EDIT: current build list being discussed
Ls6 intake/cam/heads, bassani lt's, catted x, z06 cat back, keeping current k&n intake hypertech tuner/dyno tuned



Im brand new to the C5 world. Im thinking a little more power to my 98 A4 wouldnt be a bad idea. So far my car has a K&N intake, and exhaust. Let me explain the exhaust. The stock mufflers were cut off and tips welded on. On the forward side of the axle, the Slp loudmouth mufflers are welded in. The car came this way. Im only looking for a little more power. My goal is about 370rwhp, just looking to have a little fun without loosing any relieability. This car is a daily.

Because of the way my exhaust was done, I assume I would have to do an entire new exhaust system if I added headers. I did consider possibly swapping out the cat back for a stock Z06 system and doing headers with high flow cat's later. I heard the stock Z06 is good and I thought this setup may keep the nosie down. Thats down the road and Im still researching options there.

I also read somewhere that swapping the manifold, getting into the engine, can start to causing little things to go wrong.

If any of this is a bad idea, or they are better parts, or anything I should know, please let me know. I have spent the last 3 days searching around. I have only come up with a little info, but Im not sure if its the right path for me.

 

Most limiting factor right now, probably intake. Ls6 intake is cheap and easy with results. Probably all top end tho. Vararam intakes are nice. Probably want a tune with that combo. Better torque convertor in general speeds up an auto also.

 

And I dunno personally, but new rear end gears seem to be good bang for buck w/ auto vettes.

 

Convertor and a set of 3.42's are going to be the most noticeable change you can do.

 

welcome,
like they said first thing is get a ls6 intake manifold any camaro or corvette 01+ got them
ls2 TB is worthless for a bolt on car if anything find a ported throttle body, it wont give you more power but will have better/faster throttle response
gears is great also is a upgraded torque converter just depends if you mind dropping a few mpgs
my car is a 01 A4 I'm switching my 3:15s for some as we speak 3:42s
got a Vararam with a bigger air bridge and ported TB car equipped with ls6 intake already.
with borla stinger catback, i would like long tubes but living in California i wont pass smog
all that stuff will help top end,
but you should check if you have 3:15s or 2:73 gears the best performance you will get will be on Gears and or a torque converter.
i would find a good shop to tune your car predator cannot pull out all the power you like plus they will tune the transmission to react better with and fix shiftpoints if you do stall it or gear it.

 

Try a trans tune to wake it up. I believe ECS is still providing a mail order tune for around $100.

If that's not enough, then converter and/or gears will make it more fun to drive.

Headers and a tune is about the only mod that will get you more than a 10hp gain.

 

Im ok with only gaining a little power. I understand i wont get much, and im truely not looking for much.

So the predator can tune the transmission? Hows that work? My Mach 1 was a 5spd so i didnt know anything about it. Is there a better unit than the predator?

Are you all saying i should swap the k&n intake?

How should i go about all this? Can i put these parts on piece by piece and save the tune till last? Or should i do them all at once right before tune?

Im glad you all mentioned the tb. So a portes ls1 tb would be the best for everything else?

 

I got the ECS tune at Carlisle last week. I am pretty sure it was $150 and the mail-order tune is the same price (I asked about it as I have my own mods slated). The AR headers and that tune REALLY woke the car up. I have a 6-spd Coupe (2000). I seem to recall the price for C5 autos was also $150. C6 autos were $250 for some reason. I believe in both cases the transmission settings were altered.

 

Any idea of a ball park where id be with these mods?

I think ive come up with a goal. I want to look and sound as stock as possible. Yet still be a challenge for newer cars like camaro ss's, challengers, etc. Maybe even a ls2 vette. Not really in the 1/4 mile but when it turns into more spirited driving.

 

You and I have some things in common...I'm like 6 months ahead of you on this. I just installed Z06 catbacks on American Racing Headers. Awesome combination, I have about $2100 in it, it sounds like sex. Your current exhaust is loud and not my style but to each his own.

Your LS6 intake should be $3-400, it depends how you obtain it, look on the FS/W section for going rates. The LS1 & 6 TBs are the same diameter so I'm not sure I follow putting the LS2 TB on the LS6 intake...from what I hear the TB is a mod you don't need until you are fairly far along. A CAI like Vararam would be more productive for you at this stage.

I would personally group your mods and pay ECS for a mail-order tune...they tune with any bolt-ons for $150 mail order, and they've seen all the combos and know what they are doing. I don't mean to disparage the Diablosport at all, I have 0 experience with it, I just know guys who have blown up their cars with handheld tuners, and none who've had it happen from a reputable tuner's services. I have heard of it but ECS is reputable enough they will set you right if that happens, which I think is extremely unlikely.

Honestly if you are not looking to compete in the 1/4 mile with the Camaro SS (hard to do in a reliable C5 without driveline upgrades IMO), but rather spirited driving...I would put suspension upgrades ahead of these engine mods. I had no idea how much of the car I was not using because I didn't feel it was surefooted. I have 2012 Z06 shocks and ZR1 sways on my car, it is night and day. Do something like that, then lighten the car some, especially your unsprung weight (lighter wheels, ditch the runflats), and you will have a really fun car.

 

Any chance i could head the exhaust somehow? Video? Unless your local to MD lol. Im not too fond of loud exhaust anymore either but mine has really grown on me. Thankfully the C5 is refined enough that its fairly quiet inside. I love that about the car.

I never knew you could do zr1 sway bars and stuff. Thats a damn fine idea!

As for the tuner, the predator was just an option. Only one ive had expierence with. I thought about going back to the same guy who did my Mach 1. Hes pretty well known in the Mustang/Lightning world. I told him i didnt want to go crazy with the Mach and he did a grea job. That car was smooth and a blast to drive. I believe he does f bodies and Vettes as well. I know he only uses the tuner as a medium to transfer it to the car. I have nothing against a mail order tune either. Dont you need the software to load it into the car? Just comparing all the options.

Id just like to be able to hold my own if the occasional c6, or ls3 ss decides to pick on the little 5.7. I got a buddy thinking of getting a 2010 SS...i cant just let him walk all over me lol.

 

Will PM you.

 

I don't think you want ZR1 sways. The C6 Z51 bars would give a better balance for a C5 without tubs and they're the best deal around new. Think 275F/335R wheel combo's to require the C6 Z06 or ZR1 bars.

 

Oh ok, I dont plan on swapping the wheels. I like the stock polished 5 spokes on it.

I really need to check out a car with some of these mods. See what the difference is, how the cars drive/ride.

 

Heh, I think you are right. I double checked and Z51 is what I actually have. In my defense those two designations look pretty similar. Anyway, yeah, thumbs up for the Z51 sways.

 

UPDATE: i now have a goal...well, kind of a problem. My g/f just picke up an 03 Cobra. Its a vert so its got a little weight, but its got intake, catback, 2.8 pulley and tuned. Not sure of the exact numbers, we want to take it and have the a/f ratio checked and see how much power it makes. Anyway...i cant let her just demolish the vette. Now im regreting the automatic... Ive still only got the catback, and intake. I found diablosport doesnt make a tuner for the 98. They said the wiring is different in 97,98 and in 99 they were able to work with it. I dont know much about other tuners and havent found much in my search. So far my research has led me to this list:
Try to find some used long tubes, catted mid pipe, z06 catback, ls6 intake. Budget is a significant issue, get it dyno tuned, not sure what tuner to use. Either way, id like to atleast not get destroyed by the Cobra lol

 

If your A4 came with the normal rear and that cobra is going to rape you. You need to at least upgrade to the 3:42s and a converter. LS6 intake, long tubes, etc may get you 30hp in the upper rpm range. You need low end power.

 

Agreed. A 3.42 diff and a high stall converter will make having an automatic be something to brag about.

 

How can i tell what rear i have? I also still cant figure out if i have stock intake manifold or not.
I think i wanna add to this list. Im still doing research but i think i want 243 heads, prefer ls6 over ls2 i guess. Also an ls6 cam. I read that supposedly if you use the ls6 heads, intake, and cam, you dont even have to tune it? I dont see how thats possible but what do i know... So heres my updated build list:

Ls6 intake
Ls6 cam
Ls6 heads
Bassani headers
Catted X pipe
Z06 axle back
Hypertech chip then dyno tune

 

You can either look underneath the rear on the side of the diff and the ratio will be on a placard. Or you can look at the code in the glove box. GU2 is for 2.73, G90 is 3.15, and GU6 is 3.42.

I am pretty sure you could get by without a tune, but I would not recommend it. You will get much more out of it with a tune. And if you are going to go through all the work of changing or having the cam changed, you should do a way better cam.