allmotorKA

When I put 45mm ITBs on my KA24E, there was viturally no low end loss...gain if anything. But I would have to agree with Russ on the point to ditch those rubber couplings. Yeah, that's what they use on the motorcycles but on motorcycles they are set up as down drafts...not side drafts. If you want to cantilever those ITB's on rubber hose couplings (some of which looks misaligned to begin with) then you're only exposing yourself to unnecessary risk. Don't get me wrong, RBS14, you're actually off to a good start. Just don't half ass it...then your set up will be primo.

NismoDan

DAMN! I was researching this a few months back and thought I'd be one of the only ones to do it!
In any case, bravo, it looks sweet.
I only have 2 questions, though.
First, what are you going to do for air filtering?
When I first started putting my plans together I looked for a GSX-R airbox on eBay and found a few. I figured I'd just stick a huge pipe from the front of the engine bay back to the GSX-R airbox where it has an intake filter and then splits off for the ITB's. Did you have any plans for anything like that?
Also, do you see any problems arising from the throttle/accelerator cable and/or TPS?

Sorry to be such a bother, but I didnt know what to do about those 2 things either.

Again, bravo!

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C4L #34

KA24DESOneThree

GSX-R1000 throttle bodies start at 50mm and taper to 42mm. Simply multiplying 42mm by four, we get 168mm. The stock throttle body is all of 60mm. Am I missing something here?

Namely, why flow would be a problem. At all.

RBS14

Makoto: no can do. Original enthusiasm stands. haha

Allmotorka: I would prefer to bolt them on, but that would mean making a custom flange for both the TB's and manifold, and have both welded onto the TB's and mani. The TB's have no bolt holes or mounting points. I highly doubt the current setup will be a problem, as the TB's are very very solidly secured to the mani. It is very hard to move them at all.

Jarbilong: I'm using the GSXR tps. It is very easy to interface to the MegaSquirt. won't take long at all. I'll be running 4 individual sock filters. I'll slip them over the stacks, clamp them on, and I'm done.

ka24desonethree: I concur.

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atom

You can't make a comparison like that because theres a plenum where air is being drawn into the engine. Try thinking about it in reverse, 60mm/4 = 15mm. Obviously 15mm ITB's are not going to work. What's more important would be the intake manifold runner diameter, not the TB diameter.

EDIT: bah brain fart, actually 30mm ITB's would have the same flow as a single 60mm, not 15mm. It's still not gonna work.

TokyoNights

RBs14 cool that youre even attempting this, cant wait to see the results. Im building a high comp s13 de motor and was considering ITB's. What do you guys think about using e30 m3 throttle bodys? The bore diameter is 46mm.

They would require a custom flange.

TokyoNights

RB how come you didnt use hayabusa tb's arent they a little bigger?

FRpilot

yes. turbo cars are for pussies? bahh..



and dam you red 240 hc ka block! and why did you have to get an FC.. you coulda rebuilt the hc ka better than before.. but i understand you were broke..

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RBS14

mikespeed: They are much harder to find, and quite a bit spendier. I'm a poor college student as of now, so almost every choice I make regarding the car is largely based on cost.

I'm not really pioneering anything here. It's been done on sohc, so I'm just replicating it for dohc. I know these work, have correct spacing, etc. so I went with them. If I'm not happy, I can just sell them and start over with other ones.

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TokyoNights

Gotcha, happen to know the bore sizes on the hayabusa ones? They look almost exactly the same.

Also how about injectors, are you going to use the stock injectors in stock location?

RBS14

supposedly they are 46mm. I am not 100% sure on that. yes I will be using stock injectors in stock location for now. When I max them out, I will go with 370's.

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nokeone

fuckin rockin...it'll work...might not be the end all be all..but it'll be better then stock, worth the cost that you have wisely kept low, and shit, what a fun project...=)...

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panda; rockin your socks from the Bay to LA to SD, yay!
Pink GodziRa

RBS14

werd holmes. Paired with some good tuning, it should make ka much more fun.

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that180guy

turbo shnurbo....bfd

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axiomatik

Yes, you are missing something. Four 42mm tubes are not equivalent to one 168 mm tube:


If you want to compare the two, you have to compare cross-sectional area:

60mm => 2827 mm^2

42mm => 1385 mm^2

42mm x 4 => 5542 mm^2

However, it's not as simple as "ITB's will flow 2x as much air". The throttle plates in the ITB's take up a larger proportion of the cross-sectional area than the single throttle body, with ITB's, the air doesn't have to make a 90 deg. turn transitioning from the throttle body to the intake runners, etc. But in the end, the ITB's should flow substantially better than the stock setup.

hiryu

Great thread, just what I needed to kill time in class.

Loofee95SE

Hmm, everything looks nice and all. but why don't u take it to a shop to have them weld it together..instaed of connecting both of them with silicone tubing like that... look nice tho...something I am looking in to doing myself...w the Hayabusa TB's just my .02 C

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nokeone

read closer..it has all already been explained..lol...jeeez..

1, they come just like this from the factory...he figures if it's good enough for them, it's good enough for him...

2, cost...it's not worth the money to get them professionally welded

3, replacement..if something goes wrong having them welded would be a bad idea...

kthxbye

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panda; rockin your socks from the Bay to LA to SD, yay!
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sykikchimp

so, to be clear.. the map sensor will connect to vacuum tubing that is connected to all the runners behind the throttle plates via "T"'s?

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RBS14

yea, you can see 4 gray vacuum hoses coming together into a black T. Run vacuum hose from there to the map sensor. The larger vacuum rail that is at the end of the mani that bolts onto the head is originally used for pcv system. I'll be using it for brake booster.

Noah, thanks. Zilvia.net is proof that reading comprehension needs to be focused more closely on in public schools.

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Maeda

SERIOUSLY Scoot. I replied to my own LSD post like 3 times to tell people to learn how to read.

and those ITBS are looking crappier the longer they don't go on your car.

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tastyratz

i know it was touched that we know it can idle but how is idle controlled? i know the stock tb has a little valve on it to control idle, but what about with this setup? forgive me for ignorance but i know nothing of motorcycles and youve sparked my interest. im assuming this is something else your using the megasquirt to control too. Ive got an aem ems waiting to go on in my room i could control something like this with. I have a SOHC im gonna turbo and itbs seem like they could flow more. I can find the setup for the sohc (barely) but it seems i can only find it with carbs and not the way id want to so id have to build it like you are. this is all very interesting...

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meatish

Congratulations. Your car will now sound like a small block chevy+vacuum cleaner.
Good DIY job though, looks dope.

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Mr. Pibb + Red Vines = CRAZY DELICIOUS
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TokyoNights

sooo you used jb weld to plug the injector holes eh?

RBS14

Idle control? simple. A screw on the side of the TB's that adjusts how open the throttle plates are when "closed". Just like stock. MegaSquirt just reads the tps signal and gives the engine the programmed amount of fuel. No extra valves or anything. All that stuff is gone.

$$$ not considered, I'd go for an EMS too. But MS costs under $200, so that's my choice.

Mikespeed: I actually found bolts of which the heads just barely fit into the holes, cut the heads off, put them into the holes, and then filled the rest up with jbweld. Since the injector holes are on the bottom of the tb's, the worst that could happen is that the jb would crack and fall out, not get sucked into the engine. Otherwise I would have had them welded shut. But as stated before, heliarc welding is mondo expensive.

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TokyoNights

Engine managment is the killer,,either dish out a shitload for standalone or the cheap but pain in the ass megasquirt. I hope you get the MS worked out

atom

Or you could just make a plenum and attatch your maf to it........

RBS14

^^^^^

which would be total weaksauce!!! Open ITB's make considerably more power than with a plenum covering them. I'm doing this to open up top end breathing. Putting a plenum on them would just decrease their ability to suck in a ton of air during higher rpm's.

Mikespeed: I've got a ton of time, so MS is perfect for me. Another friend who built his likened the difficulty level of building one to that of building a 1/18th scale model. there are soooooo many pages of instructions, which equals lots of detail on how to do everything.

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atom

A plenum isn't weak, as long as you make it big enough. The theory anyways is to make the plenum as big as the engine bay will allow so that it will practically be like open atmosphere. I was seriously considering this:

http://www.tweakit.net/shop/product_...roducts_id=127

I e-mailed them a long, long time ago and shipped to America the total cost would was somewhere near $250. Using that with a 3.5" Q45 MAF and theres no way a KA, even a built one with ITB's, is flowing enough to make that some bottleneck.

Sideways_In_SD

All you haters are fuggin weak sauce!!!

This is a pro-to-type,

That's why it looks like shit, and isn't "optimized" for "flow characteristics" and "volumetric efficency"

If you're not impressed, just say "neat" and move on, cause this is just the beginning stages.

And not everyone is sponsored by Parents Inc. so it keeps our projects low-cost, and low-tech. WOO HOO broke-as-fuck tuning!!

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