RJM GTR Intake Lower Manifold...oh yes!

bullitt5897

Ok so im going to chime in given that I have held an OEM, GTM and the RJM in my hands and on a table in front of me.

The proposed issue presented:
Why is the inside runner so "Rough"?

My Thoughts:
So what I feel we have here is an over critical look at the product based on pictures which does not give you a real understanding of the texture of the inside runners. Does the inside runner have a textured? Yes, however it is not much of a texture at all. The picture is very deceptive due to the lighting. The pre production unit that I got and should be identical to the one everyone else has received with the exceptions of some input from me on some minor changes.

The inside texture is very comparable to stock or a cast. Could it be smoother? Yes it could but one key item to remember is that this unit was designed with the intent that if you wanted you could port this thing an additional 5mm all around!!! In a Forced induction application these shallow grooves will not make much of a difference. In an N/A application you might see some improvement from polishing it but I would not bank on you making a ton of power... Maybe 2-3hp if that.

The outside jeweling was left at this level to help make sure this stays affordable for everyone. There is alot of machine time in these lowers and to go another step into smoothing the outside cosmetics is very doable and from my conversations easy to do. However, that cosmetic request could very well result in a few hundred dollar increase in price... So as a fellow consumer what do you want? Functional or pretty?

The current interior runners will not and I repeat will not hamper you. I along with several industry staples have held these in our hands. this isnt a "shitty" product but a well thought out and engineered device...

DE yes you can refine the product and polish it to a mirror finish but you and I both know that even with doing that you are not going to see a major increase in HP or TQ...

So lets be honest guys. What we have here is a a legit criticism but one that if you want done will cost you more $$$. Can you live with a cosmetic (in your opinions) issue or are you willing to actually pay $2200-$2300 for a perfectly polished unit? I would bet money that your would rather buy the unit as is for a Sub $2k price tag...

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

Elmo370z

Mmm interesting

COSMO

Regardless of how much this new item is I feel it should have come polished. Who wants to pay to have it done after they have purchased or even do it themselves for that matter. I only hope for you na guys who have taken the plunge on this thing makes power. Remember the the intake runner in the gtr is for a Forced Induction car not a na car. Again I hope the best for you guys but it should have already been tested prior to selling...
And if I'm not mistaken at least gtm polished their intake..?

(On mine I noticed increased efficiency throughout the power band on an FI car) Dyno, or are you referring to the gtm intake runner you already had on your car???

bullitt5897

Also just to note. From my conversations and experience with the manufacturer they can polish upon request. Like I mentioned earlier this is not a hard thing for them to do but just costs more. So if you want mirror finished runners ask for it if and when you order. otherwise you can spend the money and have it polished yourself. As far as the testing goes the designs where bench tested and now that we have preproduction and production units available we are seeing people start to give real world experience with these units. On mine I noticed increased efficiency throughout the power band on an FI car. EPS is now testing for an NA application and real world results.

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

DEpointfive0

Man... It's like you work for them or are getting one for free! Lol

In conversation with the guy, I say "probably doesn't matter" and he said doesn't matter on the outside, let's see the inside, where the pic comes up. I say 3rd pic is inside.

It probably doesn't matter for 99% of us, but I'd want it polished/let of a step on the outside. Just gives me ants in my skin

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bullitt5897

De I have the invoice for mine... I definitely paid for it!

Being as someone who has done some of the testing on it. It is most definitely the best one on the market. I just find it funny that everyone on here is acting like engineers when none of us are such. I am simply speaking from my experience since I have seen multiple of these in person and handled them. I have also installed the unit and I am in the process of getting my car up and running on this new manifold.

The funny thing is these guys are actually listening to input unlike GTM... You and I both know we all have input to help GTM and they ignored it! Every input I gave made it into the production units within 24hours... If people are willing to pay more I am sure they would be willing to polish it to a mirror finish.

But again ask yourself... If you were willing to pay $2k for this setup would you be willing to pay a couple hundred extra for a mirror finish? From my experience the 370z owners are not willing to do so...

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

Boss_302

Some of are Engineers.
Some of us have some 40 Years of car racing and car building experience.

COSMO

(The funny thing is these guys are actually listening to input unlike GTM... ) It's not guys it's only bobby Ralston. I love how he refers to The Guys on his FB page to make it seem like he has a company full of engineers. Secondly this new item was copied as most other things bobby has done in the past like his single turbo kit. At least gtm had enough sense to test theirs and polish the finished product.. Btw how is version 2 or 3 coming along since the fuel rails didn't fit on the first ones?? Fingers crossed for you guys and waiting to see ANY dynos..

bullitt5897

OK....

Actually its more than Bobby as I have had design conversations with multiple people he is working with... and so what if its a small business with low employee count... Its like saying CJM wasnt legit when he started up... I know you have beef with Bobby but lets keep this information in this thread actually factual. Also GTM did NOT and let me repeat this did NOT polish theirs. As far as fuel rails they fit perfectly on the RJM unit. It was a bit tight with the EV14 injectors, wiring harness and vacuum tubes to get the button head screws in place but once I got it to start threading it went in with ease.

Not only that Forged performance has also looked over this unit and has given big props on fitment, design and quality.

Also GTM did bench testing just like Bobby... but hey dont believe me because i wasnt the test mule for GTM for 5 years while the products on my car were for sale on their website as soon as it was on my car...

But hey call me a fan boy or whatever... I have had my hands on the product and actual multiple units... Something I know you will not be able to speak to Cosmo...

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

bullitt5897

I was speaking to those speaking up in the conversation. I know several members on here who are mechanical and electrical engineers. The ones making comments on the insides of the runners were not engineers. Also the topic of runner surfaces are highly debated even today.

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

COSMO

For starters I would not compare cjm (Charles) to Bobby. Not even close as most would agree.
Second, this has nothing to do with my beef with bobby. The facts is this new item has not been tested yet alone any r&d before selling to the community. To me that is very poor business tactics no matter who the person is selling it. I guess the others you can't take constructive criticism from must have a beef with him too? Or is your master plan to have everyone kicked off the forum who ask any questions or concerns over this? I do not and would never use any product of his if it were given to me. Soon enough the people who actually bought this will do dyno runs and see that it was not designed for na cars because if it were Nissan would have used it.. Try and calm down and actually show something rather than try selling snake oil. I know you already dynoed your car with this intake but what gets me is where is the dyno ???
Also gtm may not have polished theirs but at least it is Smooth the way it should be...

bullitt5897

Geez Harry take a chill pill bro! No one is trying to kick you off the forums... And as far as constructive criticism your giving none.

As stated before there are different methodologies to intake runner textures as there are many theories as to what one style versus another style could do. There is not a golden rule to intake runners however, from my experience you typically smooth out your exhaust runners to prevent carbon build up and the theory that rjmanufacturing is following on the intake runners is simply that by having a slight and I repeat slight rough surface on the intake runner your able to increase velocity of the airflow.

Again there are many approaches to intake runners and the results have varied from application to application.

I will stand by my statements as they are factual where as yours are based purely off assumptions.

As far as my dyno... Well let's see here we had an increased efficiency which meant my tune which was catered to the GTM manifold which is much less efficient was no longer applicable thus not an apples to apples comparison. Also I plan on being at zdayz which meant I did not have time to scrape my tune and do a full retune on my old kit and still make my sponsor obligations. Sooo excuse me if I choose to meet my financial and sponsor obligations...

Again I am basing all my info on facts...

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Shop Cars: 2013 318whp Nismo VspecII 370z *SOLD*, 2009 1000hp+ 93oct 4.0L TT 370z Fast Intentions STAGE 4 #054

COSMO

Hold on Mike allow me to grab some tall rubber boots. So it's safe to say you will be offering refunds if this item does not pan out the way it should to all who paid good money for this? And again nothing to show and there are your facts...
The fact is No r&d has been done to this new item but only an estimate on runner sizes. Fact: Inside of the runners are not smooth like they should be. Fact: There is already a second version because of Fact #1. Fact: To this day there has been nothing to show that will make any power for the na guys or fi guys (dyno please). Fact: There is No employees in RJM but bobby. Fact: This is another product of someone else's that Bobby has copied. Fact and or opinion: I can see a bunch of these on the for sale section when there are No gains but losses costing forum members time and money.

Wouldn't it make sense to produce a product tested instead of trying to sell one untested to customers? We are supposed to be using this forum to help each other rather than endorse things from a known person who already has a very bad rep here. But then again mike with all of your experience and tons of money in your build we are all just dumb-founded here...

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 ???