408 magnum tune, going lean

injector pulse duration is programmable on many controllers,
it is simply the amount of time, measured in milliseconds (ms),
a fuel injector stays open (delivers fuel) during a cylinder intake cycle.
Typical injector pulse width for an idling engine at normal operating temperature is between 2.5 and 3.5 ms.
shortening the time limits fuel, extending the time richens the mix ratio.
think of the engines cylinder as a bath tub, and the injector as the faucet ,
you control the flow of water by opening the faucet ,
the longer the faucets open the more water volume flows, closing the faucet restricts flow ,
thus TIME, controls volume, lowering the time the faucets open limits the water in the tub, regardless of the faucets max potential flow volume

https://fuelinjectorclinic.com/flow-calculator
 
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injector pulse duration is programmable on many controllers,
it is simply the amount of time, measured in milliseconds (ms),
a fuel injector stays open (delivers fuel) during a cylinder intake cycle.
Typical injector pulse width for an idling engine at normal operating temperature is between 2.5 and 3.5 ms.
shortening the time limits fuel, extending the time richens the mix ratio.
think of the engines cylinder as a bath tub, and the injector as the faucet ,
you control the flow of water by opening the faucet ,
the longer the faucets open the more water volume flows, closing the faucet restricts flow ,
thus TIME, controls volume, lowering the time the faucets open limits the water in the tub, regardless of the faucets max potential flow volume

https://fuelinjectorclinic.com/flow-calculator
No one can get into the Dodge Truck computer hence his issue.
Can not tune at all.

Injector Offset is to compensate for the injector chosen . Fuel injectors keep spraying fuel after electric current cutoff in milliseconds time.

FIC I do not like.
I explained injector Offset and so did Dave Dahlgren a master Tuner from C4 Callaway TT fame.

His injectors Suck FIC.
HAD THEM ! JUNK.
 
I have opened my eyes, thanks to you guys.

I have been trying to teach a T-rex to do new tricks.

If these dodge computers cannot be un-locked or opened up to tuning, the people selling tuners are simply manipulating the inputs.

This is what the problem is. The idle vacuum is lower that stock at idle but rises with RPM. computer sees it and leans it out.
T rex will not sit or roll over.

I can cheat the inputs too.
Of course this only applies to Dodge computers older than 2003 or so.

Thanks again.
I have been educated.
John
 
I have opened my eyes, thanks to you guys.

I have been trying to teach a T-rex to do new tricks.

If these dodge computers cannot be un-locked or opened up to tuning, the people selling tuners are simply manipulating the inputs.

This is what the problem is. The idle vacuum is lower that stock at idle but rises with RPM. computer sees it and leans it out.
T rex will not sit or roll over.

I can cheat the inputs too.
Of course this only applies to Dodge computers older than 2003 or so.

Thanks again.
I have been educated.
John
Not a strong enough interest by others to get into that ECM unfortante.
Have to go to modern Standalone EFI.
Fast XFi is a good system. Powerfull standalone ECM.
Pro quality.
 
Not a strong enough interest by others to get into that ECM unfortante.
Have to go to modern Standalone EFI.
Fast XFi is a good system. Powerfull standalone ECM.
Pro quality.

I agree with this for all Dodge, Chrysler vehicles with an ECM.
Bad enough for their wiring systems which are a NIGHTMARE!
 
Just to update this topic, I talked with a computer guy, who like fast cars.
He told me to check the drivers for the software in my Laptop.
I found there were issues, updated them, and reloaded the files.
It runs different and cleaner but is not close.
I did some data logging and am waiting on a tuner who has done these and is highly recommended.
They can get into the software and re write them.
Will update as things happen.
 
yes keep us informed and please let us in on all the details
 
Here is an update.
After many months of no communication/ poor communication from a big name tuning company, I have moved on.
I choose to not mention who for obvious reasons. Privately contact me IF you need to know.

So I have bought another tuner, one that allows ME to move tables around.
This truck now drives/runs like there is no trailer behind it. I'm pleased and will tune some more.
Yes, I know that I don't have the tuning experience that others do.
I know I am learning some new abbrivations too!

If you know of a site that explains abbrivations on the tuning tables, this this will help me.
Like PTE which I believe is 'part throttle enrichment'.

One more thing, IF I had seen this a year ago, I would of just gone to a carb and a few more cu. In's
But I'm not good at QUITING like some tuners I have talked to on the phone.
I WILL get this.
John
 
its unfortunate , but many if not most skills we learned are the result of no one else giving any value to your needs or desires,
and most people being unwilling to take the time and effort to teach others and pass on the skills they learned,
thats the major reason I started the web site.
 
After many trips from the computer to the truck, and a short drive, I have made progress.

It likes more timing--40 ( it will pull timing with rpm/load)
Fuel too, still running 14.5 to 15 under load--too lean
It actually got into light spark knock-- more like a rattle this am, so I pulled 4 degrees and also added a little fuel.

Truck now drives like it is 1,000 lighter.
Before it felt like there was a car trailer and a compact tractor behind it.
Over head was showing, this am 18 mpg ---not sure how accurate it is right now.
Tuning most of the weekend--learning all the time.
It is like a box of chocolate!
 
I've done a lot more tuning. It really runs nice.
I'd like to clean up the idle, but not the 'note! It sounds good idling.
A lot of playing with the tables, most were in the right direction, some not.
Resize injectors make changes to the map table and timing tables. And other things too.
My opinion, the factory timing was a joke. They pulled it all out at WOT.
I have really enjoyed this.

Anyone want special info I learned, send money, LOL!!!
 
Hey guys, still playing with it.
This motor likes timing and fuel.
I'm bringing the timing up quick from 24 to 38, it likes it. 89 fuel.
Open loop only.
If it surges or gives light knock on acceleration, I add fuel to different blocks on the table.
It is very responsive.
Trying to fine tune it some now.
Learning curve for what each table/setting does is time consuming.
Should of taken a class somewhere!

From the start I had too little timing and too little fuel.
I was trying to follow factory settings + 15-20% ( for the added Cu. in. but I learned the factory tune was weak.)
 
Sounds like you are getting the hand of it! How close to the final tune do you think you are???
 
I'm close. May try closed loop.
It is still lazy around 1500 rpm.
Thinking of advancing the cam 4 degrees, think it would be noticed?
This tall OD in the Dodges pulls it down to 1500 if I let it.
Cam is actually 222 intake 226 ex.

I actually walked in to the full throttle yesterday. It really pulled hard, for what it is and what it is in.
It gave some authority to the tires.
 
Thinking of advancing the cam 4 degrees, think it would be noticed?
It would move the peak of the curve lower by 300-400 rpm. I think it would be hard to notice
a small change of 300 rpm, but your mileage my vary! :)
 
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