Timed Duty : Direct Port Injection

[parmas]

Rotrex what do you think about these?

https://www.google.com.mt/url?sa=t&s...tfW8oAQRHXrdaQ

[rotrex]

there are no specifications for switch times.
the closed thing I can spontaneously come up with is Aquamist's current valve.
But even this will be rather on the slow side for sequential port injection.
The next thing is that you then have a bit of pipe to the jet. With a ID of 1.5mm it has a inner volume of 18µl per cm or 180µl per 10cm.
The fluid volume injected per cycle will be of a similar order. This could or could not lead to issues forming a nice cloud out of a remote nozzle at the right time.

[parmas]

The article below made me believe that infact sequential injection may not yield any benefit over high rpm and wide open throttle

http://www.sdsefi.com/techseq.htm

[rotrex]

found the same link and actually though I posted it here??
Here is an other interesting read with some quotes from known companies.
http://forums.holley.com/showthread....amp-Paired-EFI

[parmas]

Originally Posted by rotrex

found the same link and actually though I posted it here??
Here is an other interesting read with some quotes from known companies.
http://forums.holley.com/showthread....amp-Paired-EFI

BEST Notes

1. Sequential injection will always get slightly better fuel economy and cleaner exhaust emissions. Also, according to page 152 of "How to Tune and Modify Engine Management Systems" (book by Jeff Hartman), sequential injection always gains power at peak torque and at peak horsepower.

2. With a highly atomized mix in the port, at intake valve opening, the lighter droplets of fuel will be partly blown back up the port [intake port reversion]. This is caused by the residual exhaust pressure [overlap period] still residing in the combustion chamber. Some of this reverted mixture will adhere to port walls and condense. This puddling fuel may find its way home, on the next intake cycle, but it will cause cycle-to-cycle air/fuel ratio variances.

3. At 8000 RPM the intake valve is opening and closing at 66 times a sec. and is only open for an average of 9 Mil/Sec.

4. "Fuel injected directly onto the intake valve yields a significantly better engine response"

5. Nozzle location should be as parallel to the airflow stream as possible
not be more than 45 degrees, although it can be less.

6. On the other hand, in theory, high-idle vacuum generated by mild stock engines permits placing the injector farther upstream without significant low-speed driveability degradation.

7. Moving the injector farther away from the valve allows more time for the air/fuel to atomize properly and remain in suspension when air velocity comes up at high rpm. This should improve peak power but-because of poor low-rpm velocity-at the expense of idle quality

8. On a 1,000hp engine, the injectors were originally located 7 inches back from the valves. Doubling this distance to 14 inches was worth 50 hp on top, a 5 percent gain-but "it wouldn't idle below 1,600 rpm.

9. A decent compromise for a hot-rod engine is to locate the nozzle about 1-2 inches upstream from the manifold flange to give atomization a chance, positioning the fuel rail at the best angle you can get away with and still package the harness and fuel rails

[rotrex]

so for you, you could leave the injectors for the petrol at the OEM location.
Install a second set of methanol injectors further upstream and/or pre turbo.
Run a 10l fuel cell with own pump etc. for the methanol or ethanol.
Red Victor, a 2000HP+ street legal drag car running methanol, injects both before and after the turbos.
Add water nozzles whee you deem them useful and skip the sequential injection.

If you need to inject all your fuel within those 9ms, you need really big injectors.

Question is if this is really worth the trouble for the HP goals you have?
As your car is FWD with limited tyre width you will likely already be at the traction limit as is.

[parmas]

Originally Posted by rotrex

so for you, you could leave the injectors for the petrol at the OEM location.
Install a second set of methanol injectors further upstream and/or pre turbo.
Run a 10l fuel cell with own pump etc. for the methanol or ethanol.
Red Victor, a 2000HP+ street legal drag car running methanol, injects both before and after the turbos.
Add water nozzles whee you deem them useful and skip the sequential injection.

If you need to inject all your fuel within those 9ms, you need really big injectors.

Question is if this is really worth the trouble for the HP goals you have?
As your car is FWD with limited tyre width you will likely already be at the traction limit as is.

The present plan :

- 4 nozzles (working on sizes) into the intake plenum runners running a 50/50 mix of water/methanol. The car is street driven and could happen to stay parked hours in the sun. A 10ltr pure methanol tank in the trunk would be actually dangerous especially in direct sunlight moments.

- The engine will be a 12:1 compression so injecting at low boost is critical. Engine is targeted to reach 330bhp @ 14psi. Actually preparing the engine for 400bhp+ but the turbo is the limiting factor.

- The water/methanol injection is going to be used mainly for high compression safety even at low boost. Second is to use the WM50 system to increase efficiency of the engine by set it as a base fuel @ wide open throttle. Target is to reach current power level with the least possible boost.

- I saw FWD running high 8sec 1/4miles with 600bhp levels.... so why not shooting for 400bhp.

The question is would you prefer get to that level with More boost or More methanol ?

[rotrex]

at this CR level, you need both, boost and high octane methanol.

How do you handle the torque steer? Are you running a LSD?
It definitely sound like a exiting car to drive :-)
I had a 1989 Honda Civic Si while living in the US.

[parmas]

Preferably low boost + high octane for now.

The intension is not only fun but efficiency. The engine is intended to be more economical during light cruising and on very low boost compared to a new stock toyota engine. Also emissions should reduce dramatically with the high compression and water injection. VRT pass test will be the result.

Performance wise - I can only imagine the feeling WOT on 3rd gear will be. Intercooless + 6spd gearbox + LSd + high comp + ball bearing boost.... Well exquisite

[rotrex]

I operated my engine at a CR of 10.5 before. Low down torque and economy are better.
I went from 8l/100km to 10 l/100km just dropping CR.
On the positive side, tuning under boost became much easier and overall power in the power band from 4K to 7k rpm increased.

Under full boost, that little intake volume is irrelevant at 300l of air a second.