3:73 or 4:10

[2000 Z]

On my 2000 Z, I have a 6-speed and the codes say that I have a 3:42 gear. It seems quick but I wanted something with a little more pull. A 3:73 is not much higher but would a 4:10 be too big of a gear. How much of 1st would I have and what would be the RPM's at 70mph in 6th or 80mph in 6th? I have a comp cam installed. Gross valve lift intake-.522 and exhaust-.529. duration @ .050 is intake-212 and exhaust-218, lobe separation is 114. I don't know if any of this will help is determining but I would and could use the help in determining the right one.

[2000 Z]

Hey, thanks for the input. I won't be installing it until the summer, so I still have some time to make up my mind. I just don't want to be at 3000 rpm in 6th gear and driving the speed limit. I hear that it isn't a simple change out the gears because of the traction control that's in the rear. Someone said that you would need a Tech II or someother computer. As far as I'm concerned, I'll take the traction control out if possible.

[86RedRocket]

I know if you 1/4 race you don't really want to go past 4th on the 6-speeds, so I would see where your rpm's are at when you cross the traps in the 1/4 and see how much more you have left. I like the 4.10's, but I'm not sure how well it would work in your car since it has a cam. Basically I'm saying that you may have too much gear for you to pass the traps in 4th. You could adjust your rev-limiter though. 3.73's do good also, but I would probably shoot for the 4.10's.

[jermzz]

I just had my 3.73's installed on my camaro and i must say there is a noticable difference. Everywhere I went either wouldn't install the 4.10's in my car, or wouldn't warrenty them. The problem is that in the GM 7.5 rear end the 4.10 ring and pinion are so small, when you reach high RPM they're spinning so fast they score. Even when they're broken in correctly. They all said they saw very few cases where the gears worked out. The place I had my gears done was quick and cheap. $470 out the door and they did it in under 2 hours. I think that's a pretty good standard to go by when you're looking for someone to install your gears. I've called many many places and they all said that if you want to go with the 4.10's you really need a 12 bolt. You could also look at the ford 9", Moser makes one that bolts right into the f-body. The ford 9" will let you have 4.11's which is just a tad bit lower then the 4.10's. With the 3.73's i tach roughly 2100 rpm at 80 in 6th gear. My speedo is off, so that's an estimate. with the 3.42 you should tach about 1800rpm in 6th at 80. with the 4.10's you'd tach roughy 2300 rmp at 80 in 6th gear.

Hope this helps.

Jeremy

Bye the way 2000 Z, how much was your cam installed?

[86RedRocket]

jermzz is correct about the 4.10's. Actually the ring gear is thicker, but the pinion gear is smaller. I have seen where Richmond is trying out a new process when it comes to making gears. They actually take and somewhat polishes and surfaces them. It is supposed to cut down on wear and make them quieter.

[2000 Z]

Thanks for the info. But I don't race at the tracks, if I do decide to go, it would only be to see what it can do. For the most part it is my daily driver, I also get on it from time to time against other cars. If a 4:10 is too much for a daily driver and also too much for the 7.5 rear end then PLEASE someone say so, it's too expensive to change my mind later. I would appreciate it, I would hate to have it installed and then have problems with it tearing up or be too high in the rpms for daily driving. I have an 89 mustang also (weekend street racer) and I built it up and I have a c4 with a 2800 stall and a 4:10 gear and it moves and does good. Would there be that big of a difference between the two, could I gauge how the camaro would run by the way the mustang tach's up and cruises or will the torque converter throw off the comparison? As for the question of how much it cost for the cam installation, I did it myself. $419 for the cam and $200 for the new springs and retainers and a lot of cussing and cuts. I was talking to a guy at Ramchargers and they had a class telling of how the stock springs in the camaro's v-6 through the SS are barely strong enough to handle the stock cams. So if you do decide to do a swap, change them.

If you are using it for a daily driver you may want to look at a stall converter, it will give you a quicker hole shot without worrying about winding your mill up at highway speeds, the right one may even give you a boost in off the line torque

[jermzz]

Do you have to take the engine out to do a cam install, or can it come out the front?

Thanks for the info
Jeremy

[2000 Z]

Originally posted by jermzz
Do you have to take the engine out to do a cam install, or can it come out the front?

Thanks for the info
Jeremy

No, you don't have to take the engine out, it does come out the front. You do have to take everything out of the front. The radiator and condenser, water pump, all the other stuff stays where it is. I got the directions from the old z28 site in the how to section. If you have any other questions, feel free.

[2000 Z]

Originally posted by ron
If you are using it for a daily driver you may want to look at a stall converter, it will give you a quicker hole shot without worrying about winding your mill up at highway speeds, the right one may even give you a boost in off the line torque

My camaro is a 6 speed, I was just wondering if I could compare the cruising in my mustang, which is an automatic w/4:10, to my camaro if I was to put a 4:10 into it. Just to get an idea of what the Z would be like with the same gear.

[jermzz]

Originally posted by 2000 Z
No, you don't have to take the engine out, it does come out the front. You do have to take everything out of the front. The radiator and condenser, water pump, all the other stuff stays where it is. I got the directions from the old z28 site in the how to section. If you have any other questions, feel free.

Thanks, i'll look into it!

[garfin]

Originally posted by 2000 Z
Thanks for the info. But I don't race at the tracks, if I do decide to go, it would only be to see what it can do. For the most part it is my daily driver, I also get on it from time to time against other cars. If a 4:10 is too much for a daily driver and also too much for the 7.5 rear end then PLEASE someone say so, it's too expensive to change my mind later.

OK - I've got 4.10s with headers and a mild heads and cam pkg. I also don't go crazy on the drag strip, as my focus is road racing and autocross. I've had these gears for 2 years now and they have a little under 20,000 miles on them. I beat the crap out of the car on the road course and autocrossing, but at the strip, I only launch at about 2000 rpm on Firehawk SZ50 EPs (best 60' = 2.04 - no big deal) The guys who have problems with 4.10s at the strip are doing hard launches on drag radials. I've have seen a few stock rear ends grenade when using this formula.
As a daily driver, I love the 4.10s - the car is always on edge and rarin' t'go! I only lost about 1.5 mpg at hwy. cruising speeds. 70 mph is about 2150 rpm (give or take, depending on your tach.
One of the best bang for the buck mods out there, IMHO.

Best regardSS,

Elie

[2000 Z]

Originally posted by garfin
OK - I've got 4.10s with headers and a mild heads and cam pkg. I also don't go crazy on the drag strip, as my focus is road racing and autocross. I've had these gears for 2 years now and they have a little under 20,000 miles on them. I beat the crap out of the car on the road course and autocrossing, but at the strip, I only launch at about 2000 rpm on Firehawk SZ50 EPs (best 60' = 2.04 - no big deal) The guys who have problems with 4.10s at the strip are doing hard launches on drag radials. I've have seen a few stock rear ends grenade when using this formula.
As a daily driver, I love the 4.10s - the car is always on edge and rarin' t'go! I only lost about 1.5 mpg at hwy. cruising speeds. 70 mph is about 2150 rpm (give or take, depending on your tach.
One of the best bang for the buck mods out there, IMHO.

Best regardSS,

Elie

I'm sorry, but I am still new to some of the acronyms. What's IMHO? Thanks for news. I will be putting a 4:10 in my 00 Z 6-speed.

[TwoFast4Lv]

4.10s are a VERY nice match for a six speed car till you start putting ALLOT of HP through it. THEY 4.10s Are still nice you just need a 12 bolt or 9in

[garfin]

Originally posted by antivenomous95
Is ur car an A4 or M6, tryin to get an idea of how many MPGs id lose on the highway.

It's a 6MN. 4.10s are a bit much for an A4 everyday driver - especially on the highway. The 0.50:1 6th gear overdrive ratio is tailor-made for 4.10s and allows for effortless highway cruising, even at speeds above 70 mph.
Go to http://www.f-body.org/gears/
and dial in your tire and gear combo to see what your rpm will be at different cruising speeds. I think your questions about highway speeds and rpms will be answered satisfactorily by using this little calculation site! It sure answered a lot of my questions!

Best regardSS,

Elie