got bored..... hows it look? i think pretty darn good...

 

its not bad at all, but if i were you on the little triangle pieces on the side, I would get rid of as much as possible. Make it as round and thin as possible, at least thats what I did to mine.

 

how long did it take ya? did you use a dremmel?

 

it took him about 2-3 hours


lol he is a tb terrorist

 

Good job on the TB. I was a bit too zealous with mine and ended up grind through the side wall. Oh well, that's what JB weld's for

 

i was worried i would eat through the wall
... so i left the triangles alone

 

has anyone bored out the valves and put a larger plate in

 

^^^^i dunno but sounds fun

 

LOL

great picture...

tb terrorist LMAO

 

Have fun trying to do this in your garage...
You need to have a good vertical mill.
The bore must fit the throttle plates perfectly, or you'll get leaks that will not allow you to drop the idle speed down.

I do NOT recommend doing this with a dremel or die grinder.
The plates needs to have a very sharp geometrical edge that close exactly to the bore.


-Ted

 

Do you realise you filled up the air hole for the fuel injector and oil nozzle air bleeds?

As well as what Ted said, there's not enough meat in the casting to enlarge the bores enough to make a worthwhile performance improvement. It would be a lot of effort and/or cost for little gain.

 

Looks good, but I have 2 suggestions. 1. Smooth out the sanding marks more, you can have a polish here since it is before the fuel mix. 2. Round over the knife edges of the divider, just slightly. You will get better laminar flow that way.

 

wouldnt smoothing the apex's out make sumthin where air would slow down on entering and cause turbulance? (example a) when having the blade would pretty much split the air? (see example b) this is just my guessing

 

terbulence is a good thing. remember that. plus rounding it out would probobly make the velocity of the knife edge go up.

 

turbulence is good when it affects the atomization of the fuel, this is pre fuel delivery.

 

sorry for my ignorancy but what kingd of power do you spect from this mod?

 

i would say 2 hp if that.

 

The air needs to be turbulent before the fuel is injected into it, not just after.

Not that this really matters in this case. Any effects from slightly rough internal TB surfaces (good or bad) would be tiny. Smoothing out the sanding marks is fine, but actually polishing the inside of the TB is just a waste of time. You might as well polish the insides of you exhaust tips while you're at it...

 

nz you are a butthead but right hahahaha ROFL

 

why would polishing the intake be bad? I guess it depends on the car. My autotech teacher rebuilt the 3 cylinder engine in his geo metro and polished everything including the intake manifold, throttle body, pistons, combustion chambers, head, he's getting like atleast 75 mpg and alot more power. i guess your saying polishing would take out the turbulence in air flow, which you want, but i would guess from the spiral intake tracts/runners on a briggs and straton engine (lawnmower?) that the velocity increase is just as important so wouldn't the air entering the engine enter at a higher velocity if the intake had less turbulence? please inform me

 

I've seen some ridiculously well polished intakes and ports that worked fine. Then I saw this intake runner that looked like glass on the inside. Yeah, he had problems idling. But once it went, it was gone. This was on a carb, so maybe he could have corrected that with a standalone, but I'm not sure. The moral is. It has to be REALLY smooth, for it to cause little turbulance. there are several turns in the Intake Manifold that add sufficient turbulance not to mention boost.

 

carbs have very poor fuel atomization, nice cleaned injectors have decent atomization, dirty injectors have poor atomization. the velocity of the flow past the throttle body should be increased as much as possible, it becomes turbulent once it hits that wall directly behind it anyways. turbulence in the intake runners is a tradeoff, want top end power? get high velocity short runners. want good bottom end torque? provide turbulent longer intake runners, both require good fuel atomization, the better the atomization the more power can be derived from the A/F mixture.

 

i realize this is an old thread, but porting polishing does more than 2hp, the guy at BDC motorsports has a dyno of a ported/polished TB, without the car made 404rwhp, after the ported/polished TB, 442rwhp, 38rwhp doesnt seem that bad to me for a couple hours worth of porting. i realize it wouldnt be as much on a lower power car, but still.

 

Does anyone have any pics of a good TB port job?

 

yes but the CFM amount of air required by a 400+rwhp car is a hell of alot more then of ANY stock RX-7 or anything with a few mods.
the tb mod is one of those "great, with supporting mods"-mods