Question for drag racers
So, with 3.15 gears, 12.86. I know there are lots of variables, but how much do you think I could shave off with 3.55 gears?
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As you state, there are too many variables.
If you have the torque to handle the 3.15 ratio, you may not save a whole lot overall, though you will be a faster start with the 3.55s.
How many gears in your transmission?
What gear are you in at the end of the run?
What RPM are you running at the end of the run?
I would guess that a 3.55 ratio will require you to shift at least one additional time. Does the added torque at the line give you enough of a boost to justify an extra shift?0 -
It's a six speed automatic, I am on on 3rd gear when I cross, no idea on the rmps, but it is likely about to change in the 4th (sounds like it) [:I] 0 -
quote:Originally posted by nutfinn
It's a six speed automatic, I am on on 3rd gear when I cross, no idea on the rmps, but it is likely about to change in the 4th (sounds like it) [:I]
I can't guess how much time you would save, but with an automatic finishing in 3rd gear, I would think you would shave a noticeable amount off your overall time.
If everything it tuned and time correctly, you can theoretically put 12% more torque to the rear tires throughout the run. While you won't see a 12% reduction in your time, it may be possible to see something approaching 10%, which would put you around 11.5 - 11.6.0 -
Thank you Sir [:)] I was hoping something like this. 0 -
If you are only in 3rd then you can do much better. Lot's of power wanting to be let loose. I used to know the formula ect. but that's been a long while.
I had a big block with 4:11 gears in a 4 speed manual and it went across at 6000 rpm so your six speed auto and motor would need something to the right of that. ?0 -
Think now you will start running into traction Problem's. 0 -
quote:Originally posted by grumpygy
Think now you will start running into traction Problem's.
I am hoping I won't0 -
Next question [:)]
- would you go with a used (33k miles) entire rear end, like this delivered to my house for $950? Just planning on using the differential. Selling or keeping the rest for spares??
- or with this one, for about the same price?0 -
Get the Ford unit, there isn't any "unknowns" there. I assume that it's new or re-manufactured? Either way, break it in, and fluid change before you hammer it on the track. 0 -
quote:Originally posted by TRAP55
Get the Ford unit, there isn't any "unknowns" there. I assume that it's new or re-manufactured? Either way, break it in, and fluid change before you hammer it on the track.
It is brand new0 -
YOU WILL DO MUCH BETTER YOUR 6 SPEED WITH A HIGHER NUMBER REAR SOMETHING LIKE A 411 THE BEST WOULD BE ALMOST RED LINE IN rpm IN FIFTH GEAR FOR DRAG RACING BUT GAS MILEAGE WILL SUFFER ON THE STREET T 0 -
Ford will probably have break in instructions with it. The first fluid change is important, and it needs to be drained, as in rear cover off to do it right. It needs to be cleaned out after the break in, and install a magnetic drain plug while you're at it. Don't let some lube place suction it out and refill.
Is that automatic 6th gear an overdrive?0 -
I just ordered the differential, I will let you know how it does. Also ordered the friction modifier 4 OZ that they recommended. 0 -
quote:Originally posted by perry shooter
YOU WILL DO MUCH BETTER YOUR 6 SPEED WITH A HIGHER NUMBER REAR SOMETHING LIKE A 411 THE BEST WOULD BE ALMOST RED LINE IN rpm IN FIFTH GEAR FOR DRAG RACING BUT GAS MILEAGE WILL SUFFER ON THE STREET T
Came back to edit and saw Perry Shooter beat me to it. If 6th is OD, and it's street driven, 3.70's might be your best happy medium.0 -
quote:Originally posted by TRAP55
quote:Originally posted by perry shooter
YOU WILL DO MUCH BETTER YOUR 6 SPEED WITH A HIGHER NUMBER REAR SOMETHING LIKE A 411 THE BEST WOULD BE ALMOST RED LINE IN rpm IN FIFTH GEAR FOR DRAG RACING BUT GAS MILEAGE WILL SUFFER ON THE STREET TCame back to edit and saw Perry Shooter beat me to it. If 6th is OD, and it's street driven, 3.70's might be your best happy medium.I agree with the 3.7X gearing! I ordered my 1970 Z/28 Camaro with 3.73 gears and that was one of the best all around rear-ends for the street and strip that I ever owned!0 -
Maybe you can find something here. This is a good site.
http://wallaceracing.com/Calculators.htm0 -
quote:Originally posted by CbtEngr01
Maybe you can find something here. This is a good site.
http://wallaceracing.com/Calculators.htm
Thank you0 -
The ideal is to be topped out IN YOUR HIGHEST GEAR when you hit the traps. If you are still in 3rd you have along way to go to get the right gears. That said you must be able to get the power to the pavement. I ran 5.34 and 5.67 gears in my Boss 302 to hit the traps at 8K in high gear to do that.[8D] 0 -
quote:Originally posted by nutfinn
So, with 3.15 gears, 12.86. I know there are lots of variables, but how much do you think I could shave off with 3.55 gears?
I see you are a neighbor of mine!!![:)]0 -
quote:Originally posted by Jim Rau
The ideal is to be topped out IN YOUR HIGHEST GEAR when you hit the traps. If you are still in 3rd you have along way to go to get the right gears. That said you must be able to get the power to the pavement. I ran 5.34 and 5.67 gears in my Boss 302 to hit the traps at 8K in high gear to do that.[8D]
Actually I was in 4th gear, not 3rd. I had couple of beers in me while I watched the video [8)]0 -
quote:Originally posted by Jim Rau
quote:Originally posted by nutfinn
So, with 3.15 gears, 12.86. I know there are lots of variables, but how much do you think I could shave off with 3.55 gears?
I see you are a neighbor of mine!!![:)]
Where you be?0 -
You'd be well served to go with a high stall torque converter as well. 0 -
If you're only in 4th gear by the time you finish, you're not getting enough traction to the pavement...
Were as hi 12s are respectable, I think your car with its gear ratio can do better evident by the fact that you haven't even got out of 4th gear. Have you thought about stickier/wider tires to get more traction?0 -
Nutfinn, What are you running this time in?
That is the same best time my 70 Cougar Eliminator ran back in 1976.
I had an internally stock SCJ 428 with headers, and a Mallory dual point. Sure wish I still had that car.
Trinity +++0 -
quote:Originally posted by TrinityScrimshaw
Nutfinn, What are you running this time in?
That is the same best time my 70 Cougar Eliminator ran back in 1976.
I had an internally stock SCJ 428 with headers, and a Mallory dual point. Sure wish I still had that car.
Trinity +++
2015 Mustang GT0
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