Injector angle curve

since my cams have a big over lap, should I make changes to the injector angle curve?

Mid week bump

Have you watched this webinar?

https://www.hpacademy.com/previous-webinars/061-optimising-injection-timing/

It will answer your questions! Yes you should probably at least try different injections angles -- if you aren't tuning on a dyno, it's unlikely you will be able to optimize this, but by paying attention to which angle produces the richest Lambda/AFR, you can probably improve the fuel economy if just tuning on the road.

Mid week reply.

Find out the best end angle by making coarse changes first and see if it has an impact on the torque output. Changes in end angle has some effect to AFR in the lower load zones (or duty cycle zone if you will). The reality though is that for peak power, the end angle has very little impact, unless the injectors are way oversized. I am sure Andre can explain it in a better way, in fact I recall a similar thread on the forum but I can not find that particular post right now.

Thanks!!

There is no 'right' injector end angle and it will depend on a number of factors including injector location and spray pattern. The easiest way to find out what your engine wants or needs is to simply test the injector timing on a dyno paying attention to both torque and AFR. The webinar linked to earlier discusses it in detail.

Hello, i have one interesting question regarding the injection angle. My originally tuned map had angles of 420 to 460 degrees that raising with RPM from 0 to 5000.

I've found that my idle is the most stable at 290 degrees injection angle (at 950rpm M52B28 engine). So my angles mapping left with big difference between 1500 and 2000 RPM: 1500rpm=290 degree and 2000rpm= 450degree.

When driving with such gap there are RPM jumps inbetween 1500-2000 rpm.

Questions:

1. What are the typical numbers for 3000RPM+ on these engines/

2. How should i put the angles increments to make the engine work smooth? Also is it possible to go from 290 degrees to 450 in a range of 2000 rpm for example ?