3.42's or 3.73's for my auto?
08-17-2004, 06:31 PM
#1
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Location: South Shore MA
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3.42's or 3.73's for my auto?
Right now i'm stuck with the good ol' 2.73's and wondering what would be better for a cam and head Z? I've heard 3.73s aren't as good with the auto as the 3.42's etc.
Also would it be too optimistic to say that I could pick up close to 2 to 3 mph with the 3.73s?
Also would it be too optimistic to say that I could pick up close to 2 to 3 mph with the 3.73s?
08-17-2004, 06:46 PM
#2
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Re: 3.42's or 3.73's for my auto?
What do you have in mind for your car? I have 3.42's in my daily driver (basically stock), and it is around 2400 rpm at 60 mph. If I could have found a 3.23 used rear-end when I toasted the stock one I would have used it, but I could only find a stick rear.
08-19-2004, 02:20 PM
#8
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Re: 3.42's or 3.73's for my auto?
Originally Posted by Boother
What do you have in mind for your car? I have 3.42's in my daily driver (basically stock), and it is around 2400 rpm at 60 mph. If I could have found a 3.23 used rear-end when I toasted the stock one I would have used it, but I could only find a stick rear.
08-19-2004, 02:49 PM
#9
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Re: 3.42's or 3.73's for my auto?
Yeah with the choices we have for the 7.5 inch rear the 3.73s give the best 1/4 and street performance.
I love the 3.73s, really wake things up.
I love the 3.73s, really wake things up.
08-19-2004, 02:57 PM
#10
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Re: 3.42's or 3.73's for my auto?
If you have 2.73's, just drive all the time in Drive instead of Overdrive. You'll get the same RPMs on the highways (within 100 RPM). Gives you a good idea of life with 3.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
08-19-2004, 03:35 PM
#11
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Re: 3.42's or 3.73's for my auto?
Originally Posted by Gord's Green Z28
If you have 2.73's, just drive all the time in Drive instead of Overdrive. You'll get the same RPMs on the highways (within 100 RPM). Gives you a good idea of life with 3.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
that I have heard. You will definatly gain with 3.73's over 2.73's, stall or no stall.
08-19-2004, 03:37 PM
#12
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Re: 3.42's or 3.73's for my auto?
Originally Posted by Gord's Green Z28
If you have 2.73's, just drive all the time in Drive instead of Overdrive. You'll get the same RPMs on the highways (within 100 RPM). Gives you a good idea of life with 3.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
It's a tough choice either way. Personally I'd go 3.42....but I like cruising on the highways.
EDIT: I see you already have a 2800 stall. In that case, gears will do nothing for you. Just keep the 2.73's.
if I did go with 3.73's wouldn't I finish the 1/4 at a higher rpm? thus maybe 2mph more in the quarter?
08-19-2004, 03:52 PM
#13
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Re: 3.42's or 3.73's for my auto?
373's will put you closer to the top of third gear at the end of the quarter, the 273s have that endless 2nd gear that ends at like what 95 mph? with the 373's your 2nd gear lasts till around 80 or so, then your back in the powerband for 3rd gear until 112 or so, i forget the exact numbers, i saw it on a calculator around here.
08-19-2004, 11:13 PM
#14
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Posts: 521
Re: 3.42's or 3.73's for my auto?
Heads and cam...you going to be shifting higher than stock?
3.73 are fun for SOTP around town, I wouldn't do it for the 1/4 though. The A4's have that great 1st gear ratio (3.06) combined with the 2.73 gives great traction yet lots of gusto off the line. The 2800 stall is going to get you going in a hurry and count on a higher than rated stall with the heads/cam combo.
So 2.73 gets you going with no traction problems then lets you use 1st gear up to about 55 mph before making that dreadfully long wide ratio drop into 2nd gear. With the 3.73 you'd be shifting into 2nd at 40 mph.
With 3.73, you're outta 1st gear almost instantaneously losing the 3.06's advantage, you're having to get that extra shift into 3rd gear and spend the last half of the track grunting your way through 3rd. Don't forget about traction issues with 3.73 + 2800 stall.
2nd gear at 6400 RPM is 110 mph. Should be fine for going through the traps in 2nd.
2.73 = 6100 RPM at 105 mph
3.73 = 5100 RPM at 105 mph
And with the big stall and tall gearing combo, you get brute torque with the converter while retaining gas mileage and piece of mind while cruising down the highway. The best of both worlds. No annoying driveshaft vibrations with the 2.73's.
Personally I find that the 3.73 + 2800 stall for driving around town is almost 4 cylinder feeling. The revs are always jumping up but the car is barely moving. Maybe I'm just used to taller gears though.
I've tried 2.73, 3.27, 3.42, and 3.73 gear ratios.
If our cars didn't have such wide ratio transmissions, the gear switch would make more sense.
Do a search here for reactions after getting gears/converters. Most who have stock converters say gears got them .1 maybe .2 seconds. Quite a few get the same 1/4 mile time. But the ones who went gears after having a stall see no difference. The stall will raise you up in the RPM powerband the same way gears would but without making your last half of the track overgeared.
Stall = good
Gears = bad
I'd put an even bigger stall in there and keep the gears.
3.73 are fun for SOTP around town, I wouldn't do it for the 1/4 though. The A4's have that great 1st gear ratio (3.06) combined with the 2.73 gives great traction yet lots of gusto off the line. The 2800 stall is going to get you going in a hurry and count on a higher than rated stall with the heads/cam combo.
So 2.73 gets you going with no traction problems then lets you use 1st gear up to about 55 mph before making that dreadfully long wide ratio drop into 2nd gear. With the 3.73 you'd be shifting into 2nd at 40 mph.
With 3.73, you're outta 1st gear almost instantaneously losing the 3.06's advantage, you're having to get that extra shift into 3rd gear and spend the last half of the track grunting your way through 3rd. Don't forget about traction issues with 3.73 + 2800 stall.
2nd gear at 6400 RPM is 110 mph. Should be fine for going through the traps in 2nd.
2.73 = 6100 RPM at 105 mph
3.73 = 5100 RPM at 105 mph
And with the big stall and tall gearing combo, you get brute torque with the converter while retaining gas mileage and piece of mind while cruising down the highway. The best of both worlds. No annoying driveshaft vibrations with the 2.73's.
Personally I find that the 3.73 + 2800 stall for driving around town is almost 4 cylinder feeling. The revs are always jumping up but the car is barely moving. Maybe I'm just used to taller gears though.
I've tried 2.73, 3.27, 3.42, and 3.73 gear ratios.
If our cars didn't have such wide ratio transmissions, the gear switch would make more sense.
Do a search here for reactions after getting gears/converters. Most who have stock converters say gears got them .1 maybe .2 seconds. Quite a few get the same 1/4 mile time. But the ones who went gears after having a stall see no difference. The stall will raise you up in the RPM powerband the same way gears would but without making your last half of the track overgeared.
Stall = good
Gears = bad
I'd put an even bigger stall in there and keep the gears.
08-19-2004, 11:39 PM
#15
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Location: Memphis, TN
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Re: 3.42's or 3.73's for my auto?
So you are saying that 3.73s are not good in our cars? I was about to pick up a TA stud and girdle kit for my 10 bolt and probably throw in some 3.73s while I am in there. Guess that isn't a good idea? I have stock 3.23s in there now. By the way I do have an A4.