Ram Air Intake System

marcusus · Postby **marcusus** » Mon Jul 23, 2007 11:28 pm

I've changed the subject of this thread from the original HKS High Flow Power whatever product to this since I've found out (thanks Okibi) that there are a fair few products out there matching my needs, rather than just the one.

I was initially looking at one of these:
http://www.hksusa.com/products/?id=3190&rsku=6270

Anyone had any experience with these? Basically, I want to do something similar to this:

I'm thinking something like this would be on par with a Mania CAI since the travel to the throttle body is hugely reduced, and you're pulling cold air in straight through the gap in the bonnet/hood/whatever you wanna call it.

Thoughts/criticisms/etc?

Postby **Okibi** » Mon Jul 23, 2007 11:39 pm

Yeah a few have done that with some plumbing pipe.

I think Bevan might have some pics.

It's a lot cheaper than getting this kit
http://www5.plala.or.jp/dtec/nb_dairy/nb_k&n.jpg

marcusus · Postby **marcusus** » Tue Jul 24, 2007 9:06 pm

Actually, that's the bit I want as well. Didn't know how to start searching for it on google

Do K&N sell a similar filter? Or are they just doing that cover piece?

Was thinking about just cutting up the current intake at the right spots and length, and running the HKS mushroom filter. I'm fairly sure it would work...

Postby **Okibi** » Tue Jul 24, 2007 10:15 pm

Justin might be able to help you get hold of one ..

http://www.autoexe.co.jp/products/ramair/syasyubetsu/nb.html

But it's not listed on the Aussie Website.

marcusus · Postby **marcusus** » Tue Jul 24, 2007 10:23 pm

Hmmm... there's an item on the Australian Autoexe site named \"Ram Air Intake System\" for $967. I wonder if this is it, and whether or not that price is correct, because that's a shitload for something which looks like it can be dodgied up at a much cheaper price...

Okibi, what search criteria are you using to find this stuff?

So I guess no one else has had much experience with this type of setup?

Postby **Okibi** » Tue Jul 24, 2007 10:30 pm

Yup that price sounds about right.

If they were cheaper everyone would have one.

Search Criteria.... countless hours blindly navigating my way around Japanese MX-5 sites over many years. May the \"JDM yo\" god shine brightly on me.

Theres a NB8B in Sydney running one I think.

marcusus · Postby **marcusus** » Tue Jul 24, 2007 10:37 pm

Well, I got the idea from the race cars that Chris from MX5 Racing is running. One of them has I think the HKS power flow whatever the hell just sitting there, so that'll set me back maybe $150-$200 judging from the prices I've kinda seen around.

It's more a question of where I can source the scoop more than anything else I think. Racing beat has something similar here, but I think it's meant to be on the left side of the car (aka where the current intake sits) rather than on the right (aka our driver side) and something tells me it's not a reversible product.

Hmmm... let the hunt begin!

Postby **Okibi** » Tue Jul 24, 2007 11:23 pm

http://www.cardomain.com/ride/2281137/3

marcusus · Postby **marcusus** » Wed Jul 25, 2007 7:46 pm

NB8C wrote:but bad thing about this:
1) you will find that there is less power and less torque at low and mid range, so if u stuck in traffic jam
2) you need to realocate things within the engine bay
3) you may find that there is no penetration at all for air intake around the it is going to be positioned. ie you may want to cut a big hole for better intake
4) your 5 will drink more petrol

1 - Less power/torque than stock, or less than other CAI systems?
2 - Relocating stuff doesn't seem like a big drama. It seems like it's more removing stuff than anything else.
3 - Well, the whole point of this intake is that you don't need to cut a huge hole like the mania one does. I doubt the air coming in above the headlight will be any colder than the air that is obtained from below the windshield, plus there won't be as much temperature gain with a shorter travel.
4 - How much more? Those of you with other CAIs, what type of increase is there? I knew there was going to be an increase, but I'm curious to know how much more.

NB8C wrote:with the AutoExe's Ram Air Intake System, it is actually manufactured by Gruppe M... its still expensive but it shouldnt be expensive much as (if you know where to get one)..

Looking on the GruppeM website, I can't find Mazda as a manufacturer they build stuff for. Do they just resell it to AutoExe?

marcusus · Postby **marcusus** » Wed Jul 25, 2007 9:02 pm

NB8C wrote:1 - less power / torque than stock from the 1000 to 4500rpm, if you have a bigger exhaust system, its even worse....

Hmmm... that's quite surprising. Are other CAIs like this too? Do you know why this is? For all my thinking, I'd say at the worst it would make no difference to power/torque.

In the end, you're essentially just pulling air from a different location rather than the stock location, so why would it lower power/torque? Surely the airflow won't change simply by moving the intake?

marcusus · Postby **marcusus** » Wed Jul 25, 2007 10:50 pm

NB8C wrote:no... with CAI, as long as the induction pipe is there, the torque will not be reduced... power should be improved a bit...

with RAI, it will improve the power from mid to high rev (should be more than CAI)

so... depends on the application, for daily drive, CAI would be more suitable, but for frequently track day, RAI would be highly recommended.

Hmmm... that's interesting... got any more info on this?

marcusus · Postby **marcusus** » Wed Jul 25, 2007 11:11 pm

OK, went and looked this up on wiki. Whether or not wiki is a reliable source or not is a different matter, but here we go...

http://en.wikipedia.org/wiki/Cold_air_intake

[quote=Wikipedia]All cold air intakes operate on the principle of increasing the amount of oxygen available for combustion with fuel. Because cooler air has more density for a given volume, cold air intakes generally work by introducing cooler air from outside the hot engine bay.[/quote]
Now, I would say that the RAI adheres to this principle. You're increasing oxygen to the engine since the air is coming straight from the front and into the throttle body.

The only reason I can think of why this wouldn't be correct would be because of too turbulent fluid flow. I don't remember much out of my university physics, but I would guess that a fluid is most turbulent when its cross sectional area is changed suddenly. Have enough fluid at the area of entry, and it'll push the turbulent air in line and in the right direction down the new cross sectional area. Reduce the length of it, and you might reduce the ability for the air to streamline itself.

I guess this kinda explains why the RAI has better high end performance, because the air is coming in at such a high velocity that it doesn't really get a chance to become turbulent because the next bit of air is already pushing it in, but I don't quite get how lower speeds can result in worse performance than stock or a CAI.

Anyone care to add/correct me? I'm keen to see what you all reckon.

Postby **Okibi** » Wed Jul 25, 2007 11:19 pm

This is about inlet runners etc. but it also relates to your intake plenum.

http://www.rbracing-rsr.com/runnertorquecalc.html

Boost · Postby **Boost** » Thu Jul 26, 2007 11:56 am

Have a look at the ARC intake.
Scroll down to near bottom of page. No cutting of firewall involved.

http://clubroadster.net/forum/viewtopic ... hlight=cai

AB7 · Postby **AB7** » Thu Jul 26, 2007 1:04 pm

I tried both...cold side induction and hot side.
With hot side, having an open pod filter without any heat shiled is pretty useless. To make full use of the pod filter you need to add cold air ducting.

Cold side...you will lose low to mid range power, which makes your car very sluggish.

The best system I've seen for NB is from http://spmotorsport.com.au
but at around $750.00 its very expesive KW per $$$ value.