I need to find a Dyno and a Track where I can see how my Z would do in the 1/4 mile... I keep reading about people saying their cars w/ 2.73 gears are Slow.. My 02 Z all stock except I have the DM, is by no means Slow.. Floor it and it my rear tires break loose and will spin throughout every gear untill it hits O/D... Drove it down an Onramp last night around 10:45 pm, went from 30, I floored it, when my car did drop into passing gear, my rear tires chirped as well as my car fishtailed a little... Trust me I know my car has 2.73 gears since it has the RPO Code GU2 and it also has the Steal Driveshaft... plus my car has a little over 16,000 miles... Damn this car can get squirly when I want it tooo... Plus this was on Dry Pavement not wet....

 

Well they say on the 98-99 cars the shorties do help a little, but still not too much. But yeah I got .4 and 2 mph for the gears and headers. I'm very confident that I can get atleast another .1 out of the car just by messing with the shift points.
The 60' times were near the same and everything else was pretty consistant as far as weather and track conditions. Probably one of my better mods.

 

I went from a 13.774 @ 103.33 to a 13.419 @ 103.43 by switching out the 2.73 gears for 3.42 gears.

My gains were big in the 1/8th mile, where you'll "feel" the most gains. I went from 9.012 @ 80.78 to 8.658 @ 82.45 with the swap.

To be honest, the 3.42's will give you a BIG SOTP gain. The around town driving with 3.42's is so much better. My gas mileage went down 1.5mpg on my last -all freeway- trip home.

 

^96fbirdA4^: that's awesome. A .335 second improvement is good.................hopefully I'll see something similar then.

 

i agree

 

I think you will go slower

Your 60 ft is terrible and only get worse with a set of gears. I suggest a set of et streets or atleast nitto Drag radials. They will do more for you than any gears. BTW i know people that go low 11`s with 2.73`s. May I also suggest a torque converter . You will knock 6 tenths off your 1/4 mile from a good converter (vigilante/ Yank/ TCS) . Gears are a nice add on but you can other things at this point that will help more. BTW nittos or etstreets will get you 13.5 no problem without the gears. Also you need more than gears if you have a 2.73 you will need to change the carrier also to a 3 series carrier. Not worth the effort at this point but what do i know.

Jeremy

 

Well, I don't buy all of that... I have 2.73 gears and cut a 2.0 60' time with NO wheel spin. Nittos or DRs wouldn't put me in the mid 13 range...no way in hell. On the other hand, wth thos tires and a better gear, the 60' time will go DOWN which means lower ETs.... A converter is a BIG help there too. With stock tires the converter won't knock all that off his time either...gotta get it to the ground...

 

Well i dont think you have an ls1 or you are just not making 300+ rwhp then. I am not looking for people to agree with me . If he is doing a 2.1 60 ft without spinning he has something wrong with his ls1. Im not trying to put anyone down just trying to help a guy out. If you dont have traction you are pissing in the wind. If you do have traction and do 2.1 60 fts gears are the least of your problems go do some motor work. Im not sure what altitude he is at maby that has something to do with it. Possibly thin air or something but i would still go for the converter first and the the tires. BTW a 2002 ls1 should dyno in about 310-320 RWHP SAE..

 

Just as a worthy conversation piece, my 60' actually went down when I went from 2.73's to 3.42's. 2.129 vs 2.044

Those two "best" 60's were run at different tracks, which will make a difference, but it definitely didn't get worse. Both bests were run on a set of 245mm Kumho Ecsta Supras with somewhere between 25k and 30k miles on them.

 

Well mine is a 99, but here are a couple things to consider: convertible top, a4, 2.73 gears... I don't know what the rwhp numbers are...I haven't bothered to dyno a stock car. IT only has 55k miles so it's not ragged out either. It runs 13.95 at roughly 101. And you can't really blame the driver mod...because I have raced a lot of years, cut consistent /5xx lights and won a few events in my 94, including M5 sponsored by this site. I turned in a 1.7 60' with a 12.80 ET on a stock engine from the TB to the exhaust gaskets.
Some cars are slower than others. I've come to realize that. But to say that a car with no wheel spin and a 2.0 time is NOT due to 2.73 gears is not 100% correct

 

You have a convertible that is adding a nice amount of weight to your car. The 2002 cars are making very good power. they have the ls6 intake better exhaust manifolds than yours also. If you pulled 100+ pounds or so ( not sure how much more the converts weigh) off your car and added about 25 hp i think you would spin. With the extra weight you carry around you will need that much more power to run the #`s but then again you can always take down the top and just cruise . My coments were based on his car not taking extra weight of a convertible into it. These cars seem to be very weight sensitive ( atleast mine is ). i think a 2002 A4 with a 273 rear should be able to do a 1.85 60 with traction. I know for every .10 you take from the 60 ft you get atleast .10 in the 1/4 . so with that being said if he could do a 1.85 60 ft instead of his 2.1 he could shave off 5 tenths. thats where i got the 13.5 from originally. If he has a convert also i will take it back .

 

That added weight is what makes me want a little taller gear and I Think it would certainly help in my case...

 

offaxis: I hear what you're saying, but I don't agree with you 100%. I've seen a lot of different times posted on this board --- I'm assuming true, honest numbers --- and lots of cars running 13's with 2.0 - 2.2 60' times. Heck, on the first night I went to the track, one of 60' times was 2.3 (.2 seconds slower) yet my 1/4 mile time was still a 14.1xx (that was due to a lot of dumb Honda owners driving through the water box ).

AS LONG AS I CAN GET TRACTION, I'd like to think that the 3.73's will cut my 60' time significantly. I'd like to see it drop from 2.1 down to 2.0, and if I get DR's, maybe even a 1.8 - 1.9. Like someone else said, a converter wouldn't do any good either without traction, because it would be like dumping the clutch in a standard at ~3500 rpm for example, and the car would break loose no problem. For now I'm running street tires, but once I can afford a set of DR's, I'll get them.

ONE MORE THING: gears cost $350 (CDN). A good torque converter would cost me $1000 ~ $1500. I'm not rich. Do the math.

 

I hate when the ricers go through the water box they dont relize you dont need water on radials. Its so stupid i cant tell ya how many nights they ruined the track for all. Whoever said a converter would be like dumping a clutch at 3500 doesnt own one or needs some driving lessons but Im not gonna get into it . It sounds like you have your mind pretty made up and that is cool. I just offered a different options which I feel would be more benifit to you at this point. But hey What do i know . Take advise on the internet for what its worth most people are honest but some just repeat bad info they picked up on another board along the way. There are always people with slow cars ready tell people how to go fast on these boards. With all that said Ofcourse you will gain from going to 3.73 `s Im sure you will get the .3 tenths if you have traction. I was assuming you didnt have traction and spending money on the Tires would assure you did plus you would still have the same top speed . Plus im also not sure that gears are the only thing you need to buy when you want to install a 3 series gears into a 2 series carrier. Maby im worng but i think it will cost ya more than the 350 candian plus labor.


Good luck with your mods

Jeremy

 

Well, I'm the guy who said "a stall is like dropping the clutch at 3500 RPM (or whatever rpm)" and NO, I've never driven a car with a stall before, but that's "sort of" the idea I thought?? --> not exactly.........but it's to get the motor into the power band more??

And for the gears, I've already got them, it's just a matter of installation. All I had to do was order gears specifically for a 2-series carrier --- the ring gear is thicker, that's all. And for labour, it won't cost me a dime since my dad's a mechanic (yes he's done gears before........and warranty will also be free if he f's up anyway!). So in the end it really isn't a lot of money to me, and I know what effect a gear change has, since I switched from 2.56's to 3.42's in my old '81 Z28.