just wondering....any idea what torque increase i could expect by switchin to 3.73's. the car's completely stock right now. also, bout how much would that run me to buy them and get 'em installed by a shop? thanks

 

Torque increase would be approximately.. ohh... I'd say around 0 ft-lbs.

Rather than being an **** and leaving it at that I'll explain the theory..

Gears aren't a motor mod.. they're not going to create more power. Period. They *will* make better use of that power. I'm going to use *VERY* inaccurate imaginary numbers for this example. If you want real numbers, get a calculator. It's 2 AM, my brain isn't equipped for math at the moment.

Let's say you have 3.23:1 gears now (which you may or may not). That means, for every 3.23 driveshaft revolutions, the rear end turns the wheels 1 time. Let's say you have an auto, and it's in third gear, and the TCC is locked, to make things simple, since that gives us a transmission gear ratio of 1:1. So each revolution of your motor is the equivalent of 1 revolution of your driveshaft. So the power of one motor revolution is used to turn the rear wheels .30 times. Let's say you've got a 26" tire diameter, so your tire circumference is VERY approximately 80". Hence the power from each revolution of the motor is transferred to ~25" of pavement. The "power" increase from gears comes in here, where instead of that one revolution meeting 25" of pavement with 3.23s, the 3.73:1 gears apply that same power to just under 22" of pavement.. obviously more power is getting to the ground over a shorter distance. This is a really round-a-bout way of explaining the theory.. the simple way would be saying it's easier for your motor to turn the rear wheels with the higher gear ratios.

 

oh ok, thanks for explaining that, i've never been sure how that works before. so changing out the gears would make my acceleration better, but the lbs/ft. of torque wouldn't actually change? sorry for sounding ingnorant, but what exactly is torque? i know the higher the torque, the faster the acceleration, but what actually changes when you get engine mods that increase torque? oh, and thanks for not being an '****'..

 

Flywheel TQ will not change but rear wheel TQ will improve. Lower gears put the power to the pavement better reducing the loss of torque the motor loses going through the gearbox and rearend.

Lets explain torque this way- You are on a bicycle with 5 gears.

In high gear it takes forever for you to get going, but once you are moving you can cruise fast and easy. now put a rope on the bike and tow another bike- of course you now will not be able to run in 5th gear and more because your body weight will not pull both bikes- but in 4th gear you still can because its alittle lower gear with more torque, you just can't go as fast and basically have lost the use of 5th gear entirely while pulling.

Now in 1st gear the bike starts out fine by yourself, but when a greater load weight is added, you have to stand on the pedals harder to excellerate of the line quicker.

Here's the kicker-
By lowering your rearend gears(Lowering is higher #'s- like from 3.42 to 3.73), you now in essence lower all of your gear ratios in your gearbox( or in the case above ,your bicycle)

Now first gear you can take off just as fast with more weight as you could with the taller gears without the extra weight. You also regain the use of 5th gear even with the extra weight but you just don't have as high of a top speed.

Now all this time on your bike you never change your weight or force on the pedals You on a bike of course are equivalent to a motor in the car. Your bodys torque has not changed but the bikes torque has.

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

Now to go the other way,

Too much of a lower gear and you never use first gear on your bike. You will most likely take of in second gear instead of first because it winds out too fast.

3.73's are fine for drag racing and street driving, but in my opinion they are a bit too low for highway use above 65-70 mph. You'll start to eat the gas milage as well.

I had 3.42's in mine and actually opted to go taller to 3.23's. I put out more power than a stock 2.8 and if you have ever checked, the 3.1's came stock mostly with 3.23's (auto) They have more power to pull the taller gears through a broader power range in each gear = better drivability on the street and highway. I am very happy with my change and am still geared very low when it comes to V8 camaro standards- most of them run 3.08's stock at best.

 

oh ok thanks alot you did a great job explainin that....yeah i have 3.23 right now and was thinking about 3.73's, but i drive about 600 miles every month/2 months roundtrip from college to my house, at about 85mph.....would it not be a good decision then to put in 3.73's with that much highway driving? if it's not a good decision, what about 3.43's? would they be worth my money for that small of a step up? i imagine with 3.43's i'd be able to drive 80+ fine and also accelerate faster, but do you think it's enough faster to spend the $$ on? thanks...

 

I doubt that small of an increase would be worth the money put into it. Take that money and buy something more worthwhile, such as exhaust, intake, or get your ignition fixed up, maybe an MSD 6a box, but I doubt that'd help either.

I HIGHLY recommend a Catco High Flow Converter and the Dynomax Super Turbo catback..$154.99 at Summit for the catback.

 

I agree with Nixon! Don't waste 400-500 dollars for new gears and installation only to go to a 3.43 from a 3.23. It just ain't gonna make that much difference. You could accomplish the exact same thing by putting smaller tires on the car next time. If you really want to do this, then find yourself a used rear end and swap it out. You can do three things simultaneously: (1) lower your gears, (2) get a posi (limited slip) differential, and (3) switch to 4 wheel disc brakes. You can buy a whole posi disc brake rear for about $350.

In reality, what Nixon said will be the best use of your money. Get a cold air induction, a cat back exhaust, better plugs and wires, or the 1.52:1 ratio roller rockers. These things will either help you run better or will add horsepower to the engine. They aren't major, and will also help you with efficiency.

 

We can even run 1.6:1 roller rockers can't we? Of course I don't think they'd fit under factory valve covers....

My advice for a $500 budget (prices are calculated roughly):

shipping included
=====================
*Dynomax Catback-$165-$170
*Catco High Flow Cat-$90-$100
*K&N Air Filter-$35
(A stock replacement filter if you don't want to try making your own CAI...if you do want to try, you can get an Autozone conical for $20-$25, and another $20 or so of ducting, etc. from Home Depot will put you well on your way..but fair warning, these are prone to falling apart. I went through 3 of them myself..mostly because I wasn't happy with my results and got REALLY bored)
*Spark plugs-$25 for a set of 6 Rapidfires
*8mm wires-$50-$60 for a decent set...got my Taylor 8mm's for $55
*Blue Streak Cap and Rotor-$20

The money leftover from these parts should cover installation of the catback and cat if you choose to have them installed and welded for you...and this plan SHOULD leave you with roughly zero dollars left.
And that covers all the basic cheap mods..intake, exhaust, ignition.


By the way..this is EXACTLY what I did to my car...and I used the K&N stock replacement..gave up on making my own CAI. Using the parts I listed above and the rest being stock, I pulled a personal best 0-60 of 8.28 on the G-Tech, with a 16.48 @ 85 mph 1/4 mile. Compare that to a 10.5 second stock 0-60...not a bad improvement!

 

you ever run the quarter with the car stock? i'm estimating it'd be around 19s!!! wow our camaros suck pretty bad stock don't they!! oh well, thanks for the mod list it sounds like a great improvemnt for low $$

anybody here have, or used to have a stock 3.1L with only 3.73's as upgrades? just curious cause i wanna see what'll give better 1/4 times...the upgrades listed above, or simply switching out the gears

 

So a 3.23 will give you less acceleration, but you will be able to achieve a higher top speed. While the 3.73 will give you more acceleration but a lower top speed.
Note: This is supposed to be a question, and yes I know that that small of a ratio won't make too much of a differace but just for referance sake. Thanks.

 

Yes we can but only if you change your valve springs and retainers to hold the extra lift. the stock springs will handle the 1.52 rockers but not the 1.6 rockers. The 2.8 & 3.1 heads are not the best to be messing with due to lack of meat in the castings- the 3.4 heads are much more desirable to alter.

And yes you do need the Fiero aluminum valve covers to clear the 1.6 rockers. Stock covers aren't tall enough to clear the higher ratio rockers. I just picked up a set off of Ebay about two weeks ago for $41 dollars including gromets, oil cap, and hold down bolts.

 

CamaroRS385hp: Stock 1/4 mile times tend to be in the low 17 second range for 3.1's and in the mid to upper 17 second range for the 2.8's. Manuals also tend to drop a tenth or two because of that extra gear and beefier rear ends. Couldn't tell you whether the above-listed mods or the rear would give you better acceleration...but personally I'd just stick with the stock rear. My car did fine with the stock non-posi 3.23...just burnouts were a tad embarassing.

Pyro: Correct. Which is why you don't see many 4.10/4.11 rear end cars running around on the streets..they haul nuts but are gas hogs. (Lower top speed = higher rpms at all sustained speeds) I know..I've got a 4.10 rear in my slightly worked V8...sucker hauls nuts but the gas mileage sucks, even with all new sensors and brand new injectors.

AGood2.8....thanks for the info man. I knew about the Fiero covers, but I didn't know the springs couldn't handle 1.6's! By the way...you STOLE those valve covers!

 

I was praying that no one would see them and post Ebay finds here to drive up the price. I'm having them completely polished. And should have my headers & y-pipe soon- they are being ceramic coated as we speak.

 

Wow...you're gettin your sucker tricked out huh?? Headers AND a Y pipe? Now THAT'S what I'm talkin about!

 

So somthing like a 2.10 (I think i saw that somewhere) would get great gas milage, and be pretty fast, but just take forever to get their.

 

2.10's would be way too tall. It would take alot of throttle to get the car moving and you would entirely lose overdrive capabilities- it would be too high of a gear and your motor would not be able to push it or even hold lower end of top gear without it floored- You'd basically would only have a three speed 1-2-D- (no overdrive)
Edit: I ran some #'s for you and at 1800rpm's in Drive (3rd) you'd be turning 65mph and at 2500rpm's you'd be doing 90. 700 rpm difference in thrid gear is a 25mph variance- it would take forever to pull the car through that gear. And Overdrive at 2500rpm's would be 130mph these little motors could not push that gear to that speed. Third gear could but fourth could not hold or maintain it.

 

Wrong. Real wheel torque will remain the exact same. The car will be faster assuming you choose the correct gears, but that's only due to the way it moves your powerband around and thus makes your power useable. Actual HP/Torque measurements however will be the exact same.

 

Flywheel HP is one thing and RWHP (rear wheel horse power) is another. You have 200 HP and 250 TQ at the flywheel and only 170hp and 210 TQ at the rear wheels with one drivetrain combo and 185 HP and 235 TQ to the rear wheels with another drivetrain combo ( This will change with Converter/clutch, Transmission, driveshaft, and ring & pinion, and tire diameter changes- any one or all five.). Its all how the power is put to the pavement. This is the part that most people don't get when tying to build a fast car- It doesn't only matter what you got under the hood. This is why a lower HP car will beat a guy with all motor.

 

I don't think it would do too much, b/c if you've got a camaro with a V-6 anyway you've most likely already got 3.42 gears or maybe 3.23 if its an auto, it'll just give u more power to the pavement, not really any more torque , maybe a little better 1/4 mile times, but not really more torque

 

More power to the pavement = more torque. Don't you guys understand this? I'm not arguing here/ I'm trying to help you guys understand. I have raced cars for years and have also been around numerous dynoed setups to witness this first hand. I have learned this from an early age( before I could even drive legally -were talking 25+ years), and is why I always build my drivetrain and suspension before I do any engine changes/modifications to a car.

 

your engine will be generating the same amount of torque, its just that less of it will be taken away by the rear end and other stuff, say ur engine generates 160 lbs of torque, generally at the rear wheels its like maybe a 120-130, with different gears you'll get more of that torque to the ground, it doesn't produce and more torque in actuality

 

I thought thats what I just said? We are on the same page. You just don't loss as much to the rear wheels with a better drivetrain which in essence gives you a higher tq # at the rear wheels than with the stock drivetrain. I am in no way implying that you will ever have more Tq at the rear wheels than at the flywheel.