overkill 62mm itr TB???

^^^^ that's what i was thinking.. i didnt want to lose power.. so probably best to leave it when its ready for the tune then put it on..

i didnt want a gain from just the bolt on, but i mainly didnt want to lose power.

thanks hao

if you havn't done this mod do not give your advice or opinion.
Just do it, you won't lose power.

^^ done :) that's all i wanted.
lol

cheers jimbo

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.

what do you mean 5kw through rev range?

5kw increase?

Quote:

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Originally Posted by dupac->

what do you mean 5kw through rev range?

5kw increase?

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Yes throughout whole rev range.

Quote:

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Originally Posted by Limbo

without a tune you will not make more power.
The Throttlebody lets a certain amount of air in. Unless you can get more fuel and ingnition timing to it the extra air is not gonna make any power, but could actually loose you more power.

Comes down to basic combustion. If you put too much air you will blow out a flame, but with more fuel you need more air. Hope i explained it right

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dont think so... if u bore it out you will get more air..

if u look at an a/f graph of a car before and after intake mod its pretty much the same thing...

more air = lean mixture = 90% chance of making more power

nobody i know go backwards with a bigger TB...

i dont know why some people in this forumn seems to think you will go slower with a bigger TB..

bigger TB doesnt mean leaner air... it means more volume of air...

example.. if you are running 13.00 A/f ratio with a 60mm TB.. adding a bigger TB makes the A/F 13.50. this is not bcaus you got less fuel in your combustion chamber but means that you got more volume of air in your combustion chamber (due to a bigger TB) and if you retuned your engine to 13.00... you will have a bigger combustion because you just added more fuel to more air = MORE BIGGGER EXPLOSION = MORE POWER!!!

most cars come out of factory rich.. example.. 12.4 adding a bigger throttle body leans the mixture to maybe 12.90 that makes the combustion closer to ideal A/F thats why like fatboyz said he gets 5kw thru out the rev range..

using a bigger TB on a tuned car.. retunning must be done to ensure the combustion is not too lean that is only on cars that are tunned to the edge.. (i know a few tuners who does that)... on standard ecu cars it's definately fine.

okay.. :)

I have not heard anyone mention intake velocity......

I'm really curious about this.... because IMO... air velocity is just as important as volume in cyl filling.

I think people are confusing a little bit bigger throttle body with a much much bigger throttle body. You can go too big. If you do the car will feel lazy and lack throttle response due to the lack of air velocity as SPEEDCORE hinted at. Like if you put say an 80mm throttle body on a D series engine. Unless it is worked off its nuts (and even then very unlikely) it will not work well. It will be unresponsive and anything below wide open throttle at big revs it won't make any decent power.

Unless an engine has some mods other than I, H and E I personally wouldn't go any bigger than 10mm larger with the throttle body. Even that is bordering on too big. You really need to look at the % increase in diameter over the original throttle body. 10-15% is the limit from what I've seen work on most cars.

But these are only a guide. It also depends on the efficiency of the engine. Some engines are more efficient than others.

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Originally Posted by grumpy rooster

I think people are confusing a little bit bigger throttle body with a much much bigger throttle body. You can go too big. If you do the car will feel lazy and lack throttle response due to the lack of air velocity as SPEEDCORE hinted at. Like if you put say an 80mm throttle body on a D series engine. Unless it is worked off its nuts (and even then very unlikely) it will not work well. It will be unresponsive and anything below wide open throttle at big revs it won't make any decent power.

Unless an engine has some mods other than I, H and E I personally wouldn't go any bigger than 10mm larger with the throttle body. Even that is bordering on too big. You really need to look at the % increase in diameter over the original throttle body. 10-15% is the limit from what I've seen work on most cars.

But these are only a guide. It also depends on the efficiency of the engine. Some engines are more efficient than others.

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Grumpy..

if you are sayingthat too big is no good... what about the individual throttle body's you are selling?? arent they too much for stock engines then?? because if i do the maths and you add up all the surface areas of any quads you get more that 10% increase each throttle... (and on quards there are 4)

then how come you get more bottom end with Quads??

YES! Principles of flow.. Q=VA (basic fluid mechanics fomula)
velocity or speed is a matter of Q"flow=Velocity x Area..
you see if your area is bigger, your velocity is the same as with a Bigger throttle body you will have more flow..

doing the fomula..Q= VA ;
where Q(flow or volume) is increase because area(A) is increase...
V(velocity) remains the same. (you must remember there is always vaccum on the engine) and Q(flow) is always increasing when it is given a chance..

in your assumption you are assuming that Q stays the same and because A(area) is increase therefore V(Velocity) is reduced..
in a runnin engine that does not happen.. if it happens there will be no need for cars will not be turbo charged...(turbocharging is man's obsession with more flow in the combustion chamber using another medium mainly turbo etc...)

it is easy to know if you got enough flow from your map sensor.. in my experience.. the pressure reading on an engine is usually a negative value(vaccum) at wide open throttle..(except when an engine is tuned perfect.) meaning there is not enough air for a running B16a etc...
only at 0psi is where you know that you got sufficent flow.. that rarely happens.

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.:eek:

this is not a go at any one but i thought i'll share some of my thoughts with you guys.. im sake of ozhonda being a site where no one has any real technical knowlege and go on the site and blabber shitz..:thumbdwn:

i know grumphy knows his stuffs..he runs 11 secs.. what do you think ? what i say makes sensE??:angel:

Quote:

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Originally Posted by Hipowerracing

doing the fomula..Q= VA ;
where Q(flow or volume) is increase because area(A) is increase...
V(velocity) remains the same. (you must remember there is always vaccum on the engine) and Q(flow) is always increasing when it is given a chance..

in your assumption you are assuming that Q stays the same and because A(area) is increase therefore V(Velocity) is reduced..
in a runnin engine that does not happen.. if it happens there will be no need for cars will not be turbo charged...(turbocharging is man's obsession with more flow in the combustion chamber using another medium mainly turbo etc...)

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Umm... Bigger is NOT always better just like speedcore and grumpy have stated. There are limits to what you can actually increase the area by, especially on an engine.

Are you just gettin the Q = VA just off the internet? Because it really seems like you have man, there is alot more to that equation than you think. Yes its the BASIC equation if you know what the velocity and area is. Area is easy, but whats the velocity you are using to calculate the value of Q?, because Velocity is NOT always constant like you have just said. Q is actually volume flow rate, not flow or volume.

And what grumpy is saying is, Q is decreased because V is Decreased due to an much larger increase in A. Think of it like a smaller river running into the ocean. The area is increased once it reaches the ocean, and therefore the velocity and volume flow rate is decreased. Correct me if i am wrong. Enough of the stupid equations though.

I just have to agree with grumpy and speedcore on this one.