As I understand the later RB26's did not use ITBs anymore. Correct me if I am wrong.

 

here's a few pics of a GTiR motor with ITB's converted to NA use for some european touring cars. i dont know if they work that well

 

I know that the rb26dett that came in r33's features the I.T.B. design. I'm not sure about the new r34's but I'm pretty sure they do as well. I only really know from hands on experience.

I have to agree about the little turbos, I bet that they make a bigger difference than the ITB's but Nissan and other manufacturers must know somthing that would benefit them.. although this 2.6l beast does have amazing torque and instant throttle response and tire spinning.

one of our swapped cars.

 

that corolla is so ******* hot...thats rwd right? what motor is he running in it? 4age?

 

I know that the SR20DET that came in the Nissan Pulsar GTI-R have ITB's and its turbo'd. Not sure on how hard it would be to tune but Im sure it would rip once it was tuned right!

 

I got a picture of a mugen (I think) Honda motor with ITB's

Someone wanna host for me?

 

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

if there is a problem with throttle response when running itb's, it's usually because they are too big for the application, or they are out of sync... sync'ing 'em is easy, set the blade closing gap relative to the throttle bore before installing on the car, then use a $35 airflow meter to fine-tune</TD></TR></TABLE>

I am not to clear on this process? sync'ing the blades?

Can you tell me more about it?

Thanks

 

R34 skylines do have itb's. check out this picture from rh9.com.au
http://www.rh9.com.au/images/DSC00423.jpg

 

I want to see pics of this setup on a Honda!

 

A guy on the freshalloy nissan board took a pulsar intake and fliped the outer half of the manifold to work on a sr20det that was in a s13. This had to be done due to the manifold pointing the other wa in the pulsar. To make a long story short he said the car ran great, and had a tiny bit more responce. But he honestly thought it was a waste of time for the gains he saw. Said h powe stayed the same, just made it at a later point in the rpm band.

 

that is a sick car

 

I remember Tinker/Cody and/or boosted hybrid working on something like this a while back. Maybe it's just late and I am pulling names out of a hat

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
Just to be an argumentative *****, Nissan gets throttle response by putting tiny *** turbos that spool early onto their engines.

Also, when 25% TP (throttle position) on ITBs ideally sized for NA use nets you more flow than a conventional TB/plenum at 75% TP, I respectfully suggest that the off boost throttle response you are experiencing is the turbo spooling. Only way I can see to sidestep that is to use tiny (by NA ideal) ITBs so the throttle plates act as a restriction to flow at part throttle.</TD></TR></TABLE>

that is commonly called turbo lag, not throttle response, but i see your point.

i clearly stated that OFF BOOST performance might improve with itb's... which is exactly why people run 'em in n/a applications, and maybe why you'd want to run 'em on a turbo motor... the throttle response itself would actually be the same regardless, and the reason itb's are better than a plenum intake system is because the total air volume between the throttle plate and intake valve is a whole lot less with an itb system.

now think about what happens on an n/a 4-cylinder motor... it's a 4-cycle engine, so how many cylinders are actually pulling intake flow at the same time? what does that mean for the peak airspeed thru the single plenum throttle body, vs. peak airspeed for one of the itbs? total airflow volume is gonna be quite different, but it's the peak airspeed that determines the throttle body sizing.

to put it another way, the correct method for sizing an itb on a 4-cylinder motor is by the total airflow of the engine... sorta like you'd size a single throttle body plenum intake system.

on a turbo car, corky bell sez that you size a throttle body for 300 ft/sec max... itb's would add up the total throttle plate size for the calculations.

what you have with hondas is a market that offers largely itb's that are too big for the application, i.e., 51mm itb's... so throttle response is indeed gonna suffer.

what i'm looking at now is some sort of progressive linkage system to address that.

btw, there are a couple of common airflow meters for sizing itb's... one of 'em is less than $20(?).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trbcivic &raquo;</TD></TR><TR><TD CLASS="quote">
I am not to clear on this process? sync'ing the blades?
</TD></TR></TABLE>

what i usually do is take a thick piece of paper, cut it into a narrow strip, then lay it inside the throttle bore with the throttle plate opened up... close the throttle plate on the paper strip, then adjust it so that the paper just starts to slip out when pulled.

you should end up with 4 throttle plates that all have the same gap, relative to the throttle bore... this requires some linkage adjustment capability, and in the case of twin itb's(really carbs) like i think that bisi is running, you can only adjust one plate per pair, since they share a common throttle shaft.

so we now have both bisi and leslie durst running one barrel per cylinder... what does that tell you about itb performance in an n/a motor application?


Modified by danimal at 8:44 PM 12/2/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike1114 &raquo;</TD></TR><TR><TD CLASS="quote">I got a picture of a mugen (I think) Honda motor with ITB's

Someone wanna host for me?</TD></TR></TABLE>


Ill host it for you. Is it even turbo??

 

I have an 929RR ITB setup, I think it's 31mm-35mm per port.