4.10s on an M6 plus Nittos =
Though, the risk of breakage increases, they're lots of fun.

 

Can someone explain what the numbers actually mean, "4.10", what does that number mean in terms of gears or whatever?

 

It's the number of times the pinion gear/driveshaft has to turn to turn the ring gear (turns axles) 1 time.

So basically, if you generate X amount of power per revolution...and you have 2.73 gears, you put down 2.73 * X power (kind of)...if you have 4.10's, you put down 4.10 * X power. (I say kind of- because this is a VERY basic description)

Which is why gearing is a GREAT way to make your car faster- basically you want to cross the traps at the very top RPM range of your engine with your trans in its last gear before overdrive.

Also...
"Higher gearing" = lower numerical
"Lower gearing" = higher numerical
"Taller Gearing" = higher numerical
"Shorter Gearing" = lower numerical
"Steeper Gearing" = higher numerical

(it's late, I think I got them right)

 

Cool thanks for the info.
So 4.10s' in my M6 would definatly be driveable on the highway right? Meaning my RPMS wont be as high as an A4 highway driving i guess.

 

Wanna calculate your rpm with any given gear ratio??? Here is the formula to do so. First we'll do a Three Speed Auto which has a 1:1 ratio in drive ( high gear). mph x rear end gear ratio x 336 Divided by tire height. so a 4.10 gear with a 28 inch tall tire with a three speed auto tachs out at 2952 rpm at 60 mph. Now with a overdrive trans you need to know the overdrive gear ratio ( i think it's .73 but don't quote me i'm not positive). so almost the same formula... mph x rear end gear ratio x 336 x overdrive gear ratio divided by tire height. so if .73 is the correct overdrive ratio at 60 mphand we still use the 28 inch tall tire it will tach out at 2155 rpm. this calculation doesn't allow for converter slip so it will vary a few hundred rpm in either direction depending on how large or small a stall converter you have. Trust me i tach right around 2952 ( about 3000- 3100) with my 4.10's in my 82 Firebird at 60 mph. It's a little higher than the calculation due to the 3500 stall in the car. Hope this helps out . Forgot to mention.....doesnt work for us 6 speed guys but i love the 4.10 in my 2002 WS6 Trans Am.

 

fu*k !!!!! 3000 RPMs@60 with A4 is 2much for me

 

I guess I still don't see where you are saying 4:10's on the highway suck with a A4..How is 2500 RPM at 70 mph is to high ? Or say 75 at 2650 ? And this is with a 25.8" tall tire..

This is my experiance with my car and my almost stock 10 bolt...

It's a 2000 model T/A with 26,000 miles on it that came with 2.73's from the factory..After 500 miles I swaped them to 3.42's used no less out of a wrecked late model..I ran those till I tried a used set of 3.73's out of a M6 car that I eventually ate the ring gear teeth off because like I said there were out of a M6 car that seen plenty of track time..

I logged over 150 passes at the track running anywhere from stock 13.50's to 11.90's after the heads and cam swap at 16,000 miles..This was using converters from 3000 stall to my current old style Vig 3600..Also on ET Drags, ET Streets or drag radials which ever I wanted to try or had at the time..

The only problem was the 3.73's which I bought used and knowing they were well used during the first 16,000 miles..

I had heard so much about how the 10 bolt wouldn't last I almost bought a 12 bolt or 9" after the heads and cam swap but after talking to Mike Hoffpauir I changed my mind..

Anyone who knows Mike knows he has one of the fastest Cam only LS1 cars on this board and still running a factory 10 bolt..Scott (StreetstalkerZ) also runs a cam only car and stock 10 bolt runs low 11's with some really strong 60's..

I decided after the H/C swap I would just rebuild the 10 bolt with aftermarket parts because call me old school or just old the factory 10 bolt isn't all that bad..I ran 10 bolts years ago and they held up behind Big Blocks with no problems..

I went with a Auburn Pro Posi Unit, Moser gears , Moser Axels and a complete bearing kit also from Moser and did all the work myself..Total for parts through Moser was just under $750.Probably didn't need axels but since I wanted everything new I bought them anyway..And after 8000 miles and another 98 passes logged the rearend doesn't leak , whine or has done anything but be pretty reliable..

Granted I don't race every weekend ( actually one weekend a month) or street race and don't claim to be the rearend guru but I'm going to save my $2200 + and put it somewhere else in the car..

 

In my 68 Firebird i have 4.56's and it runs the same rpm as the 82 Firebird does (between 3000-3100). If the .73 overdrive gear ratio is correct and you have a 28 inch tall tire, 2155 (plus whatever for converter slip) so let's guess and say around 2500 rpm with a 3000-3500 converter, that's pretty streetable in my opinion. Then again i consider the 850 horsepower my 1968 Firebird makes to be streetable . It's all what your willing to put up with and that's why it pays to do your homework before doing any modifications.

 

In a car with an A4 and 26" tires you are looking at about 2500rpm @ 60 with 4.10's- not bad. Since it is a lockup trans/converter- there is no slip at 60mph highway driving.

If you want to get a decent idea of what it will be like- drive around with your car in "D" instead of "OD" this gives you a ratio of 2.73 (assuming you have 2.73 rear gears now), while with 4.10's in OD you'd have a ratio of about 2.80 or so... It will give you a "relatively accurate" idea of how it would be like driving normally with the 4.10's (RPM wise). Keep in mind- your gas mileage will be BETTER with the true 4.10's then driving around without OD- because you will be on the gas less- this is ONLY to simulate "how" it will be driving around in that RPM range.

 

Ok so an A4 will obviously be running at high RpMs' on the highway, but Ive got an M6, how big of an RPM change is there in an "M6"?????

 

Sounds like your running an auto? Thats what I have seen as well, however with an m6 its another story...your sure to break a ten bolt at the track.

 

here's a calculator for your gears it's very accurate. i clock 24mpg with my 4.10's on the interstate all day long.

 

Yes..

 

IN an M6, how annoying is it going from a dead stop into first? Is it sooo sensitive that it gets annoying or is it OK going into first?

 

Not annoying at all... I've gotten so used to the gear ratio that I couldn't imagine going back to something like stock.

 

it depends on how heavy your foot is.......you can drive your m6 in 1st,just don't burry the pedal in the floor

 

I have an M6 and on the highway I top out at 90mph @ 2400-2500 rpm. Which isn't bad but would probably be better with a 3.73 gear. In an A4 a 4.10 would probably be a little too much because you don't have enough gear reduction in overdrive.

 

tires spin VERY easy with 4:10 gears...my current SS and my old 98 Z28 both had 4:10
gears and i never had a problem...no leaks , no breaks...but a ton of FUN !!knock on wood!!!