Max speeds..

[98Camaro3.8]

Originally posted by camaroincal:
Are you sure that the gear ratios in each gear are the same on both 3.23's and 3.42's? Has anyone got to 101 mph in 3rd in there M5!??!?

The transmission doesn't give a damn what rear end gears you're running. Tranny has the same gears no matter what.

[ssms5411]

arthansen
Lookin' for 13's
Member # 5377

posted March 03, 2005 08:46 PM
--------------------------------------------------------------------------------
On the dyno with 3.42's in 4th gear at 6580 rpms I hit 137mph. If that is any help.


Damm, take it easy on the little motor will ya. [img]tongue.gif[/img]

[CtFirebird00]

I have a question about the chart on f-body.org. According to its calculations with 3.42's i would be at 2300 RPMs going 75 mph, this is exactly the same RPMs i make at 75 mph. In addition, my car runs about 2500 RPMs at 80 mph. Because my car has been wrecked i can no longer use the reference chart in the door because it is gone. For some reason i have always thought that my car had 3.08's simply because it doesn't "feel" as fast as i thought 3.42's would be. Is it possible that i do have 3.08's and that my car is just running so inefficiently that i am making the same RPMs as described for the 3.42's? By the way i have a 2000 A4 3.8L firebird. Thanks

[CtFirebird00]

I apologize for hijacking your thread camaroincal but i would also like to add that i have 235/55/16 tires which i believe are the same as factory tires.

[98Camaro3.8]

"1995+ F-Body V6" on that page is only for M5 V6s. If you've got an A4, do a search on this forum for the correct tranny gear ratios.

[camaroincal]

I just took my car out to double check. I payed close attention and 2nd gear hit the limiter at 59 mph and 3rd hit the limiter at 91 mph. So, either I have 3.42's or something is wrong with my car..If there was something wrong with my car, and I do infact have 3.23's as my rpo codes suggest, what kind of problem would be limiting my speeds but allowing the rpms to go up? I have had an exhaust rattle for some time. If the cat was clogged, could this be a sympton? loss of mph even though the car revs to 5500-6000 pretty readily (feels to me like it runs good)

[ March 04, 2005, 08:41 PM: Message edited by: camaroincal ]

[CtFirebird00]

Ok, as excited as i was about the possibility of having 3.42s i decided to give pontiac a call. When i called 1-800-762-2737 they asked me for some personal info etc. etc. and finally my VIN number. It turns out i have the code GU6 which I told them to look for specifically [img]smile.gif[/img] Now the question lurking in my mind is if the 3.42 stock "always" comes with LSD... Maybe you guys can use this number too if you have lost the option sticker and are curious to know what options you have.

[malice10985]

Camaroincal-

THe only thing that could be wrong with your car (that I can think of) would be a slipping clutch. You would know if you had a bad clutch though. It feels like crap.

CtFIrebird00- I am pretty (not totally) sure that all 3.42 cars came with LSD from the factory. I think it was part of the Y87 v6 performance package.

[camaroincal]

Originally posted by malice10985:
Camaroincal-

THe only thing that could be wrong with your car (that I can think of) would be a slipping clutch. You would know if you had a bad clutch though. It feels like crap.

CtFIrebird00- I am pretty (not totally) sure that all 3.42 cars came with LSD from the factory. I think it was part of the Y87 v6 performance package.

HMm, I have 90,000 on it and I believe it's the stock clutch. The problem is, I wouldn't be able to tell if the clutch was going bad since I have been driving manuals for 7 years now, and all of em are used cars with not so new clutches. How could I tell for sure the clutch is bad?

[camaroincal]

I just went for another drive (heh) I tried testing to see of my clutch was slipping. Put it in 5th gear at 40 mph and floored it. Really bogged and the rpm's didn't jump at all, indicating the clutch is fine. I also tried a burnout, and I burned out pretty well. [img]smile.gif[/img] Also tried starting in 3rd gear from a dead stop. The car was gonna die (stall) so it passed that test to.

Next, I wanted to match up my rpms to speeds of 65 and 80 mph. At 65, I was turning 2100 rpms. At 80, I was turning 2600 rpms....So, I check this data against the www.f-body.org/gears link, and that matched right up with 3.42 almost identically... I also just double checked my RPO codes and I do have GU5....3.23...so...I did buy the car used in 2001. The car was a 97 with 73,000 miles on it with no visable modifications. I guess it's possible that the previous owner had 3.42's installed? Another thing, it appears under the square sticker that has my rpo codes listed on the inside of the door , there looks like there used to be a rectangular sticker below it, going length wise up to down, but it was taken off. Does anyone know what this sticker is?

[98Camaro3.8]

If a previous owner did in fact install 3.42s, the speedo would probably be off.

[camaroincal]

Ya..I wish I knew what was going on...LOL

[arthansen]

Here is the methode to figure out what your rear end gears are.

1. Jack up the rear of the car.
2. Put the car in neutral.
2. Put a chalk mark on the drive shaft and at the base of each tire.
3. Rotate both rear tires (in the same direction)exactly one revolution.
4. While rotating the tires, count the revolutions of the drive shaft noting where the chalk make ends up in relation to where it started.

Now, you know the ratio. If it went:

2 turns and about 3/4 more,
you have 2.73

3 turns almost exactly,
3.08

3 turns and 1/4 more,
3.23

3 turns and almost a half,
3.42

3 turns and about 3/4,
3.73

4 turns and a little more,
4.10

Now go jack up that car and figure it out once and for all!

[camaroincal]

Originally posted by CtFirebird00:
I apologize for hijacking your thread camaroincal but i would also like to add that i have 235/55/16 tires which i believe are the same as factory tires.

I just checked my rpo codes and I as well had 235/55/16 stock tires. But I now have 245/50/16. How far would that throw my speedometer off? For instance, if my speedometer is showing me at 65 mph at 2100 rpms, what is my actualy speed and rpms? Also. as I said earlier my speedometer shows about 91-92 in 3rd gear when I hit the limiter. What is my actual speed there?

[arthansen]

Your original tires were 26.18" in diameter. Your new tires are 25.65" in diameter. That is a 2% reduction which equates to a reading that is only 1.3 mph lower reading on your speedometer at 65 mph.