4.10,4.30 OR 4.56 GEARS ?

[chitowncobra]

HEY GUYS MY NAME IS TONY AND I HAVE A 2003 COBRA. MY QUESTION TO ALL 03 COBRAS IS WHAT KIND OF GEARS TO DO MINE WITH.4.10s,4.30s or 4.56s? I HAVE GOT BBK LONG TUBES,BBK OFF ROAD H PIPE AND FLOWMASTERS AMERICAN THUNDER.SOUNDS REAL GOOD.MY DYNO WAS 392.6 RWHP AND 378.2 RWTQ. AND ADVICE WOULD BE VERY HELPFUL THANKYOU!!!

 

[03DOHC]

Too much gear unless you will use taller than stock tires. My 2 cents.

 

[chitowncobra]

4.10S;4.30S OR 4.56S

TO 03DOHC MODERATOR OR ANY ONE OUT THEIR WHY WOULD THEIR BE A DIFFERCE IN STOCK TIRES VERSE TALLER ONES? I WOULD LIKE TO CHANGE MY GEARS TO A (4.10 OR 4.30). 4.56 MAY BE A BIT TO MUCH. ANYWAY I PLAN ON PUTTING 18X9 COBRA III WHEELS WITH NITTOS ON MY (SONIC BLUE COBRA) AWESOME COLOR BY THE WAY. THANKS ANY ADVICE WOULD BE HEPLFUL!!!!!!!!!!!

 

[f4sfed]

Well, until 03DOHC comes back, I'll take a whack at it: My guess as to why he said that is 'cuz these cars make enough torque just above idle, to pull trees out of the ground. There's really no reason to get the engine RPM up so quickly. Usually you'd use a lower gear to get the engine RPM into it's power range. With these engines, it's power range is whenever the key is on. ;-)

 

[ALA G8R]

If the outside diameter of the 18inch wheels and tires is greater than stock, then you will decrease the acceleration force of your car versus stock. You will need to compensate for the taller wheels and tires by changing out the 3.55 gear. 3.73 or 3.90 may be a better choice than 4.1 or 4.3. These cars have so much RWTQ that you may not be able to maintain traction with 4.1 or 4.3. Especially if you plan on modding your engine with a chip and pulley.

My $0.02.

 

[chitowncobra]

THANKYOU 03DOCH,F4SFED AND ALAG8R FOR YOUR ANSWERS. I HAVE BEEN AWAY FROM MUSCLE CARS FOR A LONG TIME . MY WHAT A GOOD TIME TO GETBACK. MAN WHAT A CAR . I PLAN ON A CHIP AND A CRANK PULLEY THAT WAS RECOMMENDED BY OUR OWN SVT MAGAZINE THIS ISSUE. I MIGHTGO WITH 3.73 OR 3.90.

 

[03DOHC]

Re: 4.10S;4.30S OR 4.56S

Originally posted by chitowncobra
TO 03DOHC MODERATOR OR ANY ONE OUT THEIR WHY WOULD THEIR BE A DIFFERCE IN STOCK TIRES VERSE TALLER ONES? I WOULD LIKE TO CHANGE MY GEARS TO A (4.10 OR 4.30). 4.56 MAY BE A BIT TO MUCH. ANYWAY I PLAN ON PUTTING 18X9 COBRA III WHEELS WITH NITTOS ON MY (SONIC BLUE COBRA) AWESOME COLOR BY THE WAY. THANKS ANY ADVICE WOULD BE HEPLFUL!!!!!!!!!!!

Just to let you know, when you use all capital letters it means you are YELLING.

While I am not by any stretch of the imagination an expert, I have run 4.30's before, in my '97 Cobra. That was a moderately heavy car with a small, high-winding, low torque engine. The gears allowed the engine to get into power quicker. That was a great gear for that car. My '03 Cobra has something my '97 never had. A big fat wide torque curve.

This subject has been debated here before and not surprisingly has come up again. Everyone has their opinions on what is the best gear for this car. In my opinion, if I was absolutely set on gears for this car, I would install 3.90's. This gear should allow you to cross the finish line in 4th gear. With 4.10's you would probably have to shift into 5th or wind the crap out of 4th, assuming you've raised the rev limit, or run a taller tire. At least that's what the math says.

Good luck with your choice.:beer:

 

[fryingricecobra]

I just got my 4.10s installed today. Man does this car pick up fast as ever now. Not that it was slow before or anything. The only draw back I see so far is 1st gear traction wise is useless now if you slam on the gas. I am headed to some races tomorrow so we will see how good they work.

 

[chitowncobra]

thanks again 03dohc and fryingricecobra let me know how you do at the track . i guess im back at the drawing board. i just wanted to be quiker at the line. i love cruising in 3rd gear at 60-80mph then step on it going into 4th man what a blast might lose that with 4.10. then my fav.would turn into 4th. 5th would be my step on gear. maybe 03dohc 3.90 keep me in my fav.3rd.i do most my racing at the top end. and smoke those vettes. what do you think 03dohc 18 x9 w/nittos and 3.90 i went to another thread on 17s or 18s? one guy on their said 275/34-18 tires on 18 inch wheels would have the same diameter as the stockones? thanks everyone!!!!!!!

 

[03DOHC]

Re: Re: 4.10S;4.30S OR 4.56S

Originally posted by 03DOHC
Just to let you know, when you use all capital letters it means you are YELLING.

While I am not by any stretch of the imagination an expert, I have run 4.30's before, in my '97 Cobra. That was a moderately heavy car with a small, high-winding, low torque engine. The gears allowed the engine to get into power quicker. That was a great gear for that car. My '03 Cobra has something my '97 never had. A big fat wide torque curve.

This subject has been debated here before and not surprisingly has come up again. Everyone has their opinions on what is the best gear for this car. In my opinion, if I was absolutely set on gears for this car, I would install 3.90's. This gear should allow you to cross the finish line in 4th gear. With 4.10's you would probably have to shift into 5th or wind the crap out of 4th, assuming you've raised the rev limit, or run a taller tire. At least that's what the math says.

Good luck with your choice.:beer:

That was meant for a chip, pulley, and exhaust car.

 

[Silver 03 Cobra]

I had 4.10's that I swapped out for 3.90's in January. My track times have dropped off. I thought it may have been the Densecharger but I ran with my JDM set up and still ran worse. I wished I had stayed with the 4.10's. I ran my buddies 28 inch tall ET Streets this past week also. With the 3.90 gears the 28's are too tall. I was 2-3 tenths slower with these tires than my 26 inch tall ET's. I may have needed some more time to learn how to launch them but I couldn't wait to take them off. I think with a 28 inch tall tire a 4.10 gear would be a minumum.

 

[DD2000GT]

I was glad to see Ford went with 3.55 gears stock on this years Cobra - my Mom has a 99 Cobra and it is a DOG down low. I have told her several times to get at least 4.10 gears to pep up the bottom end. While it is true, the roots blower does help quite a bit - these 32 valve engines are made for crazy top end power, but the low end of the RPM band suffers.

When I was having my rear end replaced under warranty, I almost had a chance to swap out the gears, I was going to go to 4.10's - but it didn't work out (Ford sent the ENTIRE rear end, not the parts). I still will if I get the chance.

 

[chitowncobra]

to siver03snake ,dd2000gt and everybody else thanks for all your imput . i might be leaning towards (4.10s) this will be professionly installed . the tech told me he would have to recalbrate my speedometer for the gear i choose and that would be chip this will also fine tune the car to the modds i have done plus swapping out my stock tires and wheels for 18x9s this wil also help with decision on picking 4.10 gears. its getting close to decision time.
once again i am thanking everyone for their input!!!!!!!!
p.s. i am always open comments and ideas i guess im still finding out what an asesome car we all have!!!!!!!