Dorman 615-183X intake
Ive used quite a few dorman intakes esp the 4.3,.57 vortec and the ford ohc and 3800 intakes. Ive seriously never had an issue. Esp when they address the weak spots in factory intakes like the tb coolant holes for the 3800 and tstat housing issues with th Ford's.
I have not used one on an ls...yet, but we do have the ls2 dormans available now with billet rails and tbs for way less even than the price of just the bare fast92. We have the dorman ls6 also. Both apparentl flow well and have quite a bit figured out.
The negative is where the intake (upper half) meets the bottom half and is held together via a "rail" at the front and back like a china wall which uses fasteners to screw the halfs together. Then the sides of the intake, injectors/intake runners side is held down via the intake bolts. The issue is the "china" walls of the intake (front and back) will flex slightly as the intake is torqued down. The seam that meets very closely when unbolted will open slightly and create a gap and thus your potential leak point. This is with engine vacuum and not even boost yet. The fix would be to unbolt the intake (if its off the motor) its just the front and back and use a nylon adhesive/sealer at the china rails and then bolt it together. Problem solved. Then you get to enjoy the more more generous plenum volume and runner design/fast base port entry over the stocker. Gaskets are also simular to the fast intakes as well.
The rest of the intake seems to be of decent quality for the price. It did bolt on and clear my steam lines. I should also clarify that I did not actually have a vacuum leak with this intake. Another member who was testing it out with me did, he sealed his with the nylon adhesive and I haven't yet. I removed the intake to rule it out as a potential leak. I will be modifying it with sealer to run it as I have heard from the other member that hes had to add a bunch of fuel above 2500 rpms as hes now running leaner with the dorman. That means the air flow is there and thus requiring more fuel. Due to the flex that I saw I wasn't going to chance it when I have boost running through it so I will fix it before putting it back on.
Alot of these chinese companies with copy a USA made part to the T (tial knock offs, aeromotive knock offs, MSD box knock offs) and the amount of work to shut the company down (if its even a real company) is long and tedious. When they will just create a new company and sell the product immediately.
stock intake above is like 10lbs. Dorman below is heavier by like 1lbs.
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I couple of otherthings after watching the video alittle more closely. THe PCV hose on the X intake is much "shinier" and looks plasticy. The hardware while brief in the video is slightly different. The screws included in my dorman have a large hex head and washer built in and very corse thread but no point. The X intake hardware looks like zinc coated phillips wood screws. The X base has the part number casted in and the Dorman just has the dorman logo casted in. Dorman also has the torque info etc casted into the top cover... couldnt see that in the video on the X intake.
I haven't had it apart yet to comment on the internals. But the Base of the dorman (on the inside)looks like the OE nylon (dull look and can see the fibers) where the X intake looks very shiny in the video. Please refer to my pics posted in the last post to see what I'm talking about. In the inside shot you can see the dullness compared to the shinny upper half.
The vacuum hose is actually pretty nice, it's silicone coated. The opening to the vacuum ports is only about 1/16" though which seems small; not sure how that compares to stock or to the Dorman.
The Dorman seems to be molded much more accurately here.
Hardware:
FAST: Base design, +25hp over stock with 102mm throttle body ($1,600 for +25hp)
Dorman: Degraded via smaller TB and square inclusion on corner of runners
Super Auto: Further degraded via malformed runner opening
Just a theory though. I suspect the malformed runner has a very minimal effect on flow. I'd love to see dyno results compared to the FAST setup, to see just how much HP $1,600 buys vs this $130 intake and a stock TB.
The vacuum hose is actually pretty nice, it's silicone coated. The opening to the vacuum ports is only about 1/16" though which seems small; not sure how that compares to stock or to the Dorman.
The Dorman seems to be molded much more accurately here.
Hardware:








