RJM GTR Intake Lower Manifold...oh yes!

juicinjake

you know, i dont usually comment very much, but reading this im just kinda shaking my head. i also have one of these... it might look like rough machining on the outside in the pictures, but i believe the light is just fooling you guys. despite having "big scoops" its smooth to the touch all around. sure, they used a bigger ball mill and make less passes to speedup external machining, but you have to remember that every minute that thing is on the machine, is money that the customer would have to pay for. thats the reality of manufacturing, and the piece is expensive enough as is. as someone who spent that amount of money on it, im more than fine with the external texture. hell, if u dont like it, powder coat it! i think that would look awesome tbh. enough about the outside though; moving on... the inside texture is very, very smooth... comparable to any other CNC head ive ever inspected, purchased or installed. im not gonna spend my time collecting resources, posting links, or doing all that typical forum bs that you guys waste your time with trying to win arguments. i dont have time for that... you guys can do your own research... but the industry has widely accepted cnc porting and the COMMON resultant texture. they didnt settle, either! the technology proved itself through test after test, over a very long period of time (and its still going, apparently). most tests have proven that identical ports with mild hand ported/cnc texture differences flow more or less the same cfm. the real advantage to a cnc is that its 100% repeatable. it doesnt get lazy. it doesnt take lunchbreaks. it just delivers, time and time again. its fast and repeatable. that said, there is all this relatively meaningless talk about the port texture, but no talk of the port shape, the thing that REALLY matters... when i saw the FIRST picture of the proposed rjm lower, it resembled the gtm piece, which produces a NASTY double bent in the runner... a huge restriction at high mass flow rates. i didnt think it was a good idea and i was not on board with it at all whatsoever. however, when the photos of the revised runner layout were posted, it changed my mind about the piece, and so i bought one to test it out. the gtr upper manifold intake port and vhr lower intake port (in the head) exist at different angles such that the transition between the two pieces is difficult to design correctly. after holding it in my hands and installing it, religiously inspecting port alignment and ultimately driving on it (today), i am very happy with the piece, considering the money spent. the rjm lower is gasket matched at the inlet, making it bigger than the gtr upper. thats the real restriction in the combination of those two parts that is an issue worth talking about. are the runners gonna be too long? are the plenums gonna be too small? ill find out on the dyno soon, but if that combination isnt ideal, its no fault to the rjm piece. if i dont make power, then ill modify the upper arrangement until i do. now, here is a little more info on the install.. . the fuel rails are a tight fit, but everything on the vhr is a tight fit, really. u go making things radically bigger, putting manifolds that werent designed for that engine/valve covers on top of it, and you can expect some tight fitment in places, but i just overcame all those issues in pursuit of the install. the vr38 platform has a ton of aftermarket intake manifold options, where we have a few. this product opens that world up to those who are willing to shell out cost plus gtr tax on those other intake manifold options. either you shell out for this, or you shell out for the aam... or you do nothing. most people will choose the latter option, combined with sitting around on the internet complaining about stuff they are never gonna buy. i personally dont have the time to waste on that. with regards to the rjm in general, yea sure the jury is still out i suppose, but i personally am very happy with my purchase.

COSMO

And that's all that matters is that your happy. And it's not complaints but facts and concerns regarding this intake. Not too many people here would fork out 2k for a untested product with No data or r&d to back it up but to each their own.. I speak of facts because I have in fact bought into bobby's bs products before and been burned and its still costing me money to this day to fix. BTW can he leave the state of FL now ???

juicinjake

i understand that... and your concerns with regards to testing pre-release are legitimate. i am willing to take the plunge to inform the masses. i also appreciate you understanding that im about facts and that im not here to argue. i have purchased this intake, the aam, and have several various modified stock intakes that i will all be testing back to back on my 13 370z as soon as the aam manifold is done. as for rjm dynos, we aren't far off on my end.

370Z JT

Are you the one doing the NA testing for them?

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juicinjake

yes