Throttle Body Bored

[kimo]

Have read that in Jazz Fourm. Has anyone done it before




Just recent installed a new throttle body which is bored front and back for better airflow. This is technically and supposed to be 'better' than the Spoon version as it has a larger diameter both front an back. The diameter is enhanced 3mm on both sides. Giving it a 48mm instead of the stock 45mm diameter.

Field Report :
The ride difference after the installation is instantaneous. Super The greatest gain is during the pick up. The car needs only an extreme light throttle to move off, which means, the car has gain some torque at low end and needing less fuel to pull the car on start.

For mid-end power from 2000 to 3000RPM, the car is more willing to pull to higher RPM faster while on the move. Thus, although there is no dyno test done on the ride as yet, it seems to have gain some consistent power across the band, with the most noticeable gain at the lower end.

Fuel Consumption:
As there is a more efficient air flow, I would reckon the car would possibly drink a little more fuel if I were to maintain my current driving pattern. Thus, as discussed with Julian, it is better to adapt to a light throttle driving as the ride is able to pull itself with less fuel. Thus, the ultimate fuel consumption will depend greatly on the driving pattern (As highlighted many times in this forum). If a light throttle driving pattern is to maintain, the FC is likely to improve.

Damage to the pocket:
This mod costs slightly above $300. Considering the power gains across all bands and it is relatively significant, I would say that cost/Horse Power increase is well worth the investment.

A simply diagnostic check to ensure that the general functions of the car is functioning. No faults were detected. The slow idling rate was also adjusted so that it remains the same at stock, ensuring that no additional fuel is burnt unnecesasry while at stationary.

[edw-R]

That's cool. What do you mean "3mm on bolt side"?

[fried]

That's cool. What do you mean "3mm on bolt side"?

BOTH sides.

3mm bore on intake side, and 3mm bore on intake manifold side.

[kimo]

Correct, it's even done better than Spoon where only 1 side at the intake side.

[fried]

Correct, it's even done better than Spoon where only 1 side at the intake side.

acually - i have a feeling spoon would only modify the intake side to match an aftermarket intake. i dont think there are aftermarket intake manifolds avaible for the jazz, which is why spoon have not bored out the intakemanifold side.

instead - spoon have probably made a big bore intake side, tappered to a slightly smaller bore butterfly and intake manifold side opening.

atm - ur 48mm bore is possibly trying to push a certain capacity of air into a 45mm opening in the intake manifold - and subsequently hitting the outer edges, and not flowing at its best velocity because of this.

i say "possibly" because i am not aware of the size of the intake manifold opening on ur jazz IM. i only suggest that spoon have put alot of time/money/research into finding out whats best for their honda engines. :thumbsup:

but still a great mod :thumbsup:

[asiansquad]

got any pics of it?

[edw-R]

acually - i have a feeling spoon would only modify the intake side to match an aftermarket intake. i dont think there are aftermarket intake manifolds avaible for the jazz, which is why spoon have not bored out the intakemanifold side.

instead - spoon have probably made a big bore intake side, tappered to a slightly smaller bore butterfly and intake manifold side opening.

atm - ur 48mm bore is possibly trying to push a certain capacity of air into a 45mm opening in the intake manifold - and subsequently hitting the outer edges, and not flowing at its best velocity because of this.

i say "possibly" because i am not aware of the size of the intake manifold opening on ur jazz IM. i only suggest that spoon have put alot of time/money/research into finding out whats best for their honda engines. :thumbsup:

but still a great mod :thumbsup:

Agree with you!!:thumbsup:

[kimo]

Check this link for pictures

http://forum.sg-fit-jazz.com/viewtopic.php?t=8902&start=0

[TypeG]

Also a spoon TB cost around $3XX-400 only

[kimo]

The above cost the same.


Also a spoon TB cost around $3XX-400 only

[panda]

nice mod!

[TypeG]

The above cost the same.

but it is from spoon which has done a lot of investigation and research plus u got a stock TB still when u want to turn back to stock (for some reason)

not saying your one is bad but just a bit pricy imo

[STTICH]

Also a spoon TB cost around $3XX-400 only


dont they cost a bit more ?

[spoon fit]

i got mine for $4xx

[TypeG]

u lier sunny
lol
can get one at around $3XX

[spoon fit]

yes, danny got it for $3xx

[STTICH]

damn.. great price guys :thumbsup:

[Jazzle]

so what gain u guys got with the spoon TB?

[muli]

why dont ppl bother dyno their car, only ppl i can think that have dynoed their cars is me and jus-10.

[GSI-PSI]

so im guessing youve gained 1kw from ya honds spazz?

[TypeG]

so im guessing youve gained 1kw from ya honds spazz?

is 1 kw a gain?

[muli]

so im guessing youve gained 1kw from ya honds spazz?

whats a spazz, some spastic spelling skills there?

[kimo]

So what is the gain, it it worth the money

[Jazzle]

well.. i guess it's more a gain in driving feel than just power gain?? coz $3xx is abit too much for 1kw gain isn't it?

[Jus-10]

Doing the TB and to get the max gain out of it you need to take care of the entire intake/exhuast setup (so new intake, extractors and full exhaust).

After you have done those do the TB....then get it tuned. Otherwise it's probably not really worth doing at all.

[kimo]

can't we install a bigger TB from another Honda

[pillow]

why dont ppl bother dyno their car, only ppl i can think that have dynoed their cars is me and jus-10.

Out of interest, what did you (or Jus-10) make on the dyno?

[Jus-10]

mmmm from memory i got about 74-75 at the wheels

[muli]

i got just over 66kw at wheels with intake and muffler. Stocko it was just ova 60kw

[Jus-10]

Really??? What dyno was that on (brand)? It's a fairly significant difference to my results.

With just an exhaust on mine (everything else stock) it was making about the 67-68 mark.

We need to get more peeps on the dyno

[pillow]

mmmm from memory i got about 74-75 at the wheels

That's pretty decent. What size motor's are in the Jazz? 1.5?

[Jus-10]

Both me and Muli have the 1.5

[muli]

jus-10 is pretty impressive considering the original pumps out 81kw at the engine

[kimo]

Check this out:

http://www.sg-fit-jazz.com/spoontb.htm

[tinkerbell]

Field Report :
The ride difference after the installation is instantaneous. Super The greatest gain is during the pick up. The car needs only an extreme light throttle to move off, which means, the car has gain some torque at low end and needing less fuel to pull the car on start.


no it does not.

it means that you are letting more air in for less throttle input.

it means you have gained nothing but a quicker opening throttle which opens the throttle plate a % more than you did before.

ie - the only benefit of this mod on a stock engine is it *feels* faster.

sorry, but this is reality.

[fwyn]

feels? i dun think its feel faster. it is definitely faster. more air in, even on a stock engine. its the same as changing to pod filter, more air. so sucking in more air doesnt make the car go faster but only *feel* faster? more air and more fuel, as always in any car mods


no it does not.

it means that you are letting more air in for less throttle input.

it means you have gained nothing but a quicker opening throttle which opens the throttle plate a % more than you did before.

ie - the only benefit of this mod on a stock engine is it *feels* faster.

sorry, but this is reality.

[tinkerbell]

you cant compare apples to oranges.

so can you explain what effect installing a single 75mm throttle body would create?

as you say, more air and more fuel = more power?

[tinkerbell]

further - if you could explain why spoon throttle body leaves the stock IM side bore size and only polishes and tapers the air filter side, ie no increase in air flow volume

that would be great too.

[fwyn]

why dun u just explain? i m not here to create arguments, all i know is i have changed the TB on my car. it doesnt *feel* faster. in fact, it is faster. there might b no increase in the qty of the air volume, but wat abt the faster rate of volume of air being suck in?

[tinkerbell]

so which TB have you installed?

the spoon one?

or another one?

[TypeG]

i agree with tinkerbell too
u let more air in, no matter a pod or a bigger TB, the car itself may not require so MUCH air to run it. furthermore, u got A LOT MORE air IN but there is no bigger header or catback exhuast to let those air OUT.

[muli]

you people seriously argue about the lamest shit hey. Say the standard airbox is restrictive and you put a custom air-intake, now who says the exhaust system isnt going to be able to cope with pushing more air out, maybe it might not be as restrictive as the intake system?

[tinkerbell]

i agree with tinkerbell too
u let more air in, no matter a pod or a bigger TB, the car itself may not require so MUCH air to run it. furthermore, u got A LOT MORE air IN but there is no bigger header or catback exhuast to let those air OUT.

kind of,

my point in relation to throttle body size increase is that by increasing the size of the hole that the air flows through only increases the amount of air that flows through as a proportion of the throttle plate opening.

for example:

PRIOR to TB increase:

10% throttle = 10% air
30% throttle = 30% air
50% throttle = 50% air
70% throttle = 70% air
90% throttle = 90% air
100% throttle = 100% air

AFTER TB increase:

10% throttle = 15% air
30% throttle = 40% air
50% throttle = 65% air
70% throttle = 85% air
90% throttle = 100% air
100% throttle = 110% air

so at 90% throttle you are at what you were previously at at 100% throttle

the fact that the engine cannot use the 110% air opening at 100% throttle due to the rest of the air path being restrictive, means that unless you have a really free flowing system, with larger cam opening times and better "breathability" then

all the larger throttle body does is create an *illusion* of more power,

simply because you are letting more air in earlier...

does this make sense?

again, i ask - why not just use a 75mm TB?

or alternatively, i could ask - why is the JDM B18C Integra Type R throttle body ONLY 2mm larger then the B16A2 throttle body (which is abt 1.5% size increase)?

and these engines are very different in terms of output - 118kW vs 147kw?

[fadz]

peepz, thers a slight power gain,apart from that...ur vtec will roar twice as hard, with a bigger throttle. but ye for greater results once u do change ur throttle , tune ur ecu.

[fwyn]

so which TB have you installed?

the spoon one?

or another one?

spoon....

[fwyn]

you should see the whole mod as a package. every mod is there for a reason. no matter wat there will b slight improvement, more or less depending on each part. like wat u said, so now u have all the outflow done from header to muffler yet u use stock air box, the car may not require so MUCH flow to let it go through. now my question is, after you change all the outflow system and stick to the oem air box, is the performance of your car increased?


i agree with tinkerbell too
u let more air in, no matter a pod or a bigger TB, the car itself may not require so MUCH air to run it. furthermore, u got A LOT MORE air IN but there is no bigger header or catback exhuast to let those air OUT.

[fwyn]

your point is definitely correct. now after changing the TB (of cos with suitable size increase), when you press 10% throttle it is sucking in X% more inflow of air. theoritically, you save time. your car does go faster.

as to y dun use 75mm TB its the same as y dun use 5" pipe for our car. i m sure too much air rushing in and out of the system will cause lag. manufacturers of TB as well as exhaust system all know this. does TB increase hp? i would say no. does it make the car goes faster? by timing the second, yes it does.


kind of,

my point in relation to throttle body size increase is that by increasing the size of the hole that the air flows through only increases the amount of air that flows through as a proportion of the throttle plate opening.

for example:

PRIOR to TB increase:

10% throttle = 10% air
30% throttle = 30% air
50% throttle = 50% air
70% throttle = 70% air
90% throttle = 90% air
100% throttle = 100% air

AFTER TB increase:

10% throttle = 15% air
30% throttle = 40% air
50% throttle = 65% air
70% throttle = 85% air
90% throttle = 100% air
100% throttle = 110% air

so at 90% throttle you are at what you were previously at at 100% throttle

the fact that the engine cannot use the 110% air opening at 100% throttle due to the rest of the air path being restrictive, means that unless you have a really free flowing system, with larger cam opening times and better "breathability" then

all the larger throttle body does is create an *illusion* of more power,

simply because you are letting more air in earlier...

does this make sense?

again, i ask - why not just use a 75mm TB?

or alternatively, i could ask - why is the JDM B18C Integra Type R throttle body ONLY 2mm larger then the B16A2 throttle body (which is abt 1.5% size increase)?

and these engines are very different in terms of output - 118kW vs 147kw?

[tinkerbell]

spoon....

well, my comments are not related to the Spoon item at all, as the Spoon item retains the OEM internal diameter, however - it improves the flow quality through a taper - which is technically known as a 'Venturi' effect

my comments are all in relation to the original post which claimed a gain in torque by using an 3mm "overbored" throttle body.

as i said - careful to compare apples to apples, not apples to oranges ;)

[tinkerbell]

you should see the whole mod as a package. every mod is there for a reason.

exactly, the system is only as good as the weakest part,

not as stong as it's biggest part :thumbsup:

*balance* is the key :)

[fwyn]

well, my comments are not related to the Spoon item at all, as the Spoon item retains the OEM internal diameter, however - it improves the flow quality through a taper - which is technically known as a 'Venturi' effect

my comments are all in relation to the original post which claimed a gain in torque by using an 3mm "overbored" throttle body.

as i said - careful to compare apples to apples, not apples to oranges ;)

ok.... :thumbsup:

[tinkerbell]

so why not just install a 75mm throttle body and then reset the ecu?