Is there anyone swapping the rear gears; if so, what are you using? I was considering going to 4.10s.
Gear Inquiry......
- Thread starter §ilver§nake
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3.90's should work very well for most sane mods.
After driving her for a WHOLE DAY, I'm tryin' to decide between 4.10 and 4.56's. I mean after all, she's got TWO overdrives. First gear goes to OVER 40 mph! With a 6-speed, I figured first gear would be more of a creeper type gear (not that I'm disappointed).
I think im going with 3.90, but 4.10 would probably be a little better for 1/4 racin. I dont think id go with 4.56's, probably too steep. With the factory redline of 6500, i think youd run out of rpm before you finished the 1/4,especially if youre modded. Plus, the overdirve in 6th gear isnt much different than the Overdrive in the old T45's
In my less than brilliant calculations the 4:10 seemed the perfect stretch for staying out of 5th gear at the end of the 1/4.My programming is set for a 6700 rpm limiter but peak HP comes in lower and until all my final trims and timing advance is employed I just wont know.Hope this helps,Great night Dave S.
Thanks for the input, guys. I had forgotten about the 3.90s; that would put 6th gear closer to the current 5th gear in my 97. My concern is going too low in first and hooking up.
Silver 03 Cobra
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I have had 4.10's in my 03 for over a month now. I have a little problem hooking up right now but I had the same problem with the stock 3.55's. All I know is my times are a lot better. I'll post my times but I have gotten flamed in the past. But, unless you have run at Wilkesboro Raceway Park, you don't know how slick a track can be. I ran 8.12 at 91.8 mph this past Thursday night on street tires. I'm not into full throttle until halfway down the track and that's with a 2.10 60 ft. I just ordered a set of Mickey Thompson ET Streets. They should put me above 95 mph and well into the sevens. After I run at WRP, I plan on going to Farmington and then Bristol Dragway to see just how much better the car will run on a good track. My car is mobbed at the track and although my ET is not that good my trap speeds are appoaching some bad ass cars running there.
If you are serious about racing don't waste your money on 3.90's. I wouldn't put them on for everyday driving. It's just not that big a difference from the 3.55's. I got over 91.9 mpg driving 85 mph going from NC to Fla this past weekend with the 4.10's. The car drives so much better around town with power on demand without having to slam the throttle to generate boost for power. The 03 owner I just installed a set of BBK LT's is sold. I will be very interested to see what 03 owners are running at Bowling Green the end of Sept. I t hink after that race, people will be jumping on the 4.10 band wagon.
If you are serious about racing don't waste your money on 3.90's. I wouldn't put them on for everyday driving. It's just not that big a difference from the 3.55's. I got over 91.9 mpg driving 85 mph going from NC to Fla this past weekend with the 4.10's. The car drives so much better around town with power on demand without having to slam the throttle to generate boost for power. The 03 owner I just installed a set of BBK LT's is sold. I will be very interested to see what 03 owners are running at Bowling Green the end of Sept. I t hink after that race, people will be jumping on the 4.10 band wagon.
I agree the 4.10's would rock in this car:rolling: but the only concern i would have is what speed are you shifting out of 4th at because i read on here it is around 121mph@6500rpms which is cutting it close for those that are trapping near there already.
It should run out at 6200 give or take 100 and with blower heat generated with stock intercooler this can be bad on hot days.Below 70 degrees 4:10's should be optimal.Dave S.
if youre going to go with 4.10's, especially if youre going to do some seriouse mods, have the rev limiter bumped up to 7000, and youll be inawesome shape. then youll have the 4.10's, and have room to grow in the 1/4. All the older 4.6's had the 7k redline, and theyre commonly using 4.30's. If i do decide to do the chip in the near future, ill probably do the 4.10's and raise the limiter.
A few month's ago someone on here posted a link to a site that gave a way to do the math to figure out how fast a car would run in each gear depending on rear end ratio, tire size, RPM, and the trans gear ratio. I did the converison's for 4.10 gears and with the stock tires at the 6500RPM redline the Cobra should run 121mph in 4th. The 3.90 gear ratio converted out to being able to run 127mph in 4th gear at the 6500rpm redline. Those were the only 2 that I ran the numbers for but, being that we have seen the speeds that HAVEIGHT 13R has posted it is obvious that the 4.10's are going to be TOO low for the 1/4 if you are not wanting to have to shift into 5th gear. If you guys get the power up to that level then 3.73's or 3.90's are going to be the best gear choice. My vote is for the 3.90's, hope that helps. ;-)
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