Here is the story
1995 ta a4 no cat 2.5" flowmaster muffler welded in to stock pipes(bought it like that) kn cone, stock 2.73's.The car ran 14.2 @ 99 with a 2.17 60.

I installed 3.42's and then moved in NC. Got a mail order tune and took it to the track in rockingham. The track is about 1000 ft lower elevation so I thinking this thing is gonna fly. 14.01 @ 98.6 with a 2.01 60'. In ohio the weather was nice about 55 out. NC the weather was foggy and thick and about 65. I was pissed so I hooked up my wideband and found out the a/f was 10.4 to 1.So I'm hoping the bad air and the rich a/f made the car slower.I know I ran 2 tenths quicker but add in the lower elevation and the tune and the time sucks.The a/f is now at 12.7 to 12.9 and the car is running good after some adj's to the tune.I tired to hit the track today but it was to cold and they closed the track.Next sunday I'll find out I guess.

Do you think the muffler is worth changing out for a new 2.5 system or the flowmaster(80 ser) good enough.The welds look horrible b/c of the stock piping and 2.5' muffler.

I was hoping for 13.6-13.8 @ 101-103.

 

ttt

 

Try rewritting you question using the standards of conventional English. I have no idea what your question was. Seems like a bunch of tangentialy related facts to me.

 

I ran my car at the track earlier this year.It ran 15.0 at 94 with like a 2.3 something 60ft best on street tires.At the time it had g2 air induction,holley filter,airfoil,tb bypass,2.73 gears.
I ran it again in fall.I had added in 3.42 gears and magnaflow catback.
I also ran nittos but if you look at couple of runs with similar times to the stock tires I shaved about 5 tenths off.So I think in my case the gears were worth about 3 tenths and the catback mabye a couple tenths.That seems about right the mph went up about a mile per hour and dont' think gears raise the mph much.This is in my 3800 raceweight vert at 1900 feet elevation.
I also think going from 3.08 to 3.42 took off about three tenths or so in my 80 ta,did that swap last year.I would say two to three tenths or so from gears if you have the traction to benefit from them.I put some 4.10 in a 97 ta I used to own and it got slower on street tires.
I can't account for the mags sometimes getting no improvements.The grapes of wratch lt1 article also swapped from like 2.73 to 3.42 with not much if any improvement at least that one time but it was different tracks and different days.In the end the car still almost hit 12s with very little actual mods.drag tires,3.42 gears,2800 vig,shortie headers..torque arm..no internal mods at all.
I think the gears did help out.
And if nothing else the car is 1000% better and more fun to drive those 2.73 are just pathetic gears..3.23 are acceptable but 3.42 is to me the perfect all around gear in those autos.But some guys still love their 3.73 and 4.10s too even in the autos.Each to his own.
Add a good stall now and you should see some good results.I have a 2800 vig to install in my car this year and wet nitrous kit,1.6 rockers and mabye a few other mods by springtime.Should be a fun year.

 

Tires? 60' times? Those are the big things that hinder gears. If he was running street tires with both, then it was probably traction issues. Run some DRs with 2.73s, then the 3.42s stomping the gas off the line.... you should notice a BIG difference. When i was running 3.73s in my car for a few days with the A4, 1st and 2nd gear were crazy out of the hole.

Eric...
I doubt it'll be worth the change out, the flowmaster isn't holding you back too much. Get that puppy tuned good and you'll see better results. AFA the muffler.... I went with the Hooker catback, which was under $300 for everything and it sounds great. Not too loud at idle or going down the highway, but it screams at WOT. Sounds much better than the flowmaster muffler for these cars, IMO. For rust prevention, i picked up a couple cans of black grill spray paint (800*) and painted the pipes. Other than the few scraped areas, it hasn't rusted anywhere else in the last 2 years i've had it.