The objective of these tests were to see what the effects of our water/methanol injection kit, NOS and the use of both and the effects

It also was to prove that installing a NOS nozzle before the MAF had zero positive verus installing after the MAF
Tests showed in fact that the PCM who calculates delivered torque cannot measure increased torque since the MAF cannot measure NOS content even when NOS is flowing through the MAF

Dynoshop used was : Extreme Dyno Tuning

Weather 89 degrees, 3,600 feet elevation
Mustang Powerdyne load bearing Dyno adding load to equal 3,500 lbs of car.
NOS = 150 shot installed before the MAF on purpose to test a point
50/50 ratio water/meth injection
Water temps never got over 187, oil temps 192 for all 4 runs.
Went in with full tank gas, still on full when left shop
NOS 10 lb tank was full minus 1 street NOS run
NOS Tank was monitored for it's heated temps was from 90 to 150 degrees
Dyno weather station verified to be working correcting

Rear end gear 3.73, dyno started at 75 MPH.

All 4 runs were done with hood down and small fan close to ground level in front of car

Corrected SAE numbers rearwheel for Team ZR-1's 1999 Rebel

Quick Results




Dyno results

N/A - powertrain only



Water/Methanol only



WI and NOS functional



NOS only



Scanner data when using NOS
This shows that the PCM saw zero increase in torque even though NOS is flowing through MAF. Is a false notion you MUST install NOS nozzle before the MAF and in fact best case is AFTER the MAF



Scanner data for all 4 dyno pulls



NOS dyno pull

I do not trust the numbers chassis dyno's report so to do a small compare here is Steve - C5 with heads, CAM, headers, larger injectors that was on the same dyno I was on with the Rebel.

Compare these closely and tell what you see

This is from start to end of 1 dyno pull for both C5s that both end of pull just over 130 MPH.

Graph is RPMs, MPH, elapsed distance and time






Here is a compare of MPH and the time it took Steve's C5 (S-MPH) and the Rebel

This is taking the PCM scanner data recorded during the NOS pull and by using math to see if dyno results were close to real

NOS clearly had more increase on torque then HP

Installed the NOS nozzle AFTER the MAF and did a testrun where our WI controller not only controlled when WI was on but also was the trigger for NOS coming on.

This test proved 2 cyberspace myths are FALSE

1. NOS must be injected BEFORE the MAF
2. You cannot run NOS with WI also on.

Both are total bull and in this configuration function just fine.

This really tells you vendors who sell NOS for nice fat profits know crap about how NOS functions and its effects to the engine when PCM is properly custom tuned

Here is the scanner data and as seen IAT (intake are temp) dropped from 80 to 45 degrees in a 80 degree weather and fuel trims when at part throttle around +/- 2 % and at WOT were at zero.



This shows that there is far more negatives when NOS is sprayed through a MAF and also the dangers to damage to the MAF

Here is the analyzed scanner data for that testrun

As we see the PCM cannot see the effects of NOS itself including the added torque when NOS is on since torque is calculated by airmass and NOS does not release its oxygen until in the cylinder and its heat releasing the O2 atoms

Here is third test with NOS and then calculating all scanner data by math to see what the realworld numbers look like

What happens in SD tuned cars?
Does the PCM calculate torque using the VE table?

Timing is an air quantity related function too (G/Cyl vs. rpm). How calculates the PCM G/Cyl? from the MAF signal? (G/sec).
And again: what happens in SD?

This is not about SD tuning, if it makes sense or not. It's just to know how the PCM works without the MAF signal.

As you know I dislike SD so I cannot answer NOs effect when SD is used but as to the MAF anytime PCM is being lied to as to the true airmass then torque values reported are also incorrect and reason I rarely would consider changing MAF and VE tables not only for correct Tq values but also line pressure for A4/A6s

I have seen many, many OBD scanner recording and when MAF is screwed with the delivered torque values PCM reports are never correct and have seen auto shifting effected due to then line pressure also then being calculated wrong

Good example is GM finding A4 failures due to over oiling 3rd party aircleaners getting onto MAF sensors and line pressure then reported incorrectly

This test result of having N20 spraying into the MAF that those believing this is a must have their head up their ass.

Taking the stock GM MAF table ( shown in red line ) and plotting the actual airmass with N20 on and spraying into the MAF reported no different then when N20 is off.
In fact even with this stroked engine producing 460 rearwheel HP (590 with N20 on ) the grams per second is no different then what stock reports and shows even porting a MAF does not require hacking the MAF table values in the PCM.

If as others state N20 must spray into the MAF then the actual values would be much different yet N20 is spraying into the MAF yes the grms/second is the same as if N20 was off