3:15 or 3:42

[Jim D]

I'm going to change the rear in my 99. I was going to put 3:15's in ,but a lot of people tell me to go to the 3:42's. I'm 62 years young and mostly a cruiser, but on occasion, I like to give it to a young guy with the 4" mufflers. Is ther a big difference going to the 3:42 from 3:15 or is the 3:15 what I want for my style of driving, thanks Jim.

 

[JBsC5]

Jim,

I would recommend you contact East coast supercharging.

They have been doing many quality rear gear conversions.

I believe going to 3.42 will be very easy for them since a lot of guys with six speeds have been going to 3.90's and 4.10's.

they are in New JErsey near Englishtown. They recently moved from Monclair to that area further south.

Chris the owner is one of the nicest guys and if you like heres his email contact:

Email: chris@eastcoastsupercharging.com.
AOL Instant Messenger: Chris NJC5.
Home Page: www.eastcoastsupercharging.com.

I bet he could take the 3.42's hes taken out of countless cars recently and maybe put them in your carrier...(not sure about the 2.73 gear casing..but I bet with your use..meaning not drag racing at the track..it would hold up fine.

I wouldn't suggest doing the 3.15s. Not enough of a difference for the trouble. JMO

 

[Jim D]

Actually Chris is going to do the change , whatever I decide on, thanks Jim.

 

[02 C-5]

I would do the 3:42's !! You will not lose gas mileage . O.K. alittle
It will be fun

 

[Ctfoodguy2000]

Here is a "stupid" question.... what gears would be in my 02 Coupe, 6 speed?? Or how can I find out?

 

[JJU]

Gas milage wil be a little worse with 3.42.

 

[02 C-5]

6-Speeds come with 3:42 .

 

[bluecoupe]

Here's an article about installing new rearend gears.

http://www.corvettefever.com/howto/18978/

 

[Ctfoodguy2000]

Thank you!

 

[Don&Kelly]

I'm 63 y/o & I went from the 3.15's to the 3.42 & am really glad that I did .. lots more pickup .. still get great gas mileage ... if you read the different posts most vette owners are going the the 3.42 or even lower (higher?) gears .. You'll love it..

 

[JBsC5]

Just an FYI..the new Pontiac GTO is going to have the same rear gears for both automatic and stick shift. I thought it would be the 3.42's but I've read it was a 3.46 but that might have been a typo.

Either way its the corvette 4 speed automatic and a (~)3.42 rear gear.

I think the transformation to 3.42 is an excellent choice.

A 3500 yank torque convertor with 1.6 str is also a nice addition while your in there. I drove a car with that combo and it was so streetable..I'll never forget it. It was like driving a lexus

Good luck

 

[Jozef]

I own a 1999 with 3.15 gears. At 70-80 mph I average 26.7 mpg.
I have no complaints but never drove a vette with 3.42 gears.

I'm very happy with the C5 and considering purchasing another C5 but this time a convertible but still keeping the 1999.

 

[erenneckar]

I elected the 3:15 performance rear end and is it ever! I was out yesterday for a nice little drive... 120 MPH on a back road! I got the active handling to engage for the first time too, but not at 120 MPH. Oh' by the way, my Vette wasn't even breathing hard but i had a big smile on my face that couldn't be wiped off.

 

[JBsC5]

You guys with 3.15 rear gear automatics are right.. the car has amazing performance right out of the box..

I remember going to pocono raceway with my 1999 A4 3.15 C5 and the car didn't even breath hard. The car is extremely capable.

The cars performance at the dragstip was amazingly consistant too. With a change to the pcm and an intake the car was running 12.88's-12.9's and the trap speeds were 109.5 mph..

I would suggest that if a person is modifying the car...that thats when the 3.42 makes sense because your paying for the labor to open up the rear and change from 2.73's and go to 3.42's. Some A4 guys went to 3.73's and are very happy too.

Happy holidays!

JB

 

[BayouVette]

All depends on what you want to do with the car. I would say just go to 3.42's. Its pretty much the same price and either way you will need to get your PCM tuned for the gear change from the 2.73. I went from 2.73 to 3.15. I had them in the car for about 3 or 4 months and I already bought some 3.42's, but I like to go the track. Right now with the 3.15 and my PT2900 convertor if i nail it with traction control off I'm not goin anywheres. The only thing thats rollin is the smoke.

 

[Jim D]

Update, I decided to go with 3:42 rear, East Coast Supercharging is installing tomorrow. I'll give a report after I play a little , thanks for eveyone's input, Jim.