What can you tell me about ITBs on an NA 13b??
 

So now that i have a 2nd car my FC is no longer my main means of transportation. I can now modify it relatively heavily and i have a spare motor i can work on. Ive already got the motor disassembled and i need to get a rebuild kit for it. Im playing around with ideas on what to do with this motor and a friend mentioned Individual throttle bodies which i didnt even think of. I dont know anything about ITBs or how to assemble them and was wondering if someone can tell me about them. The ITB idea has sparked my interest, and i kno their are some companies like tweakit.net and another company that makes kits for this, but i dont if this is a route i should take. Are these kits bolt on? Is their anything else im going to need to install ITBs other then a new ECU? Is their a custom setup i can go with? Keep in mind i cant fabricate and dont really have anyone i can turn to for fabrication needs so bolt stuff is a must. Unless someone on the forum will fabricate for me, obvisoulsy for pay. Are ITBs even worth it? So anyway, im just wondering if someone can explain ITBs for me and how i go about installing or building a set.
Thanks

And i searched by the way lol

i'm not aware of any kits that you can buy or mix-n-match to get "true" ITBs on a 6-port motor. however, you have 2 options that i am aware of to come close. you can either get an IDA manifold and throttle body or you can get a DCOE manifold and throttle body. i think they can give you decent lung capacity and great response and power with appropriate injectors for whatever porting and EMS you choose.

Cool, ill look into that. Do you know where i can pick those manifolds up? Anyone else have anything to add?

Mazdatrix for sure, possibly Racing Beat, too.

i have itb's on my 6 port.

i'm using an older racing beat del'orto manifold.

i tried 2 different carbs (del'orto & holley 600cfm) and wasn't satisfied with either. they kept fouling the plugs and it was a constant hassle to get the car to start.

i got fed up and decided to go with itb's and i couldn't be happier. the car (71' 510) starts right up everytime.

anyway the itb's come from a company called TWM.

http://www.twminduction.com

i got the 50mm variety.

the car made 168 whp with a racing beat header and stock porting. the guy that did the work and tuning said he thought that was pretty strong for a non ported 6-port.

really the only thing about the itb's that i don't like is they are kinda "weird" when opening them up.

when the throttle is closed, like at a stoplight, and then when you push the gas pedal the itb's are kinda "stiff" and don't want to open and so you push a little harder on the gas pedal and then the itb's crack open and i end up spinning my tires unintentionally.

note: this could just be a simple thing like my throttle return spring is too "stiff" making it hard to initially open the throttle.

it's really not that big of a deal and i'm i'm really glad to not have a carbed car anymore.

carbs suck.

i think you should have at least 15 more horses in there.

it's probably my exhaust. it's only 2.25 inch and has a large muffler. also it was tuned in the dead of winter. once it warms up i'm gonna have it re-tuned.

but.....i kinda like it quiet so the exhaust is staying..

plus the car only weighs 2100 lbs(2300 with driver & 1/4 tank of fuel). so 168 whp seems to move the car rather nicley.

www.fuji-racing.com is supposed to be offering a complete ITB kit here in the next few weeks. That being said they are notorious for taking their time to get stuff to market. their kit was supposed to be available the 1st week of december and it just keeps being pushed back.

It is supposed to be a complete kit though. everything you would need to bolt up and get the engine running minus the ECU and tune. And I wouldnt be surprised if they have a package that includes an ECU too. fuji-racing@aol.com is their address. Why not send them an e-mail and rattle their cage.


BC

check tweakit.net and search for IDA

actually, i think jumped the gun in my last post. even though i read it, it didn't seem to register with me until hours later (just at random) that you're using that 2-piece DHLA manifold with your setup and it certainly isn't all that great. i had one and though it did like it, i always felt it was a hindrance for the higher RPM breathing.

anyway, my point is i still stand by my statement that there is probably more to be had, but i don't think it will be as much as 15. i was thinking of another person's stock 6-port that made 180+, but it was a better manifold setup - so, i apologize for mis-speaking.

^^yes, it's the 2 piece manifold. and yes, it is lacking a little in the upper rpm's.

is there a manifold you would recommend or would it need to be fabricated?

I had an individual throttle body idea I would love someone to try on a performance 6-port.

Do a 2 TB system as usual with the primary and 2ndary ports communicating at a small "inline" plenum (as is usually done on ITB 4 ports- looks like header collector) to take advantage of all the DEI pressure waves for the low rpm and midrange like stock.

The primary and 2ndary will have to have same port timing for this to work out best and the bigger volume the better for power (the limits of the housing will keep it from being too big on 2ndaries).

Now, for the aux ports (6 ports) just have a longer 6 port rotating sleeve tuned length strictly to the Hemholtz frequency at desired rpm with a velocity stack and air filter at the end of it. Have the ports open at a chosen rpm at WOT (basically a rotating sleeve 2ndary throttle system). Tuning just w/ hemholz should give best top end power in the narrow range the 6-ports are helping (you have enlarged primary and 2ndary ports).

I am thinking Haltech here.
You will probably have to tune using the TPS funtion due to the ITB and short runner and resultant vacuum signal, but you could tune to MAP if the signal is clear enough and use a default WOT RPM "Full Throttle Map" for when the 6 ports open.

This would work best w/ Renisis rotors and as early opening port timing as you can get w/ them (much earlier than standard rotors). You would need a degree wheel to figure out port timing for the manifold lengths taking the rotor chamfers into account.

I have been working on an ITB setup for a little while now for my 6 port. I still haven't hammered out the calculations for the runner length though. I plan on running 45mm secondaries with 38mm primaries. I already have the 38mm to get dimensions for manifold design. The crotch rocket TBs are really nice, built in TPS, cable pullys, vac nipples. I just have to bore out the injector holes on the secondaries to fit the big mazda injectors. I will be running the primary injectors in their stock location in the center housing.
Here's a pic of the manifold I have planned.
http://www.derekfons.com/rxbeetle/im...ull/intake.jpg

Nice looking model!

Looks like it it set up for non funtioning Aux port valves. :)

I think it would make more power than stock manifold due to the flow improvements, but could make even more power through the RPM range with some changes.

I think unlike the model shows, the Aux port length may be very different than the 2ndary port length though and that may lead to problems with your shape/packaging as proposed in this model.

This is because runner length will vary due to timing duration and 2ndaries and Aux port will open at the same time but the Aux will close MUCH later and so have a much shorter runner (err, like stock aux "runner"!).

I believe it would work like you have modeled if there was no change in diameter from the 2ndary port runner to the common runner for the 2ndary and Aux ports (like stock) as the change in diameter/volume you have at the "plenum" will set off the pressure wave reversion in the 2ndary runner and so set the 2ndary runner length at the juntion.

Also, having port runners joined to an inline plenum (as pictured for the 2ndary and Aux ports in your model) is pretty good for dynamic effect (or tournament affect as Mazda also calls it), BUT the Aux port and 2nary port are not suitable for DEI interaction as the closing port timing is so different.

DEI uses the highpressure exhaust reversion when the intake port opens to reflect back to the opposing port just as it is about to close. DEI also uses the high pressure reversion wave as one port is about to close to reflect back and inititate flow on the opposing port that is just about to open. DEI is optimized when the opposing ports' timing is identical

So, DEI would work well for your primary ports on front and rear rotor (look at stock 3rd gen manifold for Mazda's inline plenum on primaries) OR your 2ndary ports on front and rear rotor (again 3rd gen UIM has beautiful example, but even better opposing faced runner design not inline plenum) OR for your primary and 2ndary ports together on the same rotor if their timing is made the same (as is usually done on "ITB" 4 port rotaries).

I know you said you hadn't gotten into finding lengths you would need based on port timing and that is what all the above info relates to.

Anyways, when you do research up the runner lengths you need for Hemholtz and then DEI affect re read my previous post on my intake manifold idea and let me know if you think my manifold idea is a good or bad one.

I also want to make a high performance 6 port motor, but I am thinking small primary port P-ports and huge RE/REW 4 port sideports.

Think of an air nozzle design where the compressed air flow adds airflow mass through the divergent cone and the vacuum ports perpendicular to flow.

Jude Ito has already made a drag motor like this that topped conventional race P-port HP numbers and my currrent motors primaries are set up to siphon the 2ndaries and it works awsome.

Thanks BLUE TII all that info time to get crackin on more research. I'll start a new thread after I research more and tweak the design accordingly. More models, pics, and dimensions to come. And if it works I'll make a bunch of em :D

I don't want to jack this thread so here is some actual thread related info.
\/ previous thread on this subject, time to start reading
https://www.rx7club.com/showthread.p...&highlight=dei
see attachments for 38mm throttle body pics
this does not have the tps or pulley on it, only one of the sets does. this is actuated off the other set which has all the hardware on it.

You are correct BULE TII. No sleeves, I epoxied my aux ports, it's hard to see the contour but it's a pretty good transition and I'm crossing my fingers that the epoxy holds up.
http://www.derekfons.com/rxbeetle/im...l/P1010187.JPG

I'll keep this breif, just for perspective sake...
(ITBs ITBs ITBs not changing subject!)
My engine plan is:
6 port (street port intake and exhaust with no diffusers)
9.4 C/R rotors
2 added dowels
no aux ports
progressive ITBs 2X45mm 2x38mm
low pressure turbo (~10psi)
megasquirt
300whp


Yes it's odd, yes I know it may have shortcomings, but I like fab, research, creation, and taking a chance exercising my abilities. Positive results would just be icing on the cake.

I finally registered on nopistions.com, there is a lot of technical info there to the point that I get the feeling that reading at 1:30 am is not going to stick with me. Is there a good book out there on intake design? Something that is more time efficient than searching forums? I stumble across theories on the forums and search the hell out of em, try to understand the physics and formulate a means of applying what I "learn" or think I have learned. I have all the tools bring my ideas to fruition but never enough time, a little less time on the forums might help this. :D

Reviving a bit of an old thread here... but what ever happened with these "bunch" of manifolds... any more progress on this design? Very interested, have a very similar setup coming along as the one two posts above and would love to add the ITBs idea into it.

Anyone have any performance comparisons between running the fujiracing complete IRTB kit from http://www.fuji-racing.com/fujiracing_005.htm versus the IDA TB's from tweakit at http://www.tweakit.net/shop/product_...7e95371a3bc598 using their IDA webber 6 port manifold http://www.tweakit.net/shop/product_...7e95371a3bc598 run under a microtech lt10s in a large streetport 6 port s5 block? Would tuning be workable using only the 4 injectors integrated into the TB or would I have to have bungs welded into the LIM for tuning purposes? Also if staying NA there would be no reason to get the plenum for the tweakit TB's shown at http://www.tweakit.net/shop/product_...7e95371a3bc598 is there? If i'm correct that is simply to allow turbo applications a quick gulp of air when you romp on the throttle untill the turbo can spool up and give adiquate air for the tb's... I'm leaning heavily towards the tweakit tb's in a 55m - 50mm taper and IDA webber manifold in 50mm with six port sleves left in but not functional and pineapple racing inserts to help out with flow. The 4 550cc injectors I have should be lots of fuel for this setup but i'm wondering how i would tune this with a lt10s since I dont see any provisions made to mount a map sensor, I guess something custom would have to be plumbed in. Other than that it looks fairly plug and play, and performance should be a nice increase over the ported s4 manifolds i'm running now. If anyone has an alternative setup that they think might produce a bit better power please let me know your opinions as i havent ordered anything yet. The major advantage of this system in my eyes is that it will remove the stock LIM and allow plenty of space to fit a turbo in the future using standard manifolds available for the FC.

No one in the states is runing the fuji IRTBs yet. Jimmy is putting together a rotary miata as we speak that he is going to use his IRTBs on for proof of concept. According to him they have been used successfully in Japan for some time now.

If you arent running a higher redline or boost the 460's should be more than adequate for fueling.

just curious what those are from.

Street bikes. many 600s come with the 38mm TB and a few of the big bikes come with 40, 42, and 45mm throttle bodies. Progress on my project has been slow. I picked up "scientific design of exhaust and intake systems" and I have scavenged some materials up. The only real work I have put in has been trying to cram the Porsche transaxle in my poor VW. I think some KY lube will do the trick... I did take a TIG welding class at night so I think I can handle building an aluminum manifold now and not be totally embarrassed by my workmanship.

Thought You Might Be Interested In This.
 

Just finished this setup on my N/A 1/2 bridge 4 Port. It is all hand made and a copy of an Aussie IPRA setup. Don't expect me to make another as the time involved is pretty high, but it can be done with some work and creative thinking. I am using a Megasquirt for fueling and as many stock Mazda parts as I can for reliability and flexibility.

I am on the chassis dyno at RPM, in Kitchener, Wednesday night to tune and find out how it compares to the Holley setup I was using last year. I was pulling 184 RWHP/ 144 lb/ft of torque last year so I have a decent target to aim for. Differences already are lightening throttle response and a really wild intake note.

All in my costs including the Megasquirt are close to $2,000 USF.

Eric

Wow this will be such a bump in the thread but I’m curious if you adapted the MegaSquirt to the stock harness and reworked the harness to accept different sensors and such or did you rewire the entire engine? I’m curious because I plan on doing ITBs on my S4 and I would like to adapt the MegaSquirt to the stock harness, but I’m curious about the TPS and how you did the injectors whether you used all 4 injectors on the throttle bodies or if you only used two for the secondary and then the stock primary. I was curious if it would be possible to use the stock primary injectors (or at least their locations with upgraded injectors and billet rails) along with all 4 injectors on the throttle bodies? Might be too much fuel, but I’m also new to the platform and don’t know too much about it.

welcome to the board. :)

possible? yes. however, it's probably overkill - particularly if there's no radical porting involved. that said, it won't be too much fuel if you choose appropriately sized injectors and/or tune the car properly for the hardware.

Mazda, themselves, actually took a similar path with the S1 Rx-8 (the 6-port engines), but they switched to 4 injectors with the S2 cars.

Thanks for the welcome! My only thought with using all four injectors along with the stock primary location was just if I wanted to throw boost at it while it’s ITB. But knowing that I only really need the two and the stock primary or all four on the throttle body that helps a lot! Is there any information on a megasquirt adapted to a stock harness with ITBs? I feel like it might not be too complicated to really figure out but I also don’t know what I’m getting myself into lol