You haven't given specs on the motor?

If you don't really wanna share, PM them to me. I'll keep them hush hush.

 

tuning shouldn't be too bad if you know (or tuner knows) what they're doing.

Just have to pay attention to the timing a bit more than usual. AFRs will be pretty straight forward.

 

Don't listen to him, hes wrong.

 

I happened upon this yesterday while looking for something else:

http://video.google.com/videoplay?do...07340&q=gt28rs

 

More shit that can break, imho. There are far, far better ways to use the $$/hp in a turbo setup.

 

i'd say stay n/a or just sell the ITB setup. which i do have a turbo kit maybe we can trade.

itb's and turbo has been done can be done. but there are better ways to spend the money to do it.

 

ITBs with a turbo setup is pretty sick, but I'll agree that the advantages aren't nearly as worthwhile as with an N/A setup. No matter what, you're going to get better throttle response, and better velocity into the head. Transport delay is transport delay, and ITBs have less of it because of where the throttle plate is.
All of the pressure changes take place before the throttles, so it's not a case of open the throttle, pressurize the plenum, go into the engine. It's open the throttle, into the engine immediately.



This is a crappy way do make a plenum box, don't do that. The delivery to the individual cylinders is uneven, because box doesn't have enough cross sectional area. You wouldn't put a log style turbo manifold on your engine, why put a log style intake plenum on your carefully planned ITB setup??
You're better off with a larger plenum, and having the inlet come in closer toward the center. You could make the box a triangle too, like a bigger version of a common intercooler end tank. You want the plenum box to interfere as little as possible with the airflow going into the throttle bodies, and it would be really nice to have velocity stacks on the ends of the runners, spaced a little above the floor of the plenum. All of this also applies to standard plenums too (without ITBs) but you really want to maximize the benefits of the ITBs or there isn't any point in having them.

I'd suggest making a plenum box as close to the hood as you can, and as close to the firewall as you can, and feed the intake pipe in as close to the center as possible for the most equal path to the runners, or make the box triangular. A little more volume is worth it if all of the cylinders are getting as close as possible to equal flow. Also, try to keep the velocity stacks away from the sides of the plenum, so they can feed air in from all sides.

Also look into adding an accumulator tube to the engine side of the ITBs if you haven't already, it will make it run smoother and really help out tuning. Anything to help smooth out vacuum pulsing and inprove transient response is a good thing.

 

I love you. I just copy/pasted all of that for future reference

 

Haha.

 

you can, but it will be a big pain in the tail