posted on December 12, 2007 23:43
ITBs = Individual Throttle Bodies. This is a term that probably originated from the Honda camp back in the late 90's. I think it came from all the Honda nerds that used to say "ITR" for Integra Type R and they thought "ITB" sounded similarly cool. Yes, they THOUGHT. Anyhow, for a naturally aspirated engine, ITBs are the optimum method to control air flow into an engine. It is much easier to adjust runner lengths (air horn lengths) and throttle plate areas all while getting maximum airflow and maintaining maximum airflow velocity. This is why you'll find most race engines from SCCA to F1 with ITBs.
The one part that almost ALL aftermarket ITB installs in America seem to ignore is an AIR BOX. It's great that each cylinder is now getting kick ass air, but now they're getting HOT kick ass air. It's fine on the dyno because most fucking idiot tuners tune cars on chassis dynos with the hood up. When is the last time you drove down the street with your hood up? In the past, I've tuned many ITB setups on Hondas and they all worked great on the dyno when you do one run at a time. Everytime I told the owner, "Bro, you need to be adding an air box or at least some sort of cold air ducting." The reply was always, "Yeah, I'm going to do that sooon." Of course the next time the guy came back for tuning with a new engine because he smoked the old engine from having no air filters and detonation from hot ass air, sure enough there would be NO AIR BOX again. Anyhow, so dudes will spend thousands on an ITB set up and then not build an airbox or route cold air toward the throttles. Pointless stupidity....
This is a proper airbox for a K20A Acura RSX made by Clockwise Motion in the UK.
Anyhow, so walking around PRI I saw an ITB setup for a VQ35DE that I thought looked really fucking cool. If you popped the hood and saw this, you would dig it too:
This setup is made by Jenvey who I believe is an Australian company. Then I started to think about it: wow there isn't much room under the hood of a 350Z is there? This setup would be great in a race car of some sort, but stupid as fuck in a unibody 350z or G35 where you'll find most VQ's. There's no air box, no provision for cold air, no room under the hood, the headers are like 9 inches underneath the air horns, etc. I feel sorry for the dumbfuck that installs these throttles in a 350z or G35 unless he had these horns sticking out of the hood. Then it would look almost as stupid as the Stillen supercharged cars where you have to buy a hood with a giant hump in it
. Or similarly stupid solution would be if you ran a Pro Stock hood scoop
. Since this is America, you'll probably find these ITBs on some show fag's car at Hot Import Nights anyway.....
Anyhow, so the lesson for today is: IF YOU HAVE ITBs, MAKE SURE YOU FABRICATE AN AIR BOX WITH COLD AIR DUCTING AND AND AIR FILTER!!!