I know this is about a Stang but please bear with me. Look at my mods in the sig. I am planning gears soon. I am wondering how many tenths and mph, 3.73, 3.90, 4.10, and 4.30 gears will give me in the 1/4 mile with my current mods? 3.73 gears are great for top speed and a daily driver. 4.30 gears are best for the dragstrip. I was just wondering what the difference would be between all these gear ratios at the strip. Anybody know? Thanks in advance.

 

I have heard gears knock off UP TO .5 of the 1/4. So my guess would be somewhere between .2 and .5 off.

If you have a 5-speed I would go with 4.10's or 3.90's. If you have an auto, I probably wouldn't go over 3.73's.

I wouldn't get 4.30 gears unless you have a 5 speed AND you motor is modified to rev really high (7000rpm+). Traction would really become a big issue too. On a stock/near stock motor, 4.30's would probably slow you down.

Just my opinion.

 

You're 0-2. Not only is this not about an F-body, but it's in the wrong forum too.

Dyno'd the car? For optimum acceleration performance gear the car to cross the line at peak HP in 4th gear. But generally 3.73s or 4.10s would be a good choice. 4.10s would put you right around 105 MPH in 4th gear at 5500 RPM (near your peak HP). IMO 4.30s would be too much gear. They're better suited to a DOHC car.

 

I heard that you are supposed to gear the car to be near redline in 4th gear at the traps for max 1/4 mile power. My redline is 6000 rpm, my rwhp peak is 5000 rpm. I have a 1 to 1 4th gear and should trap about 103 right now.

 

Not redline per se, but peak HP. Most engines are capable of revving past their peak HP RPM. I can rev my engine to 6500 if I want. But its pointless, as my peak HP occurs at 5500RPM.

Regardless of what others say, you can gain a few MPH from better gearing. Optimal gearing should add another 2-3MPH to your traps.

For a targeted 105MPH trap, and a peak HP occuring around 5000RPM, 3.73s would be perfect. All this is assuming a 26" diameter tire (stock diameter).

Steeper gearing would cause you to either shift into 5th gear, or more likely spin past your peak HP. Not only that but 4.10s add more mechanical torque to the wheels than 3.73s, increasing any traction problems you might have.

 

Trouble is I race at 4000' elevation most of the time and I only trapped 96 mph the last time out. I expect to trap about 98-100 with gears and the other mods I have added since then. I also have very sticky BFG DRs that I don't spin AT ALL with right now. Would 4.10s be better considering these facts?