http://www.japanparts.com/db/partsli...ey=226-015-001

Do you have any comment on it?
Is it suited a 4AT?
Should I retune (knightsports basic tune) my ECU after change?

 

Funny, I just happened to see this as well...

 

i'm failing to see what this offers us(as in the LARGE majority of owners) in the first place? common sense dictates that this will flow more air, but how much more? is the manifold suited to flow more air that is not forced via FI?

i'd be interested in hearing a 'what throttle bodies have to offer' discussion

 

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/itbs-can-done-136329/ provides some discussion, I've been following that since it's inception

 

I would get it if it was not over 900 dollars.

 

Regardless of whether it did anything or not?

Like paulmasoner I'm kind of curious of the exact function. Better response because air is let in faster because a larger opening? Would the ecu adjust to not open the same amount as the oe size?

Anyone actually have some info on the idea/subject? I don't want to let my semi-ignorance impede a potentially valuable discussion :D

 

some engines like boxers from Subaru, when they get a bigger TB they need to retune their maps to get the extra performance. and it does help. A LOT.

Im not sure about how will this work on our car tho.

Edited : Wait a minute, Sorry for my limited knowledge of japanese but, on the site it saids that this is just a job to "enlarge" the throttle body, is that true ? or I misunderstand something ? on FEED's site its just 39,900 yen for the job. I guess the price on Japanparts including the core charge. correct me if Im wrong.

http://www.fujita-eng.com/rx8/index.html

 

from scanning through the thread you linked tiltmode; and from recalling some other discussions from the past(that admittedly are over my head)

it seems that the intake manifold in oem form already flows everything the renesis can naturally ingest. so my thinking for now is that for NA apps, this wouldnt be able to provide anymore power, maybe a quicker response?

for FI applications, all things change

 

FEED works on the factory throttle body to enlarge another 2mm opening
The price Japanparts quoted included the geniue throttle body

 

I'd be curious if 2mm would make any noticable difference with a turbo or supercharger. Seems like a really small increase.

 

close enough, this proofs that my japanese knowledge is improving

Well some people might have doubts, but Im sure Fujita knows their stuff ... especially when it comes to rotary engine ...

900+ bux is a bit steep ... I'll think about it, let me add it to my list of upgrades ...

oh for your original question, Im dont think it will help the 4AT model much, as you dont have the extra ports for extra airflow anyway.

 

If you take the throttle body off you will notice that the back side of the throttle boby is tappered to a smaller diameter intake manifold. This would make me think that the throttle body being any bigger would not provide any real gains without a new intake manifold in na form and minimal gain in fi form.

 

tiltmode thread link is a good one, and the discussion about aftermarket TB really depends on what you do with your 8 and its use, track/race car vs. daily driver/tuned weekend warrior... For the later this is a bit excessive without doing alot of adjustment to the intake mainfold(most race cars have custom built manis) like RotaryGod states the intake manifold is extremely well disgned and an aftermarket larger diameter TB really cant be utilized to a justifiable means for daily use,,, FEED nows thier stuff and ususally cater to a wide market when it comes to the rotary from simple mods to very serious non road use applications...

 

Althought Fujita's car is not as "fast" as Amemiya's car on the Touge road course. Im sure Fujita has this TB out for a reason.

 

there aren't any "noticeable" gains to be had guys. trust me...$900 bucks is better spent on some light wheels!

for one, i DID round out the TB a lil bit larger and shaved off material here and there before i proceeded to polishing it up real nice... including the plate.

its minimal as it is, and i'm sure there may as well be some gains, just that its not really noticeable.

the restriction at the opening is lessened. i don't see any harm in this. however, messing with too many larger intake openings can do more harm than good as some intake ports tend to be smaller for better fuel atomization.

i don't see taking off slight material and polishing at the TB any harm, but not at $900!