GSXR ITBs on a b230?

[pinguin]

Would they work, or would they not be able to flow enough, of course this is assuming I can mount them etc...

[Mueller]

one would think they are large enough...however, you could do some homework and find out what size they are !!!!

the ninja tb's I had are 45mm each and would have been fine these motors...

[BB-Q]

Just look and see how much power they can support on a Gixer. If it's enough for your needs then yes, they're big enough.

If you do fit them please bear in mind tha the reason that most bike throttle bodies fail to work correctly is because they usually have to be spaced out a bit for the larger motors and doing so normally screws up the prescision and adjustability of them.

[245gti]

I've seen this information quoted more than once...

What is the best throttle body diameter?
Factors influencing size are; Power output, RPM, cylinder head design, cylinder capacity, position of the throttle body in the inlet tract and position of the injector.

Choice of bore size is a balanced compromise resulting from the following;
1) A larger bore leads to lower flow resistance, but obeying the laws of diminishing returns.
2) A smaller bore leads to better throttle control and response (never underestimate) and improved fuel mixing.
3) The system should be considered in total - from (at least) trumpet flange to cylinder and proportioned accordingly.

Basic references for BHP per cylinder, assuming ca 120mm from butterfly to valve head and a max of 9,000 rpm are;
Up to 30 - 30mm, up to 33 - 32mm, up to 39 - 35mm, up to 46 - 38mm, up to 51 - 40mm, up to 56 - 42mm
Up to 65 - 45mm, up to 74 - 48mm, up to 80 - 50mm, up to 87 - 52mm, up to 93 - 54mm.
These power figures may be increased by up to 10% in a purpose - designed and well proportioned system.
As butterfly to valve distance increases, butterfly size will need to increase in proportion to system taper and vice versa.
Lower revving engines and those with injectors placed before the butterfly will generally accept a larger body.

So...depending on your hp aspirations, they may or may not be big enough...

[MikeHardy]

So assuming there 45mm as long as he only want 260hp na he'll be ok haha

[Dauntless]

Great info, thanks Dale.

[MikeHardy]

oh you thinking something like this



960's are purrfect for something like this, there head mounted part of the manifold is already set up for bike throttle bodies with rubber hose fittings and it's own dedicated fuel rail

Originally Posted by ravennexus

960's are purrfect for something like this, there head mounted part of the manifold is already set up for bike throttle bodies with rubber hose fittings and it's own dedicated fuel rail

ooooooooooooooooooooooooooh

[MikeHardy]

Originally Posted by pooprah

ooooooooooooooooooooooooooh

you never noticed, first thing i thought of when i pulled a 960 manifold off.

look, 6 nice round ports that the manifold mounts with 2" sections of rubber hose, plus injector holes in the manifold so you don't need to use the bike throttle body fuel rails, port spacing is fairly bikeesque being to

i thought of tenticles wagon and pics of it when you reminded me

[Gabe244]

Reckon K-jet would be able to keep up with the throttle response?

[thelostartof]

Originally Posted by ravennexus

So assuming there 45mm as long as he only want 260hp na he'll be ok haha

which is around 520+hp boosted?

[Spac]

Originally Posted by BB-Q

Just look and see how much power they can support on a Gixer. If it's enough for your needs then yes, they're big enough.

Yes and no. The required size of a TB in an ITB set up is determined by the volume of the cylinder and the maximum revs - but the TB size in relation to revs is non-linear.

Eg: If the Suzuki is 1000cc and revs to 15k, and you want to fit those TBs to to a 2000cc car engine that revs to 7500rpm, then the TBs will probably be considerably larger than is needed.

[Tom Wiley]

Originally Posted by Spac

Yes and no. The required size of a TB in an ITB set up is determined by the volume of the cylinder and the maximum revs - but the TB size in relation to revs is non-linear.

Eg: If the Suzuki is 1000cc and revs to 15k, and you want to fit those TBs to to a 2000cc car engine that revs to 7500rpm, then the TBs will probably be considerably larger than is needed.

Because of intake velocity?

[dbh86]

Yes. They work.

Easy way to figure it out: Look at how much air the bike is moving. Compare to how much air you will be moving.

[Falcone]

check with Johann on vs, here's a link to his 850 n/a build where he uses itb's with great results. http://volvospeed.com/vs_forum/index...4&#entry856064

As far as not giving enough flow, the famous 850 BTCC racecar had itb's


Kind of looks like the set-up used in the link



If you have the funds and the resources definitly do it
Mike

[Mueller]

Originally Posted by Ktown_Brick

check with Johann on vs, here's a link to his 850 n/a build where he uses itb's with great results.

If you have the funds and the resources definitly do it
Mike

that manifold is insane, made from a solid billet, thought it was cast !!!!!
wonder how long it took to machine?? yea for CNC !!!!

[The Aspirator]

That manifold is seriously cool stuff.

[BB-Q]

Originally Posted by Spac

Yes and no. The required size of a TB in an ITB set up is determined by the volume of the cylinder and the maximum revs - but the TB size in relation to revs is non-linear.

Eg: If the Suzuki is 1000cc and revs to 15k, and you want to fit those TBs to to a 2000cc car engine that revs to 7500rpm, then the TBs will probably be considerably larger than is needed.

In my statement I assumed that we were talking about 4 cylinder engines. That being the case then the rpm isn't too important (without going to extremes, where low rpm airspeed could be a problem). What is important is airflow. Let's assume that the two different engines have similar VE at their similar maximum power outputs- tell me again why it wouldn't work?

An engine is a fixed displacement pump (forget turbos for a minute- they were not being discussed here).

All things being equal (such as cams etc as you have made a blanket statement to that effect), the 1000cc engine at 15000rppm will pump the same amount of air to make the same amount of power as the 2000cc engine at 7500rpm.

[Mueller]

Originally Posted by BB-Q

In my statement I assumed that we were talking about 4 cylinder engines. That being the case then the rpm isn't too important (without going to extremes, where low rpm airspeed could be a problem). What is important is airflow. Let's assume that the two different engines have similar VE at their similar maximum power outputs- tell me again why it wouldn't work?

An engine is a fixed displacement pump (forget turbos for a minute- they were not being discussed here).

All things being equal (such as cams etc as you have made a blanket statement to that effect), the 1000cc engine at 15000rppm will pump the same amount of air to make the same amount of power as the 2000cc engine at 7500rpm.

ummm, you said the same exact thing as Spac....just worded it differently

[BB-Q]

In which case he pointed out nothing. And my point still stands.

(plus- I've been looking for any excuse to use that gif....)

[volvorsport]

guys , that manifold uses jenvey stuff , and is in fact cast by jenvey .

ive had one in my hands , i think below 45mm , or even 42mm your wasting your time with bike ITBs . being able to rev to 15krpm is why they make there power .

http://homepage.ntlworld.com/mj.slater2/101_0120.JPG

[Mueller]

Originally Posted by volvorsport

guys , that manifold uses jenvey stuff , and is in fact cast by jenvey .

ive had one in my hands , i think below 45mm , or even 42mm your wasting your time with bike ITBs . being able to rev to 15krpm is why they make there power .

http://homepage.ntlworld.com/mj.slater2/101_0120.JPG

looked milled from a solid billet....unless this is a really nice cast part being machined down to size...

[Spac]

Manifold on the car looks like a nice casting.
Would seem odd to remove the 'bling' finish from a CNC'd part.

BBQ, you're overlooking the fact that an engine is not a continuous pump - rather, it draws air in in pulses. Those pulses become more like gasps as the revs rise, which greatly alters the peak air flow required.
You'll notice that 245GTi's example specified a certain, constant rev limit. This is so the non-lineararity that I mentioned can be ignored.
If you wish to be pedantic, then yes, the VE matters and VE is affected by a huge range of things that may or may not cancel each other out in certain circumstances, but my basic point still has more influence on the big picture than any of that.*

Similarly, a Wankel rotary engine can produce a heap of power through a single 2bbl 48mm carby - far more than a 4 cylinder possibly could through the same carburettor. This is because the rotary inhales in a much steadier, (relatively) continuous breath, without the 'gasps'.

I guess the simple analogy is for you to try breathing through a drinking straw. Assuming you're in a calm, non-active state, the straw will flow just enough air to allow you to breath without too much discomfort.
If you actually try this, you will quickly find that you will be most comfortable breathing slowly and deeply, rather than in fast, sharp intakes and expulsions.
I'm sure you can see correlation between the two techniques of breathing and the lager/lower revving motor, and the smaller/higher revving motor.

If we were talking about a using TBs from a 2000cc engine that revs to 7000rpm, and fitting them to a 2300cc engine that revs to 6500, blanket statements like yours would be a fair-enough approximation.
However, we're talking about TBs from a 1300cc (or smaller) engine that revs to 13000rpm (or more), being fitted to that relatively low revving 2300cc motor - so your blanket statement was misleading.

If you want, I'm sure you can easily find any quantity of published data showing exactly what I'm saying.

*I can keep beefing out this disclaimer if you really want to argue the point, but let's just assume that we're talking about one throat per cylinder, on an engine without any dramatic flaws, and with an eye on performance.