Diablosport Forums

Hey there. I read over @ chargerforumz that if you install headers you must run leaner otherwise you might blow your engine. Just wandering if this holds true for the 3.5 engine as well? I will be getting a dual exhaust setup in a few months and will be installing JBA shorty headers.

You don't run leaner, you need to add fuel, which makes it richer. I would definetly think the same would hold true for the 3.5 V6.

And do you think this would be for every tune, like 91 or 93, etc
If you don't can it really blow your engine? Since hearing this i am a little worried now

It is a good idea to add about 5-10% fuel at WOT when you add headers on a HEMI car, not sure if it will matter on the V6.

So just to be safe should i add like 5 % and should i be concerned about my engine blowing?

[thought I posted this earlier]

The idea of adding headers is for better air flow through the engine.
When you get more air with the same amount of fuel you had before it's going to run leaner.
You would want to add fuel to compensate for the increased flow.

Running too lean will blow up your engine.
Running too rich will foul plugs, shorten the life of your cats, and make a lot of soot on your exhaust tips.

The PCM should be able to handle any knock you would get from just adding headers.
If the headers do anything for you then you would want to add fuel. Generally that would be in the 5% to 10% additional fuel ballpark. If you want to be safe then add the 10%. What you should do is learn how to log knock retard and learn what it means. Best way to get a good grip on that is reading through posts on just that on the car forums.

I would definitely recommend some OTHER forum than chargerforumz. If you didn't misread what was said over there and people didn't call BS on it, then you should only use that forum to look for the best 24"s to put on your car. Try lxforums, at least half the people there know what they're talking about.

Well i am more on chargerforumz as there is more info there for the charger
Thanks for all the info so to add fuel i would in my preditor, go to modified tune, WOT fuel, rich lean scale to do this adjustment am i correct? Thanks again i am still very new to the Predator
Also i guess it's a bad idea to keep the factory tune with the headers. I will be getting a dual exhaust and install my headers around March and have not yet used my Predator

Are you running hi flo cats? To add fuel yes the slide bar + or - is what you would use. I believe to add is to move to the left, but take a close look before you adjust

The new crom's on the predator show the words rich and lean and yes, it is in the WOT Fuel area, so just follow that and you'll be fine. Use the predator to log ST Knock before you add the headers. Make sure you aren't getting knock with just the canned tunes first. Then add the headers, increase the fuel with the Predator by 10% and log ST Knock again, if you get zero, then subtract 5% fuel and log again... if you get some knock, add more fuel until you are happy with the readings.

No i don't have my exhaust yet. I will be getting true duals custom made with flowmasters. I really have no idea how to log and know little about knock retard. Maybe i will check the forums out

Thanks

chargedviper wrote:No i don't have my exhaust yet. I will be getting true duals custom made with flowmasters. I really have no idea how to log and know little about knock retard. Maybe i will check the forums out

Thanks

^^^^^ Very good idea. Logging will quickly become your best friend if you plan on modding your car, especially if your modding anything to do with the A/F areas.

I would imagine data logging ain't to hard
About the only engine mod i do have is a cai which is AFE Stage 2 and i do have the catch can as well

Logging is extremely easy... you don't even need a computer as the Predator will log in real time and record as well. Set up your PIDs to log (Base Spark, ST Knock Retard, IAT, etc....get yourself ready for a WOT run, start recording, stand on the gas pedal and hang on to your "stuff" I have been able to log 10-15 minutes of data depending on how many PID's you are recording. The only downside is that each recording session overwrites the previous one so you need to load it to your PC if you want to keep the log and make another run.

BTW, AFE Stage II is a pretty nice CAI.

So when you say Base Spark, ST Knock Retard, etc are these all options you select to record? And how would logging help me finding out if i am running to rich or to lean? Should probably do this the same day my headers and exhaust is installed. Sorry for all the questions but you sound like you know your stuff

And i am definately going to the track this summer

they are all options (PID's) under "watch and record"... part of the diagnostics features of the Predator. If you don't have a wideband O2 and If you are getting Short Term Knock Retard, chances are you are running lean... knock is a byproduct of being too lean. Everything I know about the LX cars, I learned from this website (mikel, johan, johnc, sohfast94 from DiabloSport and the forum members like Quick, SRT8Tech, Mike_Levy, etc.) Read, read and read some more and you'll learn more than you thought possible about your car. Welcome to the world of modding in the 21st Century