Re: Gears - to answer the questions once and for all
 

u guys are all wet about gears in a auto to a manaul . if u had 4.10 in a manaul you would need to go with 4.30 and a 3000 rpm stall in a auto . to get the same feeling as the 5 speed with 4.10

Re: Gears - to answer the questions once and for all
 

I dont know if this matters but i was bored and put in 275/40/17 in the rpm calculator. And the Mach1 trans gear ratios. To see how right this is, and with 3.55s the shift points where at these mphs 43, 73, 111, 147, thats redline for 1, 2, 3, 4. and with 4.10s 37mph, 64, 96, 127. I just wish i knew how tall in inches my tires/wheels were. Because 4.10s look good but on a taller tire, i think 4.30s would be great for a track focused car. 4.30s shift points were, 35, 60, 91, 120.

But my question lies in, what if you had enough HP with 4.30s to trap higher then 120, then youd have to shift into 5th before the traps? Or get a taller tire and how much does a taller tire help?

I just never saw the point of people not liking gears. Im in NY most speed limits are 55 or NJ 65 is the most i see. with 4.56s at 70mph your at 2500, at 65mph its 2,400, 60mph its 2,200 and 55mph your back to 2k rpms. I know everyone doesnt go the speed limit. Im not saying i do or most the NY driver son the thruway. But its nothing soo insane that makes the car unstreetable because of how low our overdrive is. A lesser gear like 4.10s would be even less. So to sum it all up, I give thumbs up to gears. Untill im heavly boosted ill be behind at least 4.10s, after boost ill try 3.90s and lower.

Re: Gears - to answer the questions once and for all
 

usually get a taller tire. however, by the time machs make power to trap higher than 120, they'll have a healthy power adder, and whoever did that decision probably didn't go with 4.30s or plans on putting lower gears on it... guess it depends just how far above 120 they are. shifting into 5th would most likely kill your time and make you drop below 120 :p

as for the 4.30s being for a track focused car, i disagree. mine's a daily driver, and it'll be a while till I max out these gears with 120 mph traps...

Re: Gears - to answer the questions once and for all
 

Ya I knew the taller tire helps, i just didnt know how much an inch does. Or how Tall our tires are from ford. I know top of 4th is where you want to be, so instead of checkng out what mph top of 5th what they did. (because they were checking the topend lose) i checked out 4th. You fixed up what i wanted to say about 4.30s and 4.56s being more of a non power adder gear. I didnt mean you cant daily a car with 4.30s i checked out 5th gear at a bunch of different mphs to show more rpms. But i did make it sound like that, sorry.

Re: Gears - to answer the questions once and for all
 

a 28" tire vs a 26" tire will be the rough equivalent of going down 1-2 steps... with 4.30s it's more like 3.90s if i'm not mistaking.

too lazy to do it now, but here, you can use this, find a 28" tire size, and plug it into the first calculator:

http://www.miata.net/garage/tirecalc.html

Re: Gears - to answer the questions once and for all
 

So 3:73's or 4:10's in a 5spd mach???????? For street use only.

Re: Gears - to answer the questions once and for all
 

On the street, 4.10s feel great, except you may find you are doing the 1-2 shift before you get across an intersection during normal driving. That can be annoying. So 3.73s might be a good compromise for a street car, but the small difference over 3.55s is barely worth it, unless you are doing the work yourself. Neither the 3.73s nor the 4.10s will make you quicker in the 1/4 mile, because they cause a 3-4 shift before the traps. So if you are ever running a bolt-on, non-power adder car at the track, stick with 3.55s or go all the way to 4.30s.

With all that said, with a power adder, 3.90 or 3.73s are about right. I removed my 4.10s in preparation of adding a Vortech. Now that the blower is on, I see that I need a bit more gear than the stock 3.55s. The car pulls extremely hard, but you have to be going 80-100 mph to get that freight train feel. With a bit more gear, I think that will happen at more sane speeds, say in the 60-80 range. For instance, my car walks all over my buddy's '04 Cobra, but not until we get to about 80-90 mph. Until then we are fairly close from a roll (off the line I get him easily then never look back).

So the short version from my perspective:
mild bolt-ons, no track: 3.55, 3.73, 3.90, or 4.10
mild bolt-ons, no power adder, some track use: 3.55 or 4.30
cams, headers, ported heads, possible stroker, no power adder, street & track: 4.10
stock longblock + power adder: 3.90s or 4.10s

Fire suit on.

Re: Gears - to answer the questions once and for all
 

Somebody might want to double check my math here but going from a 26" tire to a 28" tire is roughly an 8% increase. So if you up the tire by 8% you drop the gear by 8% so that would effectively turn 4.30's into the ballpark of 3.90's. Closer to like a 3.98 so I guess we could say that 4.30's with a 28" tire would put you between a 3.90 and a 4.10.

Some reason that just seems a bit off so please someone double check my math and let me know if I screwed it up somewhere.

Re: Gears - to answer the questions once and for all
 

Not if you are already shifting into 4th with 3.55's, which I am doing and I'm stock.

Re: Gears - to answer the questions once and for all
 

[Why wouldn't you do a full throttle run in overdrive to get top speed? I bet it would be around 160+. I know you don't need overdrive on the drag strip.]


Powershifting into Overdrive is risky. Your trying to overdrive the transmission output shaft at full power...This takes Torque! Every bit the engine can muster to spin it faster than the crank. I have a friend with a built 300Z twin-turbo who blew his motor doing just that. Ease it into 5th or 6th, then roll on the throttle till your floored. Overdrive is not intended for accelleration.

Re: Gears - to answer the questions once and for all
 

Pretty nice MPH in the 1/4 for "stock"

:33:

Re: Gears - to answer the questions once and for all
 

Thanks! I did have the Cat-back though, but close enough ;)

Re: Gears - to answer the questions once and for all
 

Why would you say 4.10's with a manual wouldn't be enough?Why the 4.30's?

Re: Gears - to answer the questions once and for all
 

I would say 4.30s for an auto if we didn't have to turn off OD to make a full throttle pass. With a manual, you effectively have two more gears than we autos do.

Re: Gears - to answer the questions once and for all
 

Hey Fosters,so do you think 4.30's are the way to go?My friend has 4.10's in his 03' Mach and He runs a 12.5 @ 110 I didn't know if I got 4.30's and ran about the same time how much would my MPH be off from his?I just didn't know if 4.30's were to much or not.I really want a good ET time and a MPH in a 1/4.:OUCH:

Re: Gears - to answer the questions once and for all
 

Search, my friend.
But yes, from what I've seen, 4.30s, slicks, exhaust, CAI, and tune = solid mid 12s. :soapbox:

Re: Gears - to answer the questions once and for all
 

im droping in a viper t-56 in my automatic mach this winter and the gear ratios are as follows.

1st 2.66

2nd 1.78

3rd 1.30

4th 1.00

5th .74

6th .50

i was planning on doing 4.56's.... but that equates to a 3650 with 3.73's roughly. should i go steeper? i think motive sells 4.88'sshould i go with those or the 4.56's?

Re: Gears - to answer the questions once and for all
 

If you go steeper I don't know how you'll ever manage the 1-2 shift. It's already gonna come up in a hurry after launch.

Re: Gears - to answer the questions once and for all
 

i think redline is 36mph in 1st w/ the 4.56's

Re: Gears - to answer the questions once and for all
 

Everybody raves about 4.30 gears but what about gas mileage? My 04 is basically my sole transportation and i want improved acceleration, i had 3.73 in my 02 gt, but i cant afford really crappy gas mileage. My gt got roughly 18mpg which is doable but i cant handle too much worse. Any input would be helpful.

Re: Gears - to answer the questions once and for all
 

With the 4.10's and a 5 speed, the gears almost help the mileage. You can use 5th more easily around town. If you're doing mostly highway miles then stick with the 3.55's.

All this goes out the window if you can't keep your friggen foot out of the pedal.

Re: Gears - to answer the questions once and for all
 

sounds good to me

Re: Gears - to answer the questions once and for all
 

Am I wrong or isn't the floor supposed to stop the pedal????:confused:

Re: Gears - to answer the questions once and for all
 

ok so ive read alot of what you guys know bout gears, and it seams to make since and there is a wealth of knowledge in these threads. My question is, would using a tall gear such as (3.08) be outa the question? my situation is that im very close to the end of the 1/8th n still have to shift to 3rd. would the 3.08 kill everything n have me slower, or would it help out. a friend had a 89 lx 5.0 with few bolt-ons and 3.08's n he could get a 14.00 in the 1/4 at just over 100mph. then drive home getting 26-27mpg. im sure not wanting 14.00 outa my car but i figure the mach is a better car than the 89 lx so if finishing the track with less shifts gets it down the track wth. what do you guys think?

Re: Gears - to answer the questions once and for all
 

You want to ditch your 3.55's for 3.08's? Your going the wrong way. Bone stock your car should run mid 13's. I think your a little confused on what your dealing with.