing for DD interstate travel. I turn 2000rpm @ 60mph in 6th. No high speed vibration like others have mentioned :shrug: I have nothing to base my comparison on as I don't really race and haven't owned anything this powerful before, but as speeddemon2000 said 1st and 2nd can spin through. Winter time I've broke loose in as high as 4th going nearly 60. I drive the car once or twice a week to work 7 miles and cruise here and there in it, so overall the gearing is fine for me.

 

[GodStang]

Off topic a bit but have you tried Hoosier DRs?

No I have not. I am getting ready to switch to better ET Streets because someone gave me them for free then after that I will see where to go. I have a set of hoosiers given to me but after I got them home I realized it was showing cord. Not sure if it can be fixed. I also want to compeletly redo rim setup.

If you have any advice any at all pm it to me. You are the all knowing.

 

[Spade]

3.55 to 3.73 wouldn't make much change. More of a PITA. If you go 4.10 run a 28" tire(stock is 26") that will being your gear ratio to 3.90ish. That way if you want the extra gear at the track run a smaller tire and for the highway run a taller tire for highway speeds. Just some food for thought.

Spade