I just got back from my welder's shop. Props are due to Marc at Garland Race Shop in Port Richey. I only had rubber 3 tubes available so please pardon the incompleteness of it. These are NOT the final hoses that will be used, they are my first shot at cutting them from a few months ago. The final product will look cleaner and neater. The hoses will be shorter. This will go on my stock B18C-R motor that recently put down 178whp. The motor will stay stock until I get my cams.
I will not go into my expectations, this thread is just for pics. At least right now. :D
So, without any further ado, here we go.


Hmmm, what happened to the rest of the intake manifold??



Final product, sandblasted clean.


Side shot



A 20 ton press comes in handy !!



Look at those runners, can you see the weld line ??



Looking through 50mm of fury, Gixxer 1000 style !!



Open wide !!!



Trial setup



Final shot

 

 

Do you think it was a good idea to move the location of the injectors?

 

should be fun

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AllMotaEK &raquo;</TD></TR><TR><TD CLASS="quote">Do you think it was a good idea to move the location of the injectors?</TD></TR></TABLE>

Yes, better fuel atomization. More power.

Why get/make ITB's that have stock injector placement? Thats a lost cause right there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RHD DB8 &raquo;</TD></TR><TR><TD CLASS="quote">

Yes, better fuel atomization. More power.

Why get/make ITB's that have stock injector placement? Thats a lost cause right there.</TD></TR></TABLE>

This isn't all true. Utilizing the stock injector placement isn't going to effect performance in a measurable way considering that NEW injector technology is already efficient enough to "atomize" the fuel and provide optimal injector spray patterns. Typically, ITBs would be reserved for engines that had advanced builds and would benefit from the increase velocity of the air and the amount of the air. But, When properly tuned most engines can benefit from ITBs; Some with more measurable gains. Also, fuel will accumulate in the coupling areas of the ITB system and can cause intake backfire...I've seen it happen on my car.

 

Well just for the sake of argument.....

And there has been a lot of that lately every forum I'm actively roaming in/on.....

Just wondering out loud, why is it that many of the aftermarket ITB setups....Toda/Toyota - Jenvey, TWM etc.... insist on placing their injectors in a "GSXR'ish" location?

Sure they do not use rubber couplings, that much is evident, but there must be a valid reason.... wasn't it Bisi that said that even with current modern injectors, he was NOT able to get proper atomization unlike the carbs he prefers? (loosely paraphrased)

In all indications, it seems that the best of both worlds will be the use of a dual bank injector setup....at the price of complexity and budget.

One set in the OEM location at the flange...and another right at the mouth of the horns.....

 

That would be a great setup for a super High comp motor. But, Yeah, Its just with the DIY ITBs that its good to keep them away from the rubber coupling and things like that. But I feel that the newer injector technology is efficient enough to atomize the fuel effectively and I think modifying the location on some injectors may disrupt the flow that is intended for the injector. JMT.
And the thing with Carb'd engines is that the runner walls are rougher then injected engines for the sake of Atomization; (to stir up the air and fuel). The best thing for Fuel injected cars is to have the walls as smooth as possible to allow for great velocity of the air.
The itb setup looks great by the way. I'm going on my second set; bored out.

 

Looks nice, good work.

 

Thanks for all the replies. As for the "rubber couplings", the ones you see are just temporary. When it is all said and done, there will be very little hose that will be seen by the incoming air and fuel. The rims of the manifold and of the ITB's will be nearly touching.

As for my choice re: injector placement. Once I found out that the gixxer injectors could flow enough fuel, I wanted to keep that placement. Like Raging Angel states, there must be a pretty good reason that Toda, Jenvey, TWM, etc. all choose this location. Who am I to disagree with them.

 

tight!

 

Just to bring this back to the top a little....

for the sake of DISCUSSION.

The first time I saw ITBs done like this was when AbaZ posted them up at hmt.com.

He hinted that the rubber couplings that he utilized were done primarily just to mate the flange to the throttle bodies.

How does that differ than what is seen here?

AbaZ ensured that the flange from the intake manifold had sufficient length to join to the ITBs without any gaps or space in between. The rubber coupling/sleeve is used only to keep the ITBs connected to flange.

So unless insufficient tubing off the flange was used, there's no reason why there should be any gaps for the fuel to leak....that or the tubing that is being used is of the wrong inner diameter. This would likely cause the fuel to pool up or even leak out towards the rubber sleeves.

I haven't had a chance to look at bike ITBs up close, but in accordance to how they are assembled, (when done like GSXRs) they too, only use rubber sleeves to keep the ITBs connected to the motor.

 

Are you sure about diameter, 50 mm !!! His that the diameter at the throttle plate? I know that Hayabusa are 46mm at the plate..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nathan atwell &raquo;</TD></TR><TR><TD CLASS="quote">

This isn't all true. Utilizing the stock injector placement isn't going to effect performance in a measurable way considering that NEW injector technology is already efficient enough to "atomize" the fuel and provide optimal injector spray patterns. Typically, ITBs would be reserved for engines that had advanced builds and would benefit from the increase velocity of the air and the amount of the air. But, When properly tuned most engines can benefit from ITBs; Some with more measurable gains. Also, fuel will accumulate in the coupling areas of the ITB system and can cause intake backfire...I've seen it happen on my car.</TD></TR></TABLE>


Really? I would like to see a comparison.

As far as I've seen from experience, higher injector placement makes more power (hp/tq) throughout the powerband.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by titebast &raquo;</TD></TR><TR><TD CLASS="quote">Are you sure about diameter, 50 mm !!! His that the diameter at the throttle plate? I know that Hayabusa are 46mm at the plate.. </TD></TR></TABLE>


I doubt they're 50mm @ the plate.

Hayabusa's are about 48mm I believe.

 

They're only 50mm at the opening. I titled the pic to match the camera shot. They taper to 42mm at the other end. I have no measurement at the throttle plates.

 

very hot gl with it

 

well i feel you going to lose power cuz them injectors are too far. they look about 4" away but thats what i think but i guss will find out when u get it dyno

 

The only way to see which injector placement is better is to dyno, dyno, dyno. However, placing the injector high in the stack could promote better atomization. A downside to having the injector high in the stack would be fuel puddling. When the injector fires fuel will get stuck to the wall which will in turn create a leaner mixture. If you are using the hose couplings I wouldn't even try to put the injector high in the stack. The seperation of the throttlebodies and the flange would terribly disrupt the atomization of the fuel and create even larger fuel puddles. These fuel puddles could definitely lead to an intake backfire and hurt all that you worked so hard for. IMHO I feel that injectors in the stock location are the most reliable.

 

For those that missed what was previously stated:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NXSpoon &raquo;</TD></TR><TR><TD CLASS="quote">As for the "rubber couplings", the ones you see are just temporary. When it is all said and done, there will be very little hose that will be seen by the incoming air and fuel. The rims of the manifold and of the ITB's will be nearly touching.
</TD></TR></TABLE>

 

But there will still be a gap. The incoming fuel will find any gap and possibly puddle and create uneven cylinder fuel mixtures. You'll just have to find out for yourself on a dyno. Why not just get the 2 halfs welded and ported so there are no seams?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by msmotorsports &raquo;</TD></TR><TR><TD CLASS="quote">But there will still be a gap. The incoming fuel will find any gap and possibly puddle and create uneven cylinder fuel mixtures. You'll just have to find out for yourself on a dyno. Why not just get the 2 halfs welded and ported so there are no seams?</TD></TR></TABLE>

Yes, for the sake of argument there will still be a gap. And this concept is by no means a new one. Has anyone heard about such an occurrance happening before?? Many people have done this before me, I am not breaking any new ground here. I have yet to read a thread about someone suffering a devastating backfire on their homemade ITB's. It's not like I'll be dumping a shitload of fuel in there, the injectors are only ~270cc. So, like everyone before me I will be taking a chance with this occurrance.

As for welding the 2 parts welded together; the heat from welding will more than likely warp the butterflies. This seems to be the general consensus. Even my welder was VERY reluctant to try it.


Modified by NXSpoon at 12:48 AM 12/8/2004

 

keep in mind most HMitb's use factory injector location<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NXSpoon &raquo;</TD></TR><TR><TD CLASS="quote">

Yes, for the sake of argument there will still be a gap. And this concept is by no means a new one. Has anyone heard about such an occurrance happening before?? Many people have done this before me, I am not breaking any new ground here. I have yet to read a thread about someone suffering a devastating backfire on their homemade ITB's. It's not like I'll be dumping a shitload of fuel in there, the injectors are only ~270cc. So, like everyone before me I will be taking a chance with this occurrance.

As for welding the 2 parts welded together; the heat from welding will more than likely warp the butterflies. This seems to be the general consensus. Even my welder was VERY reluctant to try it.


Modified by NXSpoon at 12:48 AM 12/8/2004</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by msmotorsports &raquo;</TD></TR><TR><TD CLASS="quote">But there will still be a gap. The incoming fuel will find any gap and possibly puddle and create uneven cylinder fuel mixtures. You'll just have to find out for yourself on a dyno. Why not just get the 2 halfs welded and ported so there are no seams?</TD></TR></TABLE>

This theory seems reasonable, but the only thing that flaws this theory is the fact that motorcycles themselves use this type of mating between the ITB assembly and the head and/or flange.

The theory says that if there is any sort of "hose" being used as any segment of a runner in the air/fuel intake stream, there is chances of fuel accumulation or "puddling" and will consequently cause uneven A/F mixtures across all cylinders and/or worst case a back-fire type situation.

If this was truely a possibility, how could all these sport bikes get away with mating ITB's to the head using similar "DIY" techniques and principles?

 

Nice job is this the first time you have done this if so good first try nice !!!!