I have been debating going from 2.73 gears to 3.42 gears. I know there have been other posts similar to this, but I was looking for a little more clarification. I know that 3.42 gears will be quicker off the line, but what about once you get up to around 70 or 80 mph? I know that with gears a lot depends on the speed you're going, but in general, will 3.42 gears pull harder from a high speed roll than 2.73 gears? Thanks for the help!

 

IMO, no. For city driving, where you're not up at highway speeds, lower gears will be better, and give you more "snap" and quicker acceleration off the line. On the highway though, 2.73's are the gears to have. I'm probably the first board member to ever admit this, but I installed 3.73's in my car a month ago, and except for the improved feel off the line, I'm not really happy with them . My friend put 3.42's into his '96 T/A though (A4) and he's really happy with them, but I'm not sure how it is on the highway. I know that my car with 3.73's absolutely sucks at high speeds. I got my a$$ handed to me by a Cobra last week..........cruising at about ~75 mph, we both punched at the same time, and he was pulling away from me as if I threw the brakes on (I gave up once I hit around ~115 mph).

I even went to the track after installing the gears, and the car only went .003 seconds quicker, but ran 1 mph slower?! My 60' time was slightly improved (2.1 --> 2.0) but beyond that, it just wasn't pulling any harder or faster than before...........it just had more wheel spin. ALSO, I got Richmond gears, and after 2 attempts at aligning them, they still whine like a siren chasing me. At this point, I'm seriously considering putting the 2.73's back in until my car becomes a non daily driver, and I've done absolutely ever other mod possible, and they're the only thing left. I want to focus on improving traction, upgrading the exhaust, getting a stall converter, and maybe adding a camshaft before I re-visit the 3.73's. I'm going to keep them around, but put back the 2.73's. In all honesty, I feel like the car has more "dead spots" than before. With 2.73's, it will drop 2 gears a lot of times when you punch it. Now, it never drops more than 1.

Sorry for such a long post, but that's my whole $.02 worth!

 

i might stay with 2:73s longer now. i am either punching it from 30 mph roll or on the highway from a 70+ roll. but sometimes i punch it at i think around 45 mph and i swear im in my v6 . i notice my v6 gets off the line quite nice. it has 3:42s from the factory.

when in my v6 i notice 2 things my z wont do... when i am stopped and just hit the gas 1/2 throttle for a second, the rear of the car goes down more than in my z. maybe because in my z the tires just break loose when i do this? and another thing is when i have the v6 in neutral and my foot on the brake, when i put it in gear the rear lifts up alot more than my z.. all i feel the z do is go into gear, but the rear end wont lift like the v6. think its the gears in my v6?

 

I test drove a '00 T/A w/ the 2.73's.

The highway punch was definitely less than my car w/ the 3.23's.

Note, however, that I had a few free mods on at the time !

The other note is that if your car is your daily driver your mileage w/ the 2.73's will be better than w/ the 3.23's - this may or may not be of concern to you.

Oh, as a side note - this 2.73 axled car had been sitting long enough on the lot that the battery died. The dealer got the jump buggy out & started the car - I got to "teach" the car how to idle - and, how to run when you get thrashed !! That simple piece of information (about the car having to relearn idle ) just amazed the salesman ...

Kinda helps to know baout what you are selling, eh ?

Anyway, hopefully someone got a good running T/A.

My .02.


Britt

 

It all depends on what you're wanting. I like strong top speeds on the highway and 2:73 gears are excellent for that. My car can still snap your neck back nicely upon launch too.

 

ok, here's my toll. 3.73 is a taller gear, therefore it will spin a complet revolution much faster than a 2.73 will. This means that you will lose a little on the TOP speed, but will GAIN on acceleration at ANY speed. and if you car is an auto it WILL be a dog from 40 to 60, any time you floor it in between there. HOWEVER if you get a nice Torque converter, say bye bye to any dead stop. My car is not fast but it is quick, and before my TC I ran a best of 12.78 @ 109. I since broke my tranny, prob. because of the high STR of the tranny. (Too much Torque). Anyways, I would race cars on a roll on the hwy, and all manuals would jump on me, then I would catch up and pass them pretty quickly. Now, with the TC, I always get the jump. TC with 3.73's are great. And for what it's worth, According to my SPEEDOMETER (Which was re-calibrated for my gears) I have done well over 155mph with my 3.73's, which is more than fast enough. Go with the 3.73's. You'll LOVE them.

 

So Michael, what you're saying is that you agree there's a pretty bad dead spot between ~40 / 60 mph, but with a new TC it took that away? Does it also take away the dead spot around ~75 / 85 mph?? I mean, it's not like I'm looking for a kick-*** 1/4 mile car that pulls to 200 mph still, but I've noticed a real loss in the car's highway performance. ALSO, I read in your sig that you've currently got a TCI 3200 stall converter, but you want a Yank 3000 stall? If I (or someone else) were looking for a TC, would you recommend the Yank instead of a TCI?

Thx for your input.

 

I'm confused as to how a rear gear swap has lessened your performance.

Track times are hard to compare with just a few runs. Besides the varying weather and track conditions, there's also learning how to hook well with the different gears.

As for "sucking" on the highway, I'm really not sure how you're arriving at this conclusion. Perhaps it feels different and you perceive it to be slower. Anyhow, the motor is producing the same power as before at a given RPM point. If you're punching both gear set-ups from the same RPM, and from the same transmission gear, the 2.73's can't be outperforming the 3.73's, except in gas mileage. Comparing yourself to the Cobra doesn't mean much either since you never know what the other guy has.

Maybe I'm missing something, and that's now out of the question.

 

Well, I think maybe it's just at certain speeds where I was used to a 2 gear drop, and now it only downshifts one. On the highway, it won't downshift out of OD above ~75 mph, so it takes a long time to pull up over 100 - 120 mph (not that I need it to?!). With 2.73's, it would downshift into 2nd, hold there until ~100 mph, then shift into 3rd and pull upto ~150 - 160 mph. It's just a different "feel" now, but I'm still torn about whether or not I'm satisfied with the 3.73's, and regardless, the rear end has to come apart to do something about the gear whine..........that's when I'll decide whether to keep 3.73's, or put the 2.73's back.

Hey Josh2002LS1: sorry if I've butt in on your thread here?! Hopefully you're still getting the answer(s) to your question(s) though.

 

I currently have a Yank PY3600E, because I will be supercharging my car. Sorry for the confusion. I will fix that now. Yes, a TC will take away ALL dead spots. It pulls so hard from 40, feels ALMOST like it is in 1st gear. I LOVE it. Only prob. is be careful with a TC. I think the power from my TC ate my tranny. That's something I'm still working on dealing with. Other than that, I LOVED driving with my TC. A 3200 stall (Where mine is at now, because my TC is made for a Supercharged car) with 3.73's kicks A$$. I highly recommed it.

 

Thanks! Good to know.

Well, I think I'm probably going to stick with the 3.73's, 'cause they do haul serious a$$ down low. On the highway they're not necessarily the "best" gears, but I don't think they're intended to be.

Josh: You would probably be quite happy going to a 3.42 gear. They're a little taller gear than the 3.73's, so they'll have slightly "longer legs" out on the highway, yet you'll notice a big difference off the line and in the SOTP ("Seat Of The Pants") feel. I think my problem is I'm expecting the "best" of everything all at once..............not very realistic.

 

It's not that the 3.73 gears are slow on the highway. What is happening is that there will be more dead spots with those gears and at certain speeds/rpms, the tranny may not downshift low enough like it would with a lesser gear. And you'll also run out of gear a little quicker with something like 3.73's which forces the car to have to shift into another gear sooner rather than later(thus possibly taking you out of your powerband depending upon what gear you'll be going into).

All things equal, the 3.73's will pull harder than the 2.73's at any speed, but other factors can/will effect the performance of those given gears in different situations. Kinda like a lightly modified M6 with the stock 3.42's will actually hang with a fairly heavily modified M6 with 4.10's @ 100+ 'cause the the car with the 4.10's will be forced to shift more often and into weaker gears(4th & 5th) due to the fact that that motor winds out so much faster with the more aggressive gearing.

Now I'm not scientific with all of this, but it's what I've learned from other boards and people who have actually had experiences with these same exact set-ups in both automatic and manual powered LT1's & LS1's. Feel free to correct anything wrong I might have said.

BTW, the Vig 2800(true 3200) TC I had in my old A4 combined with the stock 3.23's absolutely did not get rid of my car's dead spots. It was great off the line and down low, but the car was still "weak" in that 30-45mph range. To really help combat them, you'll need a fairly big stall. 4000+ will do the trick.

 

Well your talking power at the same RPM while Pete's talking about power at the same speed. Say from 70 mph kick it with a 2.73 car and it lands in 2nd at say 4000 rpm. Do the same thing with a 3.73 car and it lands in 3rd gear at 3000 rpm and the 2.73 car leaves you in the dust. These are not exact numbers just an example.
Now throw a Yank ST3800 into the equasion and punching my 3.42 geared car at any speed will land me in the appropriate gear but the loose converter will put the rpms in the sweet spot every time. It's sometimes down right scary when it hits.

 

OK, that is exactly what I was talking about in my prior post. There are just a lot of factors when breaking this whole thing down.

And I agree. Like I also said above, a big torque converter will help with an A4's dead spots and keep the motor in it's powerband better during the shifts out on the freeway or at the dragstrip.

 

That was exactly my point. IMO, when my car had 2.73's, it would pull over 120 mph like nothing (I reached top speed of ~160 mph last year no prob), but now with the 3.73's, it's in OD from about ~80 mph and up, so to pull over that speed takes longer because of the 0.7:1 gearing through the transmission. That's why I think my car would have done better against the Cobra last week with 2.73's. HOWEVER, since anything over 60 mph is "technically" speeding, then I don't think I should be worrying about how well the car performs at 80 mph + . I think I'm going to leave the 3.73's and keep the hole-shot.