adm030

All my mods are iny sig I'm wondering if I would notice anything from adding fuel I read an article and it goes on to say that most tbi vehicles run anywhere from 11.5-13 stock and with mild mods should run anywhere from 13.5-14.5 psi of fuel pressure this is from cfm tech will this interfere with the chip that was burnt for me or not and should i gain anything from boosting my fuel pressure some. Let me know what yall think. I 'm trying to figure out what else i can do besides ripping into the motor thanks.

UnderCover89TBI

iTrader: (25)

stock tbi's run between 9-13 psi. I wanan say I read on here that bumping it up to 16 psi gains some power. but of course you lose MPG. its a good mod either way. and a lot of the guys swear on a VRFPR which is a vacuum reference fuel pressure regulator. its take a vacuum reference and adjusts the pressure as the vacuum drops as higher rpms are performed. Do a search and you'll see what other's have done and their results.

thomas1976

That chip you have is alredy pouring in more fuel. If the engine needs more fuel, ad fuel, though it has to be tuned according to the new fuel supply.

The VRFPR is used to reduce fuel supply at low rpm and idle, there is hardly any benefit with #55 lb/hr injectors up to 16psi.

Every LO3 that I have mesured the fuel pressure had 11.5 psi.

I would say the next smart step is dataloggin and tuning.

adm030

Thanks will I notice any improvement over the tune I already have, I don't plan on doing much more to the motor but I guess if I knew how to tune i would go inside the motor and change a few things. In other words do you think it would be a significant improvement over what I have now and how much do you think it would be if i could get it dialed in correctly. Thanks for your help.

thomas1976

Just noticed you have 1.6 rockers, will probably need more fuel then stock at WOT.

A coustom tune will certainly increase efficiency (including power).

xch3no2

Next invest some time & money into data acquisition.

A wide-band oxygen sensor, laptop, data cable & software are a good start.

How can you know what improvements can be made until you know whats going on?