The general opinion on the LSXRT is mixed at best. Most people will tell you to go with another GM intake. I am probably one of the very few people that has had minimal issues with the intake other than having to tighten up the bolts a couple of times. Had for almost one year. Fuel AND steam crossover tube fitment also very tight. Also just a heads up there isn't much clearance between the cowl either. It really fills up the engine bay pretty good. Looks impressive though.

If you do get one make sure it is one of the second molding ones where they changed the color to black and NOT the early ones that were gray.

 

The FAST is the best overall intake across the board for an n/a engine

 

Mainly will disagree with that comment.

$1,000+ for a intake and throttle body isn't money well spent for minimal HP gains over say a NNBS/TBSS intake. I'd so rather spend $800 less and give up that 10-15hp.

 

Yea, I've read the debates on the forums. I've also read/seen just about every magazine or well known performance shop use the Fast LSXR on every high horsepower LS build known to man. I think the LSXRT gets its bad wrap (on this forum) from being thrown onto poorly matched 4.8/5.3 builds. That being said, I personally wouldn't run one on a 4.8, or even a 5.3. The cam/stall selection would have to be perfect to work with the Fast for it to be worth while.

I'm actually thinking I should stick with a TBSS/NNBS since my cam was designed for the stock truck intake. Plus the cost factor...

Are you DBW? Which TB do you run with it? I'm trying to add up all the costs involved in both swaps, to see if its worth while.

 

I'll just leave this here.

20 LS1 Intake Manifolds: Tested!

 

Fast issues go further than that. You have to change your fuel rail setup or buy their half *** adapter and then monkey your cross over to work.

If you go DBC you lose cruise control and have to change the PCMs OS.

If you go DBW there aren't alot of options out there and the ones there are have some pretty serious work arounds. I've seen some threads with xlink issues.

 

I went with a NNBS intake with the 87mm DBW TB, ls2 injectors,and fuel rail. I think I will run the corvette filter, and retune.

Theres no way around the X-link, huh? Is it more than just a harness adapter?

 

Do what most LS tuners do! 13:1 AFR, 28* timing!


But really please don't

 

Mine too. I'd start with an LS1 Fbody high octane timing table and go up from there.