overkill 62mm itr TB???

[Hipowerracing]

here a example. Swift gti 1.3L motor. Upgraded from 45mm throttle body to 60mm throttle body, back to back dyno 5kw atw all thru rev range.

i thought you said it was right.. haha

[jdmTYPE R]

theres never a win,win situation. its like having a turbo setup small turbo boost up quicker runs out of puff quicker,bigger turbo spools up later but boost longer

[fatboyz39]

i believe bigger is better.. im running a 80mm TB on my intake manifold and i still think it's not enough..
or at least big is never big enough.

80mm t/b on a B20?

[fatboyz39]

but 140mm is huge.. it's just riceball fiqure of speech... biggest throttlebody i have supplied is 100mm~120mm billet on V8 and some 1000hp GTRs(TOPRPM using Q45 infinity TB)

8 cylinder and a turbo. Nice comparison.

big is not always better. For n/a its about air speed

[grumpy rooster]

I go away for a day and look what happens.

Hipowerracing, I think you missed the key parts of my subjective post where I said that I use that as a guide for engines with I, H, E ONLY. Once you go beyond that then it really is a case by case scenario.

Multiple throttles are a different situation to what is discussed in this thread. That topic I'm sure has been discussed before.

[Hipowerracing]

what im actually saying is bigger throttlebody does not affect air speed..
there is a misconception that a bigger TB slows air spped down... it doesnt.
because most of the air speed depends on the intake Track on your head not on your manifold...

on a manifold distribution of air and volume of air is the issue than actual air speed.

and fatboyz i wasnt comparing V8 and turbo TB.. i was just saying that was the biggest i have supplied.. or sold at our shop..

it's funny on ozhonda.. people pick on the little things you say, and make a big fuss about it not debate the real facts about the whole post..

1st)was what flow and volume meant on an equation...
2nd)it's turbo and NA comparison.. which both has no meaning to the post... HAHA...

what a way to welcome the new year... Happy new year folks..

[dynosaur]

er....... regarding to the Spoon website , it said the ITR throttle body got 67mm of diameter.

http://www.spoon.jp/product/pdfs/p24_p35.pdf

Plz corrrect me if I m wrong.
thanks

[jdm_kid]

Standard ITR throttle body is 62mm.

[steve88]

Fatboyz, honestly you make me roffle.

At the point of the TB, the velocity of air right there is irrelevant to what it is flowing at right before the valve. Think about this, 80mm is shared between 4 cylinders, so each cylinder has 20mm to breathe with for example, ITB setups run 53mm TB's EACH on average, that equates to a nearly 210mm TB.

Now you're thinking in your head, yeah so? ITB's are open. WRONG. The best ITB setup is a closed box with venturi effect leading into it (depending on placement of the intake of course)

There is ALOT more to intake design than a ****ing TB, run as big as you can because you need it when the motor is sucking all it can get at 7000rpm. If i was worried about your intake i'd be looking at a custom one designed from scratch for yourself.

Amplifying the resonant frequencies of your current intake pulses working with your camshaft and exhaust manifold.

A taper from the plenum to the port on the head is one MAJOR beneficial improvement in a performance intake, the tapering down allows for a very special effect, namely, RAM effect or Bernoulli's Principle. For those ****ing backyard engineers like Fatboyz, that's a decrease in pressure allows for an increase in velocity.

I can go on forever, but a bigger TB isn't going to make you lag down low. If anything you won't even notice you are running a larger TB in the low rpm range.

Hi power, for the fact it will slow air speed down as the pressure increases in the larger diameter area, but it's only present for that LENGTH of the TB, which is what 3cm? WOW. (Although it's not long enough for pipe pressure loss to occur)

Food for thought; Why do you think most race engines are limited by intake throttle body size?

[grumpy rooster]

After doing some more research on this I have to make a small adjustment to what I first posted. At "small" throttle openings you will feel more response as you have more open throttle plate for any given throttle %. But, at medium throttle % you will feel a doughier engine than with an appropriately sized throttle body.

[steve88]

I forgot to say,

Everything in the intake design has to work with everything, IE you CANT have a 80mm TB and a standard plenum/runner design.

[jdmTYPE R]

I forgot to say,

Everything in the intake design has to work with everything, IE you CANT have a 80mm TB and a standard plenum/runner design.

but they r talking about stock motor and you cant compare a ITB to a manifold and throttle body coz of the distant of the ITB throttle to the head is really close, thats wat give the reponse in throttle.

After doing some more research on this I have to make a small adjustment to what I first posted. At "small" throttle openings you will feel more response as you have more open throttle plate for any given throttle %. But, at medium throttle % you will feel a doughier engine than with an appropriately sized throttle body.