DTECH-RX

I'm no nitrous expert, but I would think it would be similar to tuning forced induction, using an air/fuel gauge and other indicators while slowly injecting more nitrous and tweaking the fuel map along with it. Or you could just wait for a tuner to do the R&D for you and just buy the appropriate components for the respective HP boost you want.

As for how long it would last would depend on how big the cylinder(s) is/are and how much nitrous is being metered into the engine, but of course nitrous in not really suited for long distance racing.

wakeech

oh hell no: drag only. having to carry one fuel is bad enough, no one needs two.

anyways, the tricky bit with nitro is that it doesn't need the same amount of fuel as air (i dont' know if its more or less, but not the same), and so trying to match fuel curves with a highly variable flow of nitro along with variation in air flow would prove to be quite the task... seeing as how you'd really only want WOT when you're using it anyways (accelerating at maximum), it's just plain simpler to tune it for one condition.

Boozehound

Not trying to steer back to FI, but the supercooler is a secondary evaporator that sits in the air intake. When extra power is demanded, the AC diverts freon from the evap in the cab to the evap in the intake. This in effect air conditions your intake charge. Pretty neat idea, and apparantly the hurdle up to this point was making sure that if the coolant leaked and was combusted, it wouldn't spew really toxic stuff with the rest of the exhaust.

On the more technical side, I'm interested in finding out how you can use energy from the engine to increase the power of the engine itself. Every time I do an energy balance in my head, I keep going in circles... maybe it has something to do with adding efficiency to the chemical energy of the fuel's combustion... or maybe I just need to accept Ford's dyno numbers

babylou

The Ford setup does not increase power by increasing efficiency. It simply allows a denser air charge and therefore more fuel can be injected. More power from more fuel does not equate to increased efficiency.

Boozehound

It's not a more efficient combustion? Doesn't increased charge = increased conversion of chemical energy to thermal/kinetic energy? More HC molecules combusting right? Wouldn't that be increased efficiency?

Sputnik

Okay, but to get the fuel mixture right, as in good enough that you limit the possibility of detonation, you will have to do more than something simple like adjusting fuel pressure or a simple black box that fools the ECU (like that which comes with the JR supercharger for the Miata, for example). To get fuel and timing as consistent and stable as we're talking about, you would have to replace the ecu with something programmable. At which point, you are starting from scratch, on a evolutionary design of a rotary engine (meaning, you will be the first, unless you want to wait a couple of years. And even then, those who are the first, normally aren't going to readily tell you how to do it).

Anyway, my point is not that it can't be done. My first point is that it will take as much to tune the engine to the point that you described for nitrous, as it would to tune it for FI. It can be done, but you do reach the point of diminishing returns (in this case, performance for money/time/effort spent) so that it doesn't offer a better solution than FI 99.9% of the time. My second point is that I don't see nitrous being more effective in a rotary than in a piston engine.

---jps

Sputnik

Then it is A/C based. I'm going to have to search to see if I can find a diagram of how they have things hooked up (as in do they have the evaporator directly cooling the intake charge, or do they have the evaporator cooling the water from an air/water IC setup).

It's a bit of added weight, and saps power off of the engine. So, if you can get an air/air IC to be effective for a certain setup, it would be much more preferable. If you can make an air/water IC work, it would be preferable. But that's not to say that the "supercooler" or "intracooler" don't have their places.

---jps

babylou

Boozer,

Efficiency is what percentage of chemical energy within the air/fuel mixture the engine converts to mechanical energy (power). An increase in efficiency will invariably result in increased gas mileage and usually result in increased power. For example, putting a turbo on a car will make the engine perform as if it was a larger unit. However, the gas mileage will not improve. Taking the same engine and reducing the friction in it will make more power and get better gas mileage.

SlideWRX

I wouldn't be suprised if there is 15+ hp available from a good exhaust. On the WRX, replacing each cat with a straight pipe adds ~10 hp. Dyno runs have shown about 30 hp from a catless system (yes, we have three cats). The improvement down low for us was lag improvement(doesn't apply here), but the high end would be the same as a NA motor - all Volumetric Efficiency improvement.

Also, a good cat design is available, but too expensive for OEM.

http://www.randomtechnology.com/technical.html

Shows a couple examples where the cat didn't hurt hp compared to no cat at all. I'll bet a good header and exhaust could give 20 hp without a problem. It would likely be lighter by 10-15 lbs, too.

Tom

Quick_lude

Tom, the WRX is a much different engine with a turbo no less.. Afaik, turbo charged engines have always responded very well to a more free flowing exhaust, including the turbo rotary.

Babylou brought up a good point though.. most of these "hp gains" will be realized at the very top end of the power band, probably 7K and up. And while I will drive at those rpms sometimes I think most people would love to get more gains across most of the power band. For example on my current car, swapping a set of smaller pulleys is very popular, it usually gives a gain of about 3 whp across the full power band. Can something like that be done on the Renesis? The downside of this is that the smaller alternator pulley doesn't charge it as well.. and the headlights dim at idle rpm.

Sputnik

This especially goes for cars that come turbo from the factory. The exhaust seems to be tuned from the factory for quickest spool-up and to get the best economy at cruise/idle to make their necessary fuel economy numbers. This means that a bigger exhaust really helps flow at stock boost levels. Since turning up the boost a mere couple of pounds increases airflow much more than any NA bolt-on could hope to, the size of the exhaust makes an even bigger difference.

---jps

wakeech

pulleys, a lighter flywheel, uh, lower drag waterpump(??)... there's only so much you can do, as far as reducing rotating mass without opening the engine... but anything you did to your Lude you can do to the RENESIS, even though there are less pulleys, no timing belts and whatever...