[PolynesianPowerhouse]

Well as the title suggests, Jason (JacFab) has started doing some stuff for the v6's again. so with all out there, i guess the market is finally coming around. I've been loosely away for a month or so. Some know what's gone on. But while I was away for a bit, and actually away out of state, I received a manifold for testing. When I got back on the 4th I was in a spaced out place/funk due to the family stuff, so all of this would have prob been sooner, I do apologize. But I'm getting through it all.



To start, the manifold has been ported and filled. And all I can say is AMAZING. I don't have the exact numbers on hand, but talking to Jason, there's a decent amount of air flow gains. As in, you will feel this. I'll touch more on that when I get to the GAINZ section



***Note, I do already have a ported TB in stock sizing, so for those with an complete OEM TB, the effects and gains should be close.***

To start off, the porting job and fill job, sexy! Its just like it was for the 5th gens, some work has been put into it. Looking inside you would think it should be from the factory like that. Its obviously a bit heavier,




Before I installed it, I had to tap a ¼ npt in the neck of it, as that's where the port for the 3rd outlet on the catch can goes. Problem is, I couldn't find the tap I had or bit I bought, so it took some time to get the right stuff...like a day or two. Finally got it drilled and tapped. Installed it a few hours later.




Some have posted that the install or removal of the manifold is hard, mainly the last 8th bolt at the end of the manifold resides under the cowl area on the driver side. They are 14mm bolts, I used a ¼ inch socket and wrench and got it out about 95% of the way, did the rest by finger. Yes, with my hands its a TIGHT fit, but index to thumb works. Once you remove all other 7 bolts, on that last 8th bolt, pull it up by hand most of the way, tilt the manifold backwards a bit, then dip it forwards where the nose/neck goes down. Came right out. For me it took literally 15 seconds to get it out after looking at the situation for 5 minutes and thinking what to do the easiest.



There's also two small 10mm bolts on the rear of the manifold that go through a plate. Easy as those have inserts to clasp into on the manifold. So once its loose, you can do em by hand.

Installing the new ported manifold is the same. A bit heavier so some may need to steady a bit more. Remember to hold the 8th bolt half way up, getting it back in is the reverse. One thing to note, the rear MAP sensor I think it may be, it has a security bolt. Its like a 3.5mm Allen maybe, but it has these longer lines. I'm sure there's a key for it, but after trying to reinstall it and starting to strip out the center, I replaced it with a random Phillips screw I found in my cup holder. I don't know the size, but for anyone who will remove this on the manifold and doesn't have the key... a course threaded screw will do the same and better if you have to remove it for any reason.

Startup was roughly the same. I usually just let it sit and run for a few minutes when I add anything. The computer is smart enough to self adjust. Even if you restart or unplug the battery, the computer starts at a richer setting and will have to trim and lean everything out from the opposite direction. So no worries there. you will notice some extra noise out the rear. more air in = more air out. basic logic. its not crazy, but just noticeable when your on the loud pedal.

Does it need a tune? Nope. Will it benefit from a tune? If you've been in the forum for even just 2 minutes, you know that almost any mod will benefit from a tune.


Now for the part everyone loves...the GAINZssssah!

Everything from 1000 rpm up to red line has been improved. The thick of where you feel it is around 2500 on up, and that's prob due to the TB still moves under normal motion , UNLESS you step on the pedal fast. Like how you would to launch in a drag race. Foot on the brake, and lift off the brake while simultaneously hitting the gas. Its a fast off/on motion.

But at 2500 rpm, you get more of a push back in your seat. There's def some need for improvement in this range and the addition of the manifold def has delivered.

Throttle response.... DEF huge pickup all across the board here. There's no hesitation now. For example, when you merge into traffic, and you have the rpms up, but see some slapnuts do something, and now you have to coast until they pass...once you hit back on the throttle, there's no hesitation, it just GOES. Also for those who will do AutoX or track work, there's times when you coast through an apex. getting back on the throttle...and SMOOTHLY doing so, is key. this is where it will shine for sure.

Something that I did find kinda cool. Everyone has talked about some trans shudder here and there. Some have had it worse than others. Most of us know how to back out the throttle or get on it a bit more to resolves when or if it happens. I'd still get some from time to time, some hotter days, etc... After the install however, it minimized it. You can tell when it does happen, but its not as harsh, although after the flush procedure I had, it hasn't been really harsh to where some have it. But it would be enough to be like, “ahh yep, its there”.

Now, when those times have occurred, its been REALLY REALLY soft. Something I learned from Rick Hairsine, a local who ran a 5th gen V6, is that the MAF sensor has input on shift points and or pressures within the trans. If that, which it prob does, still hold true on the 6th gens, since MAF sensors haven't evolved all that much, the airflow increase in velocity and less turbulence has had that effect on the MAF and thus the trans. So that's yet another gain I'm finding, even if its not a hp based addition.

Fuel mileage, has also increased per tank now. only using 89 until its track time, but being able to use less pedal to get the same performance helps. Still driving the same as I have been before the install. Just hit 64.5K this week, mileage wise. I believe I've had the manifold on for about 2 weeks now. With work being 60 miles round trip, I've worked for 6 days per week to keep my mind focused, and I'm sure with the weekend I know I've amassed at least 300-500 miles. So I should be somewhere around 1000-1200 miles with it on so far. Still have plans for a tune. But even without a tune, this is important for two reasons.... if fuel mileage goes up under normal driving, the engine is working more efficient. This is your power in plain sight. The more efficient an engine becomes, the more power it can put towards the wheels.

I do however, want to get to a track on a decently mellow day and just run and see what it does before the tune. I still haven't gotten a chance to do any data logs given the time constraints with aiga stuff, a hit and run, work, and had a show recently all within a 3 week range. So I'm getting around to getting stuff done and documented when I'm off work with free time.


Overall, we saw the benefits on the 5th gen. its been posted, can search for it on camaro5 or google. there's also a member on here... IanGTz28 I think, or something near that, that also had one a year or so ago... this is pretty much the same footsteps of improvements. ported manifolds work. period. since we have no aftermarket manifolds like the MSD setup, which address open areas to decrease turbulence and raise velocity. porting and filling the stock oem ones is the next best option. cost effective as well considering most will not shell out $1000-3000 for an aluminum sheet metal intake fabrication (its been sought out on the FB group, prob will benefit only boosted guys).

[MikeG183]

Really good info. Do you know if this is similar to the Overkill ported manifold? Or the additional fill process makes it even better? Also, is a larger throttle body included?

[Jason@JacFab]

In my opinion the filled floor makes it better, than an unfilled version. We won't do an intake that is not filled. The filler only increases the flow output of the ported manifold, roughly an extra 7-9%, also increases velocity, and decreases turbulence.

This particular manifold that I sent to the Powerhouse flows 19.5% better than a bone stock manifold, as tested manifold vs manifold on our in house SuperFlow flowbench. Now granted, take that with a grain of salt because the engine itself does not see an entire ~20% airflow gain because you've also got to consider the airbox, or CAI attached, and the cylinder heads. To get an actual number I'd have to rig up a test through a cylinder head with the intake valves open at various lift amounts, through the intake manifold and through an airbox. That's not really feasible, so this is how we do it, manifold vs manifold. This not only shows us that our work is better than stock, but also verifies consistency across each manifold that we do.

We will not be offering these with a larger throttle body plate permanently attached like the Overkill units, and will not be supplying a larger throttle body with them. As-is, they are designed to take a stock sized throttle body, that's either stock, or VMAX ported, or hand ported.

As such, since we are not including a bigger throttle body, etc, the price for the manifold itself is also significantly cheaper than the other option.

Now that said, we do plan on offering a tapered bore 80mm throttle body adapter as an option. It will have an 80mm opening for the throttle body on the TB side, and stock sized bore on the intake side. This tapered bore will act like a velocity stack to further increase velocity achieved off the back side of the 80mm throttle body. Unlike Overkill, you will be able to switch back to a stock throttle body at any time if you should choose to do so (for warranty purposes, selling parts, etc).

At the moment, we will only be offering the 80mm tapered bore adapter by itself, and you would need to by just the 80mm throttle body from Overkill, as we have a friendly agreement that the 80mm throttle body is "his baby" so to speak. But further negotiation is necessary, perhaps he will allow us to supply the throttle body to customers as well that wish to do down that road.

After I get the first TB adapter made, I'll be sending one to PolynesianPowerhouse to test that as well and see if he notices anything.

We have no dyno testing yet, but hopefully in the near future will be able to get that done. Just have to arrange a trip to the dyno 4 hours away where IanGTz28 has one of the manifolds on his car and has agreed to let us dyno test. We would just like to get some of our 2.0 parts done before said 4 hour trip, as it would make sense to make a day out of it. Test his v6 car with the manifold parts, then move onto our 2.0 car and test our parts. Kill two birds with one trip.

[MikeG183]

Thanks for the input, Jason (and thanks for the taking the time to do the nice write up, Polynesian Powerhouse).

I have a GMPP intake (with the corresponding GM tune) and noticed that the Overkill unit requires a reducer adapter of sorts. I've wondered if the need to restrict the opening to fit the GMPP essentially negates the gains of the larger throttle body. Do you think your manifold with the factory throttle body would have similar overall gains under those circumstances?

Also, when do you anticipate your manifold being available for purchase?

[Jason@JacFab]

Originally Posted by MikeG183

Thanks for the input, Jason (and thanks for the taking the time to do the nice write up, Polynesian Powerhouse).

I have a GMPP intake (with the corresponding GM tune) and noticed that the Overkill unit requires a reducer adapter of sorts. I've wondered if the need to restrict the opening to fit the GMPP essentially negates the gains of the larger throttle body. Do you think your manifold with the factory throttle body would have similar overall gains under those circumstances?

Also, when do you anticipate your manifold being available for purchase?

As most of the common cold air intakes, including the GMPP intake are setup for a stock sized throttle body, the "reducer" you're talking about is basically the silicone elbow that connects the throttle body to the outlet of the intake tube. As the 80mm throttle body is bigger, the "reducer" basically goes from your stock sized intake tube to the bigger throttle body.

I don't quite understand your question, highlighted in red above? As the circumstances you imply refer to the going from a small tube, to a bigger throttle body, therefore possibly negating the effects of said throttle body?

I'm fairly certain that Polynesian Powerhouse also has the GMPP intake and corresponding GM tune on his car already, before he put the JacFab manifold on... Maybe he will give some more insight on that?

Very soon I hope to have the LGX manifold up on the website, but in the mean time, I will take some orders via email. We're just kind of getting our feet under us trying to get going on them, waiting on supplies. Although I have two stock LGX manifolds on hand ready to be ported.

[MikeG183]

Sorry, yes that was a little unclear. To clarify, would going from a "small" intake tube to a larger 80 mm throttle body and unfilled ported manifold (i.e. the Overkill setup) be about the same performance gain as a filled ported manifold with a stock 72 mm throttle body?

[Jason@JacFab]

Originally Posted by MikeG183

Sorry, yes that was a little unclear. To clarify, would going from a "small" intake tube to a larger 80 mm throttle body and unfilled ported manifold (i.e. the Overkill setup) be about the same performance gain as a filled ported manifold with a stock 72 mm throttle body?

I don't want to step on any toes on that one.

but I guess to be clearer on the gains of filling vs not. I have personally tried a 72mm unfilled but ported intake, VS a 72mm filled and ported intake, and the filled is better on the flow bench. That's why we will only offer a filled version.

[MikeG183]

Sounds good. Not trying to get any toes stepped on. Just want to determine the best setup for a "small" tube intake. I'm guessing the 80 mm TB/ported intake combo would probably be better for those running a wider intake tube.

[JakeF_RS]

Originally Posted by MikeG183

Sounds good. Not trying to get any toes stepped on. Just want to determine the best setup for a "small" tube intake. I'm guessing the 80 mm TB/ported intake combo would probably be better for those running a wider intake tube.

We’d probably need testing on the intake to figure that out. IE how does the intake flow as opposed to the 72 & 80 TB. The GMPP starts at 3.5 inches (80mm).

[Jason@JacFab]

Originally Posted by MikeG183

Sounds good. Not trying to get any toes stepped on. Just want to determine the best setup for a "small" tube intake. I'm guessing the 80 mm TB/ported intake combo would probably be better for those running a wider intake tube.

Will @ Overkill and I kind of have a gentleman's agreement per se. I have told him that I will not even think about offering an 80mm version with a permanently attached adapter plate, filled nor unfilled. I will not sell an 80mm throttle body kit of my own. But I can make a plate to mount an 80mm on my intake, or even a bone stock intake for that matter, and he can supply the end user with the throttle body itself.

Likewise, last I heard, OVERKILL will not be offering a filled version of either 80mm or 72mm... But I'm pretty sure some other guy will at some point.

[PolynesianPowerhouse]

Originally Posted by Jason@JacFab

As most of the common cold air intakes, including the GMPP intake are setup for a stock sized throttle body, the "reducer" you're talking about is basically the silicone elbow that connects the throttle body to the outlet of the intake tube. As the 80mm throttle body is bigger, the "reducer" basically goes from your stock sized intake tube to the bigger throttle body.

I don't quite understand your question, highlighted in red above? As the circumstances you imply refer to the going from a small tube, to a bigger throttle body, therefore possibly negating the effects of said throttle body?

I'm fairly certain that Polynesian Powerhouse also has the GMPP intake and corresponding GM tune on his car already, before he put the JacFab manifold on... Maybe he will give some more insight on that?

Very soon I hope to have the LGX manifold up on the website, but in the mean time, I will take some orders via email. We're just kind of getting our feet under us trying to get going on them, waiting on supplies. Although I have two stock LGX manifolds on hand ready to be ported.

yup, still running the GM intake with Vmax ported TB...so the TB outer dimensions are the same.

[Kenny Camaro]

Good work Jason! Eagerly awaiting some dyno numbers.

[MikeG183]

I recently received and installed the JacFab manifold from Jason. Very nice work on the fill job. Definitely a noticeable improvement in throttle response. Probably also a slight increase in power (but not not as noticeable as the throttle response). For reference, I'm running the factory throttle body and GM performance intake (with GM tune).

[PolynesianPowerhouse]

Sorry for the wait, but getting around to things as quick as I can. After the Idaho trip in Aug, B-day in Sept, then Just got back from Universal on Monday. Work, wrestling, and life (the parts you never wanna deal with)... cash has been limited and time even moreso…. then factor in trying to schedule time at a shop. Some of you already know how that is.

So the stuff completed so far:

-JacFab Manifold ported and filled
-Vmaxx TB
-GM Intake with reflash
-Elite Eng. E2x catchcan
-2.5 inch exhaust, personal build, MagnaFlow 6 inch rounds, Mag Tru-X pipe.

wanted to wash the air filter since I haven't touched it since I installed it last year in the fall. don't think it would make too much a difference.

Pull 1 was a kinda half pull... basically he noted that with that gear, the engine would have been doing 150-160 road speed, which isn't anywhere near where id be going through the traps at.

So pulls 2 and 3 were done with 4th gear, and that's usually when I cross the 1/4 mile line, given the tires and wheels I have. I usually just switch into 5th gear then a split second later over the line. so that's the premise for using 4th gear.

Also the shop I went to usually does a lot of high end 1200+ LS builds. but we used a dyno that belongs to a place that does similar 300zx/supra/jdm builds. so for some reason torque wasn't logged or set to BE logged. but we used a speed reading to calculate from the data from HP tuners to get torque which was around 250-255 at the 5250 (5252) mark.

the Dyno was a Dynojet 224x in ground.



Pull 1 - 6th Gear



Pull 2 - 4th Gear




Pull 3 - 4th Gear



apparently the A/F got a lil lean towards the end, and that's with the GM reflash. so there's still room for more.


Tomorrow, if the gods smile down, gonna head to the track right after work. gates open at 4:30 track goes hot at 5. however, its supposed to rain, so that might be depleting. Sat is rain, and theres autoX up in PA... will try to check it out, but sunday is autoX at the home spot. so i'll more than likely be out to that one.