So you can go 253 MPH, duh.... haha :beer:
03 Cobra with 4.10 Gears!
- Thread starter Vrrooom
- Start date
So you can go 253 MPH, duh.... haha :beer:
4.10 gears, Moroso 17" slicks, stronger axles
maye a winning combo for traction at the track?
maye a winning combo for traction at the track?
Re: 4.10
First, I have owned and raced and driven cars with 4.10's (4.11's) and 4.56's, but all of them were able to wind up a lot tighter than the 6500 RPM redline set for the 4.6L DOHC.
These gears definitely have their place, but not in these cars at the strip, unless you plan on going way past the redline of 6500 RPM.
The traction issue CAN be resolved by going to much wider tires, assuming you have the rest of the drivetrain to carry them. The problem comes in at the top end, where the motor nears redline in 4th gear. If you are planning on running the 1/4 with times and speeds greater than 121 MPH, you will either have to run up past the redline of 6500 or go to 5th gear. I don't think either is desirable in this car. This is not theory, it is simple mathematics.
To trap 128MPH, you would have to wind this motor to 6900 RPM. Do you want to do that? Under a load, I don't think so...
I have said this before, 4.10's can be a lot of fun on the street, but unless you meet the criteria above, forget them for the strip.
On the plus side for 4.10's, you could run a taller tire and move the RPM curve down, about 5 MPH for each added inch. So, for
28 inch tall tires, you could run 132 MPH trap speeds at 6500 RPM, if you have the HP & TQ to do it.
The Eatons are running out of steam on the top end, so I prefer to shift long before the 6500 redline. Pushing them past 6100 or 6200 is probably not the best idea in the world, but all cars are not the same so YMMV.
Dana
First, I have owned and raced and driven cars with 4.10's (4.11's) and 4.56's, but all of them were able to wind up a lot tighter than the 6500 RPM redline set for the 4.6L DOHC.
These gears definitely have their place, but not in these cars at the strip, unless you plan on going way past the redline of 6500 RPM.
The traction issue CAN be resolved by going to much wider tires, assuming you have the rest of the drivetrain to carry them. The problem comes in at the top end, where the motor nears redline in 4th gear. If you are planning on running the 1/4 with times and speeds greater than 121 MPH, you will either have to run up past the redline of 6500 or go to 5th gear. I don't think either is desirable in this car. This is not theory, it is simple mathematics.
To trap 128MPH, you would have to wind this motor to 6900 RPM. Do you want to do that? Under a load, I don't think so...
I have said this before, 4.10's can be a lot of fun on the street, but unless you meet the criteria above, forget them for the strip.
On the plus side for 4.10's, you could run a taller tire and move the RPM curve down, about 5 MPH for each added inch. So, for
28 inch tall tires, you could run 132 MPH trap speeds at 6500 RPM, if you have the HP & TQ to do it.
The Eatons are running out of steam on the top end, so I prefer to shift long before the 6500 redline. Pushing them past 6100 or 6200 is probably not the best idea in the world, but all cars are not the same so YMMV.
Dana
Vrrooom- Tetge and Sonic Venom in SoCal run 4.10's and they like them. Maybe you can PM them for some input.
oh damn, I think Dana just crapped on our parade
Silver 03 Cobra
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3.27 :dw: 4.10?
If you gotta have a lower gear don't go over 3.90 if you are planning 480 rwhp and only if you run a lot at the track with ET Streets. With 480 rwhp and 4.10's a WRX STi will leave you in a cloud of your own smoke on the street. It won't be manageable enough on the street even with DR's. I've ran both in my 03 and have the 3.90's now.
If you gotta have a lower gear don't go over 3.90 if you are planning 480 rwhp and only if you run a lot at the track with ET Streets. With 480 rwhp and 4.10's a WRX STi will leave you in a cloud of your own smoke on the street. It won't be manageable enough on the street even with DR's. I've ran both in my 03 and have the 3.90's now.
For those of you considering running a big gear on the street, and feel that the Drag radials or even E.T Streets will help, you have to remember these tires do not perform well until you heat the crap out of them and drop the air pressure way down.
I personally don't enjoy running 9 1/2 lbs. of air in my E.T. Streets on the street, just to get them to hook. On the track, it's not an issue, but on the street, it can get pretty scary.
Dana
I personally don't enjoy running 9 1/2 lbs. of air in my E.T. Streets on the street, just to get them to hook. On the track, it's not an issue, but on the street, it can get pretty scary.
Dana
i think those with KB's or those thinking about a centrifugal blower should look at 3.73's-4.10's....especially on the centri's as they do not lose their efficiency and have less low end TQ than the Heatons and KB's.....
Then again those with KB's have way to much TQ down low for 3.55's....
i donno, IMO, if you run a larger wheel with bigger tires...then gears may be right for you...
if u want the fun factor, get gears.
Then again those with KB's have way to much TQ down low for 3.55's....
i donno, IMO, if you run a larger wheel with bigger tires...then gears may be right for you...
if u want the fun factor, get gears.
fun factor wins
If my rear end broke and my dealer had it apart to fix sure I would have them go ahead and slap gears in. I would do 4.10's for sure. I bet it would be a lot more fun on the street especially during the spring/summertime when the tires actually hook. But it is definitely not a mod I am going to pay $600 for the install thogh. When my 01 cobra's rear end blew out, the dealer installed my 4.30's for free! That was one mod that car sure did need. I was out of the intersection before guys could get off the line LOL!
I have 4.10's for sale anyone interested?
I'm interested. From looking at the spread sheet someone else posted a link to, I think maybe the 4.10 will speed me up at the track and slow me down over the road. Something I desperately need before I get my butt a huge ticket. Yes, I have a heavy foot.
Send me a PM on the particulars.
4.10s and 548RWHP is simply awesome from a roll.
But a PITA from a launch.
J
But a PITA from a launch.
J
you took the words out of my mouth.
3.90 when I eventually do gears... its just perfect for a 26" tire
I've been running the 4.10s for a while now, and I like it. I come across the 1/8mile line in third gear right before redline @ just over 91mph. On the 1/4mile I finish in 4th gear with enough to spare @ 116mph but with an 11.87 et. I know the mph seems low, but the et is there and I ran a 1.64 60' with Nitto 315 DRs and nothing else done to the suspension. I have been averaging high 1.6x 60' times with this combo.
Just my 2 cents..
Just my 2 cents..
My 03 Cobra has run with 3:55, 3:90, & 4:30 gears. The 4:30 was wild all the way to 3rd and I finish the 1/4 in 4th. With larger nitto's I believe it would hit the high 11's. I was using nitto 275/40/17. The car is stock with a black box by Brothers for the gear swap. My rear end cover blew to bits with the Kenny Brown torque arm and I had to learn to launch at 2 grand. It was a killer on the street if you learn how to leave a light. I will be putting a 4:10 in later. I have two 3:55's, one 3:90, and a 4:30 4sale. Phone 7086331671/ email [email protected]
pm me with how much for the 3.90's. Thanks
$110. plus shipping
Im real close to you..... save the 3.90's for me, I will contact you Dec 18th when I get back home. Call me on the 19th if I forget.:bash:
630-768-0761
630-768-0761
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