2.59 to 3.07, how much difference?

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Nov 21, 2003 | 05:56 PM

#21

cicch95

Melting Slicks

Joined: Jul 2003

Posts: 3,227

Likes: 50

From: Pomfret, CT

Finalist 2020 C4 of the Year - Unmodified

Re: 2.59 to 3.07, how much difference? (jstkrsn)

Quote:

I just bought 10.8 bolts the smaller size. Drilling out the flanges made them too thin for me.

I thought of that, Bob (Robertpel9) and I weren't comfortable with the play that would have made in the control arm holes. I was a machinst for 12 years, so I made the call that the wall thickness was ok on the flanges.

BTW Jstkrsn......the car we did the job on (Robertpel9's) is a 91 twin to yours!! White vert with the camel gut! Nice car you have there!!

-Rick

[Modified by cicch95, 5:57 PM 11/21/2003]

Nov 21, 2003 | 07:35 PM

#22

Dilligas

Thread Starter

Burning Brakes

Joined: Jul 2003

Posts: 933

Likes: 0

From: Rock Hill SC

Re: 2.59 to 3.07, how much difference? (cicch95)

I'm not sure which holes you are talking about, if I use the batwings off of the 84 will that help?

Nov 21, 2003 | 08:32 PM

#23

Alex D

Drifting

Joined: Mar 1999

Posts: 1,250

Likes: 1

From: Greensboro NC

Re: 2.59 to 3.07, how much difference? (Lord Odin)

Top speed is not an issue .... the Vette with the 3.07 turns about 2,400 at 80 mph, so at 5,500 you would be going well over 160 mph and that's about the ceiling for an unmodded Lt1 A4. The standard axle will have actually a disadvantage up top since they are pulling in a very tall fianal drive ratio. 3rd gear with the 2.59 axle goes to about 150 -155 mph, while in my 3.07 Vette the WOT shift from 3rd to 4th occurs at 145 mph. Go for it! My C4 is a lot more fun around town than a stock C5 since the LT1 engine has more torque up to 3500 rpm. Myc ar drives like a sling shot in town.

Quote:

Won't the top-end speed be slower with the 3.07's? :confused:

[Modified by Alex D, 7:36 PM 11/21/2003]

Nov 22, 2003 | 12:23 AM

#24

james holley

Pro

Joined: Sep 2000

Posts: 604

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From: clovis ca usa calif

Re: 2.59 to 3.07, how much difference? (Dilligas)

Why half step? If your going to do it, go with 3.54 gears. dont be the guy who sez "well I shouldah blah blah blah..."

Nov 22, 2003 | 06:22 AM

#25

Dilligas

Thread Starter

Burning Brakes

Joined: Jul 2003

Posts: 933

Likes: 0

From: Rock Hill SC

Re: 2.59 to 3.07, how much difference? (james holley)

Quote:

Why half step? If your going to do it, go with 3.54 gears. dont be the guy who sez "well I shouldah blah blah blah..."

If I were changing just the gear I would go with the 3.54 or 3.73. I have purchased a factory 3.07 rear end at a great price from a forum member, so it is more cost effective to do that swap. If I decide that I want more gear, I will have the 2.59 replaced with one of the above. :cheers:

Nov 22, 2003 | 06:31 AM

#26

cicch95

Melting Slicks

Joined: Jul 2003

Posts: 3,227

Likes: 50

From: Pomfret, CT

Finalist 2020 C4 of the Year - Unmodified

Re: 2.59 to 3.07, how much difference? (Dilligas)

Quote:

I'm not sure which holes you are talking about, if I use the batwings off of the 84 will that help?

The holes through the diff and the batwing. For the control arms.

-Rick

Nov 22, 2003 | 06:58 AM

#27

Dilligas

Thread Starter

Burning Brakes

Joined: Jul 2003

Posts: 933

Likes: 0

From: Rock Hill SC

Re: 2.59 to 3.07, how much difference? (cicch95)

How much do they have to be enlarged? I suppose I can measure the holes in my original unit with calipers and drill the replacement unit to match. Or should I install my existing batwings on the new center section? I really appreciate all the advice on this, it should make the change a lot less painfull. :cheers: