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Great to hear and it's absolutely night and day different internally than the tube style nbs/nnbs/tbss intakes as it's open as seen in pics, like a car intake. A proper full tune would be wicked to see what it can do. Old threads mentioned half a$$ed tuning where the results were so inconclusive so with proper tuning, it would be awesome to see what this intake can do BEFORE porting and AFTER smoothing out the little wedges in the reachable portions of each runner.
i agree. I think they might have changed to a 2 precise intake but it's hard to tell. The inside of the intake alone im has got to be worth power. Not to mention the huge openness shouldn't create any airflow issues to the back 4 cylinders like the stocker. I won't be able to test it like you mentioned but my current tune will swap over and I will likely be checking timing due to the new cam. I only see. Needing to go back 2"'in each runner. The parts where the halves meet up don't really alarm me as a restriction and not worth the porting prob.
i also found out one issue but that's more because I'm going to put a IAT sensor in the air purge port behind the TB. The dormans air purge boss is much taller than stock or the depth of the port is deeper by around 3/16-1/4". Soooo if your planning on jamming an IAT sensor into it your not going to protrude enough into the intake tract to get a good reading probably. So u either don't do it or you have to grind down the mounting area like 1/4" so it protrudes far enough in.
Not that hat hard and I decided to do the ladder. A dremel and a cutting bit took prob 15min.
Here is some pics pics of the cut down boss and the inside plenum area.
i also found out one issue but that's more because I'm going to put a IAT sensor in the air purge port behind the TB. The dormans air purge boss is much taller than stock or the depth of the port is deeper by around 3/16-1/4". Soooo if your planning on jamming an IAT sensor into it your not going to protrude enough into the intake tract to get a good reading probably. So u either don't do it or you have to grind down the mounting area like 1/4" so it protrudes far enough in.
Not that hat hard and I decided to do the ladder. A dremel and a cutting bit took prob 15min.
Here is some pics pics of the cut down boss and the inside plenum area.
Good job posting those pics and porting that tb. Have you not dissembled the intake . Its a 3 piece design if have pics of the 3 sections please post them also.
Definitely looks to be a much bigger air reserve than stock. I would assume high rpm will really shine like 4600+ rpm. If you lose power in the lower rpms, I wouldn't hold it against it as to maintain lower rpm power you'd need something restrictive like the nbs truck intake to maintain air velocity at lower revs. However, and this is why I'm excited, the 78 mm tb inlet may possibly maintain low rpm velocity as opposed to a 90 mm inlet, so this might be a win win.
Also, on dorman's website it said it has an 81 mm inlet so maybe check that out unless you already measured it.
Also try not to disassemble the layers as that's where users have had issues (after reassembly) as even the access holes for the hardware are apparently covered to deter you from this. They do appear to sell replacement gaskets however I'm not sure if they sell the ones between the layers, which would make disassembly a hassle as compared to a fast that does sell the internal gaskets.
Either way you should have to add LOTS of fuel to your tune to make up for the increased air so keep us posted.
Good job posting those pics and porting that tb. Have you not dissembled the intake . Its a 3 piece design if have pics of the 3 sections please post them also.
Definitely looks to be a much bigger air reserve than stock. I would assume high rpm will really shine like 4600+ rpm. If you lose power in the lower rpms, I wouldn't hold it against it as to maintain lower rpm power you'd need something restrictive like the nbs truck intake to maintain air velocity at lower revs. However, and this is why I'm excited, the 78 mm tb inlet may possibly maintain low rpm velocity as opposed to a 90 mm inlet, so this might be a win win.
Also, on dorman's website it said it has an 81 mm inlet so maybe check that out unless you already measured it.
Also try not to disassemble the layers as that's where users have had issues (after reassembly) as even the access holes for the hardware are apparently covered to deter you from this. They do appear to sell replacement gaskets however I'm not sure if they sell the ones between the layers, which would make disassembly a hassle as compared to a fast that does sell the internal gaskets.
Either way you should have to add LOTS of fuel to your tune to make up for the increased air so keep us posted.
I'm not disassembling. The runners look fine, it's just the port exit to the heads that needs attention.
I have measured the tb opening and its exactly 75mm, same as the stock truck intake. So technically the 78mm TB is really a 75mm lol. As the insides line up perfectly.
The bolts were melted over in the prototype but in this one they were never opened or melted. Which makes me believe there are no bolts on the inside and everything is sealed front and back and it uses the intake bolts to clamp the side lengths down and hold it together. I plan on adding a lot of fuel due to the cam
here is the stock and dorman tb opening with caliper.
It is impressive how crisp/cleanly the Dorman runners are cast compared to the OEM.
behind the TB the area is the plenum before the air enters the runners. The smaller the plenum the less rpm it can handle per say but rubber length matters too. The stock intake is literally a 75mm tube with a opening on the top like 1/3 the way down, that opens to another chamber and the air makes its way to the runners and then into the heads. The dorman is a giant open area right behind the TB and thus has the capability to support more rpm. The dorman casting is very nice. I've only found small casting slag around the EGR.
Definitely looks to be a much bigger air reserve than stock. I would assume high rpm will really shine like 4600+ rpm. If you lose power in the lower rpms, I wouldn't hold it against it as to maintain lower rpm power you'd need something restrictive like the nbs truck intake to maintain air velocity at lower revs. However, and this is why I'm excited, the 78 mm tb inlet may possibly maintain low rpm velocity as opposed to a 90 mm inlet, so this might be a win win.
Also, on dorman's website it said it has an 81 mm inlet so maybe check that out unless you already measured it.
Also try not to disassemble the layers as that's where users have had issues (after reassembly) as even the access holes for the hardware are apparently covered to deter you from this. They do appear to sell replacement gaskets however I'm not sure if they sell the ones between the layers, which would make disassembly a hassle as compared to a fast that does sell the internal gaskets.
Either way you should have to add LOTS of fuel to your tune to make up for the increased air so keep us posted.
forgot to respond to this. The gaskets are replacements for the runner to the head, not inbetween the sections. But I believe it's something like a rope seal that would work. The fast is also designed to be taken apart and changed the dorman is not.
It's confirmed then, the diameter is 75 mm but either way that can very easily be expanded to 80 mm + if you really wanted to. Either way I'm thankful for someone trying the intake out and hopefully going all the way to truly wring as much power as possible from this setup. If you were local I'd say free labour for the tunes to get the maf/ve tables dialed in to 0% afr/lambda error and see exactly what timing and afr makes the most power
Yeah I only would port the wedges in the intake runners anyways so that should work out conveniently.
behind the TB the area is the plenum before the air enters the runners. The smaller the plenum the less rpm it can handle per say but rubber length matters too. The stock intake is literally a 75mm tube with a opening on the top like 1/3 the way down, that opens to another chamber and the air makes its way to the runners and then into the heads. The dorman is a giant open area right behind the TB and thus has the capability to support more rpm. The dorman casting is very nice. I've only found small casting slag around the EGR.
here are the differences.
Dorman above Stock truck 75mm all the way back
The oem truck intake is actually a good performer and GM has set the bar pretty high. So any gains that a ported Dorman may have is going to be quite an accomplishment. But any comparisons as far as plenum volume and runner length can be very deceiving , the GM truck design does not need a huge volume to perform well. The two are very different approaches in designs. The Dorman design is similar to passenger car intakes. So if you are looking at volume and runner length and shapes the car intakes will give you better idea how well the Dorman might perform .
The oem truck intake is actually a good performer and GM has set the bar pretty high. So any gains that a ported Dorman may have is going to be quite an accomplishment. But any comparisons as far as plenum volume and runner length can be very deceiving , the GM truck design does not need a huge volume to perform well. The two are very different approaches in designs. The Dorman design is similar to passenger car intakes. So if you are looking at volume and runner length and shapes the car intakes will give you better idea how well the Dorman might perform .
i think u might have my OE intake confused... it's the original LS1 truck intake as seen in the pics. It's the MOST restrictive of all the truck intakes. Your newer NBS and NBSS intakes are a massive improvement over mine. The NBS and NBSS are both the top dogs of the truck intakes and are the best performing OE intake. I believe the only difference between the NBS and NBSS is the TB opening size. Either way you would be correct that the dorman will hopefully make the same power as you can't really ask for more but at the same time it shares the design with the FAST truck intake which is top dog for low rpm and top end. Guess what the major advantage over the old truck intake was with the NBS styles? They have a larger plenum area and I believe they changed the plenum design on the inside. I have lots of experience with TPI and those era of FI as that's what all my cars had. They all share the same design as my truck intake which was small plenum and long runners. TPI are maxed out my 4500 but can rev to 5200 with ported plenum, aftermarket larger runners and aftermarket base plate. I know bc I did all of it lol. Those things are tq monsters compared to the LT1, miniram, super ram etc. aftermarket designs for the cars included new shorter runners and very large pizza box sized plenum to help with high rpm air flow.
So so I will say if I was comparing the dorman to the NBS I wouldn't expect huge gains, but I'm comparing to my original oldest style. So I expect a decent gain in performance.
Also so I will say I have my ideas of why the original truck intake is a tube plenum with opening into another plenum and it has to do with water. I think GM did t to help with water being sucked through the intake and collecting in the first plenum and not making it past it. I got a glimpse of this when I was spraying a good bit of water/meth right behind the TB and when I yanked the TB there was a river of water/meth at the bottom of this first plenum.
I guess the the main reason behind this thread is to get equal performance from the NBSS intake while getting a hug bump in the looks department. Plus the aftermarket design of the intake gaskets is really nice when you compare it to the stock style. The area of the gasket on the dorman is also MUCH thicker and sturdier than the stocker and I suspect no warping issues with this.
i think u might have my OE intake confused... it's the original LS1 truck intake as seen in the pics. It's the MOST restrictive of all the truck intakes. Your newer NBS and NBSS intakes are a massive improvement over mine. The NBS and NBSS are both the top dogs of the truck intakes and are the best performing OE intake. I believe the only difference between the NBS and NBSS is the TB opening size. Either way you would be correct that the dorman will hopefully make the same power as you can't really ask for more but at the same time it shares the design with the FAST truck intake which is top dog for low rpm and top end. Guess what the major advantage over the old truck intake was with the NBS styles? They have a larger plenum area and I believe they changed the plenum design on the inside. I have lots of experience with TPI and those era of FI as that's what all my cars had. They all share the same design as my truck intake which was small plenum and long runners. TPI are maxed out my 4500 but can rev to 5200 with ported plenum, aftermarket larger runners and aftermarket base plate. I know bc I did all of it lol. Those things are tq monsters compared to the LT1, miniram, super ram etc. aftermarket designs for the cars included new shorter runners and very large pizza box sized plenum to help with high rpm air flow.
So so I will say if I was comparing the dorman to the NBS I wouldn't expect huge gains, but I'm comparing to my original oldest style. So I expect a decent gain in performance.
Also so I will say I have my ideas of why the original truck intake is a tube plenum with opening into another plenum and it has to do with water. I think GM did t to help with water being sucked through the intake and collecting in the first plenum and not making it past it. I got a glimpse of this when I was spraying a good bit of water/meth right behind the TB and when I yanked the TB there was a river of water/meth at the bottom of this first plenum.
I guess the the main reason behind this thread is to get equal performance from the NBSS intake while getting a hug bump in the looks department. Plus the aftermarket design of the intake gaskets is really nice when you compare it to the stock style. The area of the gasket on the dorman is also MUCH thicker and sturdier than the stocker and I suspect no warping issues with this.
Well Im not sure what you mean by LS1 truck intake . But there are only 2 different Cathedral port truck intakes. There is the NBS truck which refers to trucks 1999-2007 1/2 , and also referred to as Classic, this intake is the 3 bolt 78mm tb . Some guys call this the ugly intake it is the same intake but has had many different part numbers over the years. The NNBS are trucks 2007 and later. This body style had a smooth door no crease in the side. The intake on this NNBS was a new design and uses a 4 bolt 87 mm tb. This intake is also referred to as the TBSS intake because is was on the LS2 TBSS. There is another LS truck intake that was used on L92 but its rectangle port and was only used on 2007 and later with 6.2 and 6.0 engines. I don't like using the New Body Style names when referring to these intakes . Example the NNBS intake appeared as early as 2005 on Gen IV engines . I can post part # and pictures if you like.
LOL. No such thing as a LS1 truck intake. It's an LM7 intake.
Thats not accurate. LS1 dictates the style of motor or more so the intake runner design. All LS1s had a cathedral port configuration. The port changes as the engines evolved, LS1/LS2, then LS3 and finally the new rectangle port. The LM7 is the engine code not the intake code. In fact a LS1 truck intake will bolt on to an LS1 car motor with no issues and make more power than the LS1 car intake. So what do you can an LS1 car motor with an truck intake? Lol.
Well Im not sure what you mean by LS1 truck intake . But there are only 2 different Cathedral port truck intakes. There is the NBS truck which refers to trucks 1999-2007 1/2 , and also referred to as Classic, this intake is the 3 bolt 78mm tb . Some guys call this the ugly intake it is the same intake but has had many different part numbers over the years. The NNBS are trucks 2007 and later. This body style had a smooth door no crease in the side. The intake on this NNBS was a new design and uses a 4 bolt 87 mm tb. This intake is also referred to as the TBSS intake because is was on the LS2 TBSS. There is another LS truck intake that was used on L92 but its rectangle port and was only used on 2007 and later with 6.2 and 6.0 engines. I don't like using the New Body Style names when referring to these intakes . Example the NNBS intake appeared as early as 2005 on Gen IV engines . I can post part # and pictures if you like.
fine. Don't need the pics. I was just referring to the oldest original truck intake or the ugly intake. These make less power then the newer NNBS or TBSS intakes. There is a considerable change in design from the original truck intake to the new ones.
Thats not accurate. LS1 dictates the style of motor or more so the intake runner design. All LS1s had a cathedral port configuration. The port changes as the engines evolved, LS1/LS2, then LS3 and finally the new rectangle port. The LM7 is the engine code not the intake code. In fact a LS1 truck intake will bolt on to an LS1 car motor with no issues and make more power than the LS1 car intake. So what do you can an LS1 car motor with an truck intake? Lol.
That's kind of a bad way to look at things, they're just cathedral port intakes. Ls1 is a different engine and intake than an lm7, ls6, ls2..
If someone tried selling me an lm7 claiming it was an ls1 I'd laugh in their face.
01-14-2017, 09:24 AM
