Homemade ITBs

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Jan 30, 2002 | 09:19 AM

#51

93delsol

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Joined: Jul 2001

Posts: 331

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From: Pittsburgh, PA, USA

Re: Homemade ITBs (Todd Reid)

the super seven is street legal in the U.S.?

Jan 30, 2002 | 09:56 AM

#52

Todd Reid

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Joined: Jun 2001

Posts: 1,440

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From: Elkton, MD, 21921

Re: Homemade ITBs (93delsol)

yes, it was registered, titled, and insured. I used to drive it an average of about 700 miles per year on the roads surrounding my house....

Todd

Jan 30, 2002 | 10:56 AM

#53

speedillusion

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Joined: May 2001

Posts: 261

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From: 6feetDEEP, CA, 96969

Re: Homemade ITBs (martini)

you have great engineering potential. especially in the automotive field. are you getting into this career? it's great to be an automotive designer, a friend of mine is making a lot of money doing it.

Jan 30, 2002 | 12:07 PM

#54

1stGenCRXer

Joined: Jan 2002

Posts: 126

Likes: 0

From: Hampton/High Point, VA/NC, USA

Re: Homemade ITBs (martini)

Quote:

1stgen: you say you have to feed the throttle..I can live with that, it isn't a street car. And it doesn't matter when rolling? Even better...in that case, it should work well with the hondata full throttle shift?

I don't know about full throttle shifts, but as long as you have a short spaced tranny, they should work just fine. If the revs fall too far you'll have a slight stall in intake velocity and you'll have a 'bog'

Quote:

my displacement will be slightly above 1.8l. So I still haven't decided what size I'm going to get. I may try and find 45mms, and if they don't work, I'll just sell the whole thing to my buddy with the CRVTEC integra. And build myself another set.

Just to give you an idea, bored out 5.0L Ford blocks with downdraft ITB's still measure in around 40-45mm. On top of that, going much larger than the inside diameter of your intake manifold is nothing more than wasted cross section.

Quote:

As for the filtering system. I don't yet have the ***** to run it open air...So it will be filtered for the time being. I haven't figured out what I'm going to do yet. I know that just a foam filter will get sucked in. I'd like to stay away from foam elements if at all possible. I'm also planning on cuting the fiberglass front end up to put a hood scoop in. I have a ton of extra fireproof fiberglass left over. Perhaps an airbox is in order? Perhaps even make one out of some sheetmetal.

That's kind of like the setup I have. Didn't spend a lot of time on it, but I have a fiberglass backing plate with a sheet metal box fed by a length of flexible air intake hose with a remote filter. The engine takes in cooler air in city traffic that way and behaves better, although such a design *does* knock down total output a bit.

Quote:

I dunno, it's all still in the planning stage. But the more and more I look at it. The easier it seems like it would be.

I've been thinking about how I'm going to link together the throttle rotors. I would like to change the rotational ratio for more sensativity. And I would like it to be adjustable...in case I'm off a little in my initial linkage lengths....but that may not be a good way to go, because there is always the chance it will become "uncalibrated".

so there are a few things yet to figure out.

You should be able to make some throttle arms pretty easily, you only need one throttle cable, and ideally you want each throttle body tied into the one beside it, non-adjustible on one side, but adjustible on the facing side on the adjacent throttle body [hope that made sense].

Jan 30, 2002 | 12:12 PM

#55

1stGenCRXer

Joined: Jan 2002

Posts: 126

Likes: 0

From: Hampton/High Point, VA/NC, USA

Re: Homemade ITBs (Todd Reid)

Quote:

Hello again.

if you are talking about using the DCOE carbs for street use; I'd try to talk you out of it....

Again, my Lotus is 1600 cc and has the DCOE Webber 40 carbs on it. It was proffessionally set up and dyno tuned (exhaust gas pyro sensors on each exhaust outlet, etc.). It runs very well. The car weighs 1100 lbs and engine makes around 150 hp. Carefull street driving (shifting around 3500 to 4000 rpm) gives me between 14 and 16 mpg. Race track mileage (very hard driving shifting around 7500 rpm) gives about 8 to 9 mpg

My CRX is ~1600cc, car weighs 1800lbs, makes 140HP, and I still get 16mpg in the city driving hard (6500 RPM shifts). DCOE's are fine for daily driving, as are ITB's.

PS- Almost forgot, you can use foam "air horn socks" but be sure you get the steel screen backed type, foam works better than paper elements, but aren't as rigid on their own.