Here's another graph to visualize the recommended design specifications...




[Modified by teg92, 6:28 PM 12/17/2002]

 

The 20 valve 4AG ITB's have a throttle plate diameter of 43mm.

 

which harmonic are you tuning for??????

A little help is here..........

http://www.bgsoflex.com/intakeln.html

link provided by the fastest 1.5L around

 

Can you explain just a little on this? Do you mean where (in the rpm band) do I want my most power?

 

Hey teg92, on the vacuum issue...(quoted from CHEETAH in a pm)


EDIT: Another thread on ITB's for those interested...https://honda-tech.com/zerothread?id=308478


[Modified by Jeff C, 10:23 AM 12/18/2002]

 

actually you can use the map, iots much more accurate and I find that tuning it based on load in each gear is much different using a TPS for fuel than map for fuel, i.e. fuel amount required at 1st gear @ 9krpm for example is less than that for 4th gear @9krpm ... if using the TPS map, it will give the same fuel, if using load map (map sensor signal AKA speed density) you can control the fuel delivery required ... the TPS one I have tried and car was much slower because it was a dog at the lower gears and did not accelerate as good as in 4th gear since same fuel amount was given.

Oh, to clear up a misunderstanding I saw in couple posts ... earlier CRX/Civics came with the map sensor on the firewall not on the TB like the 92+ ... also, Del sol for 93 came with map on the firewall as well.

Greg

 

"" To use this pulse, the intake port must be the correct length, and only occurs during a narrow RPM band ""

hmmm, so how narrow are we talking?
1000 rpm? no thanks.
3500 rpm? sounds good!

my GSXR750 ITB's are on the way, sounds like Cheetah may have a few calls from us all in the springtime for a tuning session!


[Modified by owen_the_soyboy, 11:36 AM 12/18/2002]

 

What does that mean? Is it an advantage or disadvantage or just nothing?

 

I played around with that runner length calculator. Can someone explain what this means? It doesnt make sense to me. Toda and TWM ITB runners are only like 4" or 5", correct so way are these rpm levels so huge?


[Modified by Jeff C, 11:45 AM 12/18/2002]

 

Interesting website Jeff... With runners the length that my graph indicates for an 8500rpm motor...

It just means that at those RPM ranges physics says the air waves will be happiest and travel most efficiently... Doesn't mean the other rpms will be crap.. Every stock induction system has natural resonance frequencies...

Still though that website isn't accurate enough. Doesn't factor in anything other than length... Diameter of plate, injector placement, diameter & length of horns, port volume, etc..


[Modified by teg92, 11:50 AM 12/18/2002]

 

Man I feel like an idiot looking at all this information.
I dont have room for 14" runners so I guess I will have to make them as long as possible for the best results.

BTW, Mistabone needs the recognition for that site.

 

wrong. i have a set. the ones from the earlier ('silver-top') version are 43mm at the lip, 40mm at the plate, and 38mm at the manifold. those on the later ('black-top') models are 45mm...lip, 42mm...plate, and 40mm...manifold. they are both for street-use on a 1.6L much like the b16a (bore/stroke/rod length), but with milder stock cams and lower compression operating at a peak of ~7-8K RPM.

the honda cbr 929 ITBs are 39mm (from Honda's specs), not 40mm.

the Toda ITBs for H/A b16a/b, b18c(1/5) are based on the Toyotas, and are 48mm... lip, 45mm... plate, 43mm... manifold, as are a few others such as Hayward's for 1.6/1.8L Road-Race Spec.. they are made to make good midrange tq/power from ~5K-9K RPM with ~11-12:1 Compression and type R or larger cams.

the drag spec. Haywards and TWMs for b16a/b, b18c1/5 are 51mm...lip, 48mm...plate, 45mm...manifold.

 

i had a 4AGE MR2 and it was not ITB...TVIS is definitely not ITB, the damn thing only made 116hp on a 1.6

 

Thank you yes, we know. the 4a-ge had variations.. the one we are speaking of is the ITB model... http://www.geocities.com/MotorCity/7...geengines.html

 

then refer to it as the ae101 version..or the 20 valve. a normal 4ag has 16 valve, the ITB equipped ones were 20 valve

 

?,ot some 2001 GSX-R750 ITB's (made by Keihin) and they are-
50mm @ lip, ??mm @ plate, 42mm @ manifold...
(they also have secondary butterflies [plates] that will be removed, they're near the 50mm lip)

Also- taken from TODA japan site-
Diagram of ITB setup for B16, nicley shows arrangement of parts and injector placement





[Modified by owen_the_soyboy, 3:37 AM 12/19/2002]

 

Jeff, the length is from the valve face to the end of the air horn on the carb. Most are 10-12".

Input length is 12 inches
For 2nd harmonic, RPM range is from 9790 to 11880 with a pulse strength of 10 percent
For 3rd harmonic, RPM range is from <U>7356 to 8407</U> with a pulse strength of 7 percent
For 4th harmonic, RPM range is from 5735 to 6413 with a pulse strength of 4 percent

I don't get credit for the link, Bisi E. does. He posted the info on Dseries board a while back.


[Modified by Mista Bone, 5:51 AM 12/19/2002]

 

Oh, ok. I thought it was referring to runner length, but it was actually referring to system length.

 

To bring this back from the dead;
Can an ITB setup be had for less than 1000?
Is this possible?
Interesting I guess


[Modified by 79 civic, 5:39 AM 12/23/2002]

 

Hopefully its possible cause that is what I am shooting for, but way less than $1000.
I'll see as soon as I get the parts, they're in the mail.

 

here's some real eye candy, Stage 3 skunk cams, TWM's 10,000rpm consistent and daily driven !! I promise. we just got done doing type r suspension no less than 15 minutes ago.

 

Got syno charts for that monster??

Also for vacum, V8s do have to use a vacum canister when running a large cam. summit racing sells them for like $80 US, i think that would solve the vacum problem

 

79 civic
delete that post asap, call me
thanks

 

Wow, that thing is going to be fun...ugly, but fun.

 

i have a brand new in the box, set of twm's for a 2.2 for sale ... i need to sell them so if anyone is intererested please let me know....