Intake Valve Opening in Relation to Injector Timing

[RocketcarX]

How do you convert the info from the cam card to a useable number in relation to injector timing? I'm not finding a clear answer, or maybe I'm not asking the internet and my books the right questions.
Some info I've found says to set most cam'd combs to 500, but I dint understand that thought process.

 

[702GT]

Have you tried PM'ing Lito or BruceH? Either one of those two will for sure know about that voodoo talk.

 

[RocketcarX]

Bruce checked out when he stopped being a S197 owner. I considered Lito but felt put off because I would be asking fro his trade secrets. I will eventually crumble and have him tune the car. It requires me to use an SCT device to upload his tune or data log for him. He can't just send me an HP Tuners tune file so in the end I'm gonna have to spend another $400 for the device and $350 for the tuning if I understand correctly. I already have $800 in the HP Tuners suite plus the books and whatnot I used to learn to tune. S'getting expensive, lol.

 

[46addict]

A used x4 can be picked up for $250-300. Even cheaper if you get a x3. I'm not a huge fan of Livelink so it would be a downgrade from HP Tuners though, IMO.

And if this is the NA+nitrous car I'm thinking of, it will be more like $200 for a tune from Lito.

 

[RocketcarX]

This is link I found that seemed useful
http://efidynotuning.com/cam.htm

 

[RocketcarX]

A used x4 can be picked up for $250-300. Even cheaper if you get a x3. I'm not a huge fan of Livelink so it would be a downgrade from HP Tuners though, IMO.

And if this is the NA+nitrous car I'm thinking of, it will be more like $200 for a tune from Lito.

I have an X4 that is married I could have unlocked. I just checked the price sheet he sent me, I think it works out to $200 like you said. So that would be $350 total, not too bad.
He said after he tunes it I could pull the tune myself with HP Tuners

 

[46addict]

And have you tried adjusting injector timing just based on AFR for a given load value? Or am I oversimplifying things? I'm wondering how tuners tune for a cammed & modified car when the cam card is not available. I thought the whole point of setting the injector timing was to hit the target AFR and nothing more.

 

[RocketcarX]

And have you tried adjusting injector timing just based on AFR for a given load value? Or am I oversimplifying things? I'm wondering how tuners tune for a cammed & modified car when the cam card is not available. I thought the whole point of setting the injector timing was to hit the target AFR and nothing more.

I'm pretty sure it's to get the fuel on the back side of the valve at the right time in relation to cam duration and intake valve opening so you're not spraying onto an open valve.

 

[RocketcarX]

While we're at it, would I be correct in changing the Max Fuel Pump Flow to 8.693 lb/min

MY logic is; if to convert LPH to lb/hr is LPHx1.63 and 320lphx1.6=521 and then dividing that answer by 60 to get lb/min is 8.693 than I should change the Max Pump Flow to 8.693 lb/min

 

[46addict]

Does the program plot the flow curve in between values of 1lb/min to 8.69lb/min or do you have to figure that out on your own?

 

[RocketcarX]

Does the program plot the flow curve in between values of 1lb/min to 8.69lb/min or do you have to figure that out on your own?

I’m not certain

 

[hammeron]

you take the intake valve opening number (19 in your case) then subtract it from 360. This is
the value you put in the injector timing field. the way you have it set to 341 is correct for a
cam which opens the intake valve 19* BTDC.

How do you convert the info from the cam card to a useable number in relation to injector timing? I'm not finding a clear answer, or maybe I'm not asking the internet and my books the right questions.
Some info I've found says to set most cam'd combs to 500, but I dint understand that thought process.
View attachment 66997 View attachment 66998

 

[RocketcarX]

you take the intake valve opening number (19 in your case) then subtract it from 360. This is
the value you put in the injector timing field. the way you have it set to 341 is correct for a
cam which opens the intake valve 19* BTDC.

That’s how I got 341, thanks for the confirmation.

 

[RocketcarX]

Do I need to add a little plenum volume due to the nitrous plate and IMRC delete plates?
Still looking for any input on the lb/min fuel question.

 

[01yellerCobra]

I was taught the manifold volume was more for if the MAF was moved. Such as going to a blow through supercharger set up. You have to account for the pipe between the MAF and intake. I doubt the nitrous and delete plates made that much of a difference.

I don't have an answer for the fuel question though. I've only had to deal with adjusting the voltage table. The ECU learns what it needs eventually.