REAR END RATIO..??

**bucket** · 04-09-09, 11:49 AM

CAN I TELL MY RING GEAR RATIO

FROM THE VIN???

**Hib Halverson** · 04-09-09, 12:52 PM

No.

You can tell it from the RPO tag, however.

Is it an automatic or a manual?

**bucket** · 04-09-09, 01:59 PM

auto..where do ifind the rpo code?
( i hate being this ignorant)

**Tuna** · 04-09-09, 02:17 PM

In the C4, the RPO tag is either on the under side of the console lid or the underside of the rear compartment lid behind the passenger seat. My old '92 had it under the console lid.

G44 = 3.07 This is the auto's performance ratio and would show G92 also
GM1 = 2.59
GU2 = 2.73 I believe this is the standard ratio for auto's

More RPO stuff is located at http://corvetteactioncenter.com/tech/rpo/8496rpo.html

If either lid has been replaced, the RPO sticker may be gone.

**Hib Halverson** · 04-09-09, 03:10 PM

2.73 is generally the base ratio for Convertibles. 2.59 is the base ratio for coupes.

**nelson84** · 04-09-09, 04:05 PM

How much of a difference in performance with an auto 85 vette with 2.73 and the 3.08?

Would there be much of a difference in 0-60 or 1/4 mile times?

**bucket** · 04-09-09, 05:11 PM

TUNA..SOME GUYS HAVE ALL THE BREAKS...ARE YOU A PILOT?
THANX..FOR THE TIP
I'LL CHECK IT OUT
B

**bucket** · 04-09-09, 05:13 PM

LOWER GEARS IS THE SINGLE MOST IMPORTANT FACTOR IN INCREASING ACCELERATION..
IN HIGH SCHOOL A FRIEND OF MINE PUT 4:56 GEARS IN HIS 52 CHEV WITH A 283 4BBL...HE WAS THE TERROR OF THE STOPLIGHT RACES...LOL

**vetteoz** · 04-09-09, 07:01 PM

Originally Posted by bucket

LOWER GEARS IS THE SINGLE MOST IMPORTANT FACTOR IN INCREASING ACCELERATION..

So long as you are only driving stoplight to stoplight,
Also have to factor in revs at highway speeds and MPG

**bucket** · 04-09-09, 07:08 PM

I UNDERSTAND...AND THIS AINT 1968 EITHER...LOL

**TedC** · 04-09-09, 07:40 PM

I've only driven one auto 85 with 2.73, and it seemed pretty darn quick off the line. My 1988 had the auto 2.59, and it simply did not have the same dead stop get-up-and-go as my current 1989 vette with 3.07. The MPG difference is minimal between the 2.59 and 3.07. Tire traction was never an issue with the 2.59, just punch-and-go. Best acceleration with the 3.07 is having a full tank of gas and not to punch the throttle from a dead stop. I talked to Gordon K. about rear end ratios, and he felt GM did there homework when selecting the 3.07 as the best optional performance ratio for an auto L98. 1st gear in the automatic has a great ratio that does help.

**dogfish246** · 04-09-09, 08:18 PM

I have a 1996 Auto LT1 with 3.07 gearing and it is nice!

You put more power to the tires, but fuel economy suffers a little. I get 22-24 highway most of the time and at 65mph I run at 2k rpms.

Its worth it though!

**Tuna** · 04-10-09, 08:02 AM

Originally Posted by bucket

TUNA..SOME GUYS HAVE ALL THE BREAKS...ARE YOU A PILOT?
THANX..FOR THE TIP
I'LL CHECK IT OUT
B

As a matter of fact - yes. 2,200 hours in Air Force A-7, A-10, OV-10 and training aircraft.
My wife and I met in the local Corvette club, so we're car people. We have to have 2 Vettes - his and hers - plus a grocery getter that can haul groceries. The CTS-V can really haul groceries!

**Tuna** · 04-10-09, 08:04 AM

Originally Posted by bucket

LOWER GEARS IS THE SINGLE MOST IMPORTANT FACTOR IN INCREASING ACCELERATION..
IN HIGH SCHOOL A FRIEND OF MINE PUT 4:56 GEARS IN HIS 52 CHEV WITH A 283 4BBL...HE WAS THE TERROR OF THE STOPLIGHT RACES...LOL

A friend from my home town had a late '60 Dodge Dart with the 273 V8 and 5:13 gears. When he left the light, he usually had such a lead that others just gave up not realizing that he was flat out about 200 yards down the road.