Max Boost on stock injectors?
 

Right now I have 272's intake, exhaust safcII tuned for 11:8 and am hitting fuel cut at 20.5.. I am having the fuel cut removed and rev limit raised.. also headstuds installed... Whats the max psi I can run on c-16 on stock injectors???? I am curious to know this. As I am planning on making a good pass then not running until I do alot more mods. Thanks in advance

Andrew

32psi is the highest I've seen the stock turbo spike to on VP c16.

I was curious to more so know how much boost I could make on stock injectors keeping the a/f no leaner than 11.8:1.

With a 50/50 mix of VP c16 and Shell 93, I had an a/f ratio in the mid to high 11's while spiking 30psi... I'm sure 32psi wouldn't have changed much.

Trust me, anyone with a stock turbo has no need upgrading their injectors... too many people think it is required, but it is simply not. It's more effecient to size your injectors as close to the size that you need for your application... meaning over-sizing your injectors can be harmful to performance as well.

First person I've heard speak some truth about injectors. {thumbup}

I hit in the mid 20's psi wise on stockers but I dont think going that high is very good for them. I now have 720cc's and hit 26psi all the time. The car responds so much better when the injectors aren't being pushed to their limits, and it makes everything work better and smoother.

I'm not near 100% injector duty cycle @ 100%... hence, not at their "limits". You have 720cc injectors and running less boost than me and saying it makes everything "work better and smoother"... and "responds so much better"... can you please elaborate into technical terms or is it just a placebo effect from spending extra money on something you don't need?

I'm just trying to emphasize the wastefulness of over-sizing your injectors on a stock turbo application.

You're holding 30 psi to 7000 RPM? What's your injector pulse width at that point?

THats BS because my friend gained about 15LBS of torque with same set up and 650CC injectors. More fuel better numbers. Not needed but dont say that when you blow your engine.

ctrl + f; "spiking"; enter

At redline, it tapers down to 23~24psi or less.


In that case, let me go buy 1,000cc injectors for my stock turbo and run them at 99%duty cycle for max power.....

running insanely rich or having a very low duty cycle on your injectors does not yield more power... not sure who told you this.

I have stock injectors. I hold 21.5 psi and tapers at 21 solid with hallman. I have a spike of like 22 psi from time to time.

So what is your injector pulse width at 23.5 psi 7000 RPM?

19 psi to redline and injector duty cycle is mid 90's. I suggest upgrading to atleast 680's so you have more room to work with.

if your heavily modded, the stockers won't cut it on pump gas, even with the wablro's bump in fuel pressure. i have 264/272,10.5,hks drop in,tbe, aem ems, and i'm running around 93% duty @ 19psi@7k rpm. i'm not sure if the stock ecu adds fuel and pulls timing like the aem does, but you would want that last 5-10% of fuel the injectors have in them for different weather conditions and such. i don't see any problem running the injector up to 100%, but you want some head room. at that point the injector is held open solid just like a nozzle. the stock injectors should be able to handle racegas alot better because of the leaner af's. you figure your going from 11.5 to around 12.5 af's which gives you somewhere around 10% more injector. you could buy an adjustable fuel pressure regulator if you wanna go cheap and bump a little more pressure into the rail, but it will strain the pump more and lower it's flow rating also. there are also many different injectors out there with different flow patterns that can effect power.