Hey Everyone. So I'm pretty sure my 02 Z ate a valve. I still need to take the valve covers off and heads to really see the extent of the damage. I'm hoping a valve isn't lodged in one of my pistons....

Anyway, just wanted to spit ball some ideas with y'all around what are some possible paths forward. I want to keep the car naturally aspirated, streetable, with as much power across the entire RPM band as possible, as this is a weekend street car, with occasional auto-crossing, maybe track days in the future if I actually decide to fund two track cars lol. The car has a 100% bone stock LS6.

So considering what may or may not be wrong with the car, what are some good budget options to get an extra 120 to 140whp out of the car while keeping it NA and street friendly. This is a California car, so I'd like to make it easy to pass smog if that's even feasible. It's been a while since I've had a modified street car, as all my previous cars are full race and trailered non op type vehicles for track use only, and or just paid to get it to pass. Kinda over that though.

Considering the goals and usage, what are some good "budget" options?

 

The only "budget friendly" way I know of to get an extra 140whp AND pass emissions AND do it cheaply, would be Nitrous. Nitrous is great......When EVERYTHING works as it should. With stock, cast pistons, mixing them with Nitrous can be done, but you will need a really good tune. A little lean, add some preignition, and cast pistons can melt, crack, or break. Quickly. Many on the forum have run it with no problems. Years ago, when my car was stock, I ran a 100hp "Dry" setup. Worked great. But I eventually went inside the engine, and sold it years ago. Most companies have gotten away from dry kits, and almost all are now "wet" kits, i.e. they mix Nitrous and Gasoline, where the dry kits injected only nitrous, in front of the MAF sensor. This made the intake mixture super cold, and put the injectors into max flow. Because the computer suddenly thinks your in the Arctic circle.......

 

You may want to define what “budget” means to you. Or perhaps re-evaluate your hp goal.

A stock ls6 is about 360whp. So an extra 120-140 is 480-500 whp. To do that NA you’re looking at a pretty expensive and less streetable 5.7 build or a more expensive but also more streetable 6.0/6.2/7.0 build.

edit: just noticed the smog friendly part. I’d say there’s 0 chance of an NA 480+whp 5.7 build meeting smog requirements. I’d say LS7 swap or give up on NA and go supercharger. I don’t consider either “budget friendly” though

 

Appreciate the feedback guys. When I say budget, I'm talking less than 5k whether I do the work myself or not.

What bout the new gen 4 truck motors? A guy I know just got a L96 motor for 1400 bucks and is putting an LS3 cam in it that he got for 120 bucks. That would be well north of the 400whp mark pretty easy with a tune and long tubes. Probably still shy of the 480-580whp I'm shooting for. I'm guessing with these goals, it's probably going to be hard to get it honestly smoged. But I think with stock exhaust manifolds and a LS3 intake manifold on an gen 4 truck motor it will be easy to pass visual. I really want to stay NA for heat purposes if I get it on a big track with long durations of WOT.

 

Not a fan of NOS on a track car -- With NOS at best you may get 90-120 seconds on NOS HP -Then what ?? For a drag car it would be OK but on an autocross car NO--
You best bet to be smog legal in Calif and get 100-140 more HP would be a smog legal super charger kit---Either a Pro Charger or a Roots style SC kit---They run just slightly more than 5K with installation Buy the manufacturers pre programmed hand held tuner for about $350 more and you will get their full warranty-- A turbo hit is too complicated to install---Just my opinion

 

That L96 can be stout, but since we're 'weighing' your options, note that it also weighs 110 pounds more than an aluminum block. Why not go L92 instead? More moola, of course, but also more displacement and more punch.

 

120+ hp that is CA smog legal and less than 5k?

You sure know how to set goals that's for sure...

I'd start by looking for an L92, 6.2 aluminum block.
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