3.27 - 4.10 Gearing ???
 

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???

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?

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

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.

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.

:confused: :confused: :confused:
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.

theres not enough clearence there...

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

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."

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

Thank you much for clearing that up :)

Blue: Thanks fo r the speed correction.

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

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

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

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.

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?

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.

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

I have good enough throttle UP
I am only talking about throttle DOWN

Like this.. take your foot off the gas pedal and the rpm's drop (while not in gear) for example.. in between shifts

what I am wanting is a faster drop off

its 2 things 1 is the weight of the flywheel and clutch that helps
and it setup not to drop to fast cause if it does during a shift then it can cause problems with the trans

Yeah I just want it to drop a little faster...

I think with a lighter aftermarket flywheel it'll give me what I want :)

a alu. flywheel will do the trick I would use a fidanza or spec which is made by fidanza

Anyone know how much lighter it is??

the fidabza is a 12lbs making it 16lbs lighter

I JUST pust 4.30's in my auto.

I started out w/ 3.73's, and they just didn't do it for me.

Then I jumped to 4.10's, and realized that there was still more potential left in my DAILY DRIVER.

I now have 4.30s, and just made on helluva road trip, pulled 20 MPG's, in my auto, on the interstate, any 5-speed would do better than that......

Most of the gas mileage probels come into play b/c of the driver heaving a heavy foot......


And the gears last longer than you'd think, its just that everything happens so fast when you're in a race.................unless you're in a ricer:D

-Will

Well right now I am running exactly 2000 rpm's at 75mph in 5th gear.

Can anyone tell me what rpm's I can expect at that same exact speed for both 3.73 & 4.10 gearing??

Thanks :)

I dont know how a 02 would be in 5th at 75 with 4.10s or 3.73s
because the tr-3650 trans has a .62 5th gear where a t-45 has a .68 I know at 75 in 5th im at 2600 with 4.10s and my buddy with a 03 with 4.30s is at 2700 or so

So which one do I have ?

You know what...no offense...but maybe you should just wait on doing anything to your car before you mess it up! Get a ride from a modified car and see what you like. So far what you're describing in what you want to do, would kill your streetabilty. (With the exception of 4.10 gears.) Everyone here has given you good recommendations and it's almost like you think you know more then them to a point. Try to listen to someone's recommendations and go from there. Try to get rides from people who have fast cars that are set up in different ways. Example would be a N/A , blown, or even a nitrious cars. (And get several examples) Don't knock any of it, till you have experanced it. Then you can say if it sucks or what ever. But to compare a truck to a Mustang, is not comparing apples with apples. Besides having entirely different engines and functions... why would you compare?:confused:
I am sure you have speed shops that operate near you. Go there and show that your intrested in spending some money there. They will at least give you some sort of demo ride.
My .02 cents.

420nitro... If you're talking to me... well you just have no clue.. lol :)
I have researched every aspect of every mod that can be done to our newer breed of stangs... in depth.. more than you can imagine. However.. I dont pretend to know more than others.

It's just that everyone has different opinions than others, so if I choose to not do a mod because of other input I've gotten or because of other research I've done... well then so be it.

Everyone on here is very helpfull and full of support, input, and opinions. Thats why this is a great place to express all that.. even if some don't agree.. lol

FYI.. I have taken A LOT of advice from here.. infact EVERYTHING I've done & will do to the car has been because of these people :)

I think I've gotten the mods I'll do down to a T
Check out the other threads for more info. I assume your reply was based on this thread alone. Well I've posted many others that turned into "hot topics" if you will :)

And the only comparing I did to my truck was in reference to the 8.8 axle and it's potential strength.

Thanks for the .02 cents though :)

Well..my last post was towards you. I have not looked at your other posts, but I will try to make it an effort to look them up.
As goes for I not having a clue....Ok... no problem here, nor do I care.
The only thing that I recommend is that before you spend your hard earn cash on some parts, is to at least get an example. I have given and recieved a lot of advices that at first either sounded like great ones that turned out bad or the ones that sounded awful and were the best ones. Try to look at all of them with an open mind...but always get that example!!!!!
What example you might ask????
Well,.. I mean like have someone give you a ride or see if one of your friends would borrow you a car for a couple of hours. Some people might say "hell no" to that idea but asking never hurts. I know if someone that I knew was responsable enough..I would let him drive my single digit car! And yes I have dear friends like that. They also have FAST cars too that I would just take... if they're were any problems.;)
So my last post and this post was not ment to insult or anger you in any way. I just speak and wright in a bult way.
Good luck with your build
Sincerley
420nitro
P.S
Please excuse any misspellings

Oh yea,
If you already do this (get examples) then please disregard my last post.

Well the problem is this... I have lots of friends that have built cars... but they are either 5.0's or T-birds...

No one with a mod mustang... so I resort to reading articles, websites, and post's on here :)

As for examples.. I have none really. So I have to make do with the "virtual" stuff on here... lol

Thats why I ask A LOT of questions and talk to A LOT of different people.. as to get the best "average" (per say) advice.

How is your knowledge on this stuff? I mean I see you have a fox car though... but who knows, maybe you have experience with the new :)

Let me know if you read some of the other posts, I'd like your opinion on some stuff. Because obviously you dis-agree with some of what I am planning to do. Let me know :)

to your ???????s

you have a tr-3650 they changed trans mid year 01 from the t-45 to a tr -3650

Thanks bro!

So.. which is stronger? I assume they changed because it's better (tr-3650), right?

No problem.
As goes for the little dis agreement... just because we disagree does not mean that your wrong and I am right and visa-versa.
It only means that we have 2 different out looks.
Which is cool.
Now you ask...what I think is wrong or disagrre with...
I don't know your whole set-up but I assume its preety mild..so we go from there.
4.10 gears verses 3.27 gears.

4.10 all the way if not more. It's funny because I just had this issue with a friend that has a mod motor. Yours and his concerns were close. After a couple of months debate he did it. Never looked back. The mod motor like mentioned before needs some rpm's to run more efficent,fun,blast what ever. The 3.27 gear which I believe is stock doesn't suit the needs. I understand that you don't want to shift any faster then you do now...then don't! Instead of shifting at (I assume) 2000-3000 rpms shift at 3000-3500 rpms. Or start in second and shift to 4th and then 5th. My friend who has done this believes, the drivablity has INCREASED, due to the new gear.

Alu. flywheel.
Will hurt your bottom end torque. There is a reason why they are heavy. Yes, the draw back is in the upper rpms but technically you shouldn't be there right???
Now run a 4.10-4.30 gear and a alum. flwheel with a good clutch (spec) and now we have a completely different story! Put on a blower of some sort (I prefer Novi and Vortech) and you have a fun street car with good manners.
Now you might disagree and thats fine...or you might find it to be a good one, but relize someone will always disagree.

yes the tr 3650 is rated for more tq I think like 25 more tq

and it use a diff. reverse

Well if there is someone out there who can tell me exactly where my rpm's will be at 75mph in 5th gear... then I can atleast compare to what I'm running right now.

I'd like to know that info for 3.73 & 4.10 gears...

Is there a calculation I can use?
i.e. using the tire diameter, rpm's, speed, gear ratio.. ect ect

Yes...look at this sites Analyzer..
It's about 2800 rpms if your tires are 24 inches in height.

the analyzer on this site i thought uses a t-5s gearing which has a .68 5th gear like the t-45 but the 3650 has a .62 so it would be lower and the gts come stock with a 25.7 in tire

4.10s should be between 2400-2500 @ 75

Yes,very true my bad.
As goes for the tire though, what does he have on? Stock 275/45/17's ???

stock is 245/45/17 which is 25.7 the same as a 275/40/17

ok:)

Ok.. I forgot about the anlyzers...

And yes it's off a little because my tranny's 5th gear is different, as stated by explicit.

?? use a slightly different tire diameter to get the exact rpm's I run now... then just used that same tire diameter to get the rpm's I would be running with the different gears??

by the way, I run Goodyear 245/45 ZR17

And I cant find a anlyzer that made for this specifically.. the closest match is asking for HP.. blah blah
I'll go check out someother sites for a anlyzer thats exactly what we need to figure this one out :)

Thanks for the help peoples :)

Ok... I found a more accurate calculater...
Results:
(on a completely stock setup, with 245/45R17 tires)
(only accurate for the final drive ratio of the TR-3650)

3.27 @ 75mph = 2507rpm
3.73 @ 75mph = 2859rpm
4.10 @ 75mph = 3143rpm
4.30 @ 75mph = 3296rpm

So.. about the highest I am willing to go is 3.73's

Maybe I'll just have to do that :)
Thanks for the info guys!!

that is way off
I dont spin that high with 4.10s and I have a t-45 and .68 5th

my buddy has a 03 with the tr-3650 and 4.30s and he is lower then it says here with 4.10s hes at 3000 at 80 and im at 2800 at 80 with 4.10s

so that is not accurate at all

Ah crap... you're right.. I messed that up big time!!

Here are the real numbers...

(on a completely stock setup, with 245/45R17 tires)
(only accurate for the final drive ratio of the TR-3650)

3.27 @ 75mph = 2004rpm
3.73 @ 75mph = 2286rpm
4.10 @ 75mph = 2512rpm
4.30 @ 75mph = 2635rpm

sorry about that... those number should be right on! :)
It's accurate for my gearing, I know that atleast.. lol

And if those numbers are right, then I wouldn't mind gearing to 3.73's :)

Remember, I dont drag, so I dont need any more than that :)