All right guys i need to know from you folks with 3.9 gears if the car feels faster and how is the acceleration and most importantly the quarter mile times with those gears????

 

4.08's are more common because they are cheaper. Need to keep in mind that you want to avoid going into 5th. So if you run a short rear tire and stock rev limit you need to make sure can get there without running out of gear......


STOCK 3.357 Gear-- ECU REFLASH 3.357 ---HR Engine
6600 Rpm Redline --------7200 Rpm Redline----------7500 Rpm Redline

First------40mph ------First-----44mph-----------First-----46mph
Second ----66mph ------Second----71mph-----------Second----74mph
Third------94mph-------Third----102mph-----------Third----107mph
Forth-----120mph-------Forth----131mph-----------Forth----136mph
Fith------152mph-------Fith-----166mph-----------Fith-----173mph
Sixth-----192mph-------Sixth----209mph-----------Sixth----218mph

STOCK 3.538 Gear-- ECU REFLASH 3.538 ---HR Engine
6600 Rpm Redline -------7200 Rpm Redline-----------7500 Rpm Redline

First -----38mph ------First-----42mph-----------First-----43mph
Second ----62mph-------Second----68mph-----------Second----71mph
Third -----89mph-------Third ----97mph-----------Third----101mph
Forth ----114mph-------Forth----124mph-----------Forth----129mph
Fith -----144mph-------Fith-----158mph-----------Fith-----164mph
Sixth ----182mph-------Sixth----199mph-----------Sixth----207mph

No Reflash 3.7 Gear-- ECU REFLASH 3.7 ----HR Engine
6600 Rpm Redline ---------7200 Rpm Redline---------7500 Rpm Redline

First -----36mph-------First ----40mph-----------First-----41mph
Second ----59mph-------Second----65mph-----------Second----68mph
Third -----85mph-------Third ----93mph-----------Third-----97mph
Forth ----109mph-------Forth----119mph-----------Forth----124mph
Fith------138mph-------Fith-----151mph-----------Fith-----157mph
Sixth-----174mph-------Sixth----190mph-----------Sixth----198mph


No Reflash 3.9 Gear -- ECU REFLAH 3.9-----HR Engine
6600 Rpm Redline ----------7200 Rpm Redline-------7500 Rpm Redline

First ------35mph-------First ---38mph-----------First-----39mph
Second -----56mph-------Second---62mph-----------Second----64mph
Third ------81mph-------Third----88mph-----------Third-----92mph
Forth------103mph-------Forth---113mph-----------Forth----117mph
Fith-------131mph-------Fith----143mph-----------Fith-----149mph
Sixth------165mph-------Sixth---180mph-----------Sixth----188mph


No Reflash 4.083 Gear-- ECU REFLASH 4.083--HR Engine
6600 Rpm Redline ------------7200 Rpm Redline---------7500 Rpm Redline

First ------33mph--------First ---36mph----------First-----38mph
Second -----54mph--------Second---59mph----------Second----61mph
Third ------77mph--------Third ---84mph----------Third-----88mph
Forth ------99mph--------Forth---107mph----------Forth----112mph
Fith ------125mph--------Fith----137mph----------Fith-----142mph
Sixth -----158mph--------Sixth---172mph----------Sixth----179mph

Keep in ind this is with a 255/45/17....if you use a shorter rear tire it will effectively raise the gear ratio.

 

I'm still trying to learn about gearing but why do you want to avoid going into 5th gear?

 

Slows you down. 5th is a long gear.....also adds the time of another shift. Even the bigger power guys tend to go to a 3.3 gearset and taller tire to avoid it.

 

I knew something didn't look right...

Forth ------
Fith ------

Fourth / Fifth - Good info though.

 

For a drag racer I am surprised that you do not understand the relationship between gears, tire size and horsepower and ET. What in particular do you not understand?

 

All right guys i need to know from you folks with 3.9 gears if the car feels faster and how is the acceleration and most importantly the quarter mile times with those gears????

People with gears i need some help plz guys, i already know im not gonna go in 5th gear with these gears. Is it worth it? how is the acceleration? will i get better times?

 

The answer is simple. A 2 or 3 speed automatic transmission would be choice but cost prohibitive. So we have to stick with the 6 speed manual (certainly far from ideal for drag racing).

At what RPM are you crossing the 1,320 foot line? 5,000? 6,000? Can you push the RPM higher without an additional shift? That is why 03threefiftyz posted the numbers. If you have an additional 1,000 or 2,000 RPM at the finish line, AND the motor is making horsepower, than gears are for you.

And as 03threefiftyz mentioned, members have gone with 4.08 gears forcing an additional shift before the finish line. In general this will hurt ET.

 

Asking people what they run with THEIR gears and setup is not a good indicator of what YOU would run.

What do you run now with your mods?

If you suck a$$ at driving now the gears will exploit your weaknesses, and the other way around if you are good and can use them from the launch to the end of the track.

I see you have 280whp, if you havent run 12's yet Id go ahead and classify you as "no bueno" In that case you should look at effectively laying down your power now, before you start multiplying it further and have even more trouble launching and/or keeping up with shifts.

 

280whp on the church dynopack is NOT 280whp.......just sayin'.

 

I have no idea where he dyno'd but if it was Churches I agree with you. Either way call it 260 legit whp he should be nipping at 12's or in the 12's.

 

Ok lil kiddie before posting this do some research before postin BS, i would like to see your *** come down here in AZ and get a better time than me in ANY CAR you want, ill seat in your turboed Z and im pretty sure buddy i would get a better time. Anyways thx guys for the help, i really wanted to hear it from folks with the 3.9 gears.

 

Lol 605rwhp and you run a 11.1 IN A 0 ELEVATION TRACK haha buddy its all good

 

Bro, no need for hostility. Your runs were made at a DA of only 1500'. You aren't running at Bandimere or something. Also, berto's runs were made at ~500whp I believe.

 

Okay, first off, Alberto broke no rules, and so far, neither did you but then again thats questionable!!! so from here out keep it clean or go home, easy as that.........

I don't blame his response because your post in this thread leading to it, show a lack of understanding the technical know how that any drag EXPERIENCED individual would grasp and understand and a post like this screams newb in all aspects..........

you also haven't answered any of the dammn good questions that those that are helping you asked - in order to help you........if immediately ignored them and decided to ethug out alberto.......

my speculations for this thread - no one with any good know how will help you "NOW"

-J

 

I posted the above info so that you (speeddemon20) can make an informed decision on your own.....its common sense really. Thus, I agree with Jason.

 

all i know if i was with yall kiddies in east coast i would be breakin 12's and still not be in low 13's like some of yall in east

 

not to even mention runnin 93 octane like you guys do haha

 

Really? I've run much faster than you in similar DA's.........

 

ill keep yall posted on my runs in the winter when i have a good clutch, 13.6 on a slippin clutch is no good for me and mixed with hot weather and stuff.