I have a 98 Z28 A4 bone stock and am wanting to modd it slowly.(Lid, cam,heads,headers,off road y, catback, new intake manifold, 90mm throttle body, touque converter) My car is strictly for street use and daily driving, maybe once or twice a year at the track. What brands are the best for these applications(SLP,Bborla?) Where should I start and what should i get to make the most horsepower and Toque? Will any of this make my car not reliable on the streets?? Thanks

 

You can go fully streetable to upwards of 500RWHP. but the streetability is depding on what you want to spend. I've seen a 640 rwhp turbo ls1 that was streetable, but thats overboard.

The first question is really what are your HP goals?

Lid+filter+long tube (LT) headers+exhaust+ ported TB will give about 320 rwhp. Then you get into cam/head options. head/cam (H/C) packages can take you up to about 500 RWHP. The best bet is to not mess with the rocker arms, the stockers are great. But on milder applications the intake becomes a bottleneck at about 400rwhp, so an upgrade to an LS6 is needed. The stock TB can be ported and support about 450 RWHP. Stock heads arent a bottleneck untill about 400RWHP. But a more mild cam + ported heads can give about 30-40 HP over the same cam, and going with a smaller cam and better springs will mean a longer spring life!

To answer the question about brands, any really. For exhaust, on headers steer away from the over priced ones, like stainless steel or slp or kooks. Although QTP and Kooks are the best, the performance gains are very small untill you hit about 500rwhp. Cat-back, go with anything except for flowcrapster and borla. All have about hte same HP gains, but the flowmaster sounds horrible and the borla is just a 600dollar cutout (buy one for 30 bucks on stock exhaust if thats what you want) plus cutouts give about 5 rwhp more than catback. For the airlid, a lid is a lid. all flow better than stock. I ported my TB myself, its easy, but costs about 150 to have done elsewhere.

 

just read around the forum...check out what people are using for components like headers, heads and cams.

and read!!!

and definatly make a goal.

you can easily make 425rwhp with lid, intake, ported heads, high 22x or low 23x cam, and a dyno tune.
you'll need a good dyno tune and supporting drivetrain mods like torque converter and gears (since you have an auto).

you shouldn't have to worry about a big 90mm tb for a while...depending on your goal it probably isn't neccessary.

and before mike (Kraest) jumps in....i'm gonna say it...

"you can make almost 450rwhp with an F14 cam, dart 225 heads and FAST 90/90".....

 

Thanks for the info. I would like to see 400rwp to 450rwp. For a cutout, where do u make it and how big? Also, how would you go about doing an electric cutout? Would a cutout in the stock exhaust be okay? thanks

 

for those power levels you'll want to upgrade the exhaust. if nothing else run some 3" pipe off the headers/ypipe into a 3" cutout...then you could hook it up to the stock exhaust from the cutout back.

but honestly i would suggest going with a decent full catback that flows well, like the TSP rumber.

400rwhp is doable with a decent size cam, but driveability will be semi-compromised

450rwhp will require heads on top of the cam

 

Do you have a picture of what a cutout looks like or where i can find pictures of a cutout so i can visually see it becuase im not fully understanding where it is?