Gear Question?
Thread Starter
Racer
Joined: Apr 2005
Posts: 357
Likes: 1
From: Lenoir Tn
Gear Question?
This may be a stupid question 
but how much difference could there be in going from a 273 rear end to a 342 rear end or just driving around in 3rd gear? Is that a stupid question? 
but how much difference could there be in going from a 273 rear end to a 342 rear end or just driving around in 3rd gear? Is that a stupid question?
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: Fort Worth Texas
Originally Posted by glind46677
This may be a stupid question but how much difference could there be in going from a 273 rear end to a 342 rear end or just driving around in 3rd gear? Is that a stupid question?
but how much difference could there be in going from a 273 rear end to a 342 rear end or just driving around in 3rd gear? Is that a stupid question? 
Instructor
Joined: Jul 2004
Posts: 168
Likes: 0
From: Metairie La.
Two weeks ago I had installed a 3.42 (z06) differential and a 3000 Yank converter..... unbelievable increase in acceleration (from a stop or roll).
Add a converter if possible.
Local dealership service manager and two techs are allowed to use shop on off time to add mods to corvettes. Great price & great work.
Add a converter if possible.
Local dealership service manager and two techs are allowed to use shop on off time to add mods to corvettes. Great price & great work.
Instructor
Joined: Jul 2004
Posts: 168
Likes: 0
From: Metairie La.
Two weeks ago I had installed a 3.42 (z06) differential and a 3000 Yank converter..... unbelievable increase in acceleration (from a stop or roll) from 2.73.
Add a converter if possible.
Local dealership service manager and two techs are allowed to use shop on off time to add mods to corvettes. Great price & great work.
Add a converter if possible.
Local dealership service manager and two techs are allowed to use shop on off time to add mods to corvettes. Great price & great work.
Melting Slicks
Joined: Feb 2004
Posts: 3,137
Likes: 1
From: Insane Diego Kalifonya Baby
This may be a stupid question but how much difference could there be in going from a 273 rear end to a 342 rear end or just driving around in 3rd gear? Is that a stupid question?
Where do you like to play? I like to play from 0-100 mph. That's where your going to feel the difference. At WOT you will come out of 1st at around 30-35 2nd around 80 and 3rd somewhere around 125. Rolling under 25mph nail her she will drop into 1st scratch and scratch again coming out. I have done the swap and you get more than a "little" more pop off the line. The car is more responsive at many levels. When I had my 2.73s and doing the twisties in the mountains I used to leave the tranny in 2nd any higher gear and I always felt like I was coasting around the corners. With the 3.42s I leave her in 4th and can feel the engine pulling her back during deceleration plus I get the added benifit of the tranny down shifting 1 or 2 gears if I want it coming out of the turns just by pushing down a little or a little more on the gas. Gas milage improved 2 MPG around town from 19 to 21. Highway MPG no noticeable difference. IMHO Best mod you can do to the A4 with 2.73s. 
Originally Posted by lanceg1041
I have a 273 and always drive in 3rd around town. The only thing a 342 gear will get you is a little more pop off the line.
Last edited by VLVETTE; Jun 30, 2005 at 01:18 AM.
Safety Car
Joined: Jan 2005
Posts: 3,675
Likes: 58
From: Hayward (Bay Area) CA
Originally Posted by VLVETTE
Gas milage improved 2 MPG around town from 19 to 21. Highway MPG no noticeable difference. IMHO Best mod you can do to the A4 with 2.73s.
Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Burning Brakes
Joined: Oct 2003
Posts: 1,162
Likes: 0
From: Dubai
I agree on the best mod for A4s. GM should offer the 3.42s as an option instead of the 3.15s. I have done the gear change to my older vette and the SOTP difference was apparent immediately. Do a TC swap at the same time to get the most benefit.
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Melting Slicks
Joined: Feb 2004
Posts: 3,137
Likes: 1
From: Insane Diego Kalifonya Baby
Originally Posted by Vette_Fan
I agree this IS a great mod for A4 (2.73), but whats up with the gas milage thing? How's your car getting better milage, after switching to 3.42 ???? Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Last edited by VLVETTE; Jun 30, 2005 at 08:54 AM.
Advanced
Joined: Jun 2002
Posts: 63
Likes: 0
From: Raleigh NC
Originally Posted by Vette_Fan
I agree this IS a great mod for A4 (2.73), but whats up with the gas milage thing? How's your car getting better milage, after switching to 3.42 ???? Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Advanced
Joined: Jun 2005
Posts: 98
Likes: 0
From: Nr London England
Originally Posted by Vette_Fan
but whats up with the gas milage thing? How's your car getting better milage, after switching to 3.42 ???? Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!
Milage is supposed to drop by 2-4 Mpg. THAT IS a fact!Its like increasing BHP with intake and exhaust mods. If driven hard it WILL use more fuel. But it will also offer the same performance as before for less effort so when not at WOT many people will drive or sedatley allowing for better mpg.
The same goes for gears, if you always where flooring it and forcing the box to kick down it would not have been economical but with more pep in the higher gears you'll probably find you won't force it to kick down as much.
On the highway at a constant speed it may be a different story as to achieve the same speed you will have to run at higher rpms.
Intermediate
Joined: Jan 2005
Posts: 47
Likes: 0
From: Dallas TX
What size gearing do you have to change out the case? I have a A4 2.73 1998 and was wanting to just swap the ring and pinion for one that is 3.42. I heard they wont fit in the casing. Is this true?
