Some intake manifold comparison pics: http://www.slebidia.addr.com/images/intakes/

I hope to actually get a decent work area setup soon so I can fab up a few ZC and SOHC manifolds.

 

il add this to the mix 8)

http://www.homemadeturbo.com/forum/index.php?board=1;action=display;threadid=13687

 

Sweet. I was thinking you could chop up a OBX IM. :lol: The runners are long enough and straight enough. Great info oldschool.

 

few more pics and info here

http://www.homemadeturbo.com/forum/index.php?board=1;action=display;threadid=14730

 

good info here

http://www.honda-tech.com/zerothread?id=303926

and here
http://www.honda-tech.com/zerothread?id=260670

 

Sweet. I was thinking you could chop up a OBX IM. :lol:

i actually thought the EXACT same think last week :shock:

 

It looks as if the runners are stright enough that they would meet the TB's without too much modification. Turn a shitty IM into a decent one.lol

 

any progress guys?

 

mine should be in the mail anytime now

 

i got them in the mail on friday. Mine are smaller than what most people use. i have the 600 itbs which are 38mm. the newer 954cbr uses 42mm itbs. The 600f4i still uses 4 nozles per injector but i have no idea how much they flow :? . Hope fully my small itb equals more streetabilty and it will be easier to tune. BUT, my motor is still disassembled so i am a long way off :!:

 

we'll see how streetable my ITB's are, give me about one month. they'll be done then and the weather will hopefully be a lil' better here in michigan

 

Here is my project ... it is about halfway completed. The ITB's will evetually go onto my current motor which is a built 12:1 D16Z6 motor, in my 93 Civic Si

About 3-4 months ago I picked up a set of Honda CBR 929 ITB's off Ebay. I choose the Honda ITB's over Gxer or similar ITB's since the Sensors on the CBR929 ITBs are plug and play with the my engine harness (TPS, Injectors, IAT). At the Same time I picked a set of airhorns from an old-school VW.

Once I got the ITB's in I compared the bore spacing of the ITB'd to a Stock D16Z6 Intake Manifold ... and it is very close.

Once I determined that a OE Z6 IM would work I took the ITB's and the Z6 IM to a local Fabricator .... Graeme at Canadian Cylinder Head to fabricate an manifold to adapt the ITB's to a D16Z6 head. Because the CBR ITB's are attached to the CBR head with rubber couplers, there is 2" flanges already on ITB's so the D16Z6 IM only needs some 2" alunimum flanges shaped and welded into place and some 2" silicon couplers to join the ITB's to the Manifold. He cut, shaped, welded, and ground the 2" alunimum tubing to match the oval intake ports and to match round exit ports where the ITB;s mount. This week I got the new custom adaptor back from Graeme, it is a work of art.

Because the VW airhorns do not have the right mounting flanges to attach them to the CBR I need to fabricate some new flanges. So I took the Stock CBR Airbox and cut the old flanges out of the box

and them I trimed the flanges down

http://www.redpepperracing.com/gallery/d/94514-5/aah.jpgimg]

and then I inserted the airhorns into the flanges ... ultimately I will silicone them into the flange

[img]http://www.redpepperracing.com/gallery/d/94517-5/aai.jpg

Once I figured out the air-horn mounting ....I then mocked up the entire ITB setup on a spare head to see if there is any issues

Here is a 3/4 view

And a side view

So now I am in the process of figuring out the vacuum and coolant routing, and what I am going to do with the Injectors. I have three choices, Highflow CBR inj from RC, Modified Prelude injectors in the stock CBR location, or Prelude injectors in the Z6 stock location.

Once that is done ... the tunning becomes the issue. I think i may have resolved the low vacuum issue and how it impacts tunning and the A/F maps. A local tuner is building a custom re-curved Map sensor (he builds Turbo Maps) for low vacuum situations. This hopefully will allow me to tune properly using Hondata, with out having to resort to TPS only tunning below 5k. But this is a couple of months away ...

FYI Here is a link to a bunch of pictures of the ITB project

http://www.redpepperracing.com/gallery/v/moose/CBR-929-ITB-project/


Cheers

Moose

 

redzcstandardhatch
ITB setup pics/movies
http://dserieshonda.com/modules.php?name=Forums&file=viewtopic&t=182

http://d-series.org/viewtopic.php?p=40929
redzcstandardhatch's itb project.

first off, let me say that this is copied from a post i did on honda-tech, so you might have seen it.....i'm posting it because some people have asked for pics and figured you'd all enjoy them because its a d-series (kinda, it on the bastard dohc zc.....i love those motors)

"ok, i finally finished my homemade ITB setup for my worked over dohc zc. the engine has a mildly built/milled head and exospeed stage 2 cams. the ITB's are cbr 954 units. the velocity stacks are OLD school weber billet stainless pieces, i torched them a bit to get a differnt effect. all the aluminum plates show are one-off cnc machined by my brother on his cnc machine (check out his website for his products, http://www.nightmarechassis.com ). thanks for takin a look, i'll post a movie soon when i get it running (currently missing the header, i'm re-designing it, should be done welding it up by next week). have a good day everybody"

http://www.staticmethod.net/itb/index.html

http://www.ef-honda.com/main/viewtopic.php?t=1846

 

nice work man. very cool manifold.

 

nice work man. very cool manifold.

speaking of manifolds and spacing, those with CBR throttle bodies, have you noticed that they are in fact two twin bodies bolted together. my 929RR came in today and i took them partially apart. one could use spacers or washers to move the two halves more apart, making the fitting almost OEM. i shall try that as i continue taking it apart. (gotta love 2001 parts, bolts and nuts break loose easily).

on the unrelated note, what is that idle control looking valve next to the idle screw?
Stan

 

Ya, I did notice that they were a pair of TB'S ... but I wanted to retain the OE configuration of Linkages, etc ... I was fabricationg a manifold ... to make a manifold that flared out slightly to mate with the CBR TB's was not an issue ... In my eyes it was the least evil of the two alternatives

The Idle valve thingy beside the idle adjuster is a "Wax" cold idle valve.

Cheers

Moose

 

ok, i am interested in this project. It all looks very well done. I have a few questions.

How are you gonna control idle with this setup?
Where would the IACV go?
Where would you mount the map sensor?

Also, i have a recomendation about the injectors. Now, remember i have never attempted to make ITBs before so this is just a recomendation.
I have ported and polished alot of heads before, and from experience i found that if you leave the intake ports rough, you make more power. The reason behind this is because the roughness couses turbelance and does not allow the fuel to stick to the port. Now where i am going with this is that if you position the injectors on the throttle bodies, the fuel will enter the port pretty far from the combustion chamber, giving it more time to stick to the walls. This in turn will lead to less power. Even if the fuel end up pooling up and making it to the chamber, it will not be good because it combusts best as a mist .

 

Sorry guys, someone came through and deleted a few of the original posts. I re-pasted most of it. I keep a duplicate just in case. Let me know if i missed anything.

 

AudioMan ...

ok, i am interested in this project. It all looks very well done. I have a few questions.

How are you gonna control idle with this setup?
Where would the IACV go?
Where would you mount the map sensor?

Also, i have a recomendation about the injectors. Now, remember i have never attempted to make ITBs before so this is just a recomendation.
I have ported and polished alot of heads before, and from experience i found that if you leave the intake ports rough, you make more power. The reason behind this is because the roughness couses turbelance and does not allow the fuel to stick to the port. Now where i am going with this is that if you position the injectors on the throttle bodies, the fuel will enter the port pretty far from the combustion chamber, giving it more time to stick to the walls. This in turn will lead to less power. Even if the fuel end up pooling up and making it to the chamber, it will not be good because it combusts best as a mist .

Idle is controlled by the throttle linkages ... the idle adjuster (the shaft sticking up away from the camera) "pre-tensions" the linkage, cracking the throttle open just enough to idle.

Because there is no plenum ... there is no easy way to control idle by allowing more bleed air in (via the idle air motor) to raise idle under ECU control. As a result the IACV becomes redundant, it is left hooked up just to keep the ecu happy ...


Map sensor, You willl notice a bunch of vacuum lines runing from each of the TB's ... one from each TB is tee-ed together which then feeds the MAP and the Brake booster, two other vacuum lines from cyl 1&4 feed the FPR.

Injectors ... YUP I know about the finish required on heads ... I have done a couple myself. The Current head has a 60/80 grit finish on th intake side, to help keep the fuel in suspension. I will also put a 60/80 grit finish on the Manifold as well as gasket match the manifold to the head. The ITB's step down into the Manifold, and the manifold steps into the head.(bit of anti-reversion). The head also decreses in size from the ports to the valves pretty susbstantially (I did NOT hog out the ports after port-matching, just tapered them.)

All of these things SHOULD help keep the AF mixture swirling and off the walls.


Good point on the Injector placement ... but I think the Big problem with ITB's is that there is not much space (short small runners) to help the Fuel atomise and to mix well before it hits the combustion chamber. As a result IB manufacturers typically need to put the injectors as far up the runners as possible to help the fuel mix properly.

Also the the CBR-929 injectors use 4 orifices in the injector to spray the fuel in a more diffuse/fine spray to help atomisation. Sooo I think the wall finish is going to be vital to keep the mixture off the walls.



Cheers

Moose

 

wow, you actually answered all my questions fully. Very much appreciated. I am still very interested. You sound like you researched this alot. I just started today. I did notice that the manufactures do keep the injectors near the butterfly, and now i understand the reason.
Just wondering, what size injectors does the 929 have? i have installed a few ITBs (like 2 of them), but i never payed much attention to their design. mainly because i am not much of a n/a guy, i like boost.

Let all of us know how it turns out.

 

Have you ever considered drilling air bleed holes in the throttle plates. Some carbs use to use them to control idle. Not sure if it would work though on fuel injection.

 

AudioMan ...

I have NO idea what size the CBR injectors are ... I have this VERY question out on various car and bike boards ... with no definitive answer.

I really need to know this as 240cc is about the minimum I can run with my setup without resorting to way high Fuel pressure or big injector duty cycles

I plan to take the 929 injectors out and get them flowed in the next week or so ....I will know for sure WHAT there flow rating is....

There is a BUNCH of threads on HondaTech on ITB's ... there is a bunc-o-information out there .. finding can be a bitch though

HondaDog ... no I have not considered controlling idle in that way ... the current system works well for the CBR .. why F**k with it How-ever I have thought about moving the vacuum pickup points to original Z6 injector locations (epoxying in new vacuum nipples) and using the IACV to feed "bleed" air into the runners (via the ITB vacuum points) to increase idle under ECU control.

Cheers

Moose

 

It sounds like you been thinking on this one long and hard. much respect. I think your solution will work well. I think the cbr's inj holes would be better, but you are more knowledgable than I am at this.

 

Some intake manifold comparison pics: http://www.slebidia.addr.com/images/intakes/

I hope to actually get a decent work area setup soon so I can fab up a few ZC and SOHC manifolds.

the A6 intake is the best one to use we ported and polished one and ran it on our flow bench and it was beter then any of the outher intakes that you have on your list by far :shock:

 

as for the injector sizing i was thinking about it for a while and here is what i came up with.

A motor is a motor right?
What seperates the 929 motor from a d16?
They both are 4 cylinder and both have close to the same power output.
So why can injector sizing be done the same way?
IF you put 130hp (y8) into the injector formula, for a 4 cylinder engine you get 213cc at 80% duty.
well, the 929 puts out about 140hp. put this in the formula and you get 230cc at 80% duty.

we all know that is not gonna run the injectors at 80% duty that is why the y8 has 240cc injectors in it, thats about 70% duty.

Now if the cbr runs its injectors at 70% duty that would be about 260cc.

This is just a theory, but they could not be less then 230cc