I can agree with most of what you say, but it doesn't seem like he is heavy modding. So in this case, I am extremely doubtful he will delete the cats. With the cats and a flow master my truck has great tone. I chose the flow master OVER the borla. Was throaty and absolutely no popcorn. Again, it's all personal preference. If I was building a performance car, my thoughts would be different. As for the CAI, your absolutely right, but running a CAI with a programmer which reads and modifies your A/F mixture based on air temp and flow, in theory, would improve power and mileage. But with a louder exhaust, and louder intake, let's face it, nobody can get there foot off the gas long enough to say either way. I've personally never had a problem with oil filters, aside from break in and cleaning the plates on the throttle body, which is to be expected. But I've never really had a high performance car with an oil based filter on it.

So are you saying I should get a CAI, or no?

All I can say is the best mod, is a supporting mod. Explore your options. FMX_89 makes some great points and obviously knows what he is talking about. Personally, I run a CAI on my truck because I hated the old air box. Made my tuck look like shit, but I can't say it's really helped too much, maybe 1 mpg but all my power came from the custom tune I run, which takes the CAI into account. And I run an oiled filter too, because that's what came with the k&n kit lol. It's a truck, not a race car. It's sounds good, it looks good, and it works.

Edit: with the tune, exhaust and Cai I gained like 5 mpg which is huge one a 6.0 liter. So I'm saying definitely do research, I had my ecu custom tuned by a friend that runs a performance shop. Make sure you trust the help you hire, you can really mess shit up.

This post was edited by kill22 on Jun 30 2014 12:23pm

All K&N filters are oiled cotton gauze as far as I know.





A tune will not show any more gains with a CAI than a stock air box IF the stock air box is not a restriction. Oiled air filters can deposit oil on the MAF which can cause all sorts of issues. If oil made it to the TB blade then it's on the MAF and possibly the IAT depending on where it's located.





OP. Put an exhaust on it if you want it to sound good. If you intend on driving the truck all the time and don't plan on diving in to internal engine mods to make big power leave it alone after that. Do a good tune up on it and drive it. If you want to get it tuned there is probably a good LSX tuner within an hour drive of where you live. If not most tuners will do a mail order tune that will be pretty damn close on a stock truck. They can lean out the fueling a bit in cruising RPM zones, adjust how the trans acts, add some timing, etc. If you get it tuned for premium they can add 6-7° of timing which will net you 10-15hp and a mpg or so. It won't pay for itself though due to the increased cost of fuel. It's a DD truck. I would get it tuned for 87 if I were you. The biggest difference you will be able to feel is a big increase in throttle response. Handheld tuners are a bad joke. Alvin @ PCMForLESS is a really good tuner that specializes in mail order tunes for Trailblazer SS's and other oddball vehicles. He tuned a C5 Z06 we swapped a 402 LS2 into. It made 528whp on his dyno.

The biggest fuel mileage gain you could get is to switch to electric fans if yours has a clutch style. That would be money well spent in my opinion.

got some borlas on my ls6, loving them

PM ride and get info from him on the LT's he bought from Huron Speed.

Good info, thanks for the advice.

My flow master 40 series drones quite a bit, 14-1600 rpm is loud as Shit in the cab compared to 3k+ but outside the truck at those high rpm sounds pretty dam nice imo... 4.8 l

This post was edited by IB0T on Jul 1 2014 06:37pm