Don Nguyen

iTrader: (2)

Looking for people on here who actually have swapped out their factory intake manifolds for some sort of aftermarket offering. I've read a lot of posts regarding pros/cons, but mostly from people who got the information second hand.

Since the truck intake is too tall to fit, I started looking at LS intakes, but I was quite surprised to see them going for $180 - $300 (if anyone has one they'd like to sell for a lot less let me know). So being at that price point, I figured maybe for a bit more monies, it may be worthwhile to simply go aftermarket.

Who has done some before/after testing with different intake manifolds? Ideally something that's similar size to LS intake manifolds, since that's what I can fit.

truckdoug

iTrader: (25)

skip the dorman stuff for boost. mine barely works for NA

Don Nguyen

iTrader: (2)

Funny, cause I was just reading about those in a thread. What issues did you have with yours?

007FJ

iTrader: (28)

I'm running a LS6 at 17# no issues. Plenty of people have run into the low 9's and some in the 8's. (Denmah) Sloppy Mechanics has done the same kind of numbers with a LS1.

truckdoug

iTrader: (25)

Just flimsy and poor fit up

Project GatTagO

iTrader: (7)

It would be helpful to know what port heads you're using and whether you care if it has a 3 or 4 bolt TB...

Andrew

Don Nguyen

iTrader: (2)

Realistically speaking, almost anything can be done, it's just if certain changes can help make things be done more easily. Such as an LS1 intake manifold can make you 600rwhp @ 15 psi, but maybe with an LS6 intake manifold can make you 650rwhp @ 15psi as an example.

From what I read, seems like the dorman intakes are not made properly to handle any real boost pressure and ends up cracking.

Don Nguyen

iTrader: (2)

Didn't think about that. I have stock 799 heads. I'll be running a DBW tb, I am not sure if they are 3 or 4 bolt for those. If I could run my truck TB on the LS intake manifold that would be ideal. If not, I have a NW 102mm TB that I was going to originally use for an NA build on it as well if it fits.

Project GatTagO

iTrader: (7)

So you have cathedral port heads...do you have a gen 3 or gen 4 engine? The ecu that you use makes a difference as well...all this is tied together and needs to be considered as a system.

Andrew

Don Nguyen

iTrader: (2)

Originally a gen 3 l33 engine but with a gen 4 block, so pretty much still a gen 3. Pcm is from the gen 3 5.3 2005 truck it came out of.

Realistically speaking, what all effects would the intake manifold have between the gen engines and types of pcms besides the intake port fitment.

Project GatTagO

iTrader: (7)

Gen 3 engines used the 3 bolt TB and the gen 3 ecu can do cable TB or DBW. Gen 4 engines used the 4 bolt TBs and gen 4 ECUs all had DBW, without the option of using a cable TB...

A used LS6 is probably the best option for a 3 bolt low profile intake. LS1 intake has the same figment but makes less power, but that may not matter much with boost.

Andrew

Don Nguyen

iTrader: (2)

I'll probably end up with an LS6 intake. I wouldn't mind an aluminum intake manifold, but I am not sure how much heat soak issues those have. Was really considering the FAST intake, but seen enough people blow them up with boost that I don't really want to risk that expense.

With the LS6 intake, I will probably be able to use my gen 3 TB on it as well, so that'll keep things easy to swap over.

truckdoug

iTrader: (25)

you can also you an ls2 intake with a $25 ebay TB adapter. i use one on my turbo truck with a NNBS intake.

Don Nguyen

iTrader: (2)

My friend has a spare LS6 intake manifold with a maybe quarter inch square section missing from it. Would it be crazy to think that plastic welding that area up with a much larger piece on the outside of the intake manifold cause a problem?

I've seen several guys put large holes in their truck intake manifolds to shave/clean up the top and then plastic weld everything back together without any issues.

Project GatTagO

iTrader: (7)

That's a good option as well. There are also numerous DBW and cable 4 bolt TB options. Supposedly the LS2 intake doesn't work as good as the LS6, but it is close. Again, for boosted applications, probably very little difference.

Another thing to consider is MAP sensor placement. LS1/LS6 is in the rear...LS2 is in the front...

Andrew