Hey guys,

I need some more opinions. I'm about to buy some rear end gears for my ProCharged 05 and can't decide on which ones. I'm stuck between 3.73's and 4.10's. I'm going FRPP thus the 3.90's not being an option. Which will I get more enjoyment out of? I do 90% of my driving on surface streets, but do occasionally drive the 120 mile stretch of 395 to visit family up in the High Desert. Will 4.10's still be managable on the highway thanks to Overdrive? I really want a bit more grunt on the street as my car is currently making most of its power in the higher RPM's.

Any and all opinions are much appreciated!

Kris Horton

 

A lot of people who went to 4.10s are switching back to 3.55s or 3.73s because first gear becomes useless

 

Kenne Bell recommends NOT changing the gears w/ their supercharger. So stock for a GT, 3.55s. Save the money for LCAs or something. [img]style_emoticons/<#EMO_DIR#>/thumb.gif[/img]

 

<div class='quotetop'>QUOTE(Lowe! @ March 9, 2006, 10:29 AM) Quoted post</div><div class='quotemain'>
Kenne Bell recommends NOT changing the gears w/ their supercharger. So stock for a GT, 3.55s. Save the money for LCAs or something. [img]style_emoticons/<#EMO_DIR#>/thumb.gif[/img]
[/b][/quote]

I've got an automatic though, which has the 3.31's not the 3.55's. Not to mention this will be a potentially free purchase/install. Also, a Kenne Bell supercharger makes a ton more torque than my centrifugal.


Kris

 

<div class='quotetop'>QUOTE(KrisHorton @ March 9, 2006, 10:35 AM) Quoted post</div><div class='quotemain'>
I've got an automatic though, which has the 3.31's not the 3.55's. Not to mention this will be a potentially free purchase/install. Also, a Kenne Bell supercharger makes a ton more torque than my centrifugal.
Kris
[/b][/quote]



My bad Kris.. You have the 3.31's... In that case grab yourself the FRPP 3.45's!

 

Is that a big enough change to notice? I'm looking to make my car pull nice and hard (well, even harder, haha!) but don't want to completely sacrifice highway driving. Will there be a "seat of the pants" difference just going from 3.31's to 3.45's?

 

Ahh. You might go w/ the 3.73s in you case then.

 

<div class='quotetop'>QUOTE(MSP @ March 9, 2006, 10:44 AM) Quoted post</div><div class='quotemain'>
My bad Kris.. You have the 3.31's... In that case grab yourself the FRPP 3.45's!
[/b][/quote]


Yes, perhaps the 3.73 is best.. You can trap out with those @ 125MPH @ 6025RPM, with a 26in tire!

So, being that the 3.31 feels like 331FT. Pounds of thrust, the 3.73 is 373Ft Lbs.. Thats a 42 lbs difference in thrust!! You will feel it! LOL!

The 4.10 is 410Ft lbs of thrust, and is 55ft lbs difference in thrust over the stock 3.55.. 79Lbs of thrust over the 3.31's This is why guys love the 4.10's...

You should be safe going with the 3.73's... Its actually what I always recommend.. I have the gear but have not had it put in yet, because I'm loving the RPM range of the stock 3.31's.. I also have enough thrust with them..

 

<div class='quotetop'>QUOTE(dustindu4 @ March 9, 2006, 9:57 AM) Quoted post</div><div class='quotemain'>
A lot of people who went to 4.10s are switching back to 3.55s or 3.73s[/b][/quote]

Not me... 4.10s are staying. [img]style_emoticons/<#EMO_DIR#>/thumb.gif[/img] I'll just run a 28" tire at the track. I'll still be able to trap over 120mph with that set-up.

 

I thought that FRPP makes 3.90's now??

 

BTW, do yourself a favor and get a new differential while ur at it. People here have had the best luck with the Detroit Trutrac, it's only an extra $400 and won't cost you extra to put it in, they need to remove the differential anyway to put the gears in. Lot of people here are losing their stock differential with power adders. It will save you money in the long run.

 

If you put in an aftermarket posi unit (e.g., Detroit, Auburn, Eaton, etc.), then what becomes the "weak" point in the rear end? The axles? I have heard that it might be better to leave the stock posi in there as kind of a sacrifical lamb so to speak, if you plan on sticking with the stock axles. The theory is that it would be cheaper to repair it than to replace snapped axles. I don't know how much of this is true, just something I read. [img]style_emoticons/<#EMO_DIR#>/dunno.gif[/img] But, since I'm going though my car pretty thoroughly right now, it's something I've been thinking about.

 

Hmm, I might go with Detroit Locker. I have a contact there, I'll have to ask him if he thinks it's going to make the axels prone to breaking...

Kris

 

<div class='quotetop'>QUOTE(KrisHorton @ March 10, 2006, 11:33 AM) Quoted post</div><div class='quotemain'>
Hmm, I might go with Detroit Locker. I have a contact there, I'll have to ask him if he thinks it's going to make the axels prone to breaking...

Kris
[/b][/quote]
Uhhh... what do you expect him to say? "Yea, buy our product, and your axles will snap" [img]style_emoticons/<#EMO_DIR#>/icon_mrgreen.gif[/img]

 

Given that he's a tech and not a salesperson, he might be a little more straightforward with me...just a thought.

 

Either way, I'm still interested in what he has to say. Thanks.