IMOTEPHT

I have a 1999 Trans am LS1 A4. Just wondering what I might be looking at for 1/4 numbers and speed.

~SLP lid
~Smooth bellow
~K&N filter
~EGR mod
~TB bypass
~TB bump stop
~Free ram air on the filter box and plastic cover below

SMALLBLOCKHERO

iTrader: (2)

similar to mine without cat back. i have 2.73s and run 13.6-13.7s at 103 mph

IMOTEPHT

2.73's are stock in a A4 aren't they? Whats a good catback to get thats not to expensive. I don't need anything crazy I'm just going to drive this car and track it a few times.

ErikElvis

iTrader: (1)

you could have 2.73's or 3.23's. I dont know the codes but you can look them up real quick and get it off your driver door build sticker. expect anywhere from 13.5 to 13.9. If you get below 13.5's you'll be doin good.

Edit: and for a catback you really cant beat the SLP LM's for the money. All stainless and very free flowing. I have a LM2 and its not obnoxious at all. especially with stock mani's.

Duffster

iTrader: (103)

I concur...high 13's until you get used to the car at the track.

IMOTEPHT

Cool.

95 Z28

iTrader: (21)

If you're going to keep your stock exhaust mani's for a while go with the loudmouth...it sounds great with stock mani's/cats. Won't hurt the pocket book either. Or you can look into Hooker, they're cheap and sound good. I'd bet you'll run in between 13.5 and 13.7, maybe a little lower if you have 3.23s.

IMOTEPHT

How do I exactly find out if I have 3.23's? I just put a 80 series flowmaster on today cuz it was cheap.

95 Z28

iTrader: (21)

I think you can look on your door jam at the options your car came with...I believe the 3.23 option is GU5 ...if it has that then you have them. Someone correct me if I'm wrong though. You should get a cutout too, cheap and definitely worth it.

IMOTEPHT

What is a cutout and what does it do for performance?

SCHP98ls1B4C

iTrader: (2)

Your door codes gu5 is 3.23 good gears and gu2 is grandma gears

95 Z28

iTrader: (21)

It bypasses the muffler, you can uncap it and run open exhaust at the track and it will give you a little more power when you have it open. The manual ones can be had for like 30 bucks. If you're not sure what I'm talking about then take a look at some of the vendors exhaust accessories sections on their websites.

IMOTEPHT

It said GU5

green28

iTrader: (8)

So you've got the 3.23 gears. For referance I ran 13.5 @ 103-4 with just a lid and loudmouth. And I have 2.73 gears.

bjamick

iTrader: (31)

I will suspect prob 13.2-13.6 @ 103-106 depending on 60' and weather.

Jakes Dad

Does it have a Black hood? What color is the car? Can you bring it out of the hole, thats a DID for those that have only raced on the street.

Matt D

iTrader: (49)

I would say 13.3-14.0 depending on weather, driver, and traction.

Here is a good read for you: https://ls1tech.com/forums/generation-iii-external-engine/520845-mod-guide-induction-exhaust-please-read-before-posting.html

IMOTEPHT

Mine is that mystic color if your talking about mine. So the 3.23's were just a extra option or something? Then it looks like I'm looking at mid to high 13's.

SMALLBLOCKHERO

iTrader: (2)

HUH!?....funny thing is...i i took out my cut out. and put on my TSP rumbler cat back and picked up tenth and .5 mph. and it ran more consistant.

and yes 2.73 to 3.23 were optional gear sets for the A4. wether it was justa production line car or ordered( i beleive all B4C A4 cars were 3.23 never seen a 2.73 one yet)

IMOTEPHT

Now are the A4's faster than the 6 speeds?