Tweaks for the L27
 

So I was going to attempt to bolt on a supercharger to this engine, but I was told it was a very bad idea and it would be easier for me to do an entire swap. Given that I can't afford the downtime or cash it takes for a new swap, what kind of tweaks would you suggest to upgrade the performance of this engine. I've got 151,600 miles on it right now, and the transmission was rebuilt at 148,600 miles.

Look at the tech info on the top of the website. You will find all kinds of ideas for performance.

You are asking for Performance upgrades not mechanical issues...moved to Performance & Brainstorming.

Instead of focusing on performance upgrades, first make sure your engine is tuned up to it's highest potential. Let's start with the basics...how old are your plugs, wires, and O2 sensor? How clean is the inside of your throttle body and your MAF sensor? How is your cooling system? Keep in mind that although these questions seem like they have nothing to do with performance, they DO help in regaining LOST power.

I have a 93 SSEi with an L27 core. I also have (well, sorta have anyways) a 94 SSE with an L27. I will say this time and again...a properly tuned and maintained stock engine will easily make more power than an engine with simple mods like an air intake that hasn't been maintained. When we got the 94, it STILL had it's original plugs, wires, and O2 sensor. And it had some power to it. Once I changed all of them, cleaned the TB, and a few other housekeeping chores, it REALLY woke up. Jrs3800 has driven it, and even he is amazed at how much power the L27 puts out. (Of course, it has the 3.06 ratio trans, which really makes it fun to drive). What I am getting at though, is that no matter what "mods" you make to it, they won't do much good unless your engine is tuned up well.

That, my friend, is the first step ;)

Good call. I'm going to have to check the throttle body and MAF sensor. As for the plugs, they're NGK Iridium IX which I installed about 5 months ago (with new ACDELCO wires), and the O2 sensor was replaced about 4 months ago. The fuel filter was replaced about 1.5 years ago, and I already have a pretty impressive CAI designed.

What else should I look for in terms of things to do to regain lost power? Howe exactly do I go about taking off the throttle body and MAF sensor? I'm assuming they're part of that same unit where my intake pipe goes in. How do I clean that up though? I've also heard of people telling me to port out my throttle body with a dremel. Any ideas on whether or not I should or how I would even do it? I haven't taken off my throttle body before so I really don't know what it looks like.

You're going to have to get alot more familiar with your engine to pull off more power. Doing the TB and MAF cleaning will restore alot of throttle response.

From there, an intake and MILD exhaust work (don't go too far) for starters, then you can start thinking about a cam or rockers. Just remember that when you start modding, you sign an unwritten contract with satan himself for a transmission. ;)

L27's won't benefit much if it all from dremel porting. Those TBs are already matched quite well to the manifold, and there is NO room to port the opening at the intake.

Other things to look out for are your lower intake gaskets. Though not directly related to performance, they could degrade performance over time by introducing small amounts of coolant into the intake stream. This is a bigger problem on L36's, but L27's are also somewhat plagued by them.

Yella Terra makes full roller-rockers for L27's. May not be worth much by themselves, but with a cam they may work wonders.

For dressup, L36 F-Bodies (Camaro, Firebird) used aluminum valve covers that will directly bolt to S1 L27/L67's. After a good beadblast and clearcoating, they look real good. BUT...that should be in the detailing section ;)

AND SPEAKING OF TRANSMISSIONS - Please check your RPO codes. What final drive gear you have will tell us what mods will help and what ones won't do anything for you, and may even hurt.

have a shop wield the outside of your exhaust manifolds, then use a die grinder to remove the wields from the inside. have them repair any cracks while they're at it. now would be an awesome time to get them jet-hot coated as well, but that may be a little cost prohibitive. this will help keep underhood temps down.

a high flow cat will offer a small improvement, but will really prove helpful as you add more mods later.

many change mufflers, using magnaflow or similar mufflers for a camaro. this offers better sound, but little performance improvement.

*edit* man i cannot spell