Ok so I've been looking at this stock throttle body I've got laying around waiting to be polished. Had an idea when I removed the secondary butterfly's out of the upper intake since there bigger I know it would be a good thing to add more volume of air going into the motor. So has anybody bored out there stock throttle body secondary butterfly's to the size of the upper manifolds butterfly then matched and taped holes in the bar the held the butterfly's in the throttle body orignialy? I think FEED has a throttle body with larger butterfly's thus what got my wheels turning lol thanks any input is appreciated

 

Yes, BDC does this as well. You can search ported throttle body I believe.

 

Rotary works has a nice one from what I understand

 

I am actually going to be going with the RW TB in the near future. It is a topic of debate because they are known to cause a vacuum leak, it is a simple fix however.

Most users have noted crisper throttle response.

 

Ok cool thanks guys guess I'll be giving it shot then

 

I didn't....

In all honesty, I'd stay away from the RW TB as well as other RW products. I should have listened to the reviews and shouldn't have bothered getting one.

If you still want one and since the vacuum leak is such an easy fix, i'll sell you mine.

 

Yea I've read the and heard the same gonna be sticking with stock but will be porting out 55mm for secondary's and 50mm on primary then rematching it to the upper and modifying the gasket

 

If you just look at the TB and the design of the openings and throttle plate shafts, you will see many points of poor design. A few can be easily corrected to reduce turbulence and thus increase air flow.

 

Yes there are rough casting blunt edges etc. polishing it really helps knock down the turbulence.Port matching the throttle to the upper then the upper to the lower helps even more cause I don't know about everyone else's but my stock mazda stuff wasn't round and extremely not bored the same acording to the oil marks where the gasket was too big? Haha not anymore 😄

 

Rotorsports Racing can port out your TB, replace the butterflies, and then have your UIM/LIM extrude honed so everything is port matched along with a teflon coating on the interior and ceramic coating on the exterior (of the UIM/LIM).

I had it all done about 4-5 years ago and have not been disappointed

 

What was the price of all that?

 

About a grand if I remember correctly.

 

If you're not over 500 whp, the throttle body upgrade is a waste of time in my opinion. You won't see much gains.

 

Well poop I was hoping this would net an additional 100hp j/k I figured as much I thank you for your input though I'm starting to rethink the whole idea anyway since there's just so much to do to get it all to work and I'm no machinist I'm a body tech so that being said think im just gonna polish the **** outta it and call it good

 

Also there's a place online called maxbore.com they do these mods also he quoted me 375.00 to polish and bore it with a warrenty not sure if anyone's used him though at least for a rx7

 

HOLY ****!!!!!lol

 

any decent ceramic coating is gunna run you $300+, alone, just to start with. For the combo of both coatings, the (proper) porting, port matching, flow matching between front/rear runners, increased bore size in the TB, matching butterflies, etc., etc., etc... I don't know that it's really that outlandish all things considered.

 

Oh, they can also just do the tb modifications as well, I'm sure that would be priced differently

 

RC Engineering does throttle body porting. I think it runs around $450.00 if I am not mistaken.

 

I Dremel Tools and a few hours of grinding can accomplish a lot. That is if you have the skills and know what to do.

 

Having seen a feed TB install on another car, it would be a waste of time unless the manifold was matched.....and the only practical way would be extrude.....step between them was in the millimeters! Might have to consider the downstream restriction too, with a custom elbow/intercooler outlet to avoid negating any gain. Usual suspects are 2.75" diameter from memory.

 

The benefits of Extrude Honing- increased airflow by approximately 45%, but the biggest benefit is the manifold & runners are flow tested throughout the procedure & balanced within 1% of each other- so flow is better equalized to both engine rotors- combined with the large bore TB results in a substantial improvement- with no loss of throttle response.
TB can't be simply enlarged- new throttle plates must be installed as well

 

Extrude Honed Manifolds here:
https://www.rx7club.com/3rd-generati...folds-1066469/

 

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Which means you have no hands on or practical experience with them yourself. I believe it would be beneficial for you to spend a bit of time reviewing the thoughts of those on this forum who have used their products. A good 85% of the replies range from "Terrible" to "Steaming pile of ****"