Worse the 370 cc injectors can only flow enough fuel for 63 x 8=504 x 0.8 = 403 HP and Nitrous is run MUCH richer than 11 AF so 403 x 0.95= 382 HP at the very very very most.

WHY JWT used A MAXIMUM of 75 HP JET [375 HP] to add some safety to the 4,000 rpm rich point [most air and fuel consummed per rpm at engine torque peak].

They increased the normally aspirated 11.0 millisecond injector open time to 13.25-13.75 millisecs ..........13.75/16.6= 82.8% duty cycle on the ragged edge of not being enough if 30F outside at sealevel.

So anything more than 75 HP JET will require more fuel pressure or extra injectors.

80% duty cycle is max to keep the injector coils cool for reliable operation.

Not sure I'm being clear:

At every rpm that a 75 HP jet of Nitrous is used the injector open time MUST be 2.25-2.75 milliseconds longer than what ever the base [non nitrous] injector time would be!

That 2.5 milliseconds at 44 psi is how much extra fuel the Nitrous needs to react with fuel.Also the JWT ecu leans out the mixture above the torque peak to make the non Nitrous gains it's famous for..........this has to be disabled. Why they mount a piggback board inside ecu which has one prom fror non Nitrous and a separate Prom board for use with Nitrous!!!!! and just select the appropriate program for the conditions.

Q45tech wrote:Not sure I'm being clear:

At every rpm that a 75 HP jet of Nitrous is used the injector open time MUST be 2.25-2.75 milliseconds longer than what ever the base [non nitrous] injector time would be!

That 2.5 milliseconds at 44 psi is how much extra fuel the Nitrous needs to react with fuel.Also the JWT ecu leans out the mixture above the torque peak to make the non Nitrous gains it's famous for..........this has to be disabled. Why they mount a piggback board inside ecu which has one prom fror non Nitrous and a separate Prom board for use with Nitrous!!!!! and just select the appropriate program for the conditions.

Correct me if Im wrong, but since the nitrous system runs with the race gas, that shouldnt matter because it wont detonate with the higher octane, correct? I assume your assing that we're using 91-93 octane fuel, and if we bump that up to say around 100 (or whatever most race gas is), the 80-82% duty cycle would still be compatible with the 100 shot, whereas 75 shot may be safe enough for just pump use. IE if you werent to upgrade the fuel system, then 75 shot would be your MAX... However, according to your figures, 100 shot is BARELY on the line, and being conservative its just a little over (depending on where you start, 278 base HP or 300ish base HP)

WIth all this pulsing things, it seems just as easy (instead of trying to make all this work by itself) to not spray until say you get to 3000 RPM or so (after the TC stalls).. hold the throttle right before the kickdown switch, and then once you get it up there, spray.. with the 4.08, the tires squeal a little anyway... It also seems that it would be easier to build a centrifugal supercharger than to make nitrous work like that...!

Jason... Is there anyway I can get my bottle heater back safe... Where would I install my thermo swtiches back in to make them be effective...

Also, im not sure what I heard for sure, maybe ill take a video this weekend.....

All this is hurting my brain, and it makes me want to just take the damn thing out to regain what little trunk space the Q has..... but I couldnt do that, this is the BAD Q45.....

I think it would be in your best interest to change to a 75hp jet or use the 100hp shot very rarely.

Q45tech wrote:WHY JWT used A MAXIMUM of 75 HP JET [375 HP] to add some safety to the 4,000 rpm rich point [most air and fuel consummed per rpm at engine torque peak.

If the JWT is programmed for a 75hp shot, then why do you have a 100hp jet installed? Or even worse, you stated before that a 175hp shot was used to reach a 12sec 1/4 mile time. If that is true, then that goes to show you that a high HP short can be used in very shot intervals.

Wes or Fred: Do you know if the Nitrous system has a pressure release valve? And if so, where is it vented to?

I dont have a lot of details except that is supposed to bewell sorted.

Rex had a 175 shot in it, it worked for a lot of hard runs with the 175 in it.

Until..

The bottom end of a VH45de is pretty strong so is the rest of engine.The rings arent as strong as the rest of the engine, if someone were to put in upgraded rings it would be a "built" engine.

Fred..

Isn't there another weak link in the rotating assembly. The rods or something like that. Or are the rings the weakest part of the engine.

What type of rings do you suggest the OEM ones be replaced with, material wise?

I plan on finding these things out..... As soon as I get ahold of Rex, im sure i'll find these things out... Maybe even get him to post up

PMQ, theres another thread you created about nitrous... The simpler questions might be better in there

I would assume its got the updated PROM... IE its for 100 shot...

The rest of the engine is considered pretty strong. (six bolt main bearings, closed deck etc).I dont know anything about which kind of rings, I hope someone else might have some to add.

They can stand up to a no small amount of, abuse and are weak only in relation to the rest of the engine.

Fred..

I agree..... HOwever, i find it ironic that most engine failures are mostly from thrown rods..

I tested out the nitrous today, and all I have to say is that (as per Jason) that I do wish it was on al the time.. Id love to throw on the B.A.D. supercharger, hmmm, maybe Rex has an extra I can borrow

I alos looked under the plenum today, and noticed the main coolant hose is only clamped on one side

elwesso wrote:I alos looked under the plenum today, and noticed the main coolant hose is only clamped on one side

If the hose is a proper fit, you don't even need a clamp. A clamp helps to seal an improperly sized hose to the metal.

elwesso wrote: HOwever, i find it ironic that most engine failures are mostly from thrown rods..

That's why I asked if there werre any other weaknesses. It seems that the Rods or Bearings may be a weak link.

Did anybody read my suggestion for a dual stage Nitrous setup? It's at the end of the 1st page in this thread.

In case you missed it thats what dennis has proposed.. Something that uses minimal nitrous at the begining and then lays it on after 4000 RPM or so...

Maybe its time you start reading posts other than yours!

Had a chat with Ben Pila at JWT today, he spoke with the Engineer (Clark or Jim probably) on a couple of points for clarification.

For the record, I was WRONG about the plat plugs per JWT.

me: "What level proms are available?"him: "We only produce a 100 shot."me: "The engagement turns on at ? & shuts off 2-300 rpm before rev limit."him: "On at 2200 off around 7000."me: "When engaged, it's an instant on 100hp?"him: "Correct"me: "To set timing on an n2o module equipped........"him: (after verifying) "Yes, you jump the center & 5v wire on the TPS connector to force a timing change" me: "Suggested plugs?"him: "Stock."me: "Stock heat range?"him: "No, stock, like stock stock, OE NGK plats."me: "............................."him: "Hello?"me: "Uhhh...."him: "We run 700hp race motors with nitrous & plat plugs."me: "But even NOS, whose hardware kit you use...."him: "Yes, yes, we know, but they're not using JWT engine management."

So there you have it. NOS adamantly discourages them in an n2o application, so does NGK & aftermarket supercharger/turbocharger manufacturers like Vortech/Paxton, Jackson Racing, FMax, etc., any tuner I've ever worked with (guys who do it for a living & are damned good) but JWT recommends stock NGK plats for their Nissan nitrous kits.



Think I'll keep my opinions on that to myself, but that's their business.

It's not the Platinum plug by itself that's an issue, it's the size of the shot or equivalent high boost (8+ psi as a very general rule) that would concern me. Boosted cars come with plat plugs, small shots are ok with them too. A 100 shot is a good size spray with a non-forged internal engine.

Also, as previously stated by me, (although I requested time to verify) it was the TPS connector jump not the MAF. Sorry, it's been a 3-4 yrs since I did it. But it still is very important to verify that stuff, other wise you might make a correction & have the ECU ignore it. Then you check it again, change it again & it still doesn't take.

I *think* I figured out what Rex did on this car to get a 175 shot. Your aux fuel system must have a regulator that bumps the fuel pressure when the n2o mode, race cell & pump are simultaneously activated? That way you'd have increased pulse width & increased pressure (like an FMU on a s/c application) when the system engages?

Either that, or you have/had a 175 prom there that was a one-off program, but I don't think that and/or race fuel alone through an already taxed injector would offset the difference between a 175 shot pill (jet) & the 100.

PMQ, yes there's a pressure relief valve on the bottle. Without a dump tube it evacuates itself into the passenger compartment (trunk). POP!! PSSSSSHHHHHHHHH!!!!!!!!!!!!! Keep a change of underwear in the glovebox in the event it ever goes off while you're in the car.

Wes, the "HolleyTechDocs" link in my earlier post gives you instructions & pictures for mounting the thermostat.

I'd really be interested in Tech's take on the race fuel vs 93 and it's impact on this application. 100 vs 175, or in general.

If you have a 100 shot prom, Wes, and everything is in perfect tune & working order, I don't think you need the cell & all that stuff either. This is like a bit of a puzzle, and without input from Rex on what/when/why both then and now, it might remain one.

Also, (geezus I must love to see myself type) I believe a progressive nitrous controller could be wired in to soften the blow of the 2200 rpm engagement. I'm not advocating we raise it above the 100 shot level, but introduced as a kinder, gentler 100 shot. It could be armed with the output from the ECU n2o relay harness & then on to the solenoid where a 20-100 shot could be achieved by pulsing the solenoid on & off until the max flow is desired at, say, 4000rpm.

Sorry this is so long of a post. (Again)

Jason I love reading your posts... Very informative.. I look foreward coming home and seeing a few new posts to read on my NOS thread

I'll check out that link you posted earlier...

Quote »but introduced as a kinder, gentler 100 shot[/quote] Oh doesnt that make it seem better... That sounds like Oprah almost, yeah your beating the hell out of your engine, but we'll wait and start the beating until it really gets going, then it wont hurt as bad

Jason, I would like to chat over the phone sometime, if you have a chance.. 765-621-8336... Free weekend minutes, BOOYEAH!.. Ill be available after noon to 1 tomorrow, as I am taking the ACT...

good luck on teh act's wes. I scored a 28 on my first try. It's not too difficult. U'll actually get tired of the easy questions and just whiz through it without checking your answers. That's what screwed me.

Sure, I'd be happy to give you a shout between Sponge Bob & the Power Puff Girls or breaking up a fight over who had the blue LEGO man vs the red LEGO man first.

If you don't hear from me around that time, gimme a shout at 407-884-5717 or 407-421-9603

Consider the time delay [the time it takes nitrous to flow from the solenoid to the jet, then to the same point as the fuel injector]...........how many rpms is that.................something like a 1/20-1/10 of a second depending on placement of jet. Plus cylinders 2&8 are 10" farther back.

Initially 3-6 engine revolutions some cylinders are getting nitrous and some are not.......this unbalance power [because all get rich at the same sequential instant [within 2 rpms] so some are drowned with gasoline and make almost no power while some make 25% more than stock ~~50% variations on rods and bearings.

Same problem to lesser degree happens without nitrous during the early part of initial acceleration........distance from MAF to each valve and how ecu guess at what the air flow might be in each cylinder as the rpms are rising.

Luckily if you draw a graph of power vs AF ratio you see that power decreases more slowly on the rich side than the lean side.......by almost 3 to 1.........always err on the too rich side.

A soft engagement is always better than an all or nothing shock.

You can delay the nitrous by a longer feed line from the solenoid to the jet or moving the jet towards the MAF or even in the air box in front of MAF.

Don't point the spray towards the MAF element as the thermal shock might crack the MAF sensor.

Discover what the temperature of 25% nitrous will do to 75% air at 6,000 rpm.........at engagement [2200 rpm] the nitrous maybe equal to air flow.

Remember the jet starts out as nitrous gas, then eventually blows liquid as the piping cools down.........the first second or two is always a mixture of things happening and stablizing.

Remember this is the 3rd engine in your Q.

The clarity of this morning's Marlboro Light & Maxwell House reminded me a progressive controller would only make the car run really rich from 2200-4000. How badly that would affect a run is the question.

Q45tech wrote:A soft engagement is always better than an all or nothing shock.

I was disappointed to remember the JWT was instant on. Crane made a progressive unit that pulsed, making the application much smoother & more linear. I think they discontinued it, but that wasn't for this app anyway.

Q45tech wrote:You can delay the nitrous by a longer feed line from the solenoid to the jet or moving the jet towards the MAF or even in the air box in front of MAF.

IIRC, the n2o mode is an open loop map. Even if the MAF were to get a little cold shot, it wouldn't affect the program, would it? I don't like where Wes's nozzle is. It'd be awesome to simulate which runners get blasted where the nozzle is now. You can visually see a blast cloud 10+ feet when holding a line your hand.

Q45tech wrote:Don't point the spray towards the MAF element as the thermal shock might crack the MAF sensor..

Amen, funny that GM LS1 kits from NOS spray across the MAF for fuel correction.

Q45tech wrote:Remember the jet starts out as nitrous gas, then eventually blows liquid as the piping cools down.........the first second or two is always a mixture of things happening and stablizing..

I didn't know that, I thought the instant it contacted the atmosphere it turned to gas. I've had a #2, 3, 4, line in my hand, connected to an 80lb tank & opened it, never saw liquid. Is that because it's in a vacuum when spraying?

Tech, what do you think the idea with the cell, pump, etc is/was? What is the effect of race fuel with a sytem like this?

Q45tech wrote:Remember the jet starts out as nitrous gas, then eventually blows liquid as the piping cools down.........the first second or two is always a mixture of things happening and stablizing.

I thought that's why you are supposed to purge the line(s) before using the N2O. To get rid of the N2O in gas state. Or do I have that backwards and you want to get rid of N2O in the liquid state?

What kind of effect does the decreased intake temperature caused by the N2O have on the engine? Will it cause the combustion chamber to operate at a cooler temperature?

So whats the bottom line on this...

Am I safe to use it, without a lot of ill effects.....?

PoorManQ45 wrote:I thought that's why you are supposed to purge the line(s) before using the N2O. To get rid of the N2O in gas state. Or do I have that backwards and you want to get rid of N2O in the liquid state?

What kind of effect does the decreased intake temperature caused by the N2O have on the engine? Will it cause the combustion chamber to operate at a cooler temperature?

Actually, you need to purge the n2o line after use so you don't leave a bunch of pressure(as high as 1000+ psi) on your solenoid or it will be short-lived.

The n2o does help cool the intake charge which is definately benefical. Not a huge difference, but beneficial nonetheless.

Stephen

I think it's kinda twofold, purging the air from the sytem prior to squeezing, and, yeah, Stephen has a good point about relieving the pressure after a run.

Yes, PMQ, nitrous is very cold, and supports combustion, but is not flammable. Cold, dense, more air in a given space, you just need the correct mixture of fuel.

So basically you want to run the car in nitrous mode but with the bottle off... As to get the NOS out.....

Yes, momentarily.

Part of your kit is a "Cheater" solenoid, not a "Powershot". It's a beefier unit, but in lieu of a purge kit, you could crack the line anywhere in the system to relieve the pressure after a run, or do like you say, shut the bottle off & auto-purge.

Nitrous starts out cheap, but by the time you trick it out with all the toys, it's real close to the cost of a blower.

Jason,

Any updates on our little "investigation?"

Not yet but I haven't forgot about you. AJ's been out sick Mon & Tues & I have to finish the GS 455 in prep for the Turkey Rod Run.

I'll try to reach him today.

Wes,

Talked to the Doc, he'd be happy to speak with you about the car.

He is a geniune(ly?) good guy.

Short Story;

It *DID* have a wet system *on top of* the JWT setup installed, you do have a factory microswitch somewhere & that's got to be what's activating the system with the engine off.

It *IS* a Ford/Chev dually tank switching system under the hood.

We need to chat, he's coming by the shop sometime this weekend or next week.

Call me tomorrow when you get a chance, I'll give you his number & we'll figure out a plan of attack for the sytem as *you* want it.

Goddammit I didnt notice your post.....

I'll call tomorrow, however, I could use your phone number... I cant recall it, and I dont have it saved...

765-621-8336... Call anytime, morning is good too... Remember Im an hour behind, so not real early.... 10am in either time zone would be safe

elwesso wrote:Goddammit I didnt notice your post.....

Relax, Cartman.

I'll be at the shop today getting ready for a show, try 407-299-4345 or 407-299-7806 (the 7806 rings in the back)

Hopefully he'll come by today & we can get some stuff sorted out.

Molecular Weight: 44.013 Latent Heat of Vaporization @ b.p.: 89.9 cal/g Specific Volume @ 70º F., 1 atm.: 8.7 cu.ft/lb Latent Heat of Fusion @ m.p.: 35.5 cal/g Boiling Point @ 1.0 atm. : --129.1 ºF Specific Heat, Gas @ 25º C., 1 atm. Cp: 0.2098 cal/(g)(ºC) Freezing Point @ 1 atm. : -131.5 ºF Specific Heat, Gas @ 25º C., 1 atm. Cv: 0.1610 cal/(g)(ºC) Vapor Pressure @ 70°F: 745 psig Specific Heat Ratio, Gas Cp/Cv: 1.303 Specific Gravity, Gas @ 32º F., 1 atm. (Air = 1): 1.530 Thermal Conductivity, Gas @ 0º C. : 3.4 x 10-4 cal/(sec)(cm2 )(ºC/cm) Density, Gas @ b.p..: 1.997 g/l Viscosity, Gas @ 0ºC., 1 atm. : 0.01362 centipoise Density, Liquid @ b.p..: 1.266 g/l Viscosity, Gas @ 25ºC., 1 atm. : 0.01496 centipoise Critical Temperature: 97.7 ºF Surface Tension @ -25ºC.: 10.1 dynes/cm Critical Pressure: 1054 psia Solubility in Water @ 20º C., 1 atm. 1.3 cc/cc H2O Critical Density: 0.457 g/ml

-129F /4 [for a 75 hp shot] With a 75F ambient air and 1/4 extra volume of -130F nitrous after the cooling of the pipes a ~~50F reduction in 75F to +25-+35F that would be a 4.5% density increase alone of the air when mixed with the sprayed nitrous, at 100F ambient the air in plenum might get down to +55F.

On Nissan the MAF continues to correct for air density/flow at WOT even with a eprom reprogram. But the MAF equation seems to top out at 20-<25% above normal so the 55F air [+5% density] should increase the fuel flow by 5% above what the JWT prom would do at 60F ambient in 100F ambient because the MAF is reading the resultant temperature.

Why many spray into air box to let MAF add what it can...........my point was if the nitrous doesn't mix well the MAF might see -70F -130F and crack the sensor. In Front of oem air filter might be safer. On a humid cool day you might get ICE.

Dennis,

I am thinking of relocating.... The JWT setup recommends in front of the TB, but I dont really like it there... When you nail it, the first couple of cylinders get a lot of nitrous until the RPMS build and it equals out.. I amd thinking of tapping a hole back by the brake booster that will inject the nitrous as close into the middle of the plenum as possible... Unless most think that the area near the TB is best...

I for one dont like the idea of spraying before the MAF, just knowing how sensitive it is already!!!!!