Great work so far Andy, I like your approach to maintenance.
Enzio said:
Carbon@TheFanatics said:
Also, DO progressive kits are not really progressive. Go with PWM or a custom multi-stage setup.
Carbon, please advise why you say this?
DO kits, and most other progressive kits, vary in injected volume by changing the flow rate of the pump, thus altering the pressure in the system and as an effect also the nozzle flow rate.
Problem is, these nozzles require at least 4 bar to atomize, the check valve also reduces nozzle pressure by almost 2 bar and you still have to overcome manifold pressure. These kits use ShurFlo model 800 pumps that are rated at 10bar, although they claim to output 20bar, they wont last at those pressures. Then you have to increase pressure 4 times to double the nozzle flow. So you need 4 bar nozzle pressure to atomize, and 16 bar nozzle (not pump) pressure to double the original flow. In tests these pumps have been shown to have an increase of 50% at best. For it to be truly effective over a large rev range, you need at least a 200% increase.
This is not enough to make it function across a large rev range, so you are still very limited. The other problem is how slow the pumps are to vary speed under pressure, much slower than an engine can rev, so you don't get enough W/M when you need it. A two stage system has a larger range of operation, less parts to fail, responds faster and is cheaper.
PWM is better still, although it still has drawbacks.
Hope this helps.
ps. sorry for the thread hijack Andy