Okay, I'm going in for emissions tomorrow, and assuming I pass, I'm going to rip more of the emissions stuff out of my car tomorrow afternoon (the dates just work out perfect). Now I have a question about the AIR pump.

Can I remove the AIR hoses and diverter valve and leave the pump in there? I thought I've heard of this ruining the pump, but this doesn't make sense to me since the diverter valve routes air to the atmosphere sometimes. Is this true or is it a myth?

If its true, I could remove the AIR pump tomorrow as well. What belt would I then need? I have a 1LE pulley already, so its pretty much a stock serp setup but without the AIR pump. If anyone could give me a part number from Autozone or something for the belt, that'd be great (my belt needs replacing soon as it is).

I'm removing the AIR stuff to clean up the engine bay and make installing headers even easier, as well as the head/intake swap. With the AC removed and my custom heaterbox, its already much easier to reach all of the bolts, and I can actually reach my back pass. spark plug with ease.

 

Oh, and something interesting. The stock chip for my car shows the injector constant as "20.8" which is odd considering they have 19lb injectors stock. Does this mean GM actually leans these cars from the factory?? I'll probably just run the stock chip then tomorrow since that should run it lean. Dropping that number to 18.5 actually got my BLMs close.

Since we don't get tested on NOx readings, I figure I may have it run lean to reduce the HCs and CO.

 

It's true that the diverter valve will dump the pump output to atmosphere under some operating conditions (like on deceleration) to prevent afterfire in the exhaust. The "myth" is that removing the AIR pump will free up power. If you need the space for something cool like headers, a turbo, etcetera, then it makes sense. Otherwise, the only gain will be space, not any measurable RWHP.

If you search the archives, you'll likely find the correct belt length for AIR pump removal.

As fro the injector constant, I have noticed the same thing in hacking out the stock BINs. If you have Multec injectors as opposed to Bosch or Rochester, they may be rated at a different pressure, thus the different constant when operating at the stock regulated 37 PSIG under vacuum. Look at some of the older TPI BINs for comparison. And the scalars in the programming apparently don't allow the "perfect" 21.0 or 19.0 inputs, so the next closest allowable input is used. Depending on the editor you are using, try entering "19.0" and see what the number actually is when you refresh the binary read.

 

The only reason I'm doing it is for more room and to make things easier to work on. I just put in a set of 8.5mm wires yesterday, and if the AIR stuff was gone, it would've been quite a bit easier. With the AC removed, it was much easier to work on the passenger side though already. I will be getting headers soon enough, as well as new heads and intake. I figured the gain would be like 1rwhp if even that, so that wasn't my reasoning.

I've also noticed the non-perfect scalar inputs. Its just something with the hex bin design.