ITB Basics for Miatas (FM Live)
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- Опубликовано: 29 авг 2024
- This week on FM Live, Keith Tanner discusses the basics of ITBs for Miatas. What are Individual Throttle Bodiess? What are the benefits and downsides?
Dyno chart Before/after with ITBs:
www.targamiata....
Dyno chart Short (blue) vs long (red) horns: www.cheapsports...
Original Live video recorded 1-21-21. Join us on Facebook every Thursday at 2:00 PM Mountain Time for new live content!
Flyin' Miata is the world leader in Miata performance. We offer a wide range of parts for all years of the Mazda MX-5 Miata.
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tripping the noise limit at Leguna Seca from intake noise is quite the achievement, haha
To be fair the horse fly that Kieth talked about getting sucked in would probably also trip the sound booth at Laguna, they're savage over there 🤣😂
11:18 Electromotive ecu tps/map "blend". There are many others versions from others companies that can deal with the idle tuning without using a two or four wire iac. Thank you for share such great content I am learning a lot!!
I always wondered why cars used butterfly throttles instead of slides like the old motorcycles I grew up with. Then I read that, when developing the carburetor for the first Yamaha YZ400F four-stroke, they had to support the slide on roller bearings due to the short, sharp, ferocious intake vacuum of a very powerful big-bore 4-stroke. Then it made sense. I was used to 2-strokes, which have a very long intake duration but only mild vacuum pull. With certain highly-developed reed-valve engines, intake flow can be almost continuous on a single cylinder, with minimal sharp pulsing. Not only that, but a 2-stroke carb slide is always slathered in oil, whereas a car will see "dry" gasoline at best and humid Florida air at worst. My fantasy of putting 8 Mikuni round-slide carbs on a V8 were dashed.
I want a 2-stroke Miata...
Anything is possible with enough time and money ;)
For anyone who's interested, tFM's tower brace fits over the Jenny kit in the NA/MK1. I'd highly advise using a plenum on these things as they can be too loud for dedicated street use, if it's a weekend car that hits the track from time to time it'll be fine (because you drive something else daily) but as a daily driver, ITBs are rough. The only one I've found that will fit on RHD cars is the Pipercross PX600 Plenum. It's not cheap but it fits.
They're great for NA power but I'm tempted to revert back to a stock intake purely for the drivability factor. A good intake, exhaust and a remap does a lot for these older cars.
Dude nice m5 in the background! I've got a 95 miata and e39 530 myself!
75mm and Up for velocity-stacks are usually good for my 1.6
In Japan alot of Mazda Miata drift guys use ITB , shaved head and a high lift cam ....the cost is about same as turbocharger setup , without all the engine work .... both setups get you to 200 whp . Then it all turns into a never ending money pit .
Having built and owned both turbo Miatas and high output naturally aspirated Miatas at the same time - that 200 hp number is too high for the ITB setup and the cost is too low. It's also a very different 200 hp than you get with boost. The shape of the torque curve and the nature of the throttle response is quite different.
@@FlyinMiataVideo ... agree , but if you only have $5000 to spend turbocharger is the easiest option .
@@alexisknows6513 ITB is never the easy option!
@@FlyinMiataVideo It's *probably* because they use net flywheel ps in Japan, not wheel hp.
I can't express how happy I am that I found this video. I bought a T3 billet aluminum 1.6 flange for Toyota AE101 ITBs a few years ago and never got around to installing them.
"Original Live video recorded 2-21-21." Wow, time travel!
We were just making sure you were paying attention!
I owned a ‘95 for 18 years. 😊 Loved it so much.
The e39 just chillen in the backround👌
Keep watching, it’s part of the video :)
Hi Keith, bit late to the party but I think the shape you are trying to remember is called an "Aerofoil", I have studied some papers on ITB bellmouth design as well for my 13b ITB Miata and I kept seeing a comparison between that, a regular parabola and a basic radius. Interestingly enough the parabola seemed to outperform the aerofoil under normal conditions.
I tested different lengths back to back on the dyno, but I guess my overall runners were already pretty long because the difference was almost negligable. Great and insightful video!
It was "elliptical" from the Blair article.
Great video. Presenter style helps a ton. Thoroughly enjoyed this and will now browse your library for more 👍
... hello, e39 M5. appropriate backdrop for an ITB video, given they have ITBs.. ;)
aha, 27:40 :D
Also Jenvey far as I can tell is a set of modified DCOE Webers-may be a budget way to do that but the DanST setup is likely cheaper and more available
Jenveys are a custom cast afaik
ITB enthusiasts check out Garage 4AGE channel, he is constantly testing different setups.
One of the best itbs channels ever
if you are interested in this it has gotten a lot cheaper than you would imagine. Find a speeduino standalone ecu and then get some gsxr itbs. next get an adapter manifold, i 3d printed mine out of carbon fiber nylon you could likely pay someone ear you to print one for you the files are probably out there online. hooking them up wasnt that hard but tuning them in was a slight challenge.
Excellent video thank you! Greetings from Greece
I had a friend in north carolina who was running itb’s on a stock ecu with a butter smooth 400rpm idle. car was very modified
Was it reliable?? I dont understand all the words
hi
thanks for all your contents, i have learned an awful lot off of them :)
it seams like there is no video about cam upgrades. is there any chance you guys might do it in the future?
thx
We've talked about them briefly in other videos, and for the time, $$$ and effort, we just don't think it's worth it. Check out this video from Jeremy about "Naturally Aspirated Engine Mods" for more details.
ruclips.net/video/e9dk1jGWGto/видео.html
@@FlyinMiataVideo
Crap, i missed it
My goals for hp isn't high at all so turbos might be too much for me but i will make shure to compare both ways.
thanks for the super quick response and opinion, much appreciated👍
Very nice , was thinking of ITB not any more. THANKS
Love this. Thanks for the information.
Good video overall, but there's a few points I could add. First, about the ND, I think the only logical way of running ITBs would be to keep the OEM DBW throttle tucked in a corner somewhere. You could then add your own TPS to the original throttle (or just snoop on the original sensor) and use that signal to drive your own throttle motor on the ITBs through something like an Arduino or similar microcontroller. Obviously, you would need to build an intake system that can work with the OEM MAF sensor. The MAF signal might also have to be intercepted and processed depending on the difference in flow between the OEM intake and the ITB one (especially on the ND2 if no one can figure out how to tune the OEM ECU).
Of course, you could skip this whole rigmarole by doing the sensible thing by ripping out the stock ECU and replacing it with something reasonable like a Motec or Link ECU. As for tuning ITBs, there are only two reasonable approaches. One is using a MAF as the OEMs do; BMW and Nissan on the old Skyline Gtr are good examples. Or two using an Alpha/N strategy on an aftermarket ECU. High Performance Academy has a good webinar on the subject here: ruclips.net/video/9XvXfX3QhlU/видео.html . The key points being that you need to set up a good fuel table (whether it be VE or MS based) with high resolution brake points on the TPS axis close to idle, something like 1 or 2 percent increments. Then, if you are running a turbo you can set up an auxiliary fuel table for high boost operation based on MAP, or IMAP to EMAP ratio if you have it.
Yeah, sounds like FM could totally make a ITB kit with a plenum and MAF
Better to adapt the DBW actuator to control the throttles and remap the stock ECU pedal
What a tease, Keith! We need the name of that intake trumpet profile!!!
I think you guys might have been thinking of a Cycloid curve, or maybe specifically the Brachistochrone at 34:23!
Also had an E39, pulled like a beast, but ultimately glad I got rid of it, too many little issues everywhere.
It's basically a four door supercar. Definitely needs a lot of attention.
Issues such as?
@@MrTAKIS1984 I was not the original owner, so I can't confirm how it was maintained previously, with that being said, lots of plastic in the engine bay had cracks, or would crack easily, cooling piping springing leaks (normal for aged piping), failed water pump (normal), failed electric cooling pump, EVAP Hoses cracking, Windshield Wiper Fluid Piping cracking, various shrouds cracking, front fascia cracking, front grill cracking, inside the dash would glitch out, LCD Panel failed (common) but was an annoying fix, radio LCD bugs out, cup holders are very brittle and break easily, wood paneling fails and cracks often and all over, side plastic panels of seats crack often, headliner adhesive starts to fail and drop, and more. I know a lot of this is normal maintenance, a lot is also lack of care from previous owners, but I've talked to a lot of beemer owners and friends with similar years, and a lot of these are the same issues they've had. Loved the car, was very fun, and looked great, just didn't want to deal with the forever growing list of repairs.
@@jakenuno9900 thanks man
Keith, your timing couldn't be more perfect. I just spent a year developing an ITB kit for my NSX and all of the issues you mentioned couldn't be more true. We got it sorted and it's running great as a street driver weekend track warrior. I hope you don't mind I plugged a little mention of you here ruclips.net/video/mODPROKLxzQ/видео.html
Oh, I think the name of the shape of the bellmouth you're looking for is Elliptical Profile. There's also the Simple Radius and Aerofoil profile.
Hey, make that two guys and probably a lot more.😆
Do yall offer ITB's for sale on the site for the NA or NB?
We don't. This video is information, not a sales pitch.
How would a plenum and intake tubing affect ITB torque and power output? Same as runner length - larger volume shifts the torque band down the RPM range, and the opposite for lower plenum/intake tubing volume?
I have never tested that - you're limited to just how big a plenum you can put in a Miata, of course - but IIRC there's some good info in one of my books. I'll see if I can dig it up.
Could an ITB system be developed with a common plenum before the horns and throttle butterfly's that can then use the MAF and a single filter? Sorry posted before I saw the plenum mentioned.
What you're commenting also sounds like how the Ferrari V12s operate (or the engine from the E46 M3 if I recall correctly), so that's probably the more commonly employed approach of the two. Edit: Another commenter mentioned the E39 M5 as being another car that uses individual butterflies with a common plenum.
When I saw the goal 1 intake manifold, I was thinking that throttle plates could be mounted in the runners to the head, and bell mouths inside the plenum space. Even without throttle plates, I would think that having a bell mouth in the plenum as it is currently built would allow for better flow.
Yes. This is one way to get a more reliable setup for tuning. However, plenums can take a few peak hp away. This is what I’ve seen from dyno sheets posted by itb owners.
Any special considerations for Mazda K8 v6 (1.8L) sportscar used for sprints and hill-climbs ? I plan to use the stock plenum...
I had the flat slides on my 83 GS... CLACK ,CLACK ,CLACK ,CLACK CLACK!!!! ONLY TWO POSITIONS ....off and ON!!!!!
Hi Keith I have a 2000mx5 in mint condition all original except tecna coilovers on it never driven only 133000klm im in nfld would you like to take it in the nl targa 😊
We'll pass on that, but the offer is much appreciated!
Wasnt expecting to see an e39 m5 on flyin miata! 😂
Keith has a very cool but eclectic assortment of cars :)
How did you add the IAC to your itb? Did you use the 98-05 miata iac? How did you route the hose from the IAC? Please and thank you in advance
There's some discussion of this in the video - the IAC was on a vacuum block. It did not have a separate hose to the IAC for intake air, it had its own filter. I think it was the IAC from a 1994-97.
I had my 86 rx7 13b 6 port s4 na with a side draft dcoe itb China Jen berg with a merger f250 intake arm with the air flow meter run, stock injectors... kinda street port. I have a video. I’m tryna get it running again it blew a coolant jacket iron lip... because I swapped the jacket on the rear with some old tip from a old website from the catalog mpc mastercar... I regret it.
Originally 48mm dcoe itb 460cc or I think my first run was eBay 550cc... I made the same vac mani like yours with my iacv with the 10an turbo drain flange mounted on it that fits on an smax vac mani, prime secondaries same, but I had cut the trumpets and choked them with aluminum pipe I.d. 45mm to help the f250 intake hose to grab on, n326 arm and boost sensor.
Doesn't the plenum restrict as much air as well as the stock intake pipes and manifold? Is the only.advantage then just response?
Really, the whole idea is response. It's pretty easy to avoid restriction, but there's no way to fake a small throttled volume.
I think itb’s on an nd would be easier as it’s direct injected
If some is interested in getting itb's for the nd1-2 let me know!!! I found 2 manufacturers that are willing to make them.
interested!
Sps motorsport is currently working on them.
If they were boost referenced
I.e. turbo fed where does vacuum come from for brake booster
Between filter and turbo ???
Between the throttles and the valves. This is true whether there's a turbo in the system or not. You can't get any vacuum before the throttle plates.
Thx for the video. Does an engine need a retune if changing trumpet/horn lengths on an ITB set up?
It's unlikely the different horn lengths will make that much difference to require a retune. Modern engine management is very reactive to changes and will self-adjust. Modern engine management tuners would have you believe you have to retune your car every time the sun comes out :)
fun fact: i have desinged an adapterkit to mount the e39m5 itb to the bp4w and vvt engine :D
I assume that you are running them on your car?
@@biggboysouth not now. Currenty my vvt engine is yet to build. However my itb sourcing is finished now as I had a spare set of e39 m5 itb.
I just designed myself an adapter manifold und velocity stacks and test fitted them on my spare vvt engine. The cool thing is that the intake port surface of the e39m5 is as big as the bp4w/(and) vvt intake port surface.
@@Miatasun Nice so they should not be a bottle neck at all. I will be swapping a VVT head onto my car as well and have a set of toyota 4age silver top ITBs that I will be putting on them in the near future. I did worry about the 4age ITBs being a little restrictive once I set the car up to rev higher but it'll still be better than most intakes available so I'm sure it'll be fine.
I doubt you'll have to worry about that with those e39 ITBs sounds like they are a perfect fit for the NB mk2 heads.
@@biggboysouth nice, I also hat one set of ae111 itb they are nice.
yes in theory, my 3d printed manifold adapter fits perfect. now I have to think about to get it cnc-ed or something like this
@@Miatasun I found a thread online somewhere of someone 3D printing an adapter out of a carbon fiber filament and had really good result
Does it matter if the ITB's and runners enter straight into the cylinder head or must they have a sloped downward angle? I have seen pictures of both styles.
You want them to be as close as possible to the angle of the ports - but more importantly, they have to physically fit in the car. That's why a lot of them slope downwards.
Is FM planning on adding ITBs to your catalog?
No, unfortunately ITBs are not going to be emissions legal and will not be sold by FM. Sorry.
@@FlyinMiataVideo thank you!
What happens to the iacv when swapping over to ITB’s? Is there a way to keep it?
It is possible to keep it - the usual method is a block that has mounts for the IACV and hoses running to each runner. It makes a big difference to driveability.
@@FlyinMiataVideo So the only hoses I would need to route to the IACV block would be the vacuum hoses from each runner? Would it be possible to send a photo through email for reference?
@@FlyinMiataVideo also it would it be possible to run house from only 1 runner?
@@gotaracecar2266 Shoot us an email at support@flyinmiata.com and we'll see if we can find one.
@@FlyinMiataVideo Thank you I really appreciate the help so much
My hayabusa runs two different length intake horns ( stacks )
How would itbs on a vvt motor from the nb2 work? Would that make a difference?
Definitely. We built one a while back and the VVT gave it a nice wide torque band.
Check out Glenns build over at what is now 'the slip angle'. Extremely well documented, rather famous itb NB2 build with a completely stock bottom end and about 12.5:1 compression with a built head. But started with less head work and worked up to that point. 150whp is really the limit on the stock head from what I have seen, but they respond better to shaved head/higher compression, slightly oversized valves, and high lift cams. On a budget, in theory one could send their cams to Delta cams to have them reground/reduced base circle, clearance and port the head, use nissan SR20 valves for cheap OS, shim under bucket conversion, and Volvo valve springs. But you're still in $1500+ at that point for 175 hp. And that's why we have lots of boosted Miatas lol
Keith! Also can confirm plenum + ITB and MAF will definitely work, so long as you can make the OE TPS mount and and work somehow. Probably not much power gain over a well designed intake/NB1 VICS but the sound is there and it will run reliably until one gets an aftermarket ECU.
Probably way too much work and I don't have an aftermarket ecu to look at;possible to use a barometer on an aux line to see the air pressure with the tps and use the two combined to make the map a little more accurate and reliable? Like I said maybe way too much work for an issue only a handful of people would have. The math doesn't seem too terrible to me but I honestly have a 3 RUclips video degree of knowledge on tuning.
That's the technique that's often used. Going off pure MAP doesn't work all that well. Going off pure TPS is common in the UK from what I've seen, but it doesn't work well if the ambient air pressure changes - such as climbing a mountain. So you blend the two.
Any possibility of having itb's for the nd miata? Bbr gti has a kit for the nc.
He mentioned in the video it is unlikely one will be made, and FM wont design one either
@@graham_lewis 😔😔😔 guess that we have to wait until bbr gti comes up with one for the nd miata.
@@graham_lewis well I must tell you that I found 2 manufacturers that are willing to make itb's for the nd1-2 if you're interested let me know, otherwise the mods from miata forums won't allow the spread of the information because it's against their rules 😒
Is that a E39 M5 I se in the backround?
Keith has some very interesting cars hiding in his garage!
Keep watching, it's part of the video...
Is there a way of retaining EGR with ITB's. Like plugin' it into vacuum box or intake plenum (before throttle bodies)? I need to retin it in order to stay emmision legal in europe.
I don't think any inspection will care if you added EGR to your ITB or not. For them car with aftermarket ITB is not emission legal, as you probably switched from AFM/MAF to MAP/Alpha-N and ECU from stock to aftermarket.
Do an ITB kit for the NC and I will buy it.
BBR makes one. We don't currently plan to bring it into the US, but you can buy directly from them.
@@FlyinMiataVideo yeah I'm aware of that kit, it's more that I'd prefer to support you if given the option.
We appreciate that! Probably best to go to BBR in this case, though.
i know you had mentioned the webcam 505 cams here, and also on some forum posts. what options are available today for 1.6s? i know that options are extremely limited. such as not being able to find high compression heads, and what seems to me is a lack of info in general about n/a builds especially on a 1.6. would a stand-alone ecu, free flowing exhaust, passenger side intake, and possibly some head work(porting, polishing, possibly decking) work as a start to an n/a build?
The reason you don't see naturally aspirated performance parts for the 1.6 is because the 1.8 is the same engine and makes about 10% more power due to the greater displacement - and that's before you take into account the better head designs introduced with the NB. That said, all the basic stuff that works on the 1.8 also works on the 1.6, such as the ECU, intake/header/exhaust, head work and high compression pistons.
The Webcam 505s are still available - search for "web camshafts" instead of "webcam" and you'll find them.
@@FlyinMiataVideo Thanks! Haha I know that just about everybody will tell me to switch to a 1.8 due to not only the power, but headflow, and things like being able to have it overbored. I’ve done quite a lot of “research” and reading about the subject, but there are so many things people do with the engines, I am not exactly sure where to start. I’d assume cold side intake(if i don’t care about torque), at least 2.25 inch exhaust, racing beat header, advance timing? and then would i go to decking the head, porting and polishing the head(again if i don’t care about torque), and a cam? then would an ATi damper be useful, or not yet? I know I am getting very technical and likely will have wrong info.
@@graham_lewis You can overbore the 1.6 as well - it's just not done that often these days.
The cold side intake and headwork won't cost you torque, it's just that the only way to make significant torque gains naturally aspirated are to increase displacement or change the cams and compression.
The ATi will be useful if you make any valvetrain upgrades and start to spin the engine faster - that's another way to make more power naturally aspirated. It also tends to give you more accurate information from the crank sensor if you're using a crank trigger and an aftermarket ECU.
Anyone interested checkout Ethan Vermillion he is working on a 3d printed adapter to run bike throttles. Nothing wild but all the retro noise with a slight increase in power. I'm planning to work on something myself as well- but I believe he plans to actually market his setup
Thanks for the shout-out man!
@@analoglyfe for sure! Literally setting up my printer like right now...
@@accordv6er haha awesome
@@analoglyfe got me a new dipstick handle. Bam. Now just to actually design something argh
@@accordv6er lol yup, let the fun begin
can the itb give more hp with stock injectors?? or we must change them for sure??
Stock injectors can handle the power increase from ITBs. Not all ITBs can use the stock injector, though - sometimes they're designed to use one that's a different shape.
If you run individual throttle bodies how do you get the break booster to work
You pull vacuum from between the butterfly and the head.
never hear one live but do they make more audible lifter noise as the youtube videos make it seem?
More audible valve noise is quite likely.
how do you balance ITB's?
Anyone know how one could/would rig the Jenvey ITBs and their airbox to a (modified) stock air intake, with all the pipes, MAF-sensor (mine is an NA6) and stock ECU? Has it been done?
Basically, all the air going into the plenum has to go through the AFM. You'll have to find a way to mount the idle air control valve, probably on a vacuum block and its intake should also pass through the AFM. I don't know if anyone's done it but it would be really interesting to see. Luckily, the NA6 ECU doesn't ask for much in the way of a TPS so you may be able to get away without one.
@@FlyinMiataVideo Thank you for the answer! Luckily it's winter for a few months more up here, so I have some time to figure things out before its time to take the car out from hibernation!
Wht you can suggest for mazda familia 1.3cc carburator replacement?
We can't suggest anything for that one, it's simply not a platform we work on.
The red wires can be combined with the stock ecu or only with an aftermarket???
Those are hoses, going to a vacuum block. Given the lack of a way to run a MAF or AFM without a plenum, an aftermarket ECU was required for that installation.
@@FlyinMiataVideo so, without aftermarket ecu it cant work. Sorry for asking because i dont speak very well english
@@MrTAKIS1984 It could possibly work with a stock ECU if you use a plenum that pulls air through a stock AFM or MAF. I don't know if anyone's done that on the Miata, but that's how the BMW works.
@@FlyinMiataVideo thank you
have you used or tested Jenvey MX5 throttle body kit
We have not. By the time they came out, I had enough parts on hand to play with and didn't need to pick up another ITB setup.
could you drop the name of the shape you spoke of at 34:08
elliptical!
WHO IS BUILDING A FREEVALVE HEAD FOR A MIATA????? are we talking the Koenigsegg Freevalve thing? or something else?
The Konigsegg, yeah. Some guy on RUclips hacked one onto a Miata head. Look it up .
Wesley Kagan on RUclips. It's still in development, but the guy knows his stuff. Very exciting project.
Motorcycles have ITBs .
who else want itb on nd
"Professor Batshit" LOL!!
What about Mikuni Flat slides ? 48 mill
I take it that you definitely have to lower the fuel pressure To what ? Time to change my Hydra settings ? URGHHH!!!!
There is no need to change fuel pressure.