St intake manifold on an mzr powered miata

I'm back again...

Still having a few issues with my build, looks like maybe a pcv issue this time, to get to it the intake has to come out once more, it's a real pita to get out as the tb is facing 180 degrees away from where I want (need) it to be.

All aftermarket intakes I have seen, due to the platform the engine was designed for still have the tb facing the wrong way, however even though I had read the intake performance comparison thread a couple of times did not realise the st tb was facing down...

I'm assuming this it the 2.0p focus at intake?
I did a search here but the results showed all intake thread not just at ones

Couple of things, first is there detailed information on the st intake, the comparison mentioned an adapter, I'm assuming this will be just for the runners to the head.

I also have read a few warnings about just swapping out intakes without any other mods, that the engine could start running lean.

At this point I'm not after big power, it's going to be a daily drive, just looking at making maintenance easier.

I also considered making the intake run adapter for the mx5 mk3 intake as that's the car its in with the tb facing the way I need it, trying the keep it stock this far so to avoid tuning seems to be getting me nowhere fast, AFAIK the mx5 is somewhat similar to the stock oe intake, got long/short runner and the cold start flaps (can't remember the actual name for them) the adapter is somewhat trivial for myself it's a 100mm runner and can make them to mate up.

Using the st or mx5 intake without tuning will this run into potential lean situation, any advice on tuning, at this point I'm considering versatune and learning up on efi tuning

 

Why would a different intake make maintenance easier?

 

the engine orientation has changed, it takes an aweful lot of an effort to get to the tb, and as of right now, I have a what seems to be an issue with the PCV, the tb is facing the firewall, the intake does a 225 degree turn to come back past the egine block to the fmic, also possible intake leak at the tb as its really hard to get to

 

I forgot you had the Miata. The st manifold will work for you since you are already fmic. You really should get a tune for just the intercooler so it wouldn't be extra to tune for the intake as well

If you didn't know the tb connection on the st manifold points straight down

 

Can anyone point me to someone who has done this mod?

I have a fair few questions, I was in the end trying to avoid doing it getting to the right hand side bolts would probably be near impossible (with the egr pipe as well) however it looks like my timing chain now needs to be replaced (90k miles), unfortunately the engine cover can't come off without dropping the engine with that I will be doing all the things I should of done before I put it in the car. Including putting the st intake on.

 

It seems like some people have attempted ST swaps on the Miata forums, the second thread having some good information in there. Outside of that, I run a Focus ST intake manifold on my Speed3. While it's not a Miata, I may be able to offer some help as the MZR + FoST manifold is a combination I'm familiar with.

https://forum.miata.net/vb/showthread.php?t=572596
https://forum.miata.net/vb/showthread.php?t=715277

 

@dinnerplate that would be great.

So before I went into this project I had found some threads about different swaps, and what I overlooked (because the disi swap wasn't as easy as other swaps there wasn't that many to go from) similar to those threads, piston heads is mostly USA users with a left hand drive, being in the UK, I had the extra complication of the turbo Vs steering shaft, but it does mean I got more space for the intake.

Also AFAIK, the head from the ford engines are taller than the Mazda. There was issues with clearance. But the disi 2.3 is sitting in it well at this point.

However as I have a source to get a few measurements then that will also be helpful!

So, if you don't mind here are the questions.

1.what else did you do to the setup, does the flow rate effect it that much to have to get it tuned?

2. Does the MAP sensor just swap out? Any modifications?

3. EGR pipe that goes into the speed intake, did you delete this? Does the ST have a port that can be easily adapted? I am trying my best to keep it emissions compliant here in the UK.

4. The pipe connection between the PCV valve and the intake, what's that like? I have installed a catch can a few weeks ago, while I doubt this would be an issue, any heads up here would be great

5. Swirl flaps? I have read that in the fords they are plastic and prone to fale and destroy engines, I can't remember the technical term for either but you got the swirl flaps system for cold starts and the other flaps for short/long intake runs to help with the torque.

6. Vacuum lines? Is this just a rejig of the lines to work? There going to be any issues here with the actuators, bov, purge canister?

7. Throttle body, is this a direct bolt up? Any adapters or swap out the tb for the ford to match up?

8. What is needed to bolt this to the head? The ports are different sizes/shapes, how did you go about solving this issue? I was planning on swapping the mx5 mk3 intake and had mostly designed a replacement runner from intake to the head, until I realised the valve cover would have to come off and stopped.

9. This is a question as you have access to it rather than just info from around the net, overall size? Maybe the simplest way to answer is if you have a picture? I can't see this being an issue, unless, when the intake run goes towards the front of the engine it comes close to the water pump, that when facing that way it might interfere with it, I'm assuming too that the intake doesn't go higher than the actual valve cover? My only other concern is if it comes much further out to the side near piston 4 compared the stock intake, that's the tightest place in this build. I have the width of the intake pipe to go further out (3") from stock, all the way up to the position of the stock tb, where as you can see from the pics above the chassis comes back in close to the tb.

 

Yes. Highly recommended. If you can't stomach a tune at the moment, just go easy on it.

No modifications necessary, pluck off MZR manifold, install onto FoST manifold. I will say that there was some slight issues getting the holes to line up for the MAP sensor on the FoST manifold, but it wasn't so bad that it couldn't be massaged into working.

i4 EcoBoosts don't have EGRs. I did delete it, but not directly. I have a Damond Motorsports water outlet manifold, which does not have EGR provisions at all (and further, because of this in combination with my FoST IM, I have no EGR provisions of any kind on my engine). The stock water manifold will require a block off of some kind.

The PCV port is located upstream of the throttle body directly before the runners, dead center of the intake manifold. It requires the Ford connector, as it's not a compression fitting clip of any kind (the Ford connection is much better as you can actually take it off with just two fingers).

i4 EcoBoosts don't use a VTCS system, and thus don't have swirl flaps. Actually, neither did the Zetec Focuses, so I'm assuming you were reading about Duratecs?

The PCV port or purge valve both work as vacuum lines, but the optimal thing to do is to use a sound symposer block off that has provisions for ports. I personally use a sound symposer block off plate with a single port going to my vacuum block, and everything that requires a vacuum source is plumbed to the vacuum block.

Direct OEM Mazda TB bolts right up.

It requires trimming of the manifold, the bolt holes all line up because Ford is unoriginal. My personal suggestion is to just grab a Focus ST intake manifold kit from Damond, as it will have literally everything you would ever need in it, but if you don't get the kit, just grab a spacer, a FoST manifold, and I can guide you on what to shave down. If you get the Damond kit, they do all the dirty work for you (and provide a sound symposer block off, oil dipstick mounting bracket, PCV connection, the list goes on).

Ignore the shitty wiring, that's from the previous owner and is getting deleted very soon. Water pump is to the left, buried beneath the A/C, P/S lines and wiring. There's actually not a lot of clearance concerns, the FoST intake is extremely simple in geometry and is about the same size as the stock MZR (if not smaller). The benefit that the FoST manifold has is that it's extremely well balanced, and has great flow (it's also stupid cheap at like $95 USD brand new). As for the place near cylinder 4, it's completely clear. Where the stock intake manifold bolts on to the high pressure fuel rail, there's nothing past that on the FoST manifold (compared to the stock manifold having some additional length and then the throttle body to the right of the fuel rail). It may be hard to see below due to my intercooler piping, but it doesn't even cross the threshold of the HPFP.

Truthfully I don't know why more people don't opt for the FoST intake manifold. It's cheap, reliable, flows extremely well and is extremely balanced (I've heard whispers that it's actually better than the JMF and CS manifolds for these metrics, but take that with a grain of salt because it's not something I've tested myself and can't verify). The only real downside is it's plastic, so it might not look as aesthetic as the other options--but I'm personally all for performance, fuck looks.

 

Also to note when you pull the Mazda manifold keep the black box attached to the vtcs system. Leave it plugged in and zip ties out of the way but make sure the plunger can move freely and you won't get a cel from it.

 

just confirming that the ST part number is DM5E-9424-CB from a focus mk3 2.0 2011-2018?

 

As to your question about the vtcs, this was an initial concern with some of the mx5 mk3 posts on some forums where people had read that the ford vtcs flaps broke, I cant remember the engine they where refering to but they found the ones on the mx5 where metal and thus wouldnt have the same issue

I am also assuming that when you say take it easy until tuned, this is because at WOT the ecu will use the open loop fuel map, thus fueling based on stock intake?

its not that I dont want to tune, its the cost, this project is way over budget now and im poor.

will the fact that they are not there make a difference/issue on startup? as @easter_bunny mentions about keeping the system connected this is to keep the ECU happy but what real terms will this effect the engine?

 

Yeah, no concern about flaps at all with the Focus ST intake manifold.

Yes to the second. Not just in WOT, but even in boost too (which may not necessarily be WOT).

I feel that.

There will be some cold start differences, it'll rev a little higher, and you'll also notice that when you're in 1st gear around 1500rpm it'll feel like a drop in power if it goes below that threshold, but for me personally I don't care about these things enough to keep VTCS as the pros outweigh the cons. There's no damage to the engine in either case, just things to be aware of.

The part number is DM5Z9424B, according to parts.ford.com.

https://parts.ford.com/shop/en/us/e...e-intake-manifold-inlet-20l-p-dm5z9424b?pdp=y

 

Sorry if this sounds like a dumb question, I might be getting a little confused, mainly from the acronyms and the different intakes from the different engines.

does the mazdaspeeds have both vtcs and vics? from what I have read about the mx5 intake and again could be confused with this too.
vtcs = variable tumble shutter system - this is for cold starts and gives more turbulance to the intake air to better starts
vics = variable intake control system - this is for switching between short and long intake path to get better torque at lower RPM

this is what I understood after reading the mx5 forums, and it looks like the 2.0 MZR engine was the one with the problem flaps
https://forum.mx5oc.co.uk/t/anyone-done-the-swirl-flap-delete-nc-2-0/116192/7


the MX5 VICS

mx5 VTCS



reason I ask, looking over the mazdaspeed intake I cant see (and dont remember seeing when I put the engine in 2 years ago) a second control rod, so I am assuming it has only one, and then looking at the positioin, the fact that it blocks only one side of the intake, that this would be VICS? or does this platform use it for both? I assumed this was for the VTCS as when I start the engine it makes an aweful loud cold start noise (because of the cone filter)

 

No, the mazdaspeed only has VTCS, no VICS. VTCS, from a performance standpoint, is a hindrance, as it doesn't allow the air to fill the volume that's available directly before entering the head, whereas VICS being much lower in the plenum allows for the volume to equalize before the air enters.

The Focus STs don't use either though, so by switching to the ST intake you're deleting the system entirely (so there's no concern with having swirl flaps, because they don't exist).

 

hmm interesting, I assumed it was the VICS, thanks for clearing that up!

one last question (for now) if the ST doesnt have an EGR inlet, if I do an EGR delete, apart from a CEL does this effect the emissions much on this platform? I also read that on some platforms that the EGR helps with engine temps due to the AFR changing with the EGR gas, is this the case with the mazdaspeed? (again I could just keep the EGR control unit plugged in for the CEL)

 

Yes? I'm not certain what you mean when you ask if it'll change the emissions much, but I'm assuming you mean actual g/mi or g/km output. EGR burns up unburnt fuel from the exhaust, so it'll increase carbon output by removing the EGR. Maybe not by a whole lot, but it'll still have a measurable increase of some kind.

As for the AFR, not notably. There will be a very slight change, but the EGR itself doesn't actually help much to decrease temps because the exhaust cooler that the gases go through on the speeds doesn't have a large enough heat exchanger to make a meaningful difference. In fact, it actually degrades performance on these cars/engines by contributing to the valve carbon deposits, and it increases both the charge temperature and coolant temperature.

Basically, the EGR will very slightly change your AFR, but does more harm than good.

If you really want to keep the EGR, you can plumb it in somehow I'm sure, it's just not something that I personally did nor is it something that is provisioned for on the ST manifold.

 

Sorry, I probably should of been more clear with the question, when I say much, my concern here is the emissions test here in the UK, there should be a visual inspection but there is no chance you could see it unless specifically looking for it anyway, its well hidden now, but there is a tail pipe test, there are a lot of garages that do a fake emissions test but I would prefer to actually be within the limit and not go down that rout.

 

Yeah, to that all I can say is good luck. It’s already a swapped car, and L3-VDTs don’t have a whole lot of emissions controls in the first place. Again, it’s possible to hook up the EGR, just not something I did nor was it intended on the ST intake, so you’ll be treading new water there.