Pavetim

iTrader: (15)

I am putting pacesetter LT's, TSP ORY and SLP stainless exhaust. What kind of tuning should I do for this. I know I already did hte rear O2 sensor delete. But just wondering what sort of timing and fuel stuff I should mess with. Thanks guys.

jonathan_173

I'd also be interested to find out what I need to do. I'm just setting up a magnaflow exhaust system but thinking about taking out the cats. Any suggestions?

rush7

iTrader: (2)

Pavetim, If you have access to one of either EFILive or HPTuners, your best bet is adjusting the VE tables to take advantage of the increased flow of the headers. This would provide a good start, but not imperative to do by any means.

Jonathan, while your magnaflow setup probably won't require a change in tuning, as it doesn't change the flow characteristics a whole lot, I suppose if you wanted to be dead-on perfect and had access to the software, tuning your VE tables would also be the way to go. You're also going to have to ask yourself the question of whether you can live with the SES light after you remove your cats, if not you'll need a tune of some sorts to turn the light off. Chances are you can get someone near you that has the software to just turn off your light for a small fee if that's all you need.

Pavetim

iTrader: (15)

I have hp tuners. But before I actually start tuning I need to get my innovate wide band hooked up. But VE tables basically state that the bigger the value the engine thinks it has more useable air in the cylinders right? But if my car is all stock intake wise how do you get that extra air into the cylinders? Or does it just think the air is there and then will add more fuel to try and compensate?

oange ss

iTrader: (50)

Phoenix 5.7

iTrader: (7)

are you keeping AIR or EGR? those will need to be disabled also if you are not.

Pavetim

iTrader: (15)

My car does not have EGR is is 2002 but i kept the AIR. Why would they need to be disalbed, I have the headers with the AIR provisions.

rush7

iTrader: (2)

Yes, by increasing the values in your VE table your computer thinks there is more air in the cylinder (which is very possible with the addition of headers) and adds fuel. Even if your intake stuff is still stock, the entire engine can be more efficient at pumping air since you have a less restrictive exhaust. You will have VE values that are not optimal anymore, as they would have been with a stock engine, and are probably too low (running lean). Your wideband will tell you which values those are, it sounds like you just need to hook it up and get rolling.

98A4LS1

iTrader: (1)

Then why do you decrease VE values in idle areas after installing bigger cam?

ringram

Actually if your are running closed loop the wideband wont tell you that you are running anything other than 14.63:1 AFR (ie) bang on.
You need to disable fuel trims to adjust your VE with a wideband. If you read your trims you will get an idea of how far out they are. Mine were from memory +10% stock, so basically the Table needed to be bumped up 10% to tell the PCM more air was in there and thereby reduce the amount of fuel the trims had to dump in to reach stoich.
Once VE is dialed in you can re-enable closed loop O2 fueling.

I believe you decrease values in the VE for larger cams as the overlap makes unburnt fuel go out the exhaust which means a mix of HC's and O2.. O2 makes the O2 sensor say, "hey you are running lean buddy, dump more fuel in", a vicious loop. At least thats how I understand it.