Mongo

MEH! You have 7 more cylinders to go!

Brett928S2

Hi

It actually ran quite well on 7, I had to listen hard to hear the miss lol...

All the best Brett

mark kibort

a little late here, but dont forget the little evo 2.4 liter engines that are un modified bottomends and running 450rwhp. or the un-professionally built S2000s that lasted a full race season running 330rwhp out of a punie 2 liter.

I dont think the stresses are anything that the 928 engine cant handle. I think you have to remember, its all about mass flow. If he can get the NOS and fuel in there, he should be able to get some enormous power. Dont know if 1000hp is possible, in reality, but im sure it will be more than you are giving him credit as a potential.

Mk

Darien

Hi Brett,

Please tell me you had someone with a video camera...I think we'd all like to see that run

Keep it up

Wade T

The vast majority of EVOs are the 2.0L. Those have made north of 500rwhp on stock internals. But that's a bit deceiving since they are built for boost from the factory, with beefed up bottom ends and good engine managment systems. Same holds true Supras, WRX's and other factory turbo'd cars. And, boost is a very different animal from N2O.

mark kibort

I saw the internals of the 2.0 S2000. they look pistons and rods from a lawnmower. 330rwhp, and some going much higher is easily near 1000hp on a 5 liter . But, this is run for a lot of hours on road racing courses. The point is, the components of a 928 are pretty strong. Dont think they are the weak link here.

What would you say the major differences are with boost vs N2O (NOS) in regards to engine stress?
as was said before, NOS is probably an easier way to make big hp, than boost with less of the problems as far as detonation, and a more controlled intake charge burn, due to the nitrogen bonds to the Oxygen. (not to mention the extremely cold tempurature to start)

Its all about mass flow and if can get it to ignite in a controlled fashion, the piston wont know the difference. cylinder pressures, post ignition will generate the forces that act on the piston. I dont see any major differnces, but maybe you can enlighten me.

PS, there are stock internal Evos with 500rwhp with the stock 2.0 liter displacement? I wonder why Kent Jordan and his Evo racer, had to go to the 2.4 liter stroker (might be 2.3L, i forget), to get 440rwhp at near 27psi boost. (bigger turbo, ECU changes , head work, etc)

mk

mark kibort

Here is an evo with near 600 rwhp and it doesnt look that special! ( 2 liter folks! and 31psi!!)

http://www.dragtimes.com/Mitsubishi-...slip-9783.html

AO

Brett-

You need to lay off the nitrous until you get it moving. You probably could have done better without the nitrous... ? Any plans on putting in a LSD? Anyway, glad to see it works. Bring spare plugs next time.

blown 944

as a response just to the comments you presented:

I am fully aware of small engines making big power. Most are turbo charged , a pretty big difference from nitrous oxide b/c teh forced air along with a proper exhaust can create well over 100% VE numbers.

The point I was really making is that the engine will not flow enough air to make the kind of power he was looking for.

When I was building nitrous engines one of the first things I would look at is the headflow. As I understand the heads he has are most likely flowing around 200 cfm and it would take somewhere around 320cfm to make the kind of power he wanted. Wtihout headflow all other components are severly compromised.

all other components may hold up to around 600 maybey 700 hp with a perfect setup. Again though the car is not optimally setup.

If you think I believe the 928 engine is weak that would be incorrect. If he were looking at using a very efficient s/c or a turbo to accomplish this I would think he would get closer but not with nitrous. The head and components are THE restriction here.

I guess the results speak for themselves. BTW don't bother trying to BS me about the tire spin. I have personally spun all the way down the track with a 1000 hp car and it still went 148 mph.

I am glad to see some out of the norm thinking but please be real.

mark kibort

I dont believe that flow rates will have that much to do with NOS performance. as long as you have some cylinder filling, the NOS will be much more dense, vs normal air. remember the stats I quoted previously? NOS alone, if it was just a gas would be 2X greater than air. ( 40% more Oxygen, and 50% more density at room temp)

in vapor form, it could be greater than 3x the density (which it is), giving a 4x potential greater than air for a given volume potential. ( 3x density x 40% more oxygen ) it would be no where near hydrolock. All theory , you are right, but if he can fire off NOS at each port it will stay in vapor form as it enters the cylinders, atomized near the port with gasoline.

I was able to run my car with the throttle plate closed (can you say, "restriction" and had close to 75hp of the 75HP shot powering my car up hills at sears poing on a warm up lap, as i was trying to see if it was working.
It was. no air, just NOS and fuel. we dont need 100% VE , we just need to make sure the NOS is vapor as it enters the cylinders. then, you have some pretty high densities over air. certainly enough to do 3x the HP, (i.e. 300hp x 3 =900hp)

I had one nosile feeding the plennum, so I imagine that port based injection could easliy put the fuel and air i was feeding into the entire engine, in a sigle port. (ie 600hp added to a 300hp engine based on a 75 shot on each cylinder)

I see your point though, the question is that under best conditions, will the port flow 200cfm? will you have 3-6x the density with NOS based on a fogger nossil, matched with 1/12 mass of fuel. a ball park answer would be , it should. but i dont know for sure. But, knowing what we do know, i dont think the flow restrictions are an issue. using those values, and knowing the density increases, one can see that it is possible.

mk


Here are the stats for a given volume of air or NOS, and also the density of NOS vapor vs air.

From a popular website, you can see the obvious here.

http://encyclopedia.airliquide.com/E...a.asp?GasID=55

at just above the boiling point of NOS going from a gas to a liquid, its density is still near 1000times that of what it would be as a gas. even the temp difference of boiling point vs 59degrees F, is a factor of 3.
If NOS can be injected directly in the intake, there is no doubt that the HP potential is well over what Z has said is a limitation.

mk


For NOS:

Liquid phase

Liquid density (1.013 bar at boiling point) : 1222.8 kg/m3
Liquid/gas equivalent (1.013 bar and 15 °C (59 °F)) : 662 vol/vol
Boiling point (1.013 bar) : -88.5 °C
Latent heat of vaporization (1.013 bar at boiling point) : 376.14 kJ/kg
Vapor pressure (at 20 °C or 68 °F) : 58.5 bar
Critical pointCritical temperature : 36.4 °C
Critical pressure : 72.45 bar


Gaseous phase

Gas density (1.013 bar at boiling point) : 3.16 kg/m3
Gas density (1.013 bar and 15 °C (59 °F)) : 1.872 kg/m3
Compressibility Factor (Z) (1.013 bar and 15 °C (59 °F)) : 0.9939



For Air:

Liquid phase

Liquid density (1.013 bar at boiling point) : 875 kg/m3
Boiling point (incipient boiling point) : -194.5 °C
Latent heat of vaporization (1.013 bar at boiling point) : 198.7 kJ/kg
Critical pointCritical temperature : -140.5 °C
Critical pressure : 37.71 bar

Gaseous phase

Gas density (1.013 bar at boiling point) : 3.2 kg/m3
Gas density (1.013 bar and 15 °C (59 °F)) : 1.202 kg/m3
Compressibility Factor (Z) (1.013 bar and 15 °C (59 °F)) : 0.9992
Specific gravity (air = 1) (1.013 bar and 21 °C (70 °F)) : 1
Specific volume (1.013 bar and 21 °C (70 °F)) : 0.833 m3/kg

blown 87

Mark, you still have to get it out of the engine.
On a N2O motor, if you put more in than you can get out, bad things happen.

Greg Nettles

blown 944

Ha now we are getting into scientific method. utilizing theory and speculation of mass and density as well as specific gravity is great on paper but there are so many other variables. If practice was not needed you could just throw on a 2 stage fogger system and make 2000 hp but that is just as impossible.

The problem is not getting the Nitrous and fuel into the cylinder effieciently only one time, it is repeatedly doing this effectively. If the cylinders swept volume is not at or above 100% ve (which it is not NA) there will be the probabliltiy of unspent fuel and Nitrous for a variety of reasons, spark timing duration, exhaust scavenging not to mention the likeliness of puddling in the intake runners. The cam is also one item that will no allow this much nitrous to be used effectively as well as the lack of a good ignition system.

I am not usually a naysayer at all.

I have just worked with nitrous for so long that I just can't see it working within the parameters set earlier.

To be clear just so there is no confusion. I believe you could run a 300 hp system on the engine and make about 450-500 rwhp realistically. In my experience with many systems just b/c a system is advertised as big number doesn't necessarily translate to big power. Of course I haven't worked with this particular system but to me they are all about the same.

Brett928S2

Hi

Not to knock your expertise but the above is precisely the problem with your "estimation" of whether my Wizards system will work...YOU don't know, and are guessing...and NO they are not all the same....

Let me give you an example, with my Pro Race system (which is so new its not even sold yet, although there is a Pro Stock racer in the US using it...and hes using a LOT more Nitrous than I am planning) ....anyway.....with this system....THERE IS NO REVERSION AT ALL !!! NOT EVER.....

And as far as I know, no other Nitrous system can claim that....

All the best Brett

mark kibort

if you are talking pumping losses on the restriction for exhaust, it should still be able to evacuate the spent cylinder charge, but as the mass flow goes up, so does the restriction forces, relative to the exhaust ports . i think on that side of things, the only downside is HP losses. Thats a guess on my side. I was only speaking to the density of NOS as it leaves the nossil and begins to expand and heat up.

mk

mark kibort

That would be true if you were exceeding the volume flow of the NOS and fuel. but at a first glance, even at 80% VE, you wouldnt be there . However, the one variable would be the ability for the charge to be fully ignited under the pressure of that kind of mass flow in that cylinder volume.

However, i have already run, with a closed throttle body, 75hp. kind of shows the potential, and that was a fuel and NOS fogger in the plenum.

port attached foggers could support this kind of fuel demand. basically, its like runing a harley engine on a 100 shot. (near 800 hp if it was a V8 of 5.2 liter.

It would be interesting to see the max NOS that a harley has done. I have a feeling, that that kind of mass flow is not a big deal. It isnt on a porsche GT3RS Normally aspirated, at 122rwhp /liter . i dont think its that far of a stretch to think of 200hp/liter with a well designed NOS system. we should look at the record books to see if any NOS engines are in this range. 200rwhp/liter if so, it has been done already. I bet there is a 2L NA honda civic out there with NOS that has run 400rwhp. if so, that would be our answer right there.

Mk