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As promised, I am making a thread about the dorman intakes and a few of the steps we go through to make the intake (hopefully) flow better and have less issues overall with fitment and transitions.
The Dorman Truck Intake (615-183) is probably the best designed and put together intake they have so far. Super smooth finish inside and out with very few actual issues. It does have a few areas to upgrade or delete to make it a true performer. The only REAL downside is no 4 bolt option, BUT that is also a win for th 3 bolt guys...because that means you can reuse your 3 bolt dbw tb and get a nice flowing intake instead of spending $230+ for the dr x and finding a 4 bolt tb also.
The one we found was advertised as "one piece" but when we got it, soon realized that was wrong. Its 3 pieces, and they come apart ALARMINGLY easily. That obviously leaves room for improvement. To do so and make them more boost friendly also we will permanently epoxy the intakes together and reinforce a few key areas where necessary. It does come with intake bolts which is great, and only took about 9 screws and it was in 3 pieces.
And now a few pics
The too shell...not much to see BUT much better looking than any of the other truck intakes and all the bosses needed for any bracket etc also. They can be shaved off also to clean it up.
The "center" runner section (top)
Center section (bottom)
Lower base piece
As you can see, upon first inspection, it looks pretty good as is.
One more pic.
Lower bolted to a stock bare 243 head
Oh yeah thats right. let's talk about THE LEDGE. Man is it ugly and YUGE (thats what she said)
(One more pic...promise)
Ledge from bottom side
Ill post more a little later of other transition issues and how we go about mock up and where to port and why as well as naked throttle body shots on it.
I have a feeling that ledge is there for a reason; I mean something like that doesn't get done by accident. Possibly to induce some kind of swirl or turbulence? Not that it's needed for best performance. Just speculation...
Oh- Are they in all ports?
Yeah, looking a little closer I THINK I see a line coming up from the corner diagonally thru the ledge. So you could easily be right. I guess they figured it didn't hurt flow too much in THEIR eyes...
The tbss/nnbs and l92 intakes are pretty good. The only other plastic option are the FAST LSXRT manifolds....unless PRI this coming weekend introduces a few more.
No 4 bolt gen4 truck option from Dorman yet though.
Other than the LEDGE, do the ports line up with the heads pretty good? Or is there some
port matching needed as well? Kinda hard to tell in the pic if the bottom of the port has a lip.
Other than the LEDGE, do the ports line up with the heads pretty good? Or is there some
port matching needed as well? Kinda hard to tell in the pic if the bottom of the port has a lip.
The only other part that is an issue on the base is the top of the cathedral. On a stock head that is. There is PLENTY of meat on the base to make it larger and fit most ported heads also. You've gotta be VERY careful in a few areas. They seem thicker than they are. (insert pun here)
Ill post more pic tomorrow with ledge gone and a bare tb on.
Lol, Man is it ugly and YUGE. I get that all of the time.
So this is a replacement for a standard early manifold, correct? Like for my 2000 5.3 Silverado?
Will you be doing any testing - flowbench or dyno - with this thing? I'd like to throw something better on when I swap my LS6 in my truck, but don't want to use an LS6 manifold. Been thinking about a TBSS, but this really intrigues me. I like not changing everything and keeping things close to stock but better performing for this vehicle anyway.
Flow test will be soon. Ill be posting more info and pics in a bit.
It will work for any 99-07 gmt800. It also adds so much plenum volume from the base design and removal of the ugly intake tube inside its pretty astounding. We will see if that helps or hurts though.
There are a few transitional areas esp after the tb and for the clean air pcv part and the evap amd 2 vacuum ports on top that have to be cleared up.
Inside of upper shell. Notice the very sharp ledges after tb opening (top) and the occlusions into the runners by the profile of the outside of the manifold. Marked in red. Some are from bolt holes. The bolt bosses will be ground flush then either plastic welded or plugged.
Map sensor hole is in the back.
The injector bosses stick quite a way down into the runner, but every injector is different, so the only real profiling should be on the "inboard" side of it and slope to the outside.
Next is the somewhat hard to imagine pic of the upper shell (upside down) with the inner runner piece installed. This shows the transition (or lack of) from tb to plenum.
Pic after quite a bit of profiling
And one more for this post naked tb bolted to the intake. Unported tb and unported tb snout. Fits pretty good as far as the opening goes, the iac channel and clean air pcv port need work though.
I've been eyeballing this intake a lot and looking for info on it. I feel like it would be a good bolt on and yield some decent power gains even in stock form. I've contemplated getting one and doing some smoothing on the inside of it.
Since you have it in your hands, what do you think, you think it will out perform the OEM intake even out of the box? Looking at pics I have a feeling it will, but that's pics and assumptions..
I have a strong feeling in ported form it'll blow the OEM manifold out of the water and decently compete with a fast, power per dollar, maybe not necessarily hp for hp. But I'm pretty optimistic about this manifold.
How does the runner length look compared to a FAST standard length runner?
Port alignment is nice, looks like it just needs the ledge taken down.
Last edited by 00pooterSS; 12-04-2017 at 04:20 PM.
Obviously "will it perform" is the million dollar question. There are some options out there, but for someone like me who wants to keep as much low end as possible while adding power (big, heavy truck) it might be a good option. We shall see. kudos to the "store" for doing this.
The overall fit and finish is strikingly good. The transitional parts seem to be the hang up. I think as is you would see some power gains WITH tuning. Just bolt on...no idea.
Here are a few pics of the injector area. There is a pocket above the bung that needs to be addressed.
Picture of lip/pocket below inj bung which is on the upper shell of course
Pic of assembled area with stock round fuel rail on
The only goofy part are the intake gaskets. They are made well but sometimes dont like to fit right in the gasket trough.
It does bring about an interesting notion though. no thick plastic gasket to take up space or leak...but also makes room for use of an adapter spacer for rect port heads.
Working on transitioning the inj area is going to be fun.
Here is a pic of the port after ledge removed and transitioned.
As you can see...that transition allows for some nice ported heads with no actual need to rework the lower shell on the floor of port. There is quite a bit of thickness left on the sides. Not so much up top but a little there also.
Thanks for putting this on, that port looks awesome after the massive chunk of "wtf is that there for" is removed. And I agree that it would likely need a tune change after putting it on and some decent gain should be seen. I considered a low buck project on my current truck (04 5.3 truck).. this intake, drop in cam, and long tubes. But now i'm looking at 2018 6.2 trucks lol. Small change in plans.
12-02-2017, 12:39 PM
Dorman Truck Intake info/porting (with pics) 
