rxspeed87

just curious what the flow rate for the stock TB is

also would making it so the second plates open up at the same rate as the prim plates make much difference

and do you think porting the TB not to make it larger but make more of an airfoil out of the edges so the air flows into the TB smoother make any difference... not loooking for much just a little

adamlewis

Not to knock on you or anything...But youd think if you knew enough about fluid dynamics to necessitate the asking of "flow rates", youd at least know the answer to some simpler questions like the ones asked later in your post.



One thing to keep in mind is that a very smooth, uniterrupted flow of air is not always the best for the atomization of the fuel...

As for an airfoil? wtf?...Do you know what an airfoil does? Do you know that often times, turbulence is created at the tips of airfoils?

As for the flow rate...I have no idea. Sorry.

NZConvertible

TB's don't have flow rates, only pressure drops. When flow rates are quoted it's a measure of the air flow at a particular pressure, or conversely the pressure drop at a certain airflow. If you hear or see a flow rate without a pressure it's completely meaningless and probably an overexagered claim. No. All that'll do is drop the primary port velocities and kill torque. The secondaries open at higher flow when they're needed. There're all fully open at WOT either way so there's no advantage. I think you mean knife-edging the dividers between the three throats. Yes this will reduce the pressure drop through the TB a bit. Do a search for threads on the TB mob, there's a few pics floating around of TB's with this done.

NZConvertible

There's no fuel flowing through the TB. Your theory is correct when talking carbs, but doesn't apply as much with EFI as fuel is injected very close to the ports.

mazdaspeed7

The throttle body has A LOT of potential flow. The throttle plate area of the FC throttle bodies is comparable to the area of a 78 mm single throttle body. Now it wont flow quite as much because it has more surface area, but thats still HUGE.

adamlewis

I never said there was....

A smooth flow at the TB will ( usually ) equate to a smooth flow at the injectors.

So dont put words in meh mouth!

ka8legend

Would thinning out the throttle plates and shafts and remounting flush screws worth the time & effort?

mazdaspeed7

It depends on how much free time you have. You probably wont see any measurable increase in hp, but like they say, every little bit helps.

rxspeed87

I understand turb can help with atomization of the fuel
but also by removing pumping losses and getting more air into the motor you can gain power as well. and the bends that are in the intake being the many I'm sure having a smooth flow of air UPSTREAM from the injectors isn't going to harm the atomizing of the fuel. as well as the texture of the intake manifold itself

but you knowing about fluid dynamics should already know that stuff so I'm kinda wasting my time :p

the question on flow rate was more out of curiosity then anything.

rxspeed87

aware of that one

most common are 1.5 something or another ( forget the mesurement ) for most 4bbl and FI systems I think and 3.0 that I have seen used in 2bbl unitsreason I asked about that is my secondary plates are not fully open at wot. I know it would hurt gas milage and low end power to have them both open up at the same time but wondering if it would help more in the high rpm since they are still not fully opendo you know how much of a diff this might make?

rxseven

I think some of you forget that all the air has to be sucked in through that tiny flapper door of the afm. You can't really increase the volume of airflow dramatically by doing anything beyond that point.

adamlewis

:sigh:

NZConvertible

The question was about the throttle body of an injected engine, so any mention of fuel atomisation is irrelevant. It's a long way from the TB to the injectors, but a very short distance from the injectors to the engine. It's a non-issue. You did that all on your own by bringing it up...

NZConvertible

You question implied you didn't... That's my point. You cannot compare the flowrates of two components unless they were mesusured at the same pressure. Otherwise the numbers are meaningless. No it wouldn't help because all the throttles are supposed to be fully open at the same time. You obviously have a problem with the linkage that opens the secondary throttles. Since you'd need to pull the TB off to mod the linkage, you might as well just fix it instead. For a mildly modded engine probably not much. A component's restriction increases exponentially with flow, so it would make a much more noticable difference on an engine flowing a lot more than stock.
Here's the pic I was talking about.

rxspeed87

whats the sigh for?

I could easily understand your point if I had an IR setup for fuel injection. but even if you had one intake running that was about 4-5 inches from the intake port for each intake port the fuel injectors if running right shouldn't have any problems with getting fuel to vapor


but on the stock setup of this car as NZconv said the TB is a way from the fuel injectors

and there is at least 2 bends I can think of before it even hit s the hits the injectors as well as the plenum which will change the airflow. think about how the plenum works. it brings air from a high velocity into a large area slowing the air down making it a little more dense, so you now have air kinda backing up on itself. smooth flow will get changed at that point. and again that **** inside the intake manifold is rough as hell... like that won't disrupt the intake.

the only real change I could see from doing the above listed mod is reduced pumping loss ( not much if any) and maybe a little more air into the motor...



as for the TB with the second plates not opening up all the way. they are almost all the way.. maybe I am just too picky. but on the linkage there is a gap that is to start the secondary and it starts at the right point.
also to make them open at the same time just some jb weld at that point that little gap piece that opens the second ports

no need to remove the TB