chip help and tuning questions

[Tylerz281500]

Whose the local guy to burn me a base tune, long story short last time tuning my laptop took a nose dive out the window. my motors about shot and i need ill need a new chip. can give every engine detail and trans detail, gears tires etc. wasnt planning on getting back into it just yet, figured i could throw a fellow member some bones for some work? i used to work greatly with mark back in the day, rest his soul.

secondly, is there anyone tuning 6.5L diesels? they make chips for them, i was looking at a 94 3/4 ton and my buddy mentioned they had a buddy chip, id be interested to learn more if anyone can direct me to them, or know anything about them personally.

also whats everyone doing for VAFPR's nowadays. seems like its impossible to come by

[dave w]

Send me a PM, maybe I'll be able to help out?

I've discontinued my R&D for a Vacuum Adjustable Fuel Pressure Regulator (VAFPR) for TBI. To date, my data supports using a "good match" Injector Flow vs. Static Fuel Pressure. Typically, near stock fuel pressures using the appropriate size injector works surprisingly well for most engines with performance levels of about 1 HP / Cubic Inch or less. Typically, MPFI is a better option for an engine producing more than 1 HP / Cubic Inch.

dave w

[Tylerz281500]

i think ill have plenty, i have a 454 tb ill have likely about 1hp/cyl conservatively. how would i proeprly figure injector flow vs static?

[Tylerz281500]

As far as a a vacuum adjustable can i use an external and block off the diaphragm area on the tb? as long as its a return style vacuum regualtor that is? Vacuum seems like the best way to go for better fuel control at varying throttle ranges.

[dave w]

As far as a a vacuum adjustable can i use an external and block off the diaphragm area on the tb? as long as its a return style vacuum regualtor that is? Vacuum seems like the best way to go for better fuel control at varying throttle ranges.

I subscribed to that theory, until I started researching and using actual data logs for evaluation. The quick summary, the TBI VE table is not responsive enough / or does not have compensations for the changes in fuel pressure. The variance in fuel pressure vs. vacuum cause HAVOC on the VE Tuning! Ideally the TBI would need an additional injector offset table for vacuum, like the LSx engine computers have for injectors.

dave w

[myburb]

I also experimented with variable pressure with tbi with 6395/7427 pcm an gave up as it ran much better without.

[Six_Shooter]

I've very successfully run a VAFPR on my friend's TBI injected Olds. However, there is likely a large difference between his TBI system and most others, and that is he has 4 injectors and not just two. The extra capacity of available fuel is likely why it works well. We couldn't get enough range out of the VE table to leave the vacuum reference off. We could get a good idle. OR great top end power but not both. Using the vacuum reference has allowed us to get both. He is over the 1HP/c.i. which may also have an effect on how this works.

Currently we are using a '7060, but plan to swap it to a '7427 for the (RPM) extended VE and spark tables.

[Tylerz281500]

so it seems a few things need to happen. VAFPR im thinking based on yalls judgements is not the way to go so i need to find me a new laptop and possibly 7427 swap in the near future. ill have to find the writeup on that again.

does anyone think vafpr would be a temporary solution til i can afford a new laptop or just stay away?