2.73 vs 3.15 rear end/ automatic
05-24-2005, 10:48 AM
#21
Le Mans Master
If one of the ratio guro's could post in this thread I would appreciate the following info.
At 160 mph in an A4 what would the rpms be for the following rear ends. 2.73, 3.15, 3.73, 3.90, and 4,10. Thank you, it is a question for future planning. Thread starter if you consider this a hijack let me know I will delete and start another thread.
In 4th gear of course.
At 160 mph in an A4 what would the rpms be for the following rear ends. 2.73, 3.15, 3.73, 3.90, and 4,10. Thank you, it is a question for future planning. Thread starter if you consider this a hijack let me know I will delete and start another thread.
In 4th gear of course.
Last edited by shurite44; 05-24-2005 at 10:52 AM.
05-24-2005, 11:30 AM
#22
Team Owner
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I drove a 2:73 car before I got this one...all I can say was it felt like a station wagon taking off...not a vette...I agree 3:15's are not really a performace gear set...but its better then 2:73's!
especially a must for those that never intend on modding the rear axle ratio. As hard as it is for some of us to understand... some people flat-out won't do mechanical mods to a car (going only with minor cosmetic upgrades).
And for these types, the 3.15 ratio is a great thing to have (versus the 2.73)
05-24-2005, 05:57 PM
#23
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Why is it you guys are able to swap the 2.73 and no one else can, just curious?
That alone spurred us to set down and spend the capital/time to re-engineer a few things internally to make them last under HP use and many of them are living healthy lives behind 9 and 10-second Corvette's all over the U.S.A., a few in Sweden, Canada, Australia and even two in Saudi Arabia.
Best Regards,
DTE
05-24-2005, 06:23 PM
#24
Melting Slicks
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Originally Posted by XTrooper
There's a world of difference between the two, but the plain fact is neither one of them is worth a damn and both are "desert gears" which you'll want to replace as soon as possible. I bought my car with the 3.15s and even while making 400+ rwhp, the car felt weak below 4000 rpm. Gears are your friend. 
Another thing to consider is that the 2.73 rear has a different carrier so the switch to deeper gears becomes more complicated and expensive if your car is equipped with them. If you have the 3.15s, it's a simple ring and pinion swap using your carrier.
Lastly, if you do a swap, skip the 3.42s, and go right to 3.73s. You'll be glad you did.
Another thing to consider is that the 2.73 rear has a different carrier so the switch to deeper gears becomes more complicated and expensive if your car is equipped with them. If you have the 3.15s, it's a simple ring and pinion swap using your carrier.
Lastly, if you do a swap, skip the 3.42s, and go right to 3.73s. You'll be glad you did.
If you start out with a 3:15 it`s a simple gear swap....if you start with 2:73 the whole carrier must be changed out thus substantially increasing the cost.
3:15 to 3:73 seems to be a very popular/ versatile set up.
Good luck, Rick
05-24-2005, 07:14 PM
#26
Melting Slicks
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Originally Posted by Vette_Fan
Anyone wanna chime in the difference it makes on gas milage, when going from 2.73 to 3.15 OR 3.42....?
I use to get 19-20 around town and I'm always playing. Now 21-22 it takes less to get the car moving. On the freeway at 70 use to get 27-28 now 26-27. Just took a 300 mile weekend mixed driving freeway, in town and mountains averaged 25 for the trip and I am always putting my foot in it
Last edited by VLVETTE; 05-24-2005 at 07:17 PM.
05-24-2005, 07:49 PM
#28
Originally Posted by Snake11eyeS
Will switching from 2.73 to 3.42 void your warranty?
More than likely it could void parts of your warranty.
No, seriously, that depends on a number of things. 3.42s were never meant to go into your car. So they can screw you during a warranty claim if they want.
Depends on the dealership you take it to for warranty work and if the gear swap led directly to whatever you are seeking a warranty repair for.
Aftermarket programming will be necessary, so this could jeopardize parts your warranty. If you have PCM, or BCM, etc problems later they could, at least in theory, say that it was a result of DIY programming. If your tranny dies or even if your engine dies, it would be a stretch........but they could, at least in theory, argue that it was secondary to the gears and the aftermarket programming.
They can give you a hassle on your warranty pretty much for any "significant" modification you do on the car.
In short, if you have to ask, and are concerned about your warranty........ then don't change your gears while the car is still in warranty.
Last edited by '06 Quicksilver Z06; 05-24-2005 at 07:54 PM.
06-07-2005, 04:46 AM
#29
Safety Car
Originally Posted by VLVETTE
I went from 2.73s to the 3.42s
I use to get 19-20 around town and I'm always playing. Now 21-22 it takes less to get the car moving. On the freeway at 70 use to get 27-28 now 26-27. Just took a 300 mile weekend mixed driving freeway, in town and mountains averaged 25 for the trip and I am always putting my foot in it
I use to get 19-20 around town and I'm always playing. Now 21-22 it takes less to get the car moving. On the freeway at 70 use to get 27-28 now 26-27. Just took a 300 mile weekend mixed driving freeway, in town and mountains averaged 25 for the trip and I am always putting my foot in it
Are you using the stock TC, or some kinda aftermarket TC? If an aftermarket one, which one... and from where, and how much.?
Thanks.
06-07-2005, 01:10 PM
#30
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Depends on the dealer. Some will use any excuse they can and others use common sense. You could check around and see what your local dealers say or you could go with a 3.15 which is the factory performance ratio. Programing the car for a 3.15 can be a bit easier since it can be done with the dealer's Tech 2 or one of the aftermarket progammers.
06-07-2005, 01:13 PM
#31
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Originally Posted by Snake11eyeS
Will switching from 2.73 to 3.42 void your warranty?
06-07-2005, 02:19 PM
#32
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Originally Posted by EB20003
More than likely it could void parts of your warranty.
No, seriously, that depends on a number of things. 3.42s were never meant to go into your car. So they can screw you during a warranty claim if they want.
Depends on the dealership you take it to for warranty work and if the gear swap led directly to whatever you are seeking a warranty repair for.
Aftermarket programming will be necessary, so this could jeopardize parts your warranty. If you have PCM, or BCM, etc problems later they could, at least in theory, say that it was a result of DIY programming. If your tranny dies or even if your engine dies, it would be a stretch........but they could, at least in theory, argue that it was secondary to the gears and the aftermarket programming.
They can give you a hassle on your warranty pretty much for any "significant" modification you do on the car.
In short, if you have to ask, and are concerned about your warranty........ then don't change your gears while the car is still in warranty.
No, seriously, that depends on a number of things. 3.42s were never meant to go into your car. So they can screw you during a warranty claim if they want.
Depends on the dealership you take it to for warranty work and if the gear swap led directly to whatever you are seeking a warranty repair for.
Aftermarket programming will be necessary, so this could jeopardize parts your warranty. If you have PCM, or BCM, etc problems later they could, at least in theory, say that it was a result of DIY programming. If your tranny dies or even if your engine dies, it would be a stretch........but they could, at least in theory, argue that it was secondary to the gears and the aftermarket programming.
They can give you a hassle on your warranty pretty much for any "significant" modification you do on the car.
In short, if you have to ask, and are concerned about your warranty........ then don't change your gears while the car is still in warranty.
You can ask locals on the forum or elsewhere. My dealer installed my 3:42 annd I furnished the PCM. No problems to date. Still have new car warranty.
06-07-2005, 02:48 PM
#33
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I drove both before I decided on 3.15's. It really was a night and day difference. I would have not enjoyed the 2.73's. I have gone to 3.42's now and they really seem like the sweet spot to me. I could have lived with the 3.15's if I hadn't wanted to mod the car.
06-07-2005, 06:16 PM
#35
Race Director
Chevrolets 2003 website listed performance numbers for all corvettes with all available gear ratios. Although I dont have the exact times there was a difference of 2 or 3 tenths to 60 mph and about a half second in the 1/4 mile. The numbers are in one of my old posts if someone wants to dig around for it. Interestingly enough the 2.73 A4 is the fastest C5 made with a top speed of 182 mph.
A 3.42 swap will not void your warranty if a GM diff. is installed by a GM dealer.
A 3.42 swap will not void your warranty if a GM diff. is installed by a GM dealer.
06-08-2005, 08:36 AM
#36
Team Owner
Originally Posted by jim2527
Chevrolets 2003 website listed performance numbers for all corvettes with all available gear ratios. Although I dont have the exact times there was a difference of 2 or 3 tenths to 60 mph and about a half second in the 1/4 mile. The numbers are in one of my old posts if someone wants to dig around for it. Interestingly enough the 2.73 A4 is the fastest C5 made with a top speed of 182 mph.
A 3.42 swap will not void your warranty if a GM diff. is installed by a GM dealer.
A 3.42 swap will not void your warranty if a GM diff. is installed by a GM dealer.
06-16-2017, 03:53 PM
#37
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2.73 to 3.42 switch
especially a must for those that never intend on modding the rear axle ratio. As hard as it is for some of us to understand... some people flat-out won't do mechanical mods to a car (going only with minor cosmetic upgrades).
And for these types, the 3.15 ratio is a great thing to have (versus the 2.73)
06-16-2017, 04:30 PM
#39
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Yes it is an auto. He has tried to tune it with a Dieobl Tuner( not sure on the spelling) provided by Zip Corvette with the new rear axle but it does not let him change the gear ratio.
06-16-2017, 04:38 PM
#40
Safety Car
Maybe flash the PCM with a firmware update. You should be able to change rear gears. If all else fails you could call ECS. They do PCM mail order tunes and they have seen it all.