offaxis

iTrader: (19)

I am alittle confused but this thread maby you guys can clear things up for me. I see in this thread that people lost hp going from the ls6 to the ls2 intake. I have been doing alot of searches and It seems people are picking up about 8-12 hp from a ported ls2 over the stock ls2 intake. This is where the confusion comes in. on my camaro i swaped from a ls6 intake the an unported fast 90mm intake and gained 20hp.
So If the ls6 makes more hp than a ls2 intake and I gained 20 hp going to an unported fast intake how could a port job on a ls2 intake even be compaired to a ported fast intake.....?

I now have a ls2 in my gto and I really want to do something with the intake but Im just not sure what to do after reading this thread

Justin00SS

iTrader: (5)

Yeah. And seeing as how people lost power switching from stock ls6 intake to stock ls2 intake would people with LS2 goats see an increase just switching to an LS6 intake? Even though it has a smaller tb?

LS1-450

iTrader: (33)

I agree that a gutted, trumpeted, & port matched LS2 has not been explained completely. Here is an attempt. The bottom is cut out in a rectangular fashion (see pic), then the three internal towers that connect the base to the top are removed, then a very specific epoxy can be used to trumpet the inlet to the internal runners (yellowish in pics), then sand & smooth. On the runner outlet, confirm proper alignment to head inlet runners, sand down internal ridges, & sand smooth. Once all work is completed, the three holes that remain in the LS2's bottom from removing the towers are plugged, then use nylon compatible plastic welding rod to re-attatch the base. I went a step further & sealed the welds w/ high temp silicon after welding.

Patrick G

iTrader: (14)

Interesting exercise. So what kind of gains did you see? What kind of power did your motor make?

LS1-450

iTrader: (33)

Hi, I was afraid that my post would lead to that question. It will be tuned in April sometime & I have plans to post the results after, including cam spec's.. As for now, I can only say that it netted me 12 lbs less in front end weight over the aluminum Weiand/Holley that I had been using. For sure, will post the dyno (Mustang) results once it has been tuned.

My car spends most of its' time "under the curve" & up to 6,400 RPM. For this reason & after seeing a few threads w/ LS2 trumpeted (AKA ported) results, felt that this was a good choice for me. Were my car a 7K rev vehicle, may have gone w/the FAST.

To the guys looking into this. There was a question regarding the fuel rail. Yes, a stock LS1/LS6 fuel rail can be used. The mounting legs need to be bent into position to match the LS2 intake mounting holes. Also, a Katech "O"-ring kit is need because the LS2 injector "O"-ring ports are slightly larger.

ONEBADWS6

iTrader: (22)

I love how people still rip on ported Ls2 intakes. Everyone I have done for friends has made power. A guy with a LS2 GTO with headers and a 230ish duration cam made 6 more rwhp than a GTO with the same setup and out of box Fast 90. In my opinion a well ported Fast will always make more power. But a ported LS2 is better than a box stock FAST. I swaped to a home ported FAST 90 over my LS6 intake and picked up 6mph. So maybe I have a magic dremmel I don't know. Oh and I don't cut the bottom out of the LS2's either.

LS1-450

iTrader: (33)

I think that the rip comes from the documented poor numbers shown on stock LS2 intakes. On their behalf, unless someone ownes one & can actually see the three huge internal towers, that OMI are a big part of the restriction, it's difficult to understand what the term "Ported LS2" actually means. "Ported" does not really describe what is being done.

Cool that you are able to remove the towers without removing the bottom. Do you do anything to trumpet the inlet to the internal runners. This is the part, IMO, that likely increases low end torque in a "Ported" LS2 intake. If you are able to trumpet the inlet to the internal runners, you are a magician & my hats off, because it has to be a PITA. If you are doing nothing to that area, then there is more to be gained. Regardless, the more of us whom document what is beng done & results (my bad, as I have not documented any results as of yet), the more respect the modified LS2 intakes will receive.

ONEBADWS6

iTrader: (22)

I did one where I cut the bottom out and removed the supports and worked the port entrances. The only bad part about the port entrances is they protrude into the air path. As a hole I think the runners and runner openings are far better than Fast 90mm ones. I spent so much dam time on my Fast reworking the port openings and other areas. As for the 3 braces all they do is eliminate a little bit of plenum volume. Yes the one I cut open made more power but keeping it sealed was difficult. By the time I got it to seal the friend I did it for grew impatient and wanted one done with the floor in it. All the others I have done, the major work was done to the intake opening and where the runners meet the heads. There is a HUGE restriction at that point that goes some 4-5 inches down into the runner. I think the only reason a Fast does any better is the plenum volume it has over the LS2. But I can port two LS2's in the time it takes me to do a Fast 90.

Johnnystock

iTrader: (6)

CAN SOMEONE TELL ME WHATS GOING ON HERE!!! I thought the ported FAST 90 was the unbeaten intake and the only one available so we all had to buy it!!!

Do you have any dyno sheet onebadws6?
PM sent onebadws6 for a price quote!!!

jkwalkercchs

iTrader: (21)

ok i stuck my hand in there and where u are talkin about i felt the runner protrude in thats why u have to trumpet it for better flow what if i cut those out filled them in with some plastic weld then smoothed out with an epoxy
or fusor???

just an ideal i have one and cant sale it to save my life i need high rpm power so i was looking for a professional products intake

LS1-450

iTrader: (33)

Here's what is not mentioned in my post. After welding, Herculiner is poored over the entire bottom of the manifold. The Herculiner seals the welded area completely & adds additional strength. Also, while installing the manifold, a piece of high temperature resistant header blanket is used between the bottom of the manifold & the valley cover (engine) to keep more heat away from the intake manifold & because I wasn't sure about the engine temps against the Herculiner.

Herculiner will save you time & aggravation.

jkwalkercchs

iTrader: (21)

so i cut the bottom off i was afraid of cutting into the runners so 3hours with a steak knife and the oven eye to heat it up but i got the bottom off the welding is no problem i think i can handle that how much room is between the valley cover and bottom of intake??

where can i buy a sheet of plastic to match this???

and how close is the tb to any accessories i wanna try to move it down just a little 1/2 inch at most if im chopping it up i might as well go all out

ONEBADWS6

iTrader: (22)

The PM's I had from the GTO owner have been deleated. I do not do this as a business, I have done this for a handfull of friends and sold the few extra I had some time back. To get mine to seal I used a thin gadge sheet of aluminum and self taping screws, under this I put down plenty of a plastic and metal caulk of sorts. Never had a problem since. when you remove the supports you have to seal off where they attached as they now expose part of the runners.

jkwalkercchs

iTrader: (21)

care to share this epoxy brand??
where to get???
price???

LS1-450

iTrader: (33)

The intake is made from nylon & a sheet of nylon would need to be used if you are to move the bottom of the intake down. I have an electric water pump & the assembly just barely clears it. I don't remember how close the stock WP was, but, don't think there's a 1/2." You do realize that moving the bottom down does not also move the TB down? The TB is positioned by where that part of the intake ends up once the intake & head runners are meshed.

I don't remember the epoxy name, but, there's a thread in the external section that define's it. If you can't find, send Tony Mamo (I think that's his name), the AFR guy a PM. He uses it for mock up stuff. Do not use JB weld, it won't hold.

jkwalkercchs

iTrader: (21)

well i cut the neck of i think it might clear better sense im running a plate so that will space it some and im gonna shorten the runner length some cause im going for high rpms


alrighty i need to see i think i might still use fusor though idk for sure yet

the reason i say move thr bottom down is if i just move the neck and not the bottom to ill be in the same mess having somethin blocking my airflow

LS1-450

iTrader: (33)

"UPDATE"

Bottom of manifold came loose & created a vacuum leak. Vacuum pressure sucked the re-attatched bottom, including weld & enough of the Herculiner, to create a major leak. After looking for a reasonably priced LS6 intake to modify w/ 90mm neck & almost re-installing my aluminum Weiand, I settled down a bit & decided to fix the LS2 bottom attachment issue once & hopefully for all.

This time, I bolted a phenolic plate that is wider than the cut out section of the LS2 intake to the piece removed from the LS2 intake, (invision a rectangular plate on top of a larger rectangular plate about 1/4" around the perimiter). The two plate assembly was then laid on top of the manifold opening w/ the smaller (intake piece) back in its' re-attatched location. The outer plate is larger than the opening in the manifold & bolted to the smaller manifold piece. Therefore, there is no way that the manifold piece can be sucked loose & into the manifold. The larger plate was then bolted to the intake for good measure. Finally, the whole added assembly was drenched in Herculiner. This includes, the saw cracks between the manifold removed palte & the manifold, between the bolted plates, & on top of the bottom of the manifold assembly. Will update again should an issue arrise.

As to my April yearly dyno session; have decided to spend the dyno funds on EFLive & have begun learning how to tune. Unfortuneately, this means that there won't be a dyno result of the mod. However, if I run across a dyno day or demo somewhere, will post up the results.