lt1 obd1 changing injector to ford 42lb green tops..what all i need to chane in tune? and how to change ve tables for the new injectors?
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lt1 obd1 changing injector to ford 42lb green tops..what all i need to chane in tune? and how to change ve tables for the new injectors?
ve tables never have to be compensated for larger injectors.
just change your injector constant and injector offset vs. voltage table, if you can find that data.
those are some friggn giant injectors for an LT1, what exactly are you building?
well with out changing ve tables ve table at wot is maxed.. 99.6 on 85 90 95 100 tables
just building a heads and cam for now.. getting the 42 for good deal from a racing friend and they leave room to grow
do you have a data sheet for the injectors?
is this a 1992-1993 speed density build or...
bigger isn't always better when it comes to injectors, just warning you.
anyway, volumetric efficiency is an airflow mapping, and changing your injectors alters fueling, not airflow. changing your injector size shouldn't mess with your VE much at all if your injector constant and offsets are right.
its a speed density tune.. not getting injector till thursday.. but im going bigger on my build over the winter.
cam only my injector was maxed and now i added ported heads... its bad lean.. what do i need to change for fueling?
Smaller injectors!!! 42s are good for over 550 hp maybe as much as 600 depending on BSFC. Only way you would need that would be FI or dry N20. 30-32s would be much more appropriate for a hot LT1.Quote:
Originally Posted by criticalx
ok.. on injector but what makes injector flow more per set up
you're missing some basic principles here. injectors flow a certain amount per time of injector opening. it doesn't matter if it's a civic or a bigblock chevy, a 42lb/hr injector is going to flow roughly 42lb/hr at its rated fuel pressure (which is also important, and that's why i asked if you had the datasheet for them).
so what exactly did you set your injector constant to?
I don't have injectors yet.. my injectors are set stock now.Quote:
Originally Posted by steveo
so you still have time to back out and get something reasonable, then?
yes. But won't 30 be over % 80 to start withQuote:
Originally Posted by steveo
no. 30lb injectors are huge for any 350 LT1 with a head/cam build.
So 30 will work? Where best place to get them
wherever you like, what's important is: any injector you buy, it should have a data sheet with injector offsets available
I need a set of injectors as well, but where to go so the right size and data sheet supplied? These are for a TPI set up on a 383..
for 'reasonably cheap' but good, i'd look at racetronix's injectors (accel's newer black/silver metal body are **the same injectors**). they seem to have a good spray pattern, good data sheets, and aren't crazy expensive. my last set served me very well.
ironically for a 383 tpi, buy the LT1 injectors from this guy when he takes them off, since that tpi's VE will fall off on the top end, they'll probably be plenty of fuel.
how do u Change To Fuel/Air Ratio Vs. RPM at WOT? whats each part of spread sheet mean?
are you using EE with my xdf file? or is this a '92-93?
ee with tunercatsQuote:
Originally Posted by steveo
from the tunercat help file:
WOT % Change To Fuel/Air Ratio Vs. Coolant Temp.
This table is the percent change to Fuel/Air Ratio used at or near wide-open throttle (WOT) versus coolant temperature. The values from this table and the WOT % Change To Fuel/Air Ratio Vs. RPM are summed to arrive at the WOT Air Fuel ratio.
The resulting air / fuel ratio can be calculated as follows:
WOT AFR = 14.7 / (1 + %Change vs Cool/100 + %Change vs RPM/100)
For the selected RPM, suppose the percent change to Fuel/Air Ratio from the RPM table is = - 5.1 and the percent change to Fuel/Air Ratio from the COOLANT table at the selected coolant temperature is = 22.7, then the approximate WOT AFR would be:
14.7 / (1 -0.051+.227) = 12.5:1 AFR
(in other words, higher numbers are more fuel, lower numbers are less fuel..... and a total of 13-14% in rpm and coolant temp tables should be close to a good AFR)
I got my injectors from these guys. Great prices and these people know what their doing.