Gears & Axles - 2.73's to 3.73's wow

Well after 4 nights of messing around after work finally got them put in. Saved 600 bucks though doing it myself... as long as it doesn't fall a part. After i bought the nittos 555R's i went to test them out and couldn't even turn them over with my old 2.73's from a dig, even with a 3600 stall. Somebody on here was saying that with a high stall you will only gain .1 on the 1/4 from gears. I think i gained a bit more than that from how hard it launches and the nose really comes up now and scratching for traction I am very happy with my investment and just letting people that are contemplating doing a gear swap know that it's totally worth it in my opinion. 2.73's can suck my balls.

is your car and auto? if so,did the gear swap change your shifting any?im going from 2.73s to 3.73s and was wondering if i was gonna hit the rev limiter or if i had to get the transmission retuned.

$600 for a gear install labor? Seems a little high, usually $200-$300 for a speed shop.

That depends were you are in gear install pricing. In Colorado, Jeeping is a huge sport and shops take advantage of that fact. Your lucky to get away with 500.00 per axle.

Glad you like your new gear set. I will be moving to 4.10 soon myself

is your car and auto? if so,did the gear swap change your shifting any?im going from 2.73s to 3.73s and was wondering if i was gonna hit the rev limiter or if i had to get the transmission retuned.

Yes his car is an auto....He had 2.73 gears which were only available in the A4 cars and he said he has a 3600 stall too :jest:

You should have the car tuned after a stall and gears, if you do them separately you should have it done again so it doesn't hurt the transmission and you aren't missing out on any gains.

Congrats on doing it yourself....

I just made that same change tonight. Mine would spin pretty bad with the 2.73's but I took it done the road for a test drive and it was all over the place. If it doesn't pick up at the track I'll be amazed. I hope you pick up a lot from them. Good luck!

2.73 to 3.73 is an increase of 37% torque to rear wheels,I did 3.23 to 4.56 for a 41% increase(very similar percentage) so I understand your 'WOW'.

what would the increase be from 2.73 to 3.42? wiould it be drastic?

what would the increase be from 2.73 to 3.42? wiould it be drastic?

Yes, I don't know the exact figure but its fairly close to the 3.73 so it would be a huge difference from the 2.73.

Well after 4 nights of messing around after work finally got them put in. Saved 600 bucks though doing it myself... as long as it doesn't fall a part. After i bought the nittos 555R's i went to test them out and couldn't even turn them over with my old 2.73's from a dig, even with a 3600 stall. Somebody on here was saying that with a high stall you will only gain .1 on the 1/4 from gears. I think i gained a bit more than that from how hard it launches and the nose really comes up now and scratching for traction I am very happy with my investment and just letting people that are contemplating doing a gear swap know that it's totally worth it in my opinion. 2.73's can suck my balls.

419 lbs of tq and you couldn't spin your tires even with a 3600 stall because of your 2.73 gears?
I have to ask, how is that possible?

2.73 to 3.73 is an increase of 37% torque to rear wheels,I did 3.23 to 4.56 for a 41% increase(very similar percentage) so I understand your 'WOW'.

Actually, there are a few posts in the dyno results forum where they show on graphs that changing to lower gears will cost you hp/tq, all else being equal.
Gear swaps are great for the seat of the pants feel. And if you have a stall they will make it easier to keep up with stop and go traffic too. But seriously, they just don't seem to have much of an impact on 1/4 mile times if you are already stalled.

I did the 2.73-3.73's first and it was huge difference not to mention with some dr's shaved .4 off my time. Now with a stall - crazy. lol

Actually, there are a few posts in the dyno results forum where they show on graphs that changing to lower gears will cost you hp/tq, all else being equal.
Gear swaps are great for the seat of the pants feel. And if you have a stall they will make it easier to keep up with stop and go traffic too. But seriously, they just don't seem to have much of an impact on 1/4 mile times if you are already stalled.

Well, we def will see if mine helped because it will be at the track tuesday or friday of this week! It would have been today but I got busy.

what would the increase be from 2.73 to 3.42? wiould it be drastic?
I went from a 2.73 to a 3.42 and WOW, it was like night and day. I'd live to get a set of 3.73's but all I have is a 4.10 rear. I may try it for grins but will probably end up keeping the 3.42's.

are those the 4.10s' I sold you a couple years back.
4.10s' grin ?,a bigger grin would be 4.56s' with a yank SS3600 like i've been running for 4 years,but now I'm back to the OEM 3.23s'.

What size rear tires are you running, and are you running a street tire, drag radials, or slicks? I only ask because that 10 bolt is a ticking time bomb. My buddy was running his t/a at the track, he had richmond 3:73 gears with 295 drag radials. The lights on the trees went green and his 10 bolt went snap. So just watch how hard you are launching that car.

What size rear tires are you running, and are you running a street tire, drag radials, or slicks? I only ask because that 10 bolt is a ticking time bomb. My buddy was running his t/a at the track, he had richmond 3:73 gears with 295 drag radials. The lights on the trees went green and his 10 bolt went snap. So just watch how hard you are launching that car.

He has an auto, so he should be fine.

yeah i know my 10 bolt isn't gonna hold up very long with the nittos i don't intend on running it down the track with it. Have plans for an S60 soon but transmission is first on the list. Hopefully have that ordered within the next weeks. i'm more worried about wrecking a 900 dollar stall converter when the tranny goes. But it's not i drive it like a 16 year all the time so i think i'll be okay for a while.

yeah i know my 10 bolt isn't gonna hold up very long with the nittos i don't intend on running it down the track with it. Have plans for an S60 soon but transmission is first on the list. Hopefully have that ordered within the next weeks. i'm more worried about wrecking a 900 dollar stall converter when the tranny goes. But it's not i drive it like a 16 year all the time so i think i'll be okay for a while.

Oh, I think your 10 bolt will hold up just fine on nitto's.
Untill your 60' times get down into the very low 1.5's and under your good.
And you won't see those on your current set-up.

yeah i know my 10 bolt isn't gonna hold up very long with the nittos i don't intend on running it down the track with it. Have plans for an S60 soon but transmission is first on the list. Hopefully have that ordered within the next weeks. i'm more worried about wrecking a 900 dollar stall converter when the tranny goes. But it's not i drive it like a 16 year all the time so i think i'll be okay for a while.

The S60 has been a great choice for many of My customers, hope to hear from You when You get ready.

Thanks,
Carl

When I first bought my car I was not impressed with the down low/city fun factor with 2.73s. Couldn't really break the tires loose on a slow roll, no second gear chirp
(COME ON...really) only power braking. Now with good pedal control, 3.73s are meant for any dd auto.

Well I went to 3.73's a few days ago and the gas mileage is so bad the other rearend may actually go back in. If it doesn't pick up atleast .3 this weekend they are def coming out!

Gears feel amazing... Then you go to the track and you're brought to reality.

Glad you enjoyed the mod. The mpg decrease is worse than the perfornce gain.. I usually recommend 342, same gains with not as many cons.

Well I went to 3.73's a few days ago and the gas mileage is so bad the other rearend may actually go back in. If it doesn't pick up atleast .3 this weekend they are def coming out!
After I was tuned by frost, it didn't seem to suffer mpg consumption as bad. Still 50$ a week so it's just the norm now.

I'm headed to Atl next weekend so ill be able to get an accurate number then. I spent at least 50 before the gears just judging from the last couple of days it seems like it doubled but I'm not sure.

2.73 to 4.10 here, I dont know what traction is even with 315 NT05 tires.

So would a stock car with 2.73's lose to a stock car with 3.42's? I thought gears just made a car FEEL faster.

My car has 2.73's :sad: but going 70MPH I get 27MPG! That's 6 speed territory.

'pure' stock 2.73s' typically run 14.1s',3.23s' typically run 13.8s'.

'pure' stock 2.73s' typically run 14.1s',3.23s' typically run 13.8s'.

A pure stock LS1 with 2.73's runs 14.1's?

since 2001 when I started taking mine to the strips,I would talk to the other LS1 f-bods there to find out their times and mods. 14.1s' with those crappy OEM tires and suspension were typical. Improve the tires and rear suspension will improve the 60ft. Knocking 3 tenths of the 60ft also knocks 3 tenths off the 1/4.

.3 off the 60 usually nets twice that off ET from my experience. And all my time slips have proven this to me.

since 2001 when I started taking mine to the strips,I would talk to the other LS1 f-bods there to find out their times and mods. 14.1s' with those crappy OEM tires and suspension were typical. Improve the tires and rear suspension will improve the 60ft. Knocking 3 tenths of the 60ft also knocks 3 tenths off the 1/4.

Maybe I have a factory freak then? My car is an auto with 2.73's. I ran a 13.56 my very first time out to the track, all stock with Kumho tires. It wasn't just the car's first time out to the track, but mine as well, I'd never been to the strip before.

I ran 8.4@84 with my 98 100% full weight base model Trans Am with only a lid and LM muffler.

That is considerably quicker than the times being posted.

So would a stock car with 2.73's lose to a stock car with 3.42's? I thought gears just made a car FEEL faster.

My car has 2.73's :sad: but going 70MPH I get 27MPG! That's 6 speed territory.

You can't look at a gear ratio and say car A would beat car B... That would be like saying a 98 would win because it has a slightly more aggressive cam grind than an 02.

I have seen it happen both ways... With traction, the 323 car should have an advantage.

.3 off the 60 usually nets twice that off ET from my experience. And all my time slips have proven this to me.

Thats been my experience as well.
If your trap speed is in the 100mph range anyway.

Maybe I have a factory freak then? My car is an auto with 2.73's. I ran a 13.56 my very first time out to the track, all stock with Kumho tires. It wasn't just the car's first time out to the track, but mine as well, I'd never been to the strip before.

I don't think that makes it a "freak", but it is pretty quick.
My car ran a best of 13.82 when it was bone stock with the factory 2.73 gears.