Rotary-Works TB. Pros vs Cons
 

So after seeing this TB I am completely drooling over it. I never planned on upgrading my TB but I am definitely leaning towards it now. My setup right now is geared towards throttle response and power under the curve. I want my setup to be as near perfect as possible for the street. I have a street ported and pinned motor (S5 motor with S6 rotors) , BNR stage 2 turbo, S5 lower mani to FD upper mani, FMIC setup and full standalone ECU. I have searched this, but not a whole lot of feedback yet. I was wondering what the pros and cons to installing this TB would be? Are there any dyno proven results out there? Thanks for the feedback

I'd be interested as well.

I have no experience with their product, but it seems to be of good quality.

Now I would expect, and this could be wrong, that a larger throttle body such as this would probably not provide the same throttle response and low end as smaller stock TB'S? But overall, I imagine you would see some peak gains?

You would only see gains if the stock throttle body is a chokepoint.

Go to there website. I believe I saw a before and after dyno on a bone stock FD.

I would strongly suggest purchasing anything from them as in my honest opinion they have poor sales ethics, do not properly test their products, and generally seem to have QC issues.

I'd direct each of you to their vendor area where you can find my experience with their FD Elbow and someone else has issues with one of their radiators or v-mount kits. Very poor.

You could also mod your throttle body. port and shave it. One of the first things I did to mine to get that out of the way.

I have messed with the FD one on a car I was tuning. I consider it a show piece. It's got a single adjust screw on the bottom, no fast idle system, no cruise control. It doesn't open in two stages like a factory throttlebody so that actually makes throttle response and tip-in more of a pain in the ass to get tuned right. Remember that every Mazda production rotary has had a two-stage throttle/carb design. On all the fuel injected rotaries with mechanical throttlebodies (pre-Renesis) the two butterflies for the secondary ports are mechanically connected to the butterfly for the primary ports. At low throttle only the primary ports are open, and then the secondary ports open as you push down the pedal more.

With a single throttle butterfly you lose that progressive/staged opening, which means lower air velocity and some loss of part throttle and low end. It also messes up the tip-in fuel in my experience. If it were such an obvious performance benefit Mazda would have used a single butterfly on these older engines from day 1. Rx-8 has a single blade electronic throttle but then the secondary ports are staged with through a valve in the UIM controlled by a vacuum solenoid.

As for dyno proven results, it's like anything else. Somebody somewhere on the internet will claim some gains, then there will be skeptics, and you will have to figure out who to believe. I personally don't find even an unmodified FC throttlebody to be a restriction for street setups.

Speaking of throttle response and area under the curve, are you using an s4 or s5 based BNR? You really should be using an s5.

The port work on it is awful. Those 3 CNC grooves are laughable. I wouldn't put one on my car without porting it. Matter of fact, I wouldn't put one on my car.

If looks aren't super important to you, there is zero reason to get this throttlebody when you have a BNR stage 2 turbo. You already have an FD throttlebody (which is bigger than the FC) and that turbo you have will flow about as much as stock FD twins.

^^ Those are the kind of answers I was looking for. Thanks i will just hold off on it and have the FD throttle body ceramic coated along with everything else. My thirst for power will most likely take me in the direction upwards of 400 whp with a GT35 or 60-1 eventually. At that point would it serve a better purpose?? Also, are there any modifications i can or should make to the FD throttle body for now?
Oh yeah, and unfortunately I have an S4 BNR, I wasnt as educated about the differences in S4 and S5 when i made the purchase..

Like any kind of budgeting, you have to think about return per dollar or hour invested. In this case you are concerned about broad, streetable power. The biggest thing that will affect this is your turbo, manifold, and wastegate configuration. Put your money towards that.

On my personal car I'm running a bigger turbo than a GT35 (a T04R) on an s4 throttlebody. I have this TB bolted to an S5 UIM. I kept the s4 TB because I prefer the convenience of running the s4 OMP and retaining cruise control. I'll put it to you this way. On an FD throttlebody you will have no trouble making your car so fast that every time you drive it you truly put your very life in your hands.

check out this diagram I made:

https://www.rx7club.com/attachment.p...1&d=1296443500

The FD UIM and throttlebody have the same basic components as an s5 T2, but they are arranged a little differently. The dashpot, throttle plate adjusting screw, and the throtte/cruise control linkage are on the front of the TB, the side not pictured here. In the actual pic you can see the thermowax/fast idle system and TPS located on the back side. The double throttle system is on the FD UIM as opposed to the TB on the FC. You can delete the double throttle if you want to. It is completely useless here. On the FC the double throttle is controlled by the TB coolant hose and thermal valve, but on the FD it's controlled by a solenoid on the FD it's not even doing anything.

You may have already done so, but if you want to delete the throttlebody coolant hose for the FD TB you can physically remove the whole system and plug the holes. Or you can just use a zip tie to rotate the fast idle arm thingie out of the way so your idle won't be stuck high. Just like with the FC throttlebody, I do NOT recommend removing the fast idle system unless you have devised a way to keep the idle stable when cold (without just keeping your foot on the gas). This can be done with tuning of warm up idle ignition timing and BAC valve duty if you have the capability to make these adjustments (standalone required).

As I said above, the turbine housing, manifold, and wastegate have a huge effect on the powerband and reliability of the engine. The divided manifold and dual port wastegate is better than the s4 design because it separates the exhaust pulses and reduces backpressure while also controlling boost better.

Hey guys, My FD engine is stock but with RE Amemiya Intake, HKS Exhaust, REDOM ECU.

So will this RW 90MM Throttle Body work fine for me? I mean, does my FD have to be a Drag car to install this? I just need it for Street use.

I contacted RW and what an answer they gave me... ... ... aaaand the answer I got from one of their representatives was "Not Sure!" looool!

So Better ask the one who tried than asking the doctor.

What do ya guys think?

What?
you contacted the REP and he said he "wasn't sure".??
That THERE tells you to Stay way from the thing.If the company making them has NO Clue what their product is FOR then they do not deserve your money!

..and if that doesn't sway you,then I had 3 of them and sold them ALL.
Tried one,then got broke,sold it.
Second one I had and then had second thoughts n the setup and switched back to S5 setup.
Third one I sold Was due to a tuning issue I was trying to chase,
It turned out that the TB had a boost leak.I did not know that when I sold it,I found out later,and was totally upset that I sold inferior goods.
As a matter of fact if you look at threads on them you will find some guys encountered boost leaks at the butterfly shaft seals with these Throttle bodies.

SO there ya go..2 year old thread BUMPED back to life and given info.

Boggles my mind why someone would want to spend money to loose driveablity with little to no advantage.

The car drove just fine Natey..It would really get up and go!
That second TB I had with the RTEK 2.1.
The RTEK actually told me I had a fault in my TPS wiring.I had wired it ass backwards..100 percent at idle.I fixed that and thought I was good to go.
Then after chasing a gremlin in the wiring I chucked the whole Stock wiring and went Haltech.

There are other TB's you can put on now and adapters are available.
They weren't a couple years ago.
If I build again..(NO..!)..I would try something..just not this TB..

What adapters are you referring to styx? I was interested in the RW TB a while back but the more I've read about it the more it seems like butt jewelry.

I've got a lovely bunch of coconuts!(??)
here ya go:Rising RPM - Products
Butt jewelry?..
hmm..80 mm poop when wide open throttle?..(ahahahhahahaha!)

Has anyone documented with dyno or track times a benefit of swapping throttle bodies on a street car? Meaning under 400-450hp?