More NOS NAWSSS
 

I've got MS II running fuel right now, and I'm working on getting that setup right, then I'm gonna let it run spark, and get that good. I already have a 100 shot direct port, but I'm thinking about adding a second stage. I'm thinking add a dry 50 shot fogger to the intake tube, far away from the throttle body so it can mix with the air better, for more equall distribution to each cylinder.

Megasquirt can add fuel for a dry shot of nitrous, so that's what I will do. I'm thinking of having the 50 shot come on at 3K. Here's what I'm planing to do.

I take off in first gear, the 50 shot comes on at 3K in every gear. The progressive controller will start at say a 10 shot, and ramp to a 100 in say 4 seconds. The controller will continue the countdown when I shift gears, so if I'm at a 50 shot on the controller coming out of first, that's where it will pick up in second, and continue ramping to a 100.

In first gear, I hit 3K and get a 60 shot, that build up to about a 100 by the end of first gear. I hit second, and have about a 100 shot that will ramp to a 150 as I finish second, I hit 3rd at a full 150 shot. I can adjust the ramp time of the progressive to suit my traction.

What do yall think? 150 sound good, or could I do more? Perhaps a 175 is in order. I think the motor can take it no problems as long as MS is pulling timing and knocksense is listening for knock. :nxsmile:

Thanks.

Seriously? How about a turbocharger. You could install a long, skinny pedal on the far right of the brake and clutch, and have it control your power. You could pick any amount of power you want, and just have it.

Then, when your NOS bottle runs out, you could scrap it and save some weight.

That said, it'd be cool to have the MS run something interesting. Why mix wet and dry?

I voted. I know nothing

4-cylinder 9.5:1 motor means 100 squeeze. That's roughly a 200 squeeze on a v8, or 300 squeeze on a 6.0 motor.

i think its going to be really hard to kill it. and here is my story why.

i used to have a dry zex kit on my car. was running a 50 shot and could barley feel it, so i went to a 75 shot. had a 255 in tank and some 3922 plugs. one day i was on my way home with the bottle still on and the bottle heater was still on. hit it in second and it pulled like it had never pulled before, i was like holy shit!, i let off to shift then BOOM!!!!, car shuts off. i am still rolling in nuetral, tried to re-start it, it would only start if i held the gas down some, would rev up on its own then BOOM!!! and shut back off, tried one more time and same thing. i pull over and i hear the problem, the noid was stuck open still spraying . i run to the trunk and turn off the bottle, pop the hood just knowing it was blown. the intake tube was blown off the TB, along with a cap i had on it when i took off the little box under the stock intake tube, PCV hose was blown off, the intake mani was completly iced over. put it back together and it started and ran perfect. it actually BLEW UP the muffler, you could actually hear pieces inside it bouncing around, it looked like a bomb went off inside it. but it didn't hurt the car at all

Go ahead man and give it all the beans you can through at it. Of course i am only saying this because it is not my car.

You were luck man. I've seen solenoids get stuck open at the drags before and it was not pretty.

I blew my intake tube apart once, plugs were too hot and the N2O/fuel mix was igniting before the intake valves closed turning the manifold into a combustion chamber.

Ouch! Yea, I don't wanna blow it up for sure. One good thing about direct port is the foggers spray right at the valves, reducing pudling and the chance of an explosion. Looks like all you guys say 200 FTW. I guess that's cause it's not your car, as swimming 108 said. Probably gonna add a dry 50 and see what it does.

I voted 200... just because i don't like n2o :p

You want a 100shot at the end of 1st gear??? That's a waste man... nothing but wheelspin. In 1st on dry pavement, if I did a pull from idle... it would break loose at around 5000rpm. I was making in the neighborhood of 150whp at that rpm. In 2nd gear, anything but straighline dry black asphalt equals wheelspin above about 5500rpm. That was pre MS when I was making 190whp/180wtq. I'm making more now and I pray for wheelspin to save the dif.
I think you want to dial it down a little in 1st unless you're running some sticky 225's or something.

What injectors are you running? I don't think a stock fuel system will support what you're talking about.

Hehe, 225-50-15 Yokohama's. Yea, on my stock tires a 60-80 shot is all 1st gear can take with the open diff, but with my 225's I've done a 60 shot ramped to a 100 in .3 seconds and it sets well. I have an open diff right now, but I will weld it eventually so I have a 100% 2WD car at all times. I can play with ramp times on the controller to handle traction though. I 'think' I could spray a 150 shot in second with my 225's and a welded diff, but not sure. I've grabed 2nd at a 100 shot and barely barked the 225's. It will spin 2nd to 50mph on the stock tires though if I shift aggresively.

Everyone knows someone who's blown a motor with a only a X shot. More times than not though, nitrous failures are caused from running lean, pooling, or from detenation from not pulling timing or running colder plugs. I think with MS running fuel, retarding, and watching for knock, I can push it to the limit of what the motor can make. If I spray a 150, I'll start shifting around 7K instead of winding it to 7.5K.

Edit: I'm running a stock fuel system for the engine, but I added a seperate fuel system for the direct port 100 shot. If I add a 2nd stage 50 shot, it will rely on the factory injectors to add fuel for the additional 50HP. Not 100% sure I will have room for that or not.

go balls to the wall, blow it up, and we will have a new par on what our motors can take lol


no but seriously, if its not ur daily, go nuts

if u drive it everyday and need it, be carful.. good luck

Pat you might as well put the screw to it you have all the fancy hardware to do it right. BTW how is the m90 comming?

he just said that he welded his diff together. That says to me that it is definitely not a daily driven car. but in all seriousness, if it was my car and i was dead set on running nitrous oxide. i wouldn't run that second dry shot without running better injectors. With that said i don't think that the internals will hold much past a cumulative 150 shot, even with perfect tuning.

Welded diff? Hmmmm... How many times have you replaced axels cause of that? Esp. when there's awesome lock outs up there.... I wouldn't.

Anyway. I voted 175 cause it looked lonely. Someone do 125.

I think it will hold a 200 shot. Here's why.

If you hit a 100 shot at 3000 RPM, the car will hold together. If your second stage comes in at 6000 RPM and is a second 100 shot, it's the same loading as the initial 100 shot at 3000 RPM. Realistically, I think a progressive 50-100 shot at 5000 RPM in addition to the initial 100 shot makes sense.

Mark

while that makes perfect sense mark, thats crazy as hell! I would not try a 200 shot on my built engine! Thats why youre the man!

Well, marks post makes sense. However, I did some research a while back and a 100 shot at 800 RPMs will blow a miata headgasket. I've sprayed a 75@3K on a Honda 4cylinder forever, so I guess a 100 at 3K isn't much worse. It's all about torque. If I had another 200 to spend on electronics, I would get a better progressive controller than can be setup with a laptop, so I could make maps and spary a X shot at Y RPMs. Until then, I guess it will be a 150 shot.

Hey mark, care to tell me how much torque at the crank a stock motor should be able to make safely, without bending the rods? I'm guessing 350 lb/ft. I'm gonna make a table or graph showing torque and HP at diff shots.

Edit: damnit I don't have the original CD for Excel to install a damn toolpak I need to be able to use functions in the cells.:vash: I can multiply, but can't divide. Stupid crap.

Edit Again: Ok, I figured it out.... Will have a cool nitrous table calculator thingy built soon!

Heh, if you are daily driving that thing with a welded open dif it won't be long till you should start entering yourself in drifting comps. Also, you aren't gong to break shafts you're gonna strip your pinion gear. but hey...open diffs are cheap *shrug*

I say just test it and see how far it makes sense to go. I agree with mark though, seems like maybe you can go to 200.

I got a table built in Excel where I can enter max torque, and it will spit out max HP I can make at 500 RPM intervals, and also what shot to run (max hp-stock hp). I used 300 lb/ft torque, but I already know from looking at my graphs that number can be higher.

When I'm making the chart, I have 3 series: RPM, stock HP, max HP. I want to set RPM, which is series 1, to be on the X axis, like a dyno plot. How do I do this?

I need a good number to go by for max flywheel torque the motor can produce safely.

Ok, here's a pic of the graph I made in Excel, and the numbers I used in excel. I didn't know how to scale the x-axis for RPM, but I labeled it anyway. The dot's begin from the left at 1K RPMs, and increase in 500 RPM increments. This graph is for 270 flywheel torque. If 270 ft/lbs. was the limit on a stock engine, then a 100 shot would be safe at 3500 RPMs, a 150 shot by 5500, and a 200 shot by 6500. However, I'm pretty sure I can make more torque than that safely, which means a 200 shot is starting to look pretty possible. Waiting to hear a safe max flywheel torque value...
Attachment 214699

So what's going on there? It's miata torque plus a constant amount of HP? Obviously not, since at low RPM the lines would look nothing the same. I think you're onto something, but explain it better please.

A car that made 250 hp wheel at 5200 rpm would be making about 300 ft-lbs. In the realm of reasonable. In the realm of reasonable who relies on this car to get them from point A to point B? I would definately say no.

But back up transportation if you're going to play with numbers like that. Things are over might quick in a system like that. I think you could do it, but the more you count on your car, the less of a good idea even something "safe" becomes. :-(

It's miata hp plus nitrous HP at any given RPM, that would add up to 270 ft/lbs. of torque. I need to make better graphs, but I'm not very good at excel. I'll add a thrid line later that shows max HP the motor can make at any given RPM, if it makes 270 ft/lbs. of torque. That line would simply be the addition of the stock hp plus the nitrous HP.

I may be wrong, but I think I was told the motor could reliably make about 400 ft/lbs of torque with good tuning and not bend a rod.

The max power it can make at a given RPM for 270 ft lbs is (RPM * 19.5). A straight line.

I'd like to see a plot of that line, minus the stock miata HP, and that will tell you how much of a shot you can handle at any rpm.

Ummm, no, it would be making about 250 ft/lbs at 5200 RPM.

Now as far as a "safe" value... Running a 5 speed. I am going to suggest that with a staged progressive controller, a 150 shot is pushing it. You will begin to bust transmissions. With the six speed, a 200 shot is pushing it (but doable.)

As far as the motor goes. I think it's capable of handling 300 ft/lbs of torque (total; N2O plus stock torque) with solid tuning, but I would replace the rods just as a precaution. The rods are gonna take a beating and you want something stronger than stock. I don't like the stock rods with juice at these levels even though I suspect they would stay together.

And just because I think it will stick together don't mean shit... LOL, You are definitely looking at the outer rim of sensibility. :p

Mark

Well duh, that's because spraying a 100 shot at 800 RPM would make 656 ft/lbs of torque... of course it's gonna spit the damn gasket. Just as if you sprayed a 650 HP shot at 5200 RPM... It's gonna spit the freaking gasket. Care to guess what the cylinder pressures are on a 650 shot?

When you spray a 75 shot at 3,000 RPM it makes 131 ft/lbs of torque and at 5200 RPM it makes 75 ft/lbs of torque (and guess what, at 800 RPM it makes 492 ft/lbs of torque.) However it ALWAYS makes 75 HP.

Mark

Heh, sorry, I shortcutted. What I meant to say was:
Give there are a number of reliable, 280 peak whp turbo cars out there, figure at 5200 rpm they are in the 250 hp range, and there are about 50 hp lost in the drivetrain, that's around 300 ft-lbs. So 300 ft-lbs at the crank is probably reasonable with a good tune.