Effects of gearing vs. speed
Effects of gearing vs. speed Quick question for all you hardcore guys.
I'm gonna be making enough power here shortly to be trapping low 120's. It will be on N20.
Currently have Nitto 275/40/17's and 3.73 gears. Car is an A4 with a TCI 4000 converter. Tires would be 25.7" tall.
Gonna build my axle to race this season. Was wondering if I needed to step down a ratio to 3.42's so that I don't hit the rev limiter when I'm crossing the traps.
Gear calculator says that in 3rd with the 3.73's 6000 rpm would be 123mph.
In 3rd with 3.42's would be 142mph. Of course that's not taking converter slip or tire growth into account.
I have future plans with the car to go even faster within the next year or two, into the 130-135 range. Would it be worth it to me to change ratios? Would it change how hard the car launches or how it does off the spray?
Oh, and before anyone asks, I don't have tuning software currently, but it's on the short list, so I would have my tuner change the gear ratio, but I wouldn't be able to change tire sizes quickly, so I couldn't run the Nittos on the street, and then a 27" or 28" at the track.
Any advice would be welcome.
I'm gonna be making enough power here shortly to be trapping low 120's. It will be on N20.
Currently have Nitto 275/40/17's and 3.73 gears. Car is an A4 with a TCI 4000 converter. Tires would be 25.7" tall.
Gonna build my axle to race this season. Was wondering if I needed to step down a ratio to 3.42's so that I don't hit the rev limiter when I'm crossing the traps.
Gear calculator says that in 3rd with the 3.73's 6000 rpm would be 123mph.
In 3rd with 3.42's would be 142mph. Of course that's not taking converter slip or tire growth into account.
I have future plans with the car to go even faster within the next year or two, into the 130-135 range. Would it be worth it to me to change ratios? Would it change how hard the car launches or how it does off the spray?
Oh, and before anyone asks, I don't have tuning software currently, but it's on the short list, so I would have my tuner change the gear ratio, but I wouldn't be able to change tire sizes quickly, so I couldn't run the Nittos on the street, and then a 27" or 28" at the track.
Any advice would be welcome.
Rewire your speedo sendor to your front ABS wires. I did this for my th350 swap and I can swap rear tires no matter what size difference.
Also if you are going to run a 28" tall tire for the track, do just that, use it ONLY at the track. It won't mess with anything but your speedometer, and you shouldn't even have your eyes on it going down the track. (That is if you don't rewire your speedo)
Also if you are going to run a 28" tall tire for the track, do just that, use it ONLY at the track. It won't mess with anything but your speedometer, and you shouldn't even have your eyes on it going down the track. (That is if you don't rewire your speedo)
Rewire your speedo sendor to your front ABS wires. I did this for my th350 swap and I can swap rear tires no matter what size difference.
Also if you are going to run a 28" tall tire for the track, do just that, use it ONLY at the track. It won't mess with anything but your speedometer, and you shouldn't even have your eyes on it going down the track. (That is if you don't rewire your speedo)
Also if you are going to run a 28" tall tire for the track, do just that, use it ONLY at the track. It won't mess with anything but your speedometer, and you shouldn't even have your eyes on it going down the track. (That is if you don't rewire your speedo)
i went to the track last night to make a few passes with my new 4000 stall. I also have 3.73's and i was crossing the traps at 109mph at 6100 rpm. On a that same tire size also. Im confused.
I've gone 114.5 @ 6000 before. I swear I've hit the limiter at 113 due to converter slip before in the warm weather.
Trending Topics
TECH Regular
Joined: Sep 2008
Posts: 425
Likes: 1
From: Scottsdale, Arizona
Check into a high growth tire. We did that years ago on our dragster and changed from a 3.90 gear and went to a 4.10 with a high growth tire. That helped all thru the quarter mile.
I'm just not sure if they make them for your application though. It would be worth checking into though.
Here is a pic of my car.
I'm just not sure if they make them for your application though. It would be worth checking into though.
Here is a pic of my car.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
when i went from a stock stall to a ss3600 i gained 1mph at the track with all conditions and everything taken into account...you should gain or stay the same with a good aftermarket converter...
now with a cheaply made converter or a fuddle type you are not going to be as efficient...and will lose mph...this is the exact reason i went with yank
be careful that is not true for all lines of converters...
when i went from a stock stall to a ss3600 i gained 1mph at the track with all conditions and everything taken into account...you should gain or stay the same with a good aftermarket converter...
now with a cheaply made converter or a fuddle type you are not going to be as efficient...and will lose mph...this is the exact reason i went with yank
when i went from a stock stall to a ss3600 i gained 1mph at the track with all conditions and everything taken into account...you should gain or stay the same with a good aftermarket converter...
now with a cheaply made converter or a fuddle type you are not going to be as efficient...and will lose mph...this is the exact reason i went with yank
EDIT: Duh, look at your sig. I'll probably step down to 3:42's now.
i am shifting around 6600-6700 and am leaving some on the table being 3.23 gears but i am not going to make the 10 bolt any weaker with 3.73s, when i get a 12 bolt i will definitely be getting some 3.73s...4.10s if i go with a 28" tall tires...
i used to shift my SI at 6300...
i think right now i am going through at 4900ish i believe...
...if you got 3.73s in now i would just keep them you should be fine