on the freeway today and noticed i had to really get on it to pass other cars. Just got the car it's a A4 98 Z28, It's got a loudmouth kit on it, It recently changed oil to mobile 1 full synthetic, pumped all the trans fluid out and replaced, fuel filter, trans mount and K&N filter. I'll change the plugs next week, but i don't think that will make a major differance, I just remember feeling like my old Z28 A4 93 was much faster.

 

could easily be the result of some less than ideal gearing.

alot of the A4s came with 2.73 gears, which are well known to have a "dead spot" in the rpm range.

or maybe your trans is slipping.

 

That would be my guess too.

 

I think I got 3.23 gears, I got 1 and 2 gear on the gear selector

 

my 93 came with 2.73 and 110mph speedo, she was hot all the way till the 108mph limiter(car wasn't ordered with z rated tires). My 93 ran hard, even on the day the tranny went out. I think it went out because I swaped a 95 3.23 rear.

 

I'm not sure, but didn't the LS1 cars have the 1 and 2 gear option select regardless of gearing? The sure way of knowing would be to check the RPO codes.

 

which code should it be, i can go check now?

 

Gu2 = 2.73
Gu5 = 3.23

 

damn, i got 2.73

 

If the plugs are worn or are in need of being replaced for some other reason, you WILL notice a decent change in how the car runs, idles, accelerates.....I just replaced the plugs in my car and feel like I picked up 10 rwhp! Granted, that's 10 hp is should've had before, but nonetheless. Do the wires too while you're at it.

 

2.73 explain everything, I need some lca, one of mine is crushed.

 

time for a cheap 3.42 swap from an m6

 

Yeah a 3.42 works really well in a auto LS1 for DD and highway. And you can usually pick up a complete take out rear for $300-400. Just make sure that it has the same ABS set up. TCS/ASR cars are 4 chanel and the rest are 3 channel.

 

ok, just swap rear from m6 car, now getting abs issue's, she still not faster, also got slp air lid and did eibach pro kit spring in rear, lca relocation brackets

 

Your car doesn't feel faster going from 2.73s to 3.42s? Something is WAY wrong... I could feel a difference in changing from 3.08 to 3.55s in my GT and 2.73 to 3.23 in my old Formula. 2.73 to 3.42 is a big jump and should be readily noticable...