overkill 62mm itr TB???

Just a quick one..

Mods --> b16a2
- 4-1 jdm itr headers :(
- plazaman/dynodave cai
- bc specIII 2.5'' catback
- metal cat
- skunk2 IM

with those mods.. would a 62mm ITR TB be suffiecient?

I'm looking at a tune later on down the track with better headers and afew other things aswell.. but not atm..

but for instance if i whack the TB on would it make a difference??
I'm not looking at any power gains or improve response doing this.. i just dont wanna LOSE power or response if yah get what i mean?

or should i wait til im ready for tuning or scrap the itr TB all together?

and also.. will a 62mm tb be sufficient enough for a tune with head work n shit done?

thanks Du

Quote:

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Originally Posted by dupac->

I'm not looking at any power gains or improve response doing this..

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If you don't want power or response gains why bother considering it then? :confused:

It will go well with a set of CTR or ITR cams. We made decent power mid those mods

62mm is fine. Recommend ITR cams. A b16a we did with your similar bolt-on with ITR cams made pass 105kw atw.

Quote:

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Originally Posted by SPEEDCORE

If you don't want power or response gains why bother considering it then? :confused:

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i guess this mod would help with future mods. As future mods might have to wait a little longer why not chuck on a mod that i have lying around?

get it?


then the TB would help with other mods like cams like fatboyz n benson said..
(when i have the cash for these mods) :thumbsup:

Quote:

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Originally Posted by Benson

It will go well with a set of CTR or ITR cams. We made decent power mid those mods

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Quote:

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Originally Posted by fatboyz39

62mm is fine. Recommend ITR cams. A b16a we did with your similar bolt-on with ITR cams made pass 105kw atw.

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alright!

sweet..

got any sets of cams lying around for me? :)

Quote:

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Originally Posted by dupac->

i guess this mod would help with future mods.

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So in other words... you DO want gains ;)

Quote:

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Originally Posted by SPEEDCORE

So in other words... you DO want gains ;)

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lol yeah. im not expecting it to give me gains NOW.. but when/or if i tune it would help.

but yeah got my answer
sweeeet as :D

at 1st I thought 62mm an overkill for a b16a esp when the b16b came out with a 60mm TB from memory.

I was told the driveability down low with the larger TB has a lot to do with the tuning; many simply whack a bigger TB on and hope for the best without a tune.

Just got my car ( EG ) back from the East today with an ITR 62mm TB on my B16A w/ dc2r cams+IM. Very impressed how it pulls all the way to 8500rpm (8700rpm cut) and it's drivability down low, from standing start as well as going up a hill in top gear under 2000rpm. Dynodave certainly knows his stuff when it comes to not only tuning but parts specification.

Definately faster everywhere by a clear margin than our stock aust spec dc2r.

nice..

thanks for input dude.

wel lets hope it doesnt change too much without a tune aye!

i beleive the larger throttle body wont actually increase power, but will give the impression of power gains.

i mean, to acheive 70% power you will only have to put your foot down 60%. I say this as i was reading into this same subject, but rather boring out my b18c7 TB. There was quite a discussion on this.

http://www.ozhonda.com/forum/showthr...ght=tinkerbell

can anyone shed some light on this?

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

^^^^ 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.

Quote:

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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.

Q cannot be decreased riceball... because of the constant vaccuum in the chamber..

BUT flow or Q can only be increased... in case of a NA engine..(increasing)
so velocity can only stay the same.. as area increases..and Q(flow or volume) increases

in a normal situation yes...
velocity is affected when Area is increased and Q stays the same..(constant)..

if you dont understand what im trying to say i dont blame you..
it is hard to understand something that make sense.. to some people who can't picture it...

but ask any body that have any experience on what i have said
and i did not get that from the internet.. thats what i studied in Uni

[QUOTE=riceball;1485804]

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.

[QUOTE]
SORRY I HAVE TO CORRECT YOU ON THAT!!! because
in your statement above. Q(or what you called volume flow rate(which is the same thing.))
Q dosent not change, area is increased therfore only Velocity decreases.
however you will still get the same value of Q..


AND YES Q is FLOW or FLOW VOLUME or VOLUME FLOW RATE!!! they are the same thing called differently.. if you want to get into the specifics.

but like i said earlier Q does not stay constant because on a NA engine you will always have Vaccuum...
but if you insist you are right and dont believe me thats fine :)

im just passing some knowledge here but since we got so many "smart people" here in ozhonda.. i'll keep quiet...:zip:

Quote:

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Originally Posted by Hipowerracing

FYI in your statement above. Q(or what you called volume flow rate(which is the same thing.))
Q dosent not change, area is increased therfore only Velocity decreases.
however you will still get the same value of Q..
SORRY I HAVE TO CORRECT YOU ON THAT!!!

AND YES Q is FLOW or FLOW VOLUME or VOLUME FLOW RATE!!! they are the same thing called differently.. if you want to get into the specifics.

but like i said earlier Q does not stay constant because on a NA engine you will always have Vaccuum...
but if you insist you are right and dont believe me thats fine :)

im just passing some knowledge here but ias we got so many "smart people" here in ozhonda.. i'll keep quiet...:zip:

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Man.. I really have no idea on what the hell you are saying. You say that Q does Q can only be increased, then you say that Q is constant.

and NO. Flow or Volume is not the same as volume flow rate. You stated flow OR volume, it is DIFFERENT from VOLUME FLOW RATE.

Quote:

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Originally Posted by Hipowerracing

however you will still get the same value of Q..

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Quote:

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Originally Posted by Hipowerracing

but like i said earlier Q does not stay constant

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Care to explain cause i really don't understand "smart" people talk, way too technical for me.

in a normal situtation like when you open a waterpipe.. Q is constant...
or in the case of a fuel line.. supplied by a pump... yes Q is constant. example a 280l/hr fuel pump.. no matter what your fuel pipe is your Q is 280l/hr... changing the area does not increase your 280lhr of fuel passing thru your fuel line.

but in an engine it is not CONSTANT because VACCUUM on the cylinder chamber.
as you open the throttle body the vaccuum sucking the air in changes the flow Q(or whatever you want to call it). and the bigger the area allows for more air sucked Thru hence Q can only be increasing.

when i said you get the same value of Q i(Q is CONSTANT)is when your stupid anology of the river and sea thing.. yes the river and sea still gets the same volume of water no matt if river isbigger or smaller..

but in the engine due to "suction" OR VACCUUM!!! Q does not stay constant(it increases) and by giveing it a bigger area you allow the engine to suck more as the Surface area is enlarged
>>> BIGGER Q = Velocity x BIGGER AREA
thats how you encourage your engine to get more volume of air with a bigger throttle body..
(this happens when you open step in the peddle and the engine sucks the air)..
need for a bigger Q(volume,flow of volume,whatever) as there is vaccuum in the combustion chamber. what do you do?? to increase the Q(volume,flow of volume,whatever). having the fomula Q=VA
you can either
1) increase the velocity (in situation where area stays constant) by porting the head so you have less turbulence and faster swirls speed. OR
2) increase the AREA (iin situation that velocity stays constant) by adding a bigger thorttlebody.. OR
3)do both.

okay understand?? dont worry... i think you are right and im wasting my time trying to prove apoint...

soo.. does the engine have a limit to how much suction or vacuum it can provide? Or does it just keep increasing? Providing that its a stock engine, IHE and maybe slightly bigger cams?

there is a limit.. suction is baseon the 1st draw of your 4 stroke engine...
example things that will change your suction.

1)cam timing (opening and closing of intak vlaves)
2)stroke of the engine..
3)piston bore size.
4)timing..
5)valve size
there is a list of things that can affect it..

okay i'll explain why it keeps increasing.. because your engine revs faster and faster.. suckion at 5000rpm is smaller than 10000rpm.. more agian at 13000 rpm... and so on..
the stroke thrown becomes quicker and quicker.. the downward force is faster sucking more and more..
make sense?? (in open throttle situtation).
so even on a stock engine situation is same...

engine sucks in more and more air.. thats why flow/volume/whatever you want to call it.. is increasing..

thats why quard throttles give you more power.. because it trys to make the AREA infinate.. or close to it.. to allow for the engine to suck freely..

that is the theory.. behind intakes..

Well, let me be more specific. Stock B18 engine with IHE. Stock rev limit. Would i be better off with a 80mm or a 140mm.

140mm will be the same as a 80mm...(lets say 80mmTB is Optimal for 8000rpm with stock engine)

because in all situation the suction will increase.. you will not go backwards.

let me explain.
in the case of a bigger throttlebody.. because if your rev limiters allows only 8000rpm...
you will still have a Area big enough for the Volume needed and speed at which the air will fill the combustion chamber up will not decrease because the velocity at your intake ports still stays the same..

if you add up the surface areas of a quard throttle set up it adds up to be more than a 140mm.. haha..

but of course the best engineering is enginnering for optimal not over engineering.. so if 80mm does the job.. and you dont have to modify the manifold to fit a 140mm TB.. that is good...

so my answer is using a 140mm TB {that is if you can fit that on a intake manifold..) will be the same as a 80mm TB you will not go backwards.. but if you want to rev your engine to 20000rpm at least the provisions for that is available with the 140mm TB(so to speak).

but if the head doesnt flow wat increase do u have??..

after the optimal .. no increase in power... but also no Decrease... that is to say 140mm is optimal..
but nobody knows what area is optimal... like i said im runnin 80mm which is huge.. and i need more..

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)

each quad throttle body has smaller surface area than a single TB. Each throttle will have greater velocity, yet still be able to get the large quanity of air collectively.

Same concept goes for headers and exhaust, you'd be retarted to use 3" primaries on your headers and a 5" catback.

And Happy New Year YO!

Quote:

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Originally Posted by barefootbonzai

each quad throttle body has smaller surface area than a single TB. Each throttle will have greater velocity, yet still be able to get the large quanity of air collectively.

Same concept goes for headers and exhaust, you'd be retarted to use 3" primaries on your headers and a 5" catback.

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yes because the velocity of air is actually in the intake ports that counts.. area on the single TB does affectthe velocity much..

make sense duiy?
but if you add the SURFACE AREA of the Quads it is larger than a single TB.. yeah?

but velocity isnt compromised because it is at the point of the intake ports that matters anyways.. some people say it is the actual lift and size of the valve that counts.. as that is the last area before air is tumbled into the cylinder...

but in an enclosed intake manifold..the more air the better..
So on the subject of Surface AREA.. bigger is definately better..

need back to back dyno !!!!

Quote:

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Originally Posted by fatboyz39

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.

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i thought you said it was right.. haha:D

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

Quote:

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Originally Posted by Hipowerracing

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:

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80mm t/b on a B20? :eek::eek:

Quote:

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Originally Posted by Hipowerracing

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)

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8 cylinder and a turbo. Nice comparison.

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

I go away for a day and look what happens. :D

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. :)

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..

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

Standard ITR throttle body is 62mm.

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?

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.

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.

Quote:

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Originally Posted by 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.

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:thumbsup: 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.

Quote:

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Originally Posted by 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.

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:thumbsup:

wow, nice thread guys!

several people arguing about several different things, from several different angles. :love:

all i have to add is that a 140mm TB would be a bitch to drive in traffic compared to 80mm TB, on a Honda B series...

i built race engines and my cars are faster than yours.. hee hee...
like to see what your b20 does on the 1/4 with smaller TB

and my car does it talking on the drags and circuit.. not on the dyno..

dyno ponys are bullshit.. they are used to glorify the tuners..

tinkerbell ..
the 140mm TB was just a figure of Speech.. regarding response you will not have a drop in response. that is the misconception im trying to straighten out..

Quote:

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Originally Posted by Hipowerracing

<snip> usless bullshit<snip>

tinkerbell ..
the 140mm TB was just a figure of Speech.. regarding response you will not have a drop in response. that is the misconception im trying to straighten out..

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o'rly?

i agree, my problem would be the MASSIVE increase in "response" you get going from a 80mm to 140mm TB...

you would only need to breath on the throttle pedal and the revs would climb to the limiter...

again, i'm just pointing this out, as there actually IS a point where BIGGER is not actually BETTER....

I understand that, but still don't agree that bigger is always better. On a race car where WOT is used, yes, it doesn't matter how big it is. But for a street car, where various throttle applications are required, the bigger the better will not be good for driveability.

And as I corrected myself above, a bigger throttle body will in fact give better throttle response at small throttle openings.

wow , this was quick to turn to poor posts. Some are dissing traders/builders , while some backyard guys think they know more. Who cares ? This is a thread about IS 62mm overkill throttle body for X application. And the answer is NO.

i guess we should make a new post regarding enlarged thorttle bodies ey?

why, you will just end up talking apples VS oranges again?

wow~~!! I didnt come to this thread for a while.

now I had learn alot of basic fluid mechanics knowledges n how there r related into engines.

good job man .

thank you very much for sharing :)

Quote:

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Originally Posted by 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

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looks like Spoon mixed up DC2 and DC5 std sizes?

see what all the other B series are? 62mm

see what all the other K series are? 67mm

:thumbsup::thumbsup::thumbsup:

Quote:

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Originally Posted by tinkerbell

looks like Spoon mixed up DC2 and DC5 std sizes?

see what all the other B series are? 62mm

see what all the other K series are? 67mm

:thumbsup::thumbsup::thumbsup:

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thats y....:thumbsup:

so , do u know which is the correct 1 ? :D

B = 62

K = 67

Let's bring this thread back to life.
If my IM is 64mm, is it ok to use 68mm without porting the IM or should i port the IM to match the TB? Because i thought 68mm will be to big.

i got a b18c2 with single stage IM and basic bolt on if that helps

yeah all good mines installed already good to go..

not overkill good mod of course done with other mods to suit

thanks dupac
so what size TB U using, any different using larger TB for DD

imrunning a 62mm TB with skunk2 IM.. once i upgraded them both.. i need to upgrade the intake aswell as running ont he old cai was pretty crap.. didnt seem to be getting enough air!

after that everything was running sweet

62-65mm would be the ideal for b16a.

We currently run 70mm on our b16a....abit to big but thats what we have lying around :S

Quote:

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Originally Posted by fatboyz39

62-65mm would be the ideal for b16a.

We currently run 70mm on our b16a....abit to big but thats what we have lying around :S

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Hey fatboyz39 u dink 68mm would be fine for b18c2 with Skunk2 IM? At the moment my IM is 64mm, u reckon i should port it out to match my TB or leave it

65mm throttle body will be fine.

I am running B16A with I/H/E and skunk2 IM. What I realize Hondata does record 3-4&#37; lower air pressure (map sensor) with 60mm stock throttle body at WOT, >7000rpm. I always have the impression the stock TB is restricting air flow at high rpm...

yeah it does.. nice cheap upgrade.. since the IM is already done.. may aswell go Bigger TB

bump!

soooo broke right now.

so my question is.... what if i went on a 65mm tb using the stock b16a intake mani initially? any gains?or gains from tb won't be realised until i get a mani thats port matched to the tb

car has cams/i/h/e/11:1cr

i reckon upgrade the IM aswell.. esp if ur going 65mm

Quote:

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Originally Posted by dupac->

i reckon upgrade the IM aswell.. esp if ur going 65mm

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what were your gains with both before and after install?

heaps of people here are vouching for it but i wan't to see on a graph the actual gains versus stock and where

i'm skeptical because back in my nissan days doing a lot of testing with guys here and the US.. there were no gains in im/tb.. understandably that was a different engine... i just can't see the fruits of the concepts put forward in this thread yet :)

i havent dyno or even tuned the car yet..

havent gotten to that point yet
lol

Quote:

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Originally Posted by dupac->

i havent dyno or even tuned the car yet..

havent gotten to that point yet
lol

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without the tune, any idle issues?



also my other question is, my current stock tb has the iacv block off plate and coolant bypass.. does it really matter if i get the b16a/b18c2 or ITR tb? i just noticed itr variants cost a bit more and have the iacv built in which i won't use anyway?

70mm here on a b16a

Quote:

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Originally Posted by dsp26

without the tune, any idle issues?



also my other question is, my current stock tb has the iacv block off plate and coolant bypass.. does it really matter if i get the b16a/b18c2 or ITR tb? i just noticed itr variants cost a bit more and have the iacv built in which i won't use anyway?

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i have no issues with the idle at all.. the 62mm isnt overly huge so it seems ok with the skunk im. i got the itr tb.

b18c2 the earlier models have that built in iacv ur talking about.. i know there's been issues with idles and shit like that.. rpm raise n dropping. my mate had exact same issues.

he wasrunning a b18c2 with a older model b18c2 tb with that built in iavc.. now changed it to the same tb that it was meant to be running no issues.
if that makes ssense?



i know a friend is using a 68mm on his itr and has dramas with idle and cold starts.. pain in the ass..

Quote:

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Originally Posted by Benson

70mm here on a b16a

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:thumbsup:

yours/fatboyz setup is what got me intrigued... basically same setup except for CR and IM+TB.... i'm trying to account for the missing 5-7wkw across the rpm band and the 16wkw difference in peak :p

also if yous is 70mm.. what is the ID of the intake mani your using? ITR 64/62mm?

Dupac, what you mean by iacv built onto the b18c2 tb, Do you mean the Fitv?
You guys reckon it should be fine using a 68mm Tb with out porting my IM? IM currently at 64mm.

lol yeah fitv?

i dunno theres something on the older tb's on the b18c2.. that affects the idle

I understand how this all works now after a total of 5hrs continuous research on the physics and why bensons/fatboyz 70mm Tb works with the 64mm ITR IM....


you don't match TB size to IM inlet size.. you match TB size to the plenum volume..... but in their case its working like a taper anyway.. minus maybe some turbulance cause by a flat 'lip' on the IM due to it being smaller than the TB

Quote:

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Originally Posted by MichaelDelaney @TeamIntegra

the low rod ratio of our Tegs already causes the piston speeds to be optimized for cylinder filling during the intake stroke at low-mid rpms. So if you already are having enough suck at low rpms an oversized TB bore will just make that more apparent. But as rpms increase, the time spent in the intake stroke shortens. Our low rod ratio and the pistons speeds away from TDC don't help cylinder filling under these conditions. The low rod ratio engine needs help filling at high rpms from ram air and scavenging. You need good flow speeds out of the IM plenum and down to the head to create the ram air. If the TB is too big, the flow speed dies. Couple that with a shorter fill time and a big TB bore just kills filling at the top rpms where you need it the most for low ets.

This isn't theory. People have theorized it and then shown this theory to be true in real life.

You have to understand how the engine parts work together: rod ratio, cam spec, port size, IM plenum volume and runner dimensions, and TB bore. They are all connected. Each one determines the other's size. They inter-relate. They all center around where your powerband
should be placed along your rpm range.

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