| There has been a good deal of thought over here at Z1 concerning some of our recent accomplishments and I would like to discuss a few things here. Please treat this as Steve Simmons once put it, "as a graduate level message forum" and try and back up your statements as best you can. I think this is an interesting subject and I'm sure there are people out there that can contribute some good hard data to the discussion. There have been two vehicles that we have tuned that have performed at the 740HP level using TD05-16G turbos, 60HP wet shot of NOS at the throttle bodies, and two N2O fogger nozzles aimed at the FMIC. The consistency of these two cars is astounding, only differing by less than 1% in horsepower output. There has been a good deal of information gathered about these setups but there is always more information to be had. Knowledge is power, er, horsepower. =) Kyle of SGP racing posed the question, "do you think it will make that kind of power all the way down the track?" This is indeed a very good question. Its not one as easily answered as you may think, and albeit, that is quite a vague question as well when you really think about every aspect of what occurs in the period of time that the car hurdles down the track. Bottom line, although the finality of question will be either a yes or no once testing has been done, there still is no clear-cut answer until that happens. There are a number of approaches to answering this question, but ultimately it can only be determined empirically. No, this doesn't mean to take the car to the track, turn the boost all the way up and blast off the line with full NOS running all the way and see what happens. That would be asinine. A slower approach, much like what is done on the dyno when tuning a car, would be the ideal way of doing this. Starting at low boost and triggering NOS only in 4th gear to see how she takes it, watching EGTs and 'feeling' how she progresses would be the first start. Then perhaps bumping up the boost to 18psi and once again performing a run with only 4th gear in NOS mode. So on and so forth.. In the end, I feel that what one will find is that triggering in 1st or 2nd gear will be futile; you just aren't going to hook up 700ft/lbs of torque. 3rd gear is even iffy. It would undoubtedly detriment the ability of running the best ET and MPH by trying to run that kind of power all the way down the track. Traction is your weakest link. Would the car hold up at 740+HP shooting NOS in 3rd and 4th gear in the 1/4 mile? I'd actually bet it would do it even starting from 2nd gear (if you could maintain traction) and from that point on, all the way down the rest of the track. Now this is assuredly where the difference of opinion begins, but I hope to back up my claim with reasoning that at this point in time I believe justifies the claim. Think of this for a moment:
A twinturbocharged ZTT, using GT2835's and on turbos alone it produces 700RWTQ. The amount of air and fuel in the cylinder that is required to produce this kind of force is around 830psi in the cylinder. With pressure comes temperature and the thing to keep in mind is that they are very closely linked. Pressure is actually derived from kinetic energy, and kinetic energy is what we relate to as temperature. When the cylinder is under such pressure, it is as a result of the oxidized fuel. The source of oxygen in this case is atmospheric air, about 21% oxygen by mass and 71% nitrogen. When the long hydrocarbon chain molecules of the fuel oxidize, you produce thousands of seperate oxidized compounds of hydrogen, carbon, nitrogen and a few other smaller proportions of sulphur dioxide and trace elements. This 'breaking up' of a long single fuel molecules into thousands of smaller components generates heat, and a lot of it. It also produces an enormous number of smaller particles as noted above. The combination of temperature and the drastic increase of seperate oxidzed elements causes the pressure to skyrocket. This pressure/temperature is what pushes the piston down in the cylinder and produces power at the crankshaft. Now, lets consider a more familiar setup. TD05-16G turbos producing ~520RWTQ and add a 60HP wetshot at the throttle bodies AND shoot N2O at the intercooler. We have all seen the 700RWTQ figure that Wagz's car produced. So in this scenario, we are seeing a combination of factors produce the same power results. So you gotta ask yourself the question: If the turbo only setup is making 830psi in the cylinder and the turbo+NOS setup is also producing 830psi in the cylinder, what's the difference? 830psi is still 830psi, correct? It has been my experience through the power upgrades I have made on my own car that even when I started making more power, my EGT's did not go up any more than at a lower power level as long as the A/F ratio was the same. On Patrick Heard's car (Outlaw racing), the EGT's were right in the same range as what I see on my own personal car running 400RWHP. He also is running at the same A/F as I am. This all leads me to a conclusion that logically makes sense. If the car is properly setup and will consistently produce the same, safe results, I dont see why there would be a problem with using N2O to produce more cylinder pressure. Certainly chilling the FMIC adds a bonus to the scenario because it keeps the charge temp much cooler and that wards off detonation. As well, the throttlebody injection is like an aquamist on stereoids in its cooling ability. Guys with aquamist boast of the fact that every day feels like a 60 degree day in terms of power output. This is due to the cooling factor involved with the setup. In a number of ways it actually seems safer to use N2O in the setup used on these cars. The fact that two cars, within a couple weeks time, using the same exact setups and still on a ~stock bottom end produced these numbers back to back without any problem does say a bit, but admittedly it doesn't tell us exactly what it will do on the track under heavier load. On the track:
Once the car has left the line and proceeded through 1st and 2nd gear at the 520RWTQ level, the car will be moving at about 60MPH. Entering 3rd gear, the NOS system is activated and as soon as the clutch is released and the pedal is WOT, the NOS spray begins both at the intercooler and into the throttle bodies. 60+MPH air is slipping throug the intercooler and as the turbos quickly spool back up, the N2O has already begun to cool several parts down and maintains the charged air at a much lower temperature than previously seen in 1st and 2nd gear. That cooler, denser charge has greater resistance to detonate and once the plug goes off, cylinder pressures have now gone from ~500psi to ~800psi. The A/F has now dropped from 11:1 to just below 10:1 and EGT's hold steady. Hopefully the tires hold true. 4th gear comes much quicker than 3rd and the car tops out at the top end of the track. Granted, this is my hypothetical of what occurs in the ~10s down the track, but I know what it does without doubt in the 5s on the dyno. I'm open to any corrections or suggestions on my logic. I'm hoping that someone can take a closer look into the combustion dynamics I have proposed and go from there. Thanks for reading if you are still at it - I figured I would have weeded out those that have no genuine interest in this sort of stuff a few chapters ago. =) I look forward to seeing what you have to offer on this subject. Excting times!
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