3.27 - 4.10 Gearing ???

[JBeryleC]

question....

Seems as though everyone agrees that if your gonna do gears then dont waste time with anything numberically less than 4.10's

The question is this...

My '02 GT is bone stock, and 1st gear only last a couple seconds as it is. With 3.27 (stock) gears I believe.

So.. um.. with 4.10's do you not even use 1st gear or what??

I couldnt imagine having an even lower 1st or 2nd gear, doesnt that render them unusable?

seems like changing out 3rd 4th & 5th to a lower ratio (numerically higher) might be a better option. No?
It's a cost thing, I know that... rebuilding a tranny is way more expensive than gearing a rearend. But if someone has the money, why not?

Opinions???

[xxxBlakexxx]

I am going to try to take a stab at this. I hope I am not F-ed up.

With a higher gear ratio, 1st gear will run out sooner as you implied. But, keep this in mind. The difference should be less noticeable at the lower gears because the change is just a percentage.

If with 3.23's you must shift at say 35 mph, with 4.10's it might be 32 mph. The difference is much more at the higher gears. I don't have 4.10's, so this is just an educated guess on the speed.

Also, cars with mods can generally rev a little higher as the car pulls better and rev limiters get raised. This will close the gap on the shift point.

Changing indivudual gears (and this is just a guess) I think would screw everything up. If you shift properly with the stock tranny, you should hit each gear in the power band perfectly, right?

[JBeryleC]

Well heres the deal...

We all know that we have PLENTY of pull in 1st and 2nd, even 3rd... stock!

BUT 4th & 5th have NO pull at all in low RPMS

My goal is to get those gears to have as much power at low RPM's as 1st 2nd & 3rd have.

I dont think you can achieve with with gearing lower (numerically higher) Because you'd be just raising the RPM's throughout the the whole tranny.

I dont want to have a half second 1st gear, ya know?

I think my only option is to cam the motor and build it up more to get more power overall. But LOW rpm torque is what I'm after, NOT high rpm power... we all know the GT has plenty of pull between 2800 and 3000 rpms...

I want more in the 1000-2800 range
A cam and bolt on's will do that

[blue00gt]

Actually, in 1st and 2nd gear is where you gain most of the time in the 1/4 mile by changing gears. It's all about getting the motor in the powerband faster.
As for the example that was posted, if you top out at 35mph in 1st with stock 3.27 gears, you would top out at 28mph with 4.10s (just divide 3.27 by 4.10 and multiply by the speed).
Gears don't change the powerband of the motor, they are just torque multiplication. If you want it to pull more in the lower revs you need to change parts on the engine. Even with steeper gears if you are lugging it at low rpms it's still going to feel slow. The point of the gears is to get your rpms up.
If you want your car to pull more at low rpms you should give up and put a stock 5.0 in it. Mod motors don't really start to pull until near 4k. If you re-cammed your motor to make more power down low you'll just lose top end and end up with a slower car. Sounds like you want a truck or luxury car type motor.

[JBeryleC]

caming it right will give more power all through the rpm range. Gaining low end tq while not losing any highend hp.

Thats the goal

Might just have to go with a twin screw sc.
which would require either a '03+ cobra front k member & suspension or a tall azz hood. lol

We'll see... which ever is cheaper and will give me what I want.

[91LX2Bfast]

Originally posted by JBeryleC
...Might just have to go with a twin screw sc.
which would require either a '03+ cobra front k member & suspension or a tall azz hood....

Someone passed you some bad info. You can bolt-on a Kenne Bell twin screw or any other blower kit for that matter without replacing the K member or hood.

[JBeryleC]

theres not enough clearence there...

the cobra k member is needed to lower the entire engine
or a taller hood to clear the sc

[91LX2Bfast]

What setup are you referring to?

Straight from Kenne Bell site: "Direct bolt on replacement. Connects to stock inlet system. Looks factory. Mounts on top of engine. Fits under stock hood."

[JBeryleC]

I just checked it out. WOW. I had no idea. I was given wrong info.

Thank you much for clearing that up

[xxxBlakexxx]

Blue: Thanks fo r the speed correction.

[explicitone]

4.10s do not still feel slow down low they help get off the line at 1000 or 6000 I can cruise in 5th gear @30(1200) and still pull 5th all the way to what ever with out ever needing to down shift.

yes you can still use 1st and 2nd yes the car will go through these gears faster the same with 3rd and 4th

at time when I dont feel like shifting I will start in 2nd and then shift to 4th and then to 5th no lag at all


it might be that you have a 70mm t/b with the stock plenum is know by almost everybody that it has no gain and will cause you to lose power down low and mid range and jba headers which show no gains at all on a non supercharged car the only thing they do is drain your wallet(blue00gt)

wanted to clear up somethings so all this bad info does not keep getting passed on to other newbes


OH and the k/b twin is made for the 2v motors so the is no need to change the k-member or the hood the only power adder ment for the street that these things might need to be changed is some tubro setups

[JBeryleC]

Well first gear doesnt last long enough for me already, stock. So I wont be doing gears.

I'll just build up the motor to get the lowend I want.

Thanks for all the info

[explicitone]

Originally posted by JBeryleC
Well first gear doesnt last long enough for me already, stock. So I wont be doing gears.

I'll just build up the motor to get the lowend I want.

Thanks for all the info

to bad that you live in ca. cause if you lived closer then I would love to take you for a ride and I know you would change your mind

gears are the best bang for the buck mod for any mustang

[JBeryleC]

Yeah I know all about gears... remember I have the big truck..

went from stock 3.53 gears to 4.10 then to 4.56

Amazing results, but that was on a Jet Performance E4OD tranny

I dont wanna gear the stang like that because I hate how fast 1st gear is over... it's a daily driver.

maybe if it was just for the track then yeah I'd do it.

has nothing to do with gas mileage, its just that I want longer lasting 1st gear

[explicitone]

Originally posted by JBeryleC
Yeah I know all about gears... remember I have the big truck..

went from stock 3.53 gears to 4.10 then to 4.56

Amazing results, but that was on a Jet Performance E4OD tranny

I dont wanna gear the stang like that because I hate how fast 1st gear is over... it's a daily driver.

maybe if it was just for the track then yeah I'd do it.

has nothing to do with gas mileage, its just that I want longer lasting 1st gear

thats cool

to each there own

[blue00gt]

Explicitone,
I'm not sure how much of that was directed at me, but I never said that 4.10s don't help you down low - that was the whole point of my statement about them getting you into the powerband quicker. I don't know if you've ever raced a car with almost identical power but stock gears. From a roll the faster you are going the less the 4.10s seem to help. Off the line is where you gain the most ground.
I have the JBAs because my longtubes were bottoming out all the time on the roads here. I am well aware of the lack of a decent gain with shorties on mod motors - that's why I bought the longtubes to begin with. I didn't have the heart to put the nasty looking stock manifolds back on when I pulled the longtubes. To tell you the truth I didn't really notice losing any hp when I swapped from BBK lontubes and short H-pipe to the JBA headers and Magnaflow X-pipe, but I need to get back to the track to see what's really up. As for the 70mm TB I just have it because I got it for next to nothing and am installing an upper plenum pretty quick here (based on the results people are posting for the plenums, it looks like the 70mm gives more gain with a lot of them than the 75mm).
One thing I will say is that the Spec aluminum flywheel and Spec Stage 2 clutch with lightened pressure plate gave more SOTP gain than the longtubes and short H-pipe and cost a lot less (I have to run cats).
For what little I have my car runs surprisingly well - I run even with my friend's new 5-speed Mach 1.

[JBeryleC]

What is SOTP ?

And one more question... does anyone else mind the rpm hang when you get off the pedal???

It takes forever to drop back down! And not that any of you guys care about this next part... lol... BUT for us who want to drive the car slower sometimes, it makes for rough shifts because the rpm's are still hanging higher than the next gears speed.

Make sense?

I'll ask this, but I assume I'm correct...
How to get the motor to drop faster?

1. Lighter weight flywheel and clutch (meaning less centrifugal force carrying the rpms after throttle down)
and/or
2. Higher cylinder compression ratio
Yeah?

Oh yeah... and I havent even looked, but I assumed that they came with tubular exhaust manifolds.. no?
And so... getting shorty headers gives no gain or what?

[xxxBlakexxx]

Your comment about the rpm's taking too long to drop may be a personal issue or perhaps your standards are just different than mine, but this is not a problem I have had generally with my car. The ONLY time I had an issue with this was when I was having problems with my TPS. These problems ocurred after installing my plenum and larger TB. I damaged the TPS during the job, but did not realize it until I put it all back together.

When I replaced the TPS, the rps responded as they had before. I merely suggest this since I can not hear your engine. But, you may want to try replacing the TPS. They run about $30. I would ask the parts supplier that you use if you can return it if you see no change. Also, before trying this, you may want to disconnect your battery and then hook it back up again. Then start the car and let it idle for about 10 minutes. This will re-program your computer. I don't think this will help, but it is worth a try. Takes only seconds. You must follow this same procedure when installing a new TPS too.

Just a thought.

[JBeryleC]

no no.. there's nothing broken

It's just my taste I guess.

I have a 1976 F-150 with a big block 390.. it's slightly built up... and when I get off the gas the rpm's drop just as fast as they go up when I hammer it.

the question is...
Is there anything I can change to get that throttle response from the stang?

This isnt that big of a deal, just a "hmm.. wonder if" type a thing.. lol

[explicitone]

Originally posted by JBeryleC
no no.. there's nothing broken

It's just my taste I guess.

I have a 1976 F-150 with a big block 390.. it's slightly built up... and when I get off the gas the rpm's drop just as fast as they go up when I hammer it.

the question is...
Is there anything I can change to get that throttle response from the stang?

This isnt that big of a deal, just a "hmm.. wonder if" type a thing.. lol

the only way I know of getting the big block snap is with a roots stlye supercharger