Okay, first off I posted this question on the "Computer Tuning & Diagnostics" forum, and the link is here:

https://www.camaroz28.com/forums/com...hanges-856625/

but, it was suggested that I post this here also.

Here's my question ........ if you already have a decent "mail order" tune for your somewhat modded car, (see signiture), and you just want to change from Ford SVO 30 lb/hr to 42 lb/hr fuel injectors, nothing more .......... what all is required to be changed in your current PCM tune?

Put another way, is computer re-tuning for ONLY an injector size change easy to do?

TIA for any replys in this forum.

 

Super easy for the programmer, but they will probably charge you the full amount even though its a simple retune. Personally, I would hold off unless the current injectors are not big enough for the setup or not working correctly.

 

It's a change of one number in the constants table for the injector size.

 

2QUIK6, that's what I was hoping it was ...... a simple change!

If I'm using TunerCat to make this change, do you know what table this value is found in, and ..... what should this value be for Ford SVO (i.e. "green top") 42 lb/hr injectors?

 

Constants-->Fuel Parameters-->Injector Flow Rate.

For Injector sizing read this....

For converting Ford injectors ratings to GM LT1 pressures, do the following.

Formula referenced from Greg's book, Designing and Tuning High Performance Fuel Injection Systems.

Qf = Qn x Sqrt(P2/P1)

Qf = final flow rate(GM injector flow)
Qn = reference flow rate (Ford Injector flow)
P2 = final pressure(GM pressure in bar)
P1 = reference pressure(Ford pressure in bar)

Qf = 42lb/hr x Sqrt(3 bar/2.7 bar)
Qf = 42lb/hr x Sqrt(1.11111)
Qf = 42lb/hr x (1.054)
Qf = 44.268 lb/hr

That should be the number to plug in to the Injector Flow Rate for FMS 42lb injectors.

There are also Injector offsets and short pulse adders to consider.

Read this....
https://www.camaroz28.com/forums/com...ts-lt1-770192/

 

ACE1252, WOW! I really hit the "mother lode" with your post.

This is precisely the information I was looking for in my original post, and ......... I can't Thank You! enough for it.

Thanks also to all who replied!