I dont even shift into 4th i just go through in 3rd @6700-6800
Soo happy!! 3.90's are on!
- Thread starter combatstang
- Start date
7168548 said:Marc you *ucker. You need to let me drive your car. I think I'll still win in a race though.
how? no way... maybe if you get gears, and get tires, and i drive ur car.. haha
Marc
combatstang, whose gears are they? Motive Gear I assume? I'm curious as to whether you have any howl or whine from the rearend now? I've had a 3.90 ring and pinion sitting in my garage for over a year now and just haven'y gotten around to installing them. Mind if I ask how much they charged you to do it? Thanks and congrats.
Very interesting, I think a gear change is a great Idea. Might as well use the power we have. 390's sound nice. Are they expensive to get put in and will they void a warranty, i imagine so. Are they the same 8.8 ring and pinion as a live axle? Looks like I have found my new mod. anyone know of any installers in the Abilene, Dallas/Ft. Worth area?
SWEET94COBRA said:
they will never know that the gears are in to void warrenty.. and i paid 500 installed for them..
they dont whine or howl.. x2c owner runs them in his car... if they were bad he wouldnt do it!!
i love them.. my tq is incredible
my biggest spectic was Dgussin1 he thought it was a bad idea..
so tonight he drove my car.. and was dumbfounded... he loved them... and thought my car accelerates ALOT faster than ever.. he drove my car before the gear change.. and now says my car feels much faster than before
lovin the gear change
MArc
so tonight he drove my car.. and was dumbfounded... he loved them... and thought my car accelerates ALOT faster than ever.. he drove my car before the gear change.. and now says my car feels much faster than before
lovin the gear change
MArc
I wonder how the change will read on the dyno? Glad to hear you are so happy with them.
OATS said:
i have motive's also..no whine
SWEET94COBRA said:
damn...i havent been in my car in month or so and im drawing a blank..i wanna say 75 is about 2500 in 6th
The only thing the gears will change on the dyno is that you'll experience a little more inertial loss from the drive train. Other than that, it makes NO difference. The dyno uses engine rpm to calculate torque. Even though we call it rear-wheel torque, it's not...it's torque at the flywheel assuming a lossless driveline. And except for that small inertial loss, power is unaffected by a gear change (conservation of energy.) The 3.90 would be a great gear in these cars. I've considered it myself.SWEET94COBRA said:
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75 mph with 3.90 gears in 6th gear (.63) with stock height tires (~25.7") is a calculated 2410 rpm.
The same ring and pinion fits either an IRS or live axle rear end.
A competent, experienced tech should be able to install the gears so that there is NO whining. Of note, if they whine when they are first installed, they'll likely whine forever.
Personally, I'm still debating 3.90s or 4.10s for my car when I swap to the live axle, and will likely not make my decision until I'm ready to actually order the gears.
The same ring and pinion fits either an IRS or live axle rear end.
A competent, experienced tech should be able to install the gears so that there is NO whining. Of note, if they whine when they are first installed, they'll likely whine forever.
Personally, I'm still debating 3.90s or 4.10s for my car when I swap to the live axle, and will likely not make my decision until I'm ready to actually order the gears.
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I called x2c motorsports and they use pro 5.0 gears. I'm going to order some this week but haven't decided which brand.
Looks like I have found my next mod!!!
After reading this I am really leaning towards doing this now. Sounds like a great mod. :rockon:
Hmm
See the lower gearing seems like the right thing to due but what if your running the juice or making alot more pwr. I don't think my car would finish the 1/4 or that it could hook on the street with the 390s. But on the street I guess I could just use the juice in second insted of first.
See the lower gearing seems like the right thing to due but what if your running the juice or making alot more pwr. I don't think my car would finish the 1/4 or that it could hook on the street with the 390s. But on the street I guess I could just use the juice in second insted of first.
I'm not a street racer, so I can't help you there.
The basic theory with gearing is to gear the car so that the finish line rpm is several hundred above peak HP in 4th gear as you cross the lights.
For example...if you're peak HP is at 6200 rpm, you likely want to gear the car to finish the 1/4 mile at ~6800 rpm in 4th gear. There are other things to think about, and that is a simplistic explanation that doesn't take actual tranny gearing or the HP curve into account, but it is a decent rule of thumb to go by.
Be advised that this is a drag strip theory that assumes adequate traction and aggressive driving.
Bob
The basic theory with gearing is to gear the car so that the finish line rpm is several hundred above peak HP in 4th gear as you cross the lights.
For example...if you're peak HP is at 6200 rpm, you likely want to gear the car to finish the 1/4 mile at ~6800 rpm in 4th gear. There are other things to think about, and that is a simplistic explanation that doesn't take actual tranny gearing or the HP curve into account, but it is a decent rule of thumb to go by.
Be advised that this is a drag strip theory that assumes adequate traction and aggressive driving.
Bob
I often thought about going with a set of those gears but never did it. Sounds like they're really waking up that ride! I'd be interested to see how your gas mileage is affected. Have fun!
That may be good advice, however, I'd like to ask how you came to that conclusion? What do you base it on?WS6JJP said:
CobraBob said:
Gas seems to be the same!!
im telling you guys, my car is accelerating so much faster, i cant believe this!!!
Side note: i would never change gears if using nitrous/Kb/Whipple!!
There is no need, you have 600rwhp and you need all the traction you can get..
gears are for pullied/apten cobras.. that way we can keep up with the kb guys at the track... :coolman:
On the highway, kb guys will own...
Marc
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