I'm installing headers / y pipe / intake manifold on my L03 and i was wondering what parameters i should tune/adjust to get the maximum benefit from the install?

 

The volumetric efficiency and spark tables would be a good place to start. The stock SA tables are conservative and adding the intake and headers will change the volumetric efficiency of the motor. Do you have a wideband yet? The upfront cost is alot, but it makes tuning easier as you have an additional input to use, which means less guessing.

Also, you'll be using a 3" catback as well, correct? If your using the stock stuff, you probably wont have to tune at all! It'll be nearly as restrictive as before.

 

Yea i bought some hooker headers and a 3" y pipe for it. I already have a 3" catback but i just now got the headers and stuff.. Aren't there programs that take your .bin and your car and predicts its ET?

 

So does increasing the volumetric efficiency add fuel?

Edit

When i get the intake and exhaust on should i increase the WOT air/fuel ratio at higher RPMS? How big of increments should i make and what should my target KPA be at? Thanks - Mitch

 

VE: (Volumetric Efficency) This table is the theoretical volumetric efficency of your engine. So at 50 map and 2000 RPM your engine is theoretically going to enhale 60% of the air that could physically fit into the cylinder (random numbers). From this your ECM calculates how much fuel to add in order to obtain a particular AFR. So if we lower the VE you’re going to lean the engine under those conditions and vise versa for raising it. The ECM will cap the table at 100% even though you can input values higher than this. If you max out your VE table then you need to readjust your BPC and start over on your VE table. (Just scale both in equal numbers) TBI is unique in that there are 2 VE tables. VE 1 is a 3d table and VE 2 is a 2d table. VE 2 is added to VE 1 in order to come up with your actual VE. This is done this way to save space on the chip. It’s a bit confusing until you get the hang of it. I like to “flat line” (say 30%) the VE2 table until 3200 rpm and add those values into VE1 so that what you see is what you get. Then you can continue on in VE 2 to shape your upper RPM fuel curve. Keep in mind that the last value in VE1 is added to VE2 to make your actual VE table above 3200. So if you were at 50 map and 6000 rpm, you would take the 50 map value at 3200 rpm and add the 6000 rpm % together to get your actual VE amount. We’re not going to zero out the VE2 because we need to let the VE drop at higher RPM if we zero’d it out then we wouldn’t be able to do this (this is hard to visualize, just trust me) Keep in mind that max VE is at torque peak, not at peak HP like you would think. Your VE will taper off after peak torque.

 

Whats up i just finished installing my Hooker Headers and Y pipe onto my L03 and its running really strange. I bought new wires and custom made all the plugs. After firing it up I noticed it was stuttering and almost choking when you get on the gas. I sawed off the AIR system(?) that runs from the cat to the smog pump and left the smog **** off. I found that i cracked 2 spark plugs and i replaced them and at first thought it fixed the problem but it didnt.. Maybe i bumped the distributer out of whack when i changed the plugs(late now cant check)? But the weird thing is it only starts running shitty when the car and exhaust warms up.. Was I not supposed to delete the little metal line and hose that runs from the cat up(thought it was emissions)? Its also not arching which is why I'm sure its not any of the wires. I ran WinALDL and didnt see any error codes besides the oxygen sensor but it was reading .459 O2. I did drill the hole and tightened the sensor in good.. Any suggestions?

Could the tune be that out of whack

 

Thanks for that post, i did realize that the highest VE is at your torque peak as you can tell by the chart. But im still a little confused about getting the right #'s. Hmm ill keep reading it, it'll click soon lol