sounds like your tach is off a couple hundred RPM's....this is from www.ws6zxr.com:

--------------------------------------------------------------

Injuneer
Super Moderator

Registered: Jul 2000
Location: NJ
Posts: 2320
Everybody's numbers look right..... my handy rpm calculator shows:

80MPH w/ 4L60E in O/D

2.73 - 1,993rpm
3.42 - 2,496rpm
3.73 - 2,723rpm

-----------------------------------------------------------------

The car is driven daily, usually always around town with a rare trip to the track. I expected 14mpg when I bought this car and was surprised to get 17-18mpg around town and 25 on the highway, so if I can get 14-15 around town and 22 on the highway I'd be happy.....to me I'd rather pay the extra $15 a month on gas if it makes the car that much more fun to drive.

 

I use 24.75 as my tire height in the HPP3. That's what my tape measure says and the speedo is right on. I put Radial TA 265/50/16 tires on the back. They measure 25.75 with the tape and give me 85 mph at 3000 rpm.

Nevertheless having had both 3.42 and 3.73 the revs are high for cruising on the highway over 70 mph vs the 3.42 which didn't feel like a lot more than the original 2.73.

 

Well the 3.73 is definately more "Fun" than the 3.42's, that's for sure! even in 4th gear, it goes like hell.

 

Neglecting traction how much ET gains are seen from 2.73 to 3.42 to 3.73?
I got my 3.42's for pretty cheap, DO i have to buy a new POSI unit???????? I have asked this question over 10 times on here and never once get an answer, what is a 3 series carrier?????

 

if they're 2 series gears, then no, you don't need a 3 series carrier. if they're 3 series gears, then yes, you do need a 3 series carrier (you can get the SLP Zexel-Torsen take-off limited slip differential which will work very well...and is only $100)

 

So what is everyone usng? After I get new tires I am doing 3:73's and the programming. Aren't the gears like $180 or something? Links? Thanks!

 

from what I've seen, Strange makes the best gear.....I haven't heard anyone who has had a problem with them. I'm ordering my stuff from www.thunderracing.com ......Strange 3.73s for a 2 series carrier, a solid pinion spacer, and a Ratech complete install kit......comes to around $332.

 

A 2 series carrier is for gears 2.56 to 3.08. A 3 series carrier is for 3.23 and up with some different shims for 4.10's.

A 3.73 gear for a 2 series carrier has a thicker ring gear which spaces it out to the proper position. The pinion gear is the same I think for both 2 or 3 series.

The torsen carrier uses gears instead of clutches for the posi part and doesn't wear out.

 

2 series?

 

huh? who/what are you talking about?

 

the dude who posted before me...

 

but what exactly are u asking about a 2 series carrier?

 

Will a Auburn Limited Slip Posi Unit work with my current ABS? I heard that the SLP take off unit will not work with the ABS?

This is what i am planning on buying:

Auburn Limited Slip Posi Part # 542040 GM 7.5 and 7 5/8 10 bolt corporate rear. Accepts 28 spline axles for 3.23 and up gears(3 series carrier).

 

you'll need a reluctor ring to retain ABS with the SLP takeoff. I'd rather get the zexel-torsen unit because the price simply unbeatable. yeah, the auburn is rebuildable, but the zexel-torsen doesn't need to be rebuilt.

 

Is performance any different between the Zexel and the Auburn?