M5 Best Gearing info is lacking in tech database - please help

[Cale]

As subject implied I searched database, most of info for gearing is on autos, not for my beloved 5 speed. (when I say tech database, I mean messageboard history actually)

Anyhow, I have 02 M5 w/ the 3.23s. Iam itching to drop in zex LSD and lower gears. My only problem is which gears!
Stuff to keep in mind:
My car does sit a bit. I put on the average amount of miles on a car at 1k a month.
I do maybe 2 or so hours of highway driving a week (60mph). Rest is in town.
I like to baby the RPMs--I dont get on it much, but I do like accessible power when I want it. Over the summer I will make some track runs, but Im not avid about tearing my car up either. I do want the times as impressive as they can be for a stricly N/A car though. It will see a little bit of street racing as well (nothing hardcore).
I don't want any less than 20 mpg.

So, with all that in mind plus just the facts that are known on what is best for the 5 speed, what gearing should I look at?

And like I said, I already baby the RPMs... I could probably do it just as well even with the engine rapping faster.

Thanks all

Cale

[ December 28, 2001: Message edited by: Cale ]</p>

[Bene]

You can always get 2.73 gears. Although that will hurt your ETs. Thats what stefan has on his Virus. I say stay w/ 3.23s. I like it. I get more than 420 miles/ per tank on highway driving and I get 350ish/ per tank on city driving.

[TealV6]

The tallest gear you want to put in your car for your specs would be a 3.73 gear. Myself having 3.42's with posi and on the highway often, I drive 70 (only 5 over the limit) and see about 2400 RPM like that. So you will have a few more RPM's with the taller gear.... but it's not unmanagable.

If you plan to be streetable... DO NOT GO BIGGER THAN 3.73'S.

Steve [img]graemlins/burnout.gif[/img]

[Cale]

I appreciate the reply Teal.

Now to you & then someone who has 3.73s (knowing you have 3.42) - how is your top end? When I say top end, I mean, when you're going highway speeds, and drop it into the highest available gear, does it still pull fine or "fall on it's face"?

Another question is what gear you finish in, in the 1/4 (if you've ran) ?

And finally, what'd you (questions also still directed at someone with 3.73s) to correct the speedo?

Sorry for the hassle, just doing my homework.

Thanks All [img]smile.gif[/img]

Cale

[WickEdSix9838]

Hey bene, i know this is off the subject, but looking at your webpage, is that 9.96 1/8th mile time on the same run as your 15.2??? just curious, thanx
Lance

[CamaroBill]

In response to correcting the speedo. for gear changes, the Hypertech Power Programmer III will take care of it. I've done the HPPIII mod on my car (also an M5) and noticed a SOTP gain in power. If you do the 3.73's let me know what you think because I've been contemplating doing the same, although the stock gears seem pretty good all around (easy to control wheelspin off the line and good power at speed + great mileage). I already got a LSD (mine came from the factoy with a peg leg) and was thinking of doing gears at the same time but figured I'd let someone else on the board be the "guinnea pig".

[Cale]

The HPP3 is available for my 02 v6?!?

Thanks!

Cale

[TealV6]

<blockquote>quote:</font><hr>Originally posted by Cale:
I appreciate the reply Teal.

Now to you & then someone who has 3.73s (knowing you have 3.42) - how is your top end? When I say top end, I mean, when you're going highway speeds, and drop it into the highest available gear, does it still pull fine or "fall on it's face"?

Another question is what gear you finish in, in the 1/4 (if you've ran) ?

And finally, what'd you (questions also still directed at someone with 3.73s) to correct the speedo?
<hr></blockquote>

Top end is fine.... while crusing in 5th, you can drop 4th with no issues and have plenty of "pull" power. As for staying in 5th and "hammering" the gas.... she's ok, but I've got the 3.4 and she's getting tired. If you have to pass or get moving fast, drop 4th gear.

I personally finish in 3rd. And I'm topping out 3rd at that. If I was to change to 3.73's I would definately be pushing the limits of 3rd gear or start banging off the rev limiter.

Yes, HPP3 is out for the latest V6 F-bodies. You can also, if you don't want to spend that much. Check out SLP gear change "black box". It is available for the latest V6 also.

Steve

[Cale]

Once again Steve I do appreciate the help!!

One more question though (sorry): does your 3.4 and my 3.8 rev the same in terms of where I would end up as well in the 1/4 with 3.42s (or aside from you, 3.73s?)? I wonder if the hypertech function of raising the rev limit another 500 rpm would solve this problem and allow me to finish in 3rd with persay the lower geared 3.73s --

One last call for anyone with a 5 Spd and 3.42s and or preferabbly 3.73s - where do you all end up in the 1/4?

I really do thank anyone who has some information.

Cale

[Cale]

According to http://www.quiknet.com/~ke6vut/rpmcalc.html

^^ their RPM calculator

With 3.73s gearing, a tire diameter of 25.66 (275/40/17), the M5 3rd Gear ratio at 1.34, and assuming the hypertech reprogrammed rev limiter to 6500, I could go approxmiately, somewhere in the ballpark of 99.225223 mph [img]graemlins/burnout.gif[/img] before hitting the 6500 rev limiter in that 3rd gear. Is it safe to assume I probably won't go that fast unless im running juice?

[Cale]

ttt

oops! buttons slipped!

[img]graemlins/omg.gif[/img]