Heck yea. No idea how to test it apart from bolting it in though LOL.

 

Well, I couldnt wait.

First 2.5 hours spent looking for a lug nut lock. Then I pounded 2 sockets on.

Literally snapped a sway bar end link, so ill be replacing those, thinking of looking for a better rear sway bar either a 23mm 3rd gen or 4th gen ws6/ss but cant decide. Going to buy energy suspension end links, the bump stops fell off when I looked at them so got 2 of those coming and then new stainless steel rear brake lines since mine are covered in rust. Cincinnati sucks for rust, the end links were rediculous, Car has 87k on it but underneath looks like 187k.

Planning to just stare at the TCS and ABS lights for now until I get the axles swapped over. Learning quite a bit about 3 to 4 channel. only big difference is the brake lines.

 

You absolutely can be. Once you have a 3500+ stall speed in place, a gear swap from 2.73 to 3.73 will usually net only 1 to 2 tenths of ET improvement with an LS1/4L60E combo. At that point, the biggest benefit of the swap would be the feel of tighter driveability on the street.

Gear swaps in this range do a lot more to improve actual performance (rather than just driver perception) when you have a stock stall speed. The OP should see a bigger gain as his stall speed is still much lower than optimal.

 

The 2.73's just suck on the street. I dont know how ~3600 would make it any better from that standpoint. For my car the GM55 stall speed should be fine since the cam im running isnt crazy. My drive to work is usually under 2200rpm the whole way, and half of that is 1000 - 1500 with the 2.73s. On the Highway its always in the wrong gear for any fun, roll into in 3rd and it shifts to 4th about the time you want to really hit it, or when it locks up.

 

From an actual performance standpoint (meaning ET - actual acceleration and not driver perception) it would make a massive difference. Stall speed optimization is where the real gains come from, not gear ratio changes in that relatively narrow band (e.g. 2.73 to 3.73). You'd have to go well beyond 3.73 to get a stock torque converter car to run as quick as a 2.73 + 3600 stall speed example (assuming quality converter), all else being equal. It's not just about launch either, there is also much improved shift extension.

Some folks deal with looseness better than others. Nothing wrong with doing the swap if you don't like the feel of 2.73s, that's really the best reason to do so. But had you already optimized the torque converter, much of the measurable performance gain from a 3.73 swap would be negated by the improved stall speed.

You mentioned that your converter is roughly a ~2500rpm stall speed. While it might be "fine", it's far from optimal - even for a stock cam. Something near ~4000rpm will usually provide best performance for most stock to moderate cams, but going much above ~3500 sometimes gets annoying to folks who are more sensitive regarding looseness - especially with 2.73s. Having said that, being in "the wrong gear" also becomes much less of an issue with an optimized stall speed; dead spots go away as the engine will immediately slip into it's powerband at the moment of WOT.

Just to be clear, I'm not saying that you shouldn't do the swap. You're obviously not happy with how the stock gears feel, so that's a great reason to change them. Perception is reality when it comes to something as subjective as road manners. But from a measurable performance standpoint, 2.73s can absolutely be competitive when paired with an optimized stall speed (the advantage being lower cruising rpms in lock-up, but the trade-off is a looser "feel" than with a higher numeric ratio).

 

Right I agree, foot down hard for a 1/4 mile you'll notice a difference with the stall and 2.73s are fine. There's some fast 2.73 cars out there and with nitrous my thinking was you stay in the gear longer so you should technically spray longer of you don't spray through shifts. I think turbo cars are ok with 2.73 as well.

Since I don't have the ss3600 I had to sell with my trans dropped and finding out it didn't fit (was for a vette), the gears are what I'm using to get into the Powerband quicker...plus I don't much care for the loose stall feeling around town where the 3.73s should help tons.

 

This is very true. My truck lopes hard enough with a 205/210 baby cam most people don't believe that's what it is.

 

Just asking as I'm curious, NOT being a jerk, why would you tune it to lope? Just for the sound?

 

Yup. Stock ls and even the new lt engines sound like boats and I loathe it. While tuning I just played with the idle speed, timing, and timing over/under speed settings to accentuate the lope some.

 

Cool! I didn't realize it could be manipulated to that degree!
On the other side of that coin, here in good ol' left-leaning California, If a guy put a Hot Cam (GM or WS6store HighLift) in an otherwise stock LS3, could the idle be smoothed a bunch to sound much closer to stock than it would otherwise?
Good cam, but it does lope a little... And cruising under the CARB radar is the MO around here....

 

We can cut it wider to help like we did for our customer in Germany...but you can manipulate quite a bit with idle rpm, timing, over/underspeed and afr/fuel trims at idle also.

 

Yeah, that IS the ultimate solution. I was mainly getting at "smoothing" the idle of an existing slightly ragged-idling cam. A wider LSA is the real answer if one is getting a new cam.

 

Would advancing or retarding the cam change the idle?

 

Not really. plus it isnt designed to be advanced or retarded. It has 1 less degree of advance ground in than the gm to help ptv clearance but also allow you to use a 5.3 head as well or mill without issue.

 

Hopefully I'll be back on the road soon. Gotta have someone help me carry rear ends, hoping to get it bolted back in tomorrow. Gotta put the stainless tc brake lines on I bought. Stuck with factory sway bar for now, trying to decide if a panhard rod should be bought. I like the fact this cam doesn't require anything crazy to run it, stock pushrod, lifters, spring hardware. Off idle its awesome....not sure if that's tune related or .600 lift, but that was a noticable difference. Haven't been too high in the rpms yet but I can't imagine it stops pulling. Had them aim for 6500rpm limiter

 

First drive with the 3.73s

Rolled into it in 2nd gear and was spinning. But light throttle she drives much better too. 200 for the rear, 35 for new prothane sway bar end links/bushings, 75 for a retune. Money well spent as far as I'm concerned.

There was a time in my life ls1 cars were unobtainable. In all reality I should've bought one instead of the last c4, or vr4, or rt/tt lol, but I didn't. Glad I'm finally in one that's got some mods, and I can say I did all of them. This year she went from a bone stock 87k mile car to full bolt ons, cam, some what of a stall converter, 3.73 rear, koni strt shocks may have been last year or very early this year, that was a BATTLE.

 

Blood, sweat, and tears! We dig it.

 

3.73's work well in a A4. I ran 12.1 with the stock stall with just bolt-ons. Car had lid, ported tb, slp 1.85 rockers, 918 springs, kooks 1 7/8 with kooks true dual exhaust. trans had a shift kit, rear had a torsen t2r with motive 3.73 and most of the suspension upgrades. Car also only had 12k miles and was a stripper hard top...so it was fresh.

 

Get a little whine on the highway, i should probably atleast check the fluid level. Interesting now, 70 is like 2400rpm. Let my foot off at 65 snd i get engine braking.

The best way to describe 2.73 to 3.73 with Lts, ory, bullet muffler....the noise makes sense now!

 

My battle will now be traction. Id be crazy happy with 12.1. Heck 12.4 or under id be smiling all night. Knowing my luck itll do a 12.9x. Or 13.01. Lol.

Think the one thing i want to get done before a trip to the track is a lt1 radiator.

Need to figure out tires for sure.