2.73 TO 3.15 difference
Thread Starter
Racer
Joined: Jan 2007
Posts: 486
Likes: 1
From: Jacksonville Florida
2.73 TO 3.15 difference
I have a chance to get a 3.15 diff with about 11k on it for next to free. Is this going to be anything noticeable over the stock 2.73 my car was cursed to be born with?
Couple of ?'s
1) What kind of performance gain is there?
2) How easy is the swap?
3) Does it need a retune afterwards?
Couple of ?'s
1) What kind of performance gain is there?
2) How easy is the swap?
3) Does it need a retune afterwards?
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
I have a chance to get a 3.15 diff with about 11k on it for next to free. Is this going to be anything noticeable over the stock 2.73 my car was cursed to be born with?
Couple of ?'s
1) What kind of performance gain is there?
2) How easy is the swap?
3) Does it need a retune afterwards?
Couple of ?'s
1) What kind of performance gain is there?
2) How easy is the swap?
3) Does it need a retune afterwards?
Advanced
Joined: Sep 2009
Posts: 50
Likes: 0
I went from a 2.73 to a 3.42 and it was a big difference!
As for the 3.15, any thing has to feel better than the wimpy 2.73!
You will need to buy a handheld programmer (such as Diablo Sport) to adjust the gear ratio. And while you're at it you may as well adjust the shift pressure as well; it really makes the auto feel like it has some *****.
As for the 3.15, any thing has to feel better than the wimpy 2.73!
You will need to buy a handheld programmer (such as Diablo Sport) to adjust the gear ratio. And while you're at it you may as well adjust the shift pressure as well; it really makes the auto feel like it has some *****.
Drifting
Joined: May 2006
Posts: 1,608
Likes: 11
From: Aliso Viejo So. Cal.
I'm not to sure I would go through all that work just to step up to 3.15. I went from 3.15 to 3.42 and that made a big difference. Save up and step up to the 3.42. Going from the 2.73 to 3.42 will really make a hugh difference during the launch .
.
Thread Starter
Racer
Joined: Jan 2007
Posts: 486
Likes: 1
From: Jacksonville Florida
You say 3.15 to 3.42 was a big difference for you, thats .27 of a rotation. So 2.73 to 3.15, which is .42 rotation difference should be an even greater jump than yours.
I really want the m6 diff, but like I said, this diff is pretty much free.
I really want the m6 diff, but like I said, this diff is pretty much free.
Drifting
Joined: May 2006
Posts: 1,608
Likes: 11
From: Aliso Viejo So. Cal.
But you'll wish you had made the jump to 3.42s. It was the best mod I did for the $$$ esp. after a good tune with the shift points adjusted. I'm not saying going from 2.73 to 3.15 is a bad thing, I'm just pointing out if you're going to make the swap why not step it up 2 notches instead of 1 notch? In fact, I just assumed I had a 2.73 rear (standard rear) when I went to the 3.42 but it still made a big difference.
Thread Starter
Racer
Joined: Jan 2007
Posts: 486
Likes: 1
From: Jacksonville Florida
Sadly money IS an issue and a free diff vs 500-1000 people seem to be wanting for the 3.42 is enough reason for me to go this route. Plus I will have the 3 series carrier and later on i can upgrade the gears if need be.
Thanks though!
Thanks though!
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. Good luck with the swap 
Drifting
Joined: Mar 2008
Posts: 1,473
Likes: 547
From: Orlando & Flagler Beach FL
Not looking to hijack the thread but how can I tell what rear end I have in my (new to me ) 2003 Coupe w/automatic transmission. Was the 2.73 the standard? Mine does have the Active Handling (which Im not sure if that was an option or not)
Thx
Thx
Thread Starter
Racer
Joined: Jan 2007
Posts: 486
Likes: 1
From: Jacksonville Florida
2730 rpm is 2.73, 3150 is 3.15.
Drifting
Joined: May 2006
Posts: 1,608
Likes: 11
From: Aliso Viejo So. Cal.
There is a sticker in the glove box with a list of codes (options) that apply to your car. I have seen a list that deciphers what the codes mean. Do a search and you should find it. Or someone may chime in with the list.
Race Director
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From: "It's 106 miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark, and
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You can refer to the RPO codes on the sticker in the glove box (assuming the car is a '99 or newer - on the driver's side rear compartment cover if it's a '98 or a '97).
The RPO for the 3.15 G92 and the 2.73 it's GU2.
Here's the whole list if that helps.....
http://home.fuse.net/corvette/rpo.htm
Here's a chart courtesy of Mr. Bill -
http://forums.corvetteforum.com/1569944142-post7.html
The RPO for the 3.15 G92 and the 2.73 it's GU2.
Here's the whole list if that helps.....
http://home.fuse.net/corvette/rpo.htm
Here's a chart courtesy of Mr. Bill -
http://forums.corvetteforum.com/1569944142-post7.html
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You should feel a very nice difference in the acceleration when stepping up to the 3.15 gears. Like you say, anything is better than the 2.73s. And the fact that it is almost free, all the better.
Le Mans Master
Joined: Jul 2004
Posts: 7,727
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From: Twilight zone
St. Jude Donor '05-'06
I have done this swap,and yes you will feel the difference. I went from 3:15 to 3:42's
There is a bit of detail involved and it looks a little scary, but it's not that bad if you can wrench at all.
I think they get @ $400 to swap them out or so.
Search for forum member " Mike Mercury".He has a home page with a DIY writeup with pics.It is very well documented,and IIRC ,he did it without a lift. "Cajundude" has one as well I believe.
There is a bit of detail involved and it looks a little scary, but it's not that bad if you can wrench at all.
I think they get @ $400 to swap them out or so.
Search for forum member " Mike Mercury".He has a home page with a DIY writeup with pics.It is very well documented,and IIRC ,he did it without a lift. "Cajundude" has one as well I believe.
Safety Car
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From: Whittier California
Team Owner
Joined: Apr 2001
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From: S.W. Ohio. . . . . . NRA Life Member
this is correct. The 2.73 to 3.15 jump is a 15 percent increase. The 3.15 to 3.42 jump is 8.6 percent. The 2.73 to 3.15 would be the most SOTP improvement - between the two jumps.
If there's one benefit in going from the 2.73 to the 3.15 (and not to the 3.42), it would be that the reprog can be done by a Chevrolet dealer using their Tech Tool 2. My local Chev dealer charges $70 for this.
http://mikemercury.home.att.net/342.htm