Nitrous Oxide 2011

6-14-11 It's been almost three years since completing this engine, about 2 years since (nearly) completing the EFI conversion and now finally the nitrous is nearly completed! I have set up and programmed a "dry" two stage progressive system...

In the following picture, you can see where I have upgraded from the very poorly designed and unequal flowing distribution blocks to much better designed ones (But even better will follow!)...

Here is one of the four NOS foggers, notice that I am spraying nitrous in both locations...

Here the bug is strapped down for the dyno pulls and tuning...

Mad scientist at work...

After tweaking the N/A map a bit (still needs more work) I did some pulls with a .014" jet in each nozzle.  I sprayed through the top side of the fogger nozzles and then through the bottom side with identical results.  After that I did with .014" on the low side and .020" on the high side.  Then with .020" on the low side and .024" on the high side.

I am spraying the nitrous "dry" and having the computer add the extra fuel.  With the nitrous at 900psi, having about 2 feet of line to each nozzle and the fuel injectors pointing right to the intake valves with 45psi, there appears to be no signs of any lean spikes upon activation! 

I will have to play with it more later, however, currently here are the modifications that I have programmed the system to do with the following sizes of jets....

.014" = 2 degrees of timing retard and 12.5% more fuel.

.020" = 4 degrees of timing retard and 25% more fuel.

.024" = 6 degrees of timing retard and 50% more fuel.

Here is how the relays were wired up (Click here for current wiring) for 2013 it will be a bit different too!....

The "GPOs" are low side drivers in the EFI computer that I have programmed to create a ground path at the desired RPMs.  In order, they turn on the system, switch from the 1st stage to the 2nd stage, combine the two stages for a third level of power and finally shut the system down at high rpms.  Later on I may add a first gear switch that will allow the system to not activate until 2nd gear and a fourth gear switch that will bypass the high rpm shut down (just in case I have to rev it a bit more out the back door!)

Here is how I wired up the relays that tie together the wires for the air intake temperature sensor and the coolant temperature sensor.  When activated, this "tricks" the ECU into thinking that the temps are at the high end of the scale, whereas I have mapped it to add fuel and take out timing...

(This page... http://redlineweber.com/html/Fuel_Injection/fuel_injection_software.htm has some info on the computer that I am running.)

Best numbers (at the wheels) so far on the dyno are...

...with .020" nitrous jets... 315 hp and 273 ft/lb of torque

...with .024" nitrous jets... 348 hp and 288 ft/lb of torque

The dyno chart below shows a dyno pull with out nitrous vs. one with a two stage smallish shot (.020" jets then .024" jets).  Tune is not ideal, however the air/fuel ratios are about the same.  (Also there was severe tire hop and slippage on the nitrous run, so once new tires are installed, the numbers should increase!)

For anyone not familiar with dyno charts, the red lines are the horsepower, the blue lines are the torque and the green lines are the air/fuel ratio.  (The slightly lighter of each is of the nitrous pull and the darker ones from no nitrous.)  The bottom row of numbers is the engine rpms and the vertical numbers are the air fuel ratio.  The HP and torque number got cut off of this pic.

Notice the area on the non nitrous pull from about 5,200 to 6,700 where there is a noticeable dip in the curve.  I believe this may be caused by the throttle plates and intake runners being too large?  Also the sharp drop off at about 6,800 I believe is from running such a small cam for the rest of the combo.  I believe if I were to either increase the cam size, decrease the intake runner diameter (and possible increase the length) both areas would improve.  Most likely I will eventually try a bit smaller and longer intake runners and a cam with the exact same intake lobes, but larger exhaust lobes and a wider lobe separation.  (I would like to try an FK-10 on the intake side, FK-89 on the exhaust side and 114 degree lobe centers.)

Here is a graph with three different power levels.  The first is with .014" jets in both 1st and 2nd stage locations.  The next up is with .014" on the low side and .020" on the high side and finally with .020" on the low side and .024" on the high side...

The above dyno charts have the "smoothing" feature turned on, however the following ones do not...

This first one is with .020" nitrous jets (notice how at 4,000rpms, when the nitrous is activated, the power climbs)...

This one is the same as above, but with the air fuel ratio showing (I did this one with more fuel)...

I plan to play more with the base map and then see what the engine likes best while on the bottle as far as fuel and timing.

This next one is with .024" nitrous jets.  Note: the tires starting slipping & bouncing so bad that I lifted early on the pull...

This next one is just simply the two above overlaid...

Before I take it to the track, I will finish the transaxle, replace the slicks and upgrade the safety equipment, then I plan to improve the N/A & nitrous maps.  After that, I will set it up to be able to progressively use the low stage, high stage and then combine the two to effectively get three levels of power increase out of two stages of nitrous.

After that I intend to upgrade to a WON X-10 Pulsoid set up with this controller and then...

Eventually.... this will be the ultimate upgrade .... (CLICK HERE)  ...someday!