Inlet Manifolds

[ISL33P]

The thing I always say is that you can make 2000hp (ok a little exaggerated) on a standard manifold. The whole idea is that you improve the engines effeciency. There is no denying a standard manifold "will do" but can it be improved on.....and I certainly think so! Otherwise I wouldn't do what I do.

[ISL33P]

And to the other post, I make manfifolds which make more power than a standard manifold at the same revs. Yes the can rev more as well, but that thought of long runners being the only way to go, I have disproved many times. You would be surpised how little effect the length of runners do have on a turbocharged car.

Someones would lead you to believe that air speed increases in a turbocharged/supercharged application and that couldn't be further from the truth.....something to think about

[R31Nismoid]

a question relating to all this manifold business how much power can a stock inlet handle i been looking everywhere and cant find the answer

Easily 370rwkw, 2 people (myself included) have made such.

I believe there are a couple more around also.

[wolverine]

Someones would lead you to believe that air speed increases in a turbocharged/supercharged application and that couldn't be further from the truth....

Are you able to elaborate?

[DR 32R]

I agree with this guy. Long runners for stock rev limit.

If you want less intercooler piping the Plazmaman is the go.

Someone has stated to me, a Plazaman with stock runners may give better low to mid range and earlier spool, than a complete short runner set up.

[neofenrir34]

Are you able to elaborate?

Runner length is only really a noticeable thing on NA powered cars where the the length and shape of the runners, speed or slow the airflow through them. In a force induction type of vehicle it has only a mild effect because the air is getting forced into the engine under pressure.

In big power applications well designed runners on turbo charged cars will help with efficiency but lets face it most of us will come no where close to having to worry about it that much.

Hope that helps

[neofenrir34]

Someone has stated to me, a Plazaman with stock runners may give better low to mid range and earlier spool, than a complete short runner set up.

The spool speed of the turbo is helped because of the increased efficiency of the intake system. As for the mid range torque i haven't had much experiance with that on RB engines but from other types of engines that i have seen, a decent tune will correct most loss if any.

That is all mainly due to the fact of the engine tune not being able to use the air it is getting effectively.

[wolverine]

Yes, I understand what Ariel was saying about length.

I am asking about air speed increases or lack thereof.

I have previously spoken to the guys at Plazmaman about their reasoning/research and also going back a few years Ariel was kind enough to PM me some of his thoughts on the internal design of plenums particularly with regard to runner inlet forms/shapes under forced induction (which he has no doubt refined over the years).

[ISL33P]

R31Nismoid - but what power could you make with a decent intake manifold? How much boost would it take to make that power? These are the kind of questions I ask and people can't answer. Why? It maybe just a case that no-one has challenged them on it and just believed what they have been told.....is it because everyone else says it so it must be right? I am not having a stab at you at all, just the way in which people come to some conclusions is what I am questioning.

I would like to offer anyone with an rb25 a free plenum (to keep ofcourse) for some testing, especially anyone making around that 400+rwhp mark and with enough turbo to make more. Pm me if you are in Wollongong/soutj coast/sydney and we can sort it out.

As for the air speed comment, you would be surprised to know that air speed does not change between a naturally aspirated or forced induction engine. What changes is the actual air density which things like pressure and temperature have a direct correlation.

Not for a minute do I say this is something I have discovered or am an expert on, this is a theory that has been proven over and over again and there are plenty of books to read and sites to search to support this. What I do is try to use what information is out there and apply it to what I do.

[R31Nismoid]

R31Nismoid - but what power could you make with a decent intake manifold? How much boost would it take to make that power? These are the kind of questions I ask and people can't answer. Why? It maybe just a case that no-one has challenged them on it and just believed what they have been told.....is it because everyone else says it so it must be right? I am not having a stab at you at all, just the way in which people come to some conclusions is what I am questioning.

Well I don’t know – do you? Given every setup is different, quite hard to quantify something like that.

What about response and so on? And I’m not talking on a dyno, flow benches or whatever. On the street.

A larger plenum holds more air, would take longer to fill…

It's also – defects/legalities and so on. They are as much of a factor as any potential gains & a key issue down here in Vic.

Something people are realising more and more each day, stealth factor is paramount for a lot of people.

Cost for gain is also another issue, for those modifying on a budget. By your own pricing earlier, its basically $2500 for a plenum installed - that is a lot of money and well outside the average punters budget

Spending 2.5k on a plenum is not a necessity (like injectors, ECU, turbo), and that is I think the most important point.

Nice to have, yes… But certainly not a requirement.

[ISL33P]

Well I don’t know – do you? Given every setup is different, quite hard to quantify something like that.

What about response and so on? And I’m not talking on a dyno, flow benches or whatever. On the street.

Yes I do know. I have plenty of customer feedback to support this but I thought offering this to someone on this forum I thought it would be the most genuine way of showing it and therefore not going just by what I say, ie independent

A larger plenum holds more air, would take longer to fill…

Something that can be offset by the rest of the intake system, ie runner length & design which all should be designed in conjunction....you know that plenum volume is not the be all and end all.......

It's also – defects/legalities and so on. They are as much of a factor as any potential gains & a key issue down here in Vic.

Something people are realising more and more each day, stealth factor is paramount for a lot of people.

I can totally see your point, but there is no reason why you can get any aftermarket intake to meet epa regulations. All mine can have the factory sensors installed and the vast majority of the vacuum inputs required.

Cost for gain is also another issue, for those modifying on a budget. By your own pricing earlier, its basically $2500 for a plenum installed - that is a lot of money and well outside the average punters budget

no-one said making power was cheap, but there are ways to go about it making it as effecient as possible and this is definitely one way of doing it

Spending 2.5k on a plenum is not a necessity (like injectors, ECU, turbo), and that is I think the most important point.

Nice to have, yes… But certainly not a requirement.

This is an integral part of the the engine and certainly an area that can be imporved upon especially since people are not satisfied with factory power outputs. Whether its necessary is certainly debateable from a technical point of view, but when you consider price, regulations etc, it certainly may put it in question, but there are certainly plenty of people who believe it is enough to do considering the number of intake systems that are sold....they cant all be wrong can they?

[boostn0199]

I can totally see your point, but there is no reason why you can get any aftermarket intake to meet epa regulations. All mine can have the factory sensors installed and the vast majority of the vacuum inputs required.

Just curious how could you get it meet the epa regulations cause isnt the problem itself that it is a intake modification which your only allowed to have 1? So no matter if it meets standards or not they dont allow it. Ive thought about getting a forward facing plenum but this has been the main reason to stop me.

[R31Nismoid]

Yes I do know. I have plenty of customer feedback to support this but I thought offering this to someone on this forum I thought it would be the most genuine way of showing it and therefore not going just by what I say, ie independent

So where are the results then?

Drop in circuit laps times, increase in ET/MPH etc, feel free to post them up, we’d all love to see them for sure!

Something that can be offset by the rest of the intake system, ie runner length & design which all should be designed in conjunction....you know that plenum volume is not the be all and end all.......

Indeed I do realise it’s not the be all and end all

I can totally see your point, but there is no reason why you can get any aftermarket intake to meet epa regulations. All mine can have the factory sensors installed and the vast majority of the vacuum inputs required.

Just curious how could you get it meet the epa regulations cause isnt the problem itself that it is a intake modification which your only allowed to have 1? So no matter if it meets standards or not they dont allow it. Ive thought about getting a forward facing plenum but this has been the main reason to stop me.

You can’t get them legal in Vic…

Using factory sensors/inputs means nothing when it counts as an intake modification.

Given you are only allowed one – and you must change the SMIC to a decent FMIC – totally rules out it ever being legal in Vic, which is my point.

FMIC = necessity vs plenum = not a necessity … The ugly EPA cloud rears its head far too often.

So the choice is pretty clear cut for us ole Victorians and hence we tend to use more factory parts in builds than most others.

And interesting point in itself and it often see’s factory parts tested beyond what people normally would.

no-one said making power was cheap, but there are ways to go about it making it as effecient as possible and this is definitely one way of doing it

This is an integral part of the the engine and certainly an area that can be imporved upon especially since people are not satisfied with factory power outputs. Whether its necessary is certainly debateable from a technical point of view, but when you consider price, regulations etc, it certainly may put it in question, but there are certainly plenty of people who believe it is enough to do considering the number of intake systems that are sold....they cant all be wrong can they?

Who said they were wrong? Nobody. They perhaps can afford to do so, and this is the key point.

You might make more power @ a slightly lower boost level, or some extra midrange… Value for money? Depends where you sit.

However budgetary constraints do come up from time to time and that’s what I’m saying here… Look at it like this:

Your average modd’er will spend around 6k for 280rwkw, just in the engine bay

ECU(tune)/Injectors/AFM/Turbo

A 2.5k Plenum add’s almost 50% to the bill, what sort of gains are you getting for this hike in expenditure is the first question one asks, and certainly one I couldn’t justify even over 300rwkw. My car was no slower than anyone else around that power level on the street so I was happy.

If some people can spend the cash, all power to them.

[PM-R33]

Yeah it sucks for you guys in VIC.

I could never go back to working on my car with that damn annoying factory plenum in the way of everything. Ugliest thing in the world.

[75coupe]

So nismoid is saying that its a cost factor vs performance gains issue for him.

but all the other people who are happy to spend larger amounts of money on their car are completely sane by doing so...

btw I picked up a RIPS RB25 intake plenum for $400 secondhand, I cleaned it up and I'll get it powdercoated next, so I reckon that was worth it, I installed myself so no labour charge, I did all the install work on my new turbo, injectors & plenum setup, others can do the same if they really wanted to if you actually research, have patience and are willing to learn...

I find all my parts for cheaper than shelf price, example brand new HKSGT2835 ProS with all new studs and gaskets $1600 delivered... if you search and wait you will find...

[ISL33P]

....and that's what it looks the point. Each have their own opinion and i am sure they can speak for themselves....that's what the forum is all about.

More and more of the car community are doing their own work for a few reasons (cost saving, self fulfilment and more) and hence why they are an ever growing of business based on supply only model, me included (for the time being )

As for the results to support my claims, I am just waiting on a candidate to take me up on my offer and we will have them. That way they are unbiast and cant be questioned....something that always happens when a manufacturer makes claims....it's the independance which people like to see and what i want to provide.

So anyone want a FREE plenum? I want to put this topic to rest for once and for all....its been an ongoing here for quite sometime

Edited October 26, 2010 by ISL33P

[75coupe]

Well Id love to test it for you but I dont if my 2835proS is what you want as a test setup...

I could also compare it to the RIPS plenum for you... its currently at the tuners, I should have it back really soon...

[zebra]

....and that's what it looks the point. Each have their own opinion and i am sure they can speak for themselves....that's what the forum is all about.

More and more of the car community are doing their own work for a few reasons (cost saving, self fulfilment and more) and hence why they are an ever growing of business based on supply only model, me included (for the time being )

As for the results to support my claims, I am just waiting on a candidate to take me up on my offer and we will have them. That way they are unbiast and cant be questioned....something that always happens when a manufacturer makes claims....it's the independance which people like to see and what i want to provide.

So anyone want a FREE plenum? I want to put this topic to rest for once and for all....its been an ongoing here for quite sometime

Wait....

..So you say that your plenums will make - 1500hp flow, better yadda yadda yadda.

But they have never been tested?

Am I missing something here?

[boostn0199]

Wait....

..So you say that your plenums will make - 1500hp flow, better yadda yadda yadda.

But they have never been tested?

Am I missing something here?

I think hes saying they have been tested but in order to provide proof from someone who has nothing to gain by reviewing hes product thats why he is wanting for a person from here to try it.

[zebra]

Ahk gotya