Thanks for that info...very helpful. Looking at a 2 fogger system, not sure what I'm going with for engine management yet. I was looking at an Rtek, but I plan on turbo swapping eventually so that's not going to work. I have an SAFC ready to drop in, but that doesn't do timing, so I'm not sure. Perhaps I'll keep the shot down a bit and see how the stock timing runs.



I got new front calipers and the new master cylinder installed this weekend! Also picked up a depowered TII steering rack.



I have to pull the engine again There are a couple reasons for this:

-Steering rack swap. Hella easier with the engine out.
-Motor mounts. Ditto.
-I'm not sure if I put the throwout bearing in the transmission before I mated them up *slaps forehead*

More updates and pictures as they develop.

 

if you keep the shot down under 75, closer to 50, then timing shouldn't be an issue.

I wouldnt suggest using the SAFC for two reasons. One, as you stated, it doesnt control timing, and with a wet shot fuel control isnt the issue. Two the SAFC works by lying to the computer, telling it that its receiving more or or less air than it really is so that it will look to a different fuel table cell for how much fuel to use. The problem with this is that it also looks to a corresponding timing table and may end up changing the timing for you in an unfavorable direction/situation.

For $500 the RTEK is a cheap timing/fuel control, and right now, is about the only true PnP setup. Its really exactly what you would need for a NA anyway. you could reduce the timing for a larger shot, and you could lean out the top end and pick up some significant power there too. When you go to turbo then you can just sell off the ECU with the chip it in and probably get all your money back, or damn close to it. Anyway, 'plans' to do a turbo, and actually doing a turbo are two different things. A lot of people plan, most dont go through the troube of pulling an engine many times, adding nitrous, and modding an NA and THEN go turbo. If you see where I am going with this. With the time you are going to put into drilling and tapping a nitrous system, installing all of its components, and getting some timing control you will find yourself in a position to be faster than a turbo setup anyway.... Why then would you scrap that time and effort just to start from square one again.


BC

 

Another option that I was just reading about is using propane as your fuel instead of gasoline. You run a seperate nitrous solenoid to control the introduction of propane into the intake. This would allow you to run without doing a direct port as the propane comes out in gas form. No pooling, no backfire.

its a proven, though not fully adopted, setup. The viper guys and GM V8 guys have been doing it for a while, and diesels have been running propane FOREVER.

Here is a link to the LS1tech.com discussion on propane and nitrous:

http://www.ls1tech.com/forums/showth...4&page=1&pp=20

there is a lot of really good info there. Due to the twists and turns of our intake track I am leaning towards this setup.


Long story shor ton tuning is to start with the same size nitrous and propane orifices, and then lean out the propane as you do dyno or street runs. Insure that you are keeping tank pressures equal between runs.


Items needed would be a 4.5lb propane tank (found at REI.com) some plumbing adapters, window switch (needed in ANY nitrous set up), bottle heater for both tanks, and guages to monitor pressure. Oh, and a wideband and timing solution.


BC

 

Safest? Debatable. Most effective... usually not.
Comparing a single fogger nozzle placed before the throttle body to direct port placed after the throttle body, the single fogger will always make more power; the same holds true for piston engines: a plate system will typically make more power per jetting than a direct port system. The reasoning for this is simple: the further from the engine you place the foggers, the better the atomization.

The N/A intake system makes nitrous installation a bit of a bitch... you MUST ensure the auxilary ports are open when you spray the nitrous, or backfire will result. This will take place even with a DP system in the primaries only, since nitrous injection is not a staged event referenced to the eccentric shaft rotation, like the fuel injectors are- its a constant injection. Reversion of the nitrous/fuel charge will occur back into the runners, which can then collect in the closed auxilary ports.... ugly ugly stuff to deal with.

For N/A's with stock intake manifolds, I like install a dual -microswitch checkback system onto the auxilaries, which will keep the system from engaging when the auxilaries are closed, or shut the system down if they do close. I also tend to prefer the single fogger nozzle, correctly placed, simply due to the shape of the intake runners: due to the constant 90 degree bends in the runners, direct port systems always seem to partially spray directly onto the runner walls. This system will easily support a 150 shot. On a modded N/A engine, this will be producing close to 400 hp at the flywheel, and above those power levels, you really should be looking to ditch the stock intake.

 

Yes. The AWS is only used for emmisions to heat up the CATs and thats it.

Part is of your statement is right, the other half is wrong. The BACV will bring the engine up to about 2000rpm for about 10 seconds and then will bring the RPMs down to around 1500 where the thermowax takes over. DO NOT REMOVE THE BACV! There is no reason to. The BACV helps keep the idle stable.

You may have done so. The fork on the end of the port rods will only fit over the pin in the sleeves one way. So you might be forcing the rod on the sleeve which is getting pushed up against the iron.

You should place the WBO2 sensor further down the exhaust system. Possibly about 2' away from the manifold.

Turbulence will keep fuel suspended. This is the exact reason why you do not want to polish the inside of the manifold. The rough sides creates turbulence and keeps fuel off the walls and suspended in the intake charge.

If you can get the stock system to work, keep it. Your low end WILL suffer. I recently got mine working again after having them wired open for a year or so. You can use an electric air pump to operate them if need be. If you remove them, the airflow though the aux ports could be even worse now that the port will be deeper and there will be a larger lip.

 

Did you see the intake manifold I'm using? Not the S4 one...the S5 one. I might have sprayed into the S4 one, but the S5 one looks pretty nuts.

Perhaps I should tap the intake manifold where it is horizontal, right behind the VDI...that way it only has to go around one corner and it's far enough away that the nitrous won't be spraying directly into the rotor housing?

The bung I tapped in is for the narrowband sensor. The wideband sensor is at the very end of the header.


I'll see if they are indeed backwards when I pull the manifold off....Right now the goal is stock activation, or switch activation...or stock activation with a switch bypass? I'd love a way to open them manually but keep them functioning normally otherwise.

In the meanwhile, I have to figure out a way to get the ports, VDI, and the nitrous all working together. This is going to be one hell of an afro-engineered headache. Trying very hard to stay away from purchasing 3 window switches...I think one of the writeups used an EGR solenoid...we'll see.

 

Safety, not debatable. You remove multiple turns, points of hang up, and unequal distribution. Fuel is heavier than nitrous gas, when you come to a 90* bend fuel is going to have a greater tendancy to keep going straight and land on the intake runner wall. This is partly why the fuel injectors are in the position they are in. having fuel coming out of the airstream is a bad thing for a/f ratio and pooling.

As for effectiveness, I would argue on a dry intake that isnt designed to flow fuel effectively or equally that a DP system is going to be more powerful per given 'shot' than a single nozzle farther back. particularly in an intake manifold as intricate as the S5 manifold is. Nothing to back that statement up with though.

atomization is important, but too many turns and too much time in suspension has a negative effect on atomization.

I would agree with you here.

I would argue that a direct port can be placed in as straight of a stretch of runner as is possible on the stock intake reducing the likelihood of that happening, whereas a single fogger is going to rely on the manifold to keep the fuel in suspension.



BC

 

turbulence on the runner wall keeps fuel from settling. Turbulence in the airstream can cause heavier fuel particles to break out of suspension and pool. This is particularly true in the case of 90* bends in an intake track and gaskets sticking up in the airstream. the idea behind gasket matching to an intake manifold is to prevent turbulence in the airstream between the port and manifold.



BC

 

I can see what you are getting at.

 

I don't see how keeping the fuel suspended for a longer time in the intake would make for better atomization, the fuel is heavier and will naturally want to drop away.

Also, I don't see how making more power with a single nozzle would be much of a consideration anyway. If you want to make 300whp, jet for 300whp.

The propane idea is just going to complicate things...2 bottles to fill instead of one, more cost to setup, more to go wrong, and the relative pressures between the propane and nitrous will change the air fuel ratio. I would hate for the propane bottle to get low and drop pressure until you blow the engine. Plus the advantages aren't so large when we are talking about small shots like this.

Its unfortunate there isn't a easy way to compensate for a dry shot with the 13b. I think you'd have to go with a full standalone with nitrous controls for it to work. That may be the best option, but its almost definitely going to be cost prohibitive.

 

I agree. the more i thought about it the more I found wrong with Scathcarts argument about direct port. 1st: there is a reason the secondary injectors stage after the Aux ports open... the same reason why you shouldnt inject nitrous before they are open. Pooling. However the argument that you cant inject nitrous before 3800 rpms if you keep it in the primary runners because of reversion is, I think, wrong. Nitrous pooling isnt an issue, fuel pooling is. If reversion were a real worry then mazda wouldnt have the aux system set up the way they are because pooling would be an issue before 3800rpms. it isn't, so IF you can tap the primary runners only then you are more than likely safe shooting before 3800 rpms.

further I dont believe atomization is as much of an issue either. Again, see where mazda put the stock injectors. Atomization is a concern for fuel only, not fuel and nitrous. Nitrous is a gas, it will distribute effectively evenly everywhere, so getting fuel spread out is the issue. If the stock fuel injectors do an adequate job of atomization then Im sure a DP setup will be ok, maybe not perfect, but ok.



A 4.5lb propane bottle will last at least 3-4 full bottles of nitrous before it needs to be filled.

The additional cost for a propane setup would be offset by the fact that you don't have to upgrade your fuel system.

there is LESS to go wrong because you are not relying on a mechanical means to flow fuel to the system. Fuel is being flowed via pressure. So you are symplifying the system.

Bottle pressure is maintained the same way with a propane tank as with a nitrous tank. Wrap it with a nitrous bottle heater and keep it at 85*, conveniently where the nitrous heater is already setup at. This keeps pressure around 165psi. Nitrous has a lower boiling point than Liquid propane (-88* vs -45* respectively) so it will be easier to keep bottle pressure up via a heating blanket (on relatively equally sized tanks). Its much more likely that you are to run low on bottle pressure in the nitrous tank, causing a rich condition.

And finally, something you didnt key on, but i expected some one to. NA engines are tuned to run best on 87 octane. Nitrous isnt. So either you get a standalone/RTEK and change the timing for 91/93 and always run premium, (if you dont you overheat the exhaust system, ask me how I know), mix 100 and 87 and HOPE you have at least 93 octane equivalent in your tank when you go to the track, or you rely on propanes 105+ octane fuel.


Its obvious you didnt take the time to read the link I posted. i dont blame you, but I think you should if you are remotely interested in propane, OR you are just interested in learning something new. This is similar to the same argument as I always get regarding remote mount turbos. Its a new idea, and everything thinks its foolish until someone goes out and proves them wrong. This is a proven method of fueling a wet shot without the worries of pooling in a dry manifold. The viper community has been safely doing this on engines that are far more expensive than ours. They have provided fueling for 75-250 shots through propane without issues. tunign takes a bit to get the jetting correct, but nothing that isnt dangerous if you start out rich and lean from there.

True. No good way to safely compensate for a dry shot on a rotary without a standalone. So its either a wet DP shot, dry shot with a standalone and nitrous control, or propane. You can tell which way i will be going in the next few months.

 

Has it been 4 or 5 bottles since I refilled my propane tank...maybe I should take it out and weight it...nah I think its only been 3....boom, woops. Thats the first thing that came to my mind when I thought propane bottle, although I do realize you would be stupid to not run a hobs switch on the line that will cut the system if the propane pressure drops, so that wouldn't really be an issue.

I didn't read the ls1tech link because I had already read it in the past...I have an ls1 powered vehicle that I spray, so I'm no stranger too those forums.

I'm not saying it doesn't have its advantages, it just seems like a lot more to deal with for a low hp system. You still have to open two bottles, and refill two bottles. I wouldn't imagine mounting a fuel tank inside the vehicle could be particularly safe either, so if you mount it outside, then you'd have to either rig up a remote bottle opener, or stop and get out of the car to open the bottle before you use it.

I didn't think of the low octane preference of an n/a rotary, it has been several years since I have owned one myself...good point there.

Another thing I didn't mention before is lean spikes upon activation. Isn't the propane a compressed liquid in the line? The gases in the line could make for a delay in the propane getting to the solenoid causing a lean spike unless you ran a purge on it. This is just a theory of course, seeing as I have no experience with propane/nitrous setups.

 

Thats an issue of being a responsible owner. Same could be said for not checking a fuel filter on the fuel line and clogging a noid, or not having a solenoid rebuilt at the end of a season because its too much of a hassle to remove it from the system.


Noted.

the reason this lends itself to being a better system for a NA rotary is the octane level, and the lack of stress on the stock 16+ yr old fuel system. I would imagine that mounting a pressurized tank within the frame rails would be safer than mounting it outside under the car or within the sheetmetal. In either case a DOT approved container is HIGHLY unlikely to explode upon impact, or even be penetrated.


You can set it up either way. With the bottle mounted upright its only a gas in the system. Keep the fuel solenoid at the same or shorter distance than the nitrous solenoid from the nozzle and a lean spike is a non-issue. Mount the bottle upside down and feed liquid propane to the solenoid and you will need a purge line for the system. Purging propane into the air isnt dangerous in and of itself. the liquid setup adds cooling to the intake charge, the gas setup removes some complication from the system. personally I would lean towards the gas setup so that boil off in the lines isnt an issue.



Regardless, the OP has his manifold off so if he chose to go with gas he could tap for a DP setup. I wuold suggest a standalone fuel system if he goes that route, or that he tunes the car NA for 93 octane timing, always runs 93, and then pulls a couple degrees from the torque peak andup for nitrous.

BC

 

Right now plans are to run an Rtek so I can pull some timing when spraying.

 

Try it. Been there, done that, learned better.
My coments come frm extensive testing over the past 7/8 years on shots ranging from 50hp to 400hp. Take it or leave it.

Something to keep in mind about comparing a fogger nozzle to a fuel injector is that the nitrous and fuel mix in the fogger, and the mixture is sprayed out of the jet at roughly 950 psi. Comparing this to a fuel injector at 40 psi is pretty moot: the nitrous foggers will spray much rather farther, and much tighter. Because of this, unless you have a decent stretch of straight runners to place the fogger into, such as on a TII intake manifold, you will spray, at least partially, directly onto an runner wall. The tight radius bends on the N/A intake manifolds, by far, make placing DP injectors in a situation more likely to induce fuel puddling than in a single fogger placed 6" in front of the TB (non-stock TB elbow). There ARE no straight section of runners to safely place DB injectors on an N/A intake. Testing this is simple with a flowbench and a spare intake manifold. I suppose you could even set something up with a shop vac in a pinch. I strongly suggest this before you ever engage your nitrous system.

On nitrous installs, I like DP for TII, RE, REW, and custom manifolds, and a single fogger for all N/A intakes. Best bet for an S5 intake is a single fogger before the TB, jetted to 150 hp, even with the VDI. Above that, use a different intake manifold and switch to direct port.

 

Nearly all dry systems use an FMU: fuel management unit. Quite simply put: they jack up the fuel rail pressures for fuel enrichment under nitrous injection. Our cars are no different. The probelm is this: the further you get away from the 40 psi differential pressure on the fuel injectors, the worse the atomization. This is why all cars running bosch-style EFI systems use rail pressures between 35-45 psi. Anywhere outside that, and emissions and power output drops due to poor fuel atomization. This is why the fuel pressure regulators use a vacuum/boost reference line: to maintain this ~40 psi differential. On a 20 psi boosted engine, the fuel rail pressures will climb up 20 psi, to ~60 psi: When you have 60 psi pressure the fuel into the engine, you still have 20 psi trying to push it out, so the difference is still 40 psi.
This is why large shots on dry systems are so shitty. Larger shots require higher rail pressures which decreases atomization and increases fuel puddling. Bad.

So... its not that there isn't an easy way to do it, its that there isn't a safe, effective, easy way to do it.

 

injector staging is the same on the FD and the TII, no sleeves there, fuel can go through the secondary ports instead of the auxiliarys.

All that aside is there a reason you can have the nitrous shot directly into the runners for the primaries?

You could also run a megasquirt if you wanted to.

 

Ill take your word on it. Mine was more hypothetical thinking, and less reality based. On that note, how did the engine hold up to a 400 shot? Im curious what the pratical limit of the engine is when it comes to nitrous.



Have you used the RB carb manifold with a holley type throttle body? Or just the RB manifold with some other form of TB? Really Im wondering what your setup recommendations would be for over 150 shot?

BC

 

fixed

When I said compensate I meant raising the injector duty cycle. An FMU would really only be effective on really small shots.

Maybe using the single nozzle is the best idea for the money, best is still a relative term though...

Good thing your not too attached to this motor.

 

HAHA. Well, unknown mileage, so-so compression, unknown if the OMP was working at full capacity, if at all...I'm surprised it runs as good as it did. We're going to see if it's as strong as it wants me to think it is...haha.

So what's the verdict, then? Single fogger or DP? Planning on jetting 75 and then 150 at the end of the year.


Also planning on getting a walbro rather than rely on a 21 year old fuel pump in unknown condition...i'll have to rig up an FPR, I understand...stock lines are alright, I assume? (from the tank to the bay anyways.

 

My vote would be start with a small, 50, shot and see how it goes. Use a single fogger since its probably going to be your cheapest setup. If the motor pops you are only a little bit in the whole that way.


Personally I like the propane idea, and will probably go that way myself if I dont get an RX8 first. To me it just makes since to flow a gas instead of a liquid through a dry intake. But it seems that scathcart hasnt had too much issue with using a single fogger on an S5 NA, so i doubt you will hurt yourself going with fuel.


BC

 

I vote single fogger on a modded and ported TB with a non-stock TB elbow (TIG one out of 3" aluminum widened at the TB) with the fogger placed 6" before the TB inlet, and jet to 150.
Stock lines are more than adequate at those power levels. I always recommend an aftermarket FPR.

 

Not really a fair comparison to the engine in this thread, but the engine is:
9.7:1 compression peri-port, centre-bearing e-shaft, lightened and balanced, ceramic apex seals, twin 55mm TB's, dry sump w/ 150 psi oil pressure, fuel injected on methanol. Engine still runs great. Currently in storage.


[/QUOTE]Have you used the RB carb manifold with a holley type throttle body? Or just the RB manifold with some other form of TB? Really Im wondering what your setup recommendations would be for over 150 shot?

BC
[/QUOTE]
Never used the carb manifold, EFI or otherwise. I typically use a stock TII lower, after massive modifcation, and weld up my own UIM. Trick is to match the runner lengths to the LIM, as they are not equal length.
RB manifold is pretty simple, though. Fantastic candidate for DP nitrous.

 

I have been working on a very large write-up/paper on big nitrous shots on rotaries, containing descriptives as simple as building a 50 shot on a stock engine, to specific engine porting configurations for a nitrous-intended drag engine. These engines, when set-up properly, respond very well to large amounts of NOS, much for the same reasons the engine is considered well-suited to hydrogen fuelling. Pumping 250+ into a stock 4-port engine is very rewarding: that's an extra 330 ft-lbs at 4000 rpm for a surprisngly cheap system.

 

You dont be any chance have any pics of that peri-port setup, or some of the TII LIM and custom UIM setup do you?


BC