Thinking about losing the 4.10s and going w/ 4.30s

[helty]

Ive got quite a bit of gear whine and Ive been meaning to upgrade to some 31 spline Mosers and an Eaton/Auburn/Detroit differential and a complete bearing and seal kit for a while now. Im also getting some 15x10" Weld Pro-Stars and MT ET Streets for use at the track. Ive decided to stay N/A and go the head/cam and full bolt-on route with my car. I already have 4.10s, but am seriously considering 4.30s. Ive recently become a track whore so of course I want to get everything out of my car that I can.

1. Our local track is 1000' (i know ) I want to hit the 1/4 sooner or later, will I have to shift into 5th with 4.30s in the 1/4 or will I be right at red-line? Cams are a future upgrade so keep that in mind, but what about as the car sits right now?

2. Ive also given the 3650 a healthy beating at the track, so Im thinking maybe, just maybe* a viper spec T-56 down the road (way down the road). Anyone have that link that tells you rpms given your gear ratio and tranny? Would that 6th gear really help at all compared to 5th in the 3650?

3. Throw in your thoughts on which differential I should go with. Car is a daily driver. Ive heard some positive things about the Detroit, Id like to hear what everyone else thinks.

Give me your thoughts :SNSign:

 

[BlackenedSVT]

you're crazy.

...seriously thats what i think

Upgrading to 4.30s when you already ahve 4.10s?!?! getting a T56 6-speed!?!? Where is all this cash coming from! damn man! LOL

 

[the98stang]

Ive got quite a bit of gear whine and Ive been meaning to upgrade to some 31 spline Mosers and an Eaton/Auburn/Detroit differential and a complete bearing and seal kit for a while now. Im also getting some 15x10" Weld Pro-Stars and MT ET Streets for use at the track. Ive decided to stay N/A and go the head/cam and full bolt-on route with my car. I already have 4.10s, but am seriously considering 4.30s. Ive recently become a track whore so of course I want to get everything out of my car that I can.

1. Our local track is 1000' (i know ) I want to hit the 1/4 sooner or later, will I have to shift into 5th with 4.30s in the 1/4 or will I be right at red-line? Cams are a future upgrade so keep that in mind, but what about as the car sits right now?

2. Ive also given the 3650 a healthy beating at the track, so Im thinking maybe, just maybe* a viper spec T-56 down the road (way down the road). Anyone have that link that tells you rpms given your gear ratio and tranny? Would that 6th gear really help at all compared to 5th in the 3650?

3. Throw in your thoughts on which differential I should go with. Car is a daily driver. Ive heard some positive things about the Detroit, Id like to hear what everyone else thinks.

Give me your thoughts :SNSign:

From what I've heard Detroit made the best sh1t. Lotta people said the Eaton's were no good...

 

[BlackenedSVT]

i'm guessing you dont do a lot of highway driving, but i do, as my car is my daily driver too...

So my personal thoughts are : "you were crazy to get 4.10s and nuts to upgrade to 4.30s on a daily driver"

 

[helty]

i'm guessing you dont do a lot of highway driving, but i do, as my car is my daily driver too...

So my personal thoughts are : "you were crazy to get 4.10s and nuts to upgrade to 4.30s on a daily driver"

I could get better gas mileage with my 4.10s than I did with my 3.27s if I kept my foot out of the throttle. Im not overly concerned with gas mileage anyway, I mean c'mon, I drive a V8. Im more concerned with cruising rpms and speed on a long trip. I know it will be higher with the 4.30s, but how much higher is what Im wondering. I need to find that damn link.

I just wanna get my info together and weigh the pros and cons. Better track times, higher cruising rpms......we'll see.

From what I've heard Detroit made the best sh1t

do you know which is recommended for a DD? I know theres the locker, tru-trac, spool Im pretty sure I dont want the spool, I think its the Locker, but its not a quiet piece. I dont mind that as long as it works as a DD and wont hurt the longevity of the rear end components.

Thanks guys!

 

[the98stang]

I could get better gas mileage with my 4.10s than I did with my 3.27s if I kept my foot out of the throttle. Im not overly concerned with gas mileage anyway, I mean c'mon, I drive a V8. Im more concerned with cruising rpms and speed on a long trip. I know it will be higher with the 4.30s, but how much higher is what Im wondering. I need to find that damn link.

I just wanna get my info together and weigh the pros and cons. Better track times, higher cruising rpms......we'll see.

do you know which is recommended for a DD? I know theres the locker, tru-trac, spool Im pretty sure I dont want the spool, I think its the Locker, but its not a quiet piece. I dont mind that as long as it works as a DD and wont hurt the longevity of the rear end components.

Thanks guys!

Yea I'm pretty sure the Detroit Locker was the recommended...

Just wait for hognutz, he'll help you out

 

[03ghoststang]

yup detroit tru-trac are real good L.S.D's and get the 4.30's if you want

 

[helty]

well the True-Trac is $165 LESS than the Locker. By its desctription is sounds like its more for a DD and it is LSD, yet its named the True-Trac. Hmm.....I'll keep searching and hopefully someone with a Detroit or experience with them will chime in.

http://store.summitracing.com/defau...eywordSearch&DDS=1&N=115&target=egnsearch.asp

Thanks again guys

EDIT: i just checked and summitt says it wont fit an 02, only 86-2000? wtf, i thought everything was the same in the 99-04 rear ends?

 

[blackfang]

Sweet! Nothing wrong with 4.30's for a d.d I plan on switching gears and going with 4.56's myself.

 

[jasonh_86]

4.56's That's a hell of a gear!

 

[helty]

Sweet! Nothing wrong with 4.30's for a d.d I plan on switching gears and going with 4.56's myself.

How do you like the 4.30s? (like I have to ask )

 

[blackfang]

I love them. They are a blast. I also get 24-25 mpg on the highway too.

 

[blackfang]

4.56's That's a hell of a gear!

Not for a NA 4v.

 

[jasonh_86]

Woops.. didn't see that part

 

[mustangman9812]

i am changing my 3.73's for 4.30's soon!!

 

[BlackenedSVT]

Lock this thread, bunch of lunitics in here

4.30s?! 4.56s1?!? You guys are nuts lol

And helty, if you are worried about high RPMs while driving, 4.30s aren't goign to be much over 4.10s. And 4.10s on the highway are overkill if you ask me.


Here, let me show you something. I cruise on the highway at 80mph sometimes more sometimes less...this is my reason why i am going with 3.73s this summer and NOT anything else. I commute on the highway to school every day about 20 miles plus i visit my long distance relationship, girlfriend in VERMONT almost every other weekend. So as you can see below driving at high rpms would say bye bye to my gas milage. I probably SHOULD go with 3.55s, but thast a gear, so im going with 3.73s LOL. Hope this chart below helps you out. And this is why i think you are nuts for going with 4.30s on a daily driver:

According to this gear calculator (running stock tires: 245/45/17) with a T3650 transmission:

3.27s
@ 70mph in 4th = 2,996 RPM
@ 80mph in 4th = 3,424 RPM
@ 80mph in 5th = 2,122 RPM
@ 100mph in 4th = 4,280 RPM

3.73s
@ 70mph in 4th = 3,417
@ 80mph in 4th = 3,905 RPM
@ 80mph in 5th = 2,421 RPM
@ 100mph in 4th = 4,882 RPM

4.10s
@ 70mph in 4th = 3,756 RPM
@ 80mph in 4th = 4,293 RPM
@ 80mph in 5th = 2,661 RPM
@ 100mph in 4th = 5,366 RPM

4.30s
@ 70mph in 4th = 3,939 RPM
@ 80mph in 4th = 4,502 RPM
@ 80mph in 5th = 2,791 RPM
@ 100mph in 4th = 5,628 RPM *Close to redline*
@ 105mph in 4th = 5,909 RPM *past redline* (in a GT)

(keep in mind a differnt trans, like a T45 or a T56, will give different numbers than these. I just showed you what our T3650 would be like)


Above is a table i made for you to compare from. I used this gear calculator:
http://tchracing.com/tech/gearcalc....m&givenval=80&givenvaltype=MPH&selectedgear=4

Hope that helps you. As you can see with 4.30s, depending on when you trap at the track. You WILL need to shift into 5th...which is probably going to be annoying.




EDIT: Oh i forgot 4.56s!!!

4.56s
@ 70mph in 4th Gear = 4,178 RPM
@ 80mph in 4th Gear = 4,774 RPM
@ 80mph in 5th Gear = 2,960 RPM
@ 100mph in 4th Gear = 5,968 RPM (past red-line, GT)
@ 105mph in 4th Gear = 6,266 RPM (well past GT redline, closing in on Cobra)

 

[helty]

^^thanks man, I understand your choice of 3.73s if you do a lot of highway driving. I dont do much highway driving at all and I dont mind shifting. But do you understand why 4.10s/4.30s are not that big of a deal on a DD if you dont do a lot of highway driving? I swear if (thats a big if )I kept my foot out of the throttle, I'd get better gas mileage than stock gears.

EDIT: after playing with that gear calculator (which I was looking for, thanks man ) I need that Viper Spec T-56. only 2200rpms in 6th gear @ 80mph with 4.30s

 

[BlackenedSVT]

^^thanks man, I understand your choice of 3.73s if you do a lot of highway driving. I dont do much highway driving at all and I dont mind shifting. But do you understand why 4.10s/4.30s are not that big of a deal on a DD if you dont do a lot of highway driving? I swear if (thats a big if )I kept my foot out of the throttle, I'd get better gas mileage than stock gears.

EDIT: after playing with that gear calculator (which I was looking for, thanks man ) I need that Viper Spec T-56. only 2200rpms in 6th gear @ 80mph with 4.30s

Technically, get a grandma...let her drive 100 miles on the highway in 5th gear at 80mph in a GT with 3.27 stock gears.... then put that same grandma, in a GT with 4.10s same conditions...

You will see the car with 3.27s will get better gas mileage. No denying that. 3.73s, 4.10s, 4.30s...they all keep you in higher RPMs in whatever gear your in, over the stock 3.27s. You really CANT get better gas mileage with 4.10s than you can with 3.27s. No way. higher RPMs = more gas burned.

Now...you might be able to get better gas mileage with your 4.10s than say me with my stock gears...but thats just because maybe i have a heavier foot with my 3.27s than you do with your 4.10s. BUT since you say that YOU get better gas milage with your 4.10s than YOu driving ur car with 3.27s...well thats not possible. Unless you became more reserved with your driving style after u got 4.10s all of a sudden.

bototm line, steeper gears will suck down more gas IN COMPARISON to stock gears. Only way to enhance your gas milage would be to go with 2.90 gears...which came on a rare few of 96-98 GT 5spds.

 

[JayC]

Technically, get a grandma...let her drive 100 miles on the highway in 5th gear at 80mph in a GT with 3.27 stock gears.... then put that same grandma, in a GT with 4.10s same conditions...

You will see the car with 3.27s will get better gas mileage. No denying that. 3.73s, 4.10s, 4.30s...they all keep you in higher RPMs in whatever gear your in, over the stock 3.27s. You really CANT get better gas mileage with 4.10s than you can with 3.27s. No way. higher RPMs = more gas burned.

Now...you might be able to get better gas mileage with your 4.10s than say me with my stock gears...but thats just because maybe i have a heavier foot with my 3.27s than you do with your 4.10s. BUT since you say that YOU get better gas milage with your 4.10s than YOu driving ur car with 3.27s...well thats not possible. Unless you became more reserved with your driving style after u got 4.10s all of a sudden.

bototm line, steeper gears will suck down more gas IN COMPARISON to stock gears. Only way to enhance your gas milage would be to go with 2.90 gears...which came on a rare few of 96-98 GT 5spds.

Enough of this damn gas mileage talk If gas mileage is a concern then trade your performance car in for a Honda Civic......I hear they do much better than a V8 Mustang. Some of us bought Mustangs for the performance they offer. If that is the case then a 4.30 gear will usually out-perform a 4.10 gear in most cases. I elected to stay with the 4.10's due to going with a power-adder (nitrous) , if not fore that 4.30's would be my pick. BTW...my gas mileage sucks when at the track on nitrous


Jay

 

[helty]

you're trying to turn this into an arguement and arent getting what I am saying. let me enliighten you

You really CANT get better gas mileage with 4.10s than you can with 3.27s. No way.

YES, 4.10s turn more rpms than 3.73s, 3.27s etc, IN THE SAME GEAR. BUT, with my 4.10s Im able to use 4th gear around town without bogging like I would with 3.27s. With stock gears I'd have to stay in 2nd/3rd to keep from bogging, thus running at a higher rpm. With 4.10s I can use 3rd/4th gear at a lower rpm (compared to a higher rpm in 3rd w/3.27s) without bogging, in turn getting better gas mileage. Thats what I was trying to show you. Most driving I do around town is 35-45 mph. In your case you do a lot of highway driving, so 5th gear is the limit. Of course you are going to turn lower rpms than my 4.10s, you didnt have to explain that.

Enough of this damn gas mileage talk

Im not overly concerned with gas mileage anyway, I mean c'mon, I drive a V8.