Posts: 13326
Joined: 12/29/2003 From: Southern California Status: offline
Here ya go. Ask your rear gears and possi questions or add your opinions and knowledge about gears and possi here. Two common types of possi are limited slip and T-lok both equally as good as the other.
Posts: 5579
Joined: 8/3/2005 From: Los Angeles, CA (SoCal) Status: offline
Lets make things simple:
Rule of thumb: Manual/Stick go for the 3.73's or the 4.10's for more aggressive driving Auto do 4.10's.
(the higher the gear ratio...the higher rpms will be at a given speed. Say for example you are in 4th gear doing 65mph and at 2200rpms with your stock gears...3.73's may push it to 2700rpms....and 4.10s may go to 3000rpms) ***JUST EXAMPLE....not accurate***
** Please do not ask about "gas mileage" when changing gears. If you are worried about that, then do NOT modify your mustang. PLUS it only effects the mpg IN A SLIGHT MANOR"
Every single application of gears will need a TRACTION LOCK (tlok).
What is a tlok? Well to put it SIMPLE...when you take off on the v6 mustang and all the power/pressure is pushed to ONE tire in the rear, what the tlok does is equalizes the power to BOTH of the rear tires. In summary, when you take off you get BOTH tires to spin, whereas without the tlok you only have ONE tire spinning. BOTH TIRES = TRACTION. This "tlok" goes in where the gears go..so when changing gears it would be DUMB if you don't get a tlok as you save DOUBLE labor later.
What do gears do? Basically the change the ratio in the rear end.
In essense it makes your rpms raise up much faster. Meaning when you take off in first gear you can rest assured in about 1-2 seconds 1st gear will be GONE and you will be going into 2nd gear. Now why would that be good? Well 2nd and 3rd gears are your POWER gears....so putting on gears allows you to reach what they call the "POWER BAND" much faster. Reaching the power band allows your mustang to get going a bit faster.
Remember that gears/tlok do NOT add horsepower to your mustang...they add traction abilities. They allow your mustang to get to the MAX power faster. SO the more mods you add with gears the BETTER the outcome.
When installing gears/tlok it is ESSENTIAL to get a ring & bearing kit. What this will do is replace all the ring & bearings inside the rear end...which will ELIMINATE ANY whine that you may get when you swap gears out. If you don't get this kit you are at risk for driving around and hearing an ANNOYING whine in the rear end every single day you drive it.
94-98 mustang need to get a 23 tooth speed calibrator to fix your speedometer...as it will be completely out of sync. So when you are going say 20mph it will read 50mph! When you install the gears/tlok just hand it over to the installers and they will know exactly what to do. ITs about $25 from STEEDA (where I got mine)
99-04 Mustangs need to get a programmer to reprogram their computer. There are many types of reprogrammers to pick from and run about $400 each one. But this will allow you to fix the speedometer and will also remove the rev limiter and allow for small adjustments to allow the car to pick up more acceleration/power, etc.
Recap: Gears make rpms go faster, letting you get the POWER in your stang faster. If you change gears, you NEED to get a tlok at the same time. 99-04 need to reprogram computer, 94-98 need 23 tooth gear.
Here are some COSTS for parts: (average) $200 gears $200 tlok $70 bearing kit $200-$250 installation $400 programmer (99-04)
Total cost you are looking at about $1000+
Not a cheap mod....but one AMAZING one on the mustang. You will NOT regret getting gears.....believe me :)
< Message edited by Autobadges.com -- 10/22/2005 5:23:46 PM >
DEFINATLY worth the money!!! Just a couple of things Eric didn't mention. DON'T get the cheap gears. FFRP are the best for your car. And, I HIGHLY recommend using Royal Purple Dif Fluid. Use the best. If you can't find Royal Purple, look for RedLine. Last thing. You will NEED to add a Friction Modifier to your dif fluid. And you will have to add it any time you change the fluid.
< Message edited by 03YellowPony -- 10/22/2005 8:28:27 PM >
I do want to say one thing about the tlok. Mustangs come stock with an open differential. Open differentials are very simple, just an assortment of gears that connect your drive shaft to your rear wheels. They allow the wheels to rotate at different speeds in a turn with the engine power being diverted to each. When you have traction, just driving around, mustangs have power to both wheels. So don't think only one of your wheels is working. The right wheel however, it looses traction easier than your left wheel. This could be because of engine torque or weight distribution, but thats not important. What is important, is when one wheel looses traction in an open differential, all power will be transfered to that wheel. And in mustangs, that is the right rear wheel. So when you launch hard, your right rear wheel will have all power and no traction, your left wheel will have all traction and no power. You will just inch ahead as your right tire is struggling to grab on.
So why don't we just glue the right and rear wheels together? We would launch will full traction every time. But then we couldn't turn very good. The site above explains this in depth. So we have to find a comprimise between both.
That where a tlok comes in. A tlok, to put it simply, is just a big spring with sticky discs on either end of it. You stick that in a differential, and wallah. The sticky plates try to keep both wheels spinning at the same speed, but they can slip if needed, for example, turning a tight turn in a parking lot. This keeps both wheels 'locked' during a launch increasing your traction and solving the right rear tire problem. The problem with tloks are that the 'sticky discs' or 'clutch pads' wear out eventually and need to be replaced.
There are other differentials that don't wear out but these are mechanical not friction, they are more expensive and bigger. (I think the Hummer has these)
Posts: 13326
Joined: 12/29/2003 From: Southern California Status: offline
quote:
99-04 Mustangs need to get a programmer to reprogram their computer. There are many types of reprogrammers to pick from and run about $400 each one. But this will allow you to fix the speedometer and will also remove the rev limiter and allow for small adjustments to allow the car to pick up more acceleration/power, etc.
Just a side note to the above. Although a programmer or custom chip is the best thing to do when you change your gear ratio, it's not your only option. Most shops will flash your stock chip for around 75 bux or free if they did the gears and possi. Gears and possi are one of the more expensive bolt on mods and alot of people don't have the extra 200 to 400 bux after the install, so ask your shop if they will flash your chip in the price.
< Message edited by HotRods_n_Booze -- 10/23/2005 2:56:31 PM >
Posts: 5579
Joined: 8/3/2005 From: Los Angeles, CA (SoCal) Status: offline
Chris:
You are actually very right....sometimes I have seen GTR High Performance use these actual programmers with their customers to have them running good and don't make them buy the whole unit...they are so awesome.
Posts: 17
Joined: 11/4/2005 From: Mount Laurel, NJ Status: offline
I just had 3.73 gears put in my manual 1993 mustang GT. I bought the speedometer gear and the transmission gear to go along with the gears to make the speedometer correct but the guys at the shop only put in the speedometer gear. They said it would be much more expensive to put the transmission gear in. So my question is if i didn't put either speedometer gear or transmission gear my speedometer would be reading much faster than i'm actually going correct? Well what happens when i just put in the speedometer gear? is it going to make the speedometer read only slightly faster than what i'm going?
For my 04' manual, would you guys suggest the 4.10's or the 3.73's. I saw somewhere in another thread someone talking about the 4.10's not being good on a manual? What do you guys think?
Posts: 11578
Joined: 9/19/2005 From: Pearl River, Louisiana Status: offline
OK here's my updated post now that I know much more about gears than I did a year ago.
First of all I'll fill in some vauge parts Erick and Harv left out.
94-98s have a 2.73, stock, gear ratio. Which, as stated earlier, means that per every 1 tire rotation, the driveshaft turns 2.73 times. I would personally recommend 3.73 gears for ALL 94-98s, your driveshaft will be making 1 whole turn more than it used to, and the difference will be more than noticible. Don't ask me why, but several people, since this thread, installed 4.10s on their 94-98s, and had some slight mpg and engine issues. So I say go 3.73 and keep it safe, like I said, you'll deffinitly notice a difference.
99-04s have a 3.27, stock, gear ratio. Now here's my take on the situation, if you do a lof of hwy driving, and you don't race much, then get 3.73s. When you do race, hopefully at the track, you'll have excellent off the line contol, and trust me, you'll notice a difference over stock. If you do a lot of racing, and not much hwy, or just plain out do a lot of both and don't care about how mpg can be effected, like Harv, then get 4.10s. 4.10s will, however, make a manual much harder to control when launching, so pretty much, as stated, stick to 4.10s for an auto.
In short, 3.45s are good for a totally street car, they will only yield a little more accelleration than stock, however once you get into higher power areas they'll allow for excellent off the line traction and decent accelleration throughout the powerband. 3.73s, steeper incline over 3.45s for better accelleration after you get off the line as they will cause a little more traction issues with higher powered manuals, and they will burn a hair pin more fuel but they generally are the gear of choice for most manual drivers. 4.10s, more racing and track intended (autocross), but are also still street worthy however some manual drivers will experiance a hard time controling the car off the line due to an extremely steep and short first gear.. All in all your mpg, driver pending, will drop 1-2 mpg over stock with 3.73s, and 2-4 mpg with 4.10s.
< Message edited by jthorn9 -- 5/8/2008 4:27:58 PM >