Too rich with the nitrous

[88_pacifica]

double post

[88_pacifica]

...or by some other trigger that switches the map in the computer to one set-up for nitrous (extra fuel, less timing, RPM limits, etc).

That's kinda what I meant by this part, but since many of us do their own cals I should have specifically mentioned stand-alones. There can be some trouble though as some have the capability, but don't "support" the feature as DFI (or whatever they are called today) patented ECU nitrous enrichment/control. I don't know if that is still an issue or if AEM licenced the rights... Whatever the deal is, it seems like the stand-alone would be the best way, if you can afford it.

Mike

Man, you'd think this Mike character works with nitrous applications every day or something....

[puppet]

Still wonder if our cals could be programed for this. It seems like it would just be a small bit of tweak in injector DC when nitrous is activated. The 55 jet would be divided up between (4) injectors. A little like the "switch" in the S60 cal for high boost? Has Rob(shelgame) been talked to about this?
Hardware? ... maybe a solenoid switching between a second FPR set for corrected fuel pressure?

At any rate .. this is a ton better than flowing fuel -(trying to)- in our manifolds.

Mike ... I wasn't suggesting Dave inject the nitrous and cross his fingers. You're right, that would suck.

[Dave]

Still wonder if our cals could be programed for this. It seems like it would just be a small bit of tweak in injector DC when nitrous is activated. The 55 jet would be divided up between (4) injectors. A little like the "switch" in the S60 cal for high boost? Has Rob(shelgame) been talked to about this?
Hardware? ... maybe a solenoid switching between a second FPR set for corrected fuel pressure?

At any rate .. this is a ton better than flowing fuel -(trying to)- in our manifolds.

Mike ... I wasn't suggesting Dave inject the nitrous and cross his fingers. You're right, that would suck.

From speaking withj Chris at TU his cals will have a function to cobtrol nitrous and alky among other awesome features.

[bradp]

Believe me Mike (Zin) has more credentials than ANYONE else here and maybe in the country when it comes to nitrous applications on vehicles. How many years now Mike have you been working with Mike Thermos?

[puppet]

From speaking withj Chris at TU his cals will have a function to cobtrol nitrous and alky among other awesome features.

That would be the way to go with a conservative shot. The way you have it running now tuning will be a real ----- ... with the tank below pressure it would be near impossible to get it right.

[zin]

Still wonder if our cals could be programed for this. It seems like it would just be a small bit of tweak in injector DC when nitrous is activated. The 55 jet would be divided up between (4) injectors. A little like the "switch" in the S60 cal for high boost? Has Rob(shelgame) been talked to about this?
Hardware? ... maybe a solenoid switching between a second FPR set for corrected fuel pressure?

At any rate .. this is a ton better than flowing fuel -(trying to)- in our manifolds.

Mike ... I wasn't suggesting Dave inject the nitrous and cross his fingers. You're right, that would suck.

Somewhere in a thread far far away, I laid out what features would be desirable in a custom cal, I agree that it seems easy enough to do, but since we are essentially hacking the code, it might not be as easy to get results as it may appear. I certainly am not the guy to make this happen! I can tell you what you want to have, but making it so... Well, that's out of my league!

Mike

[zin]

Believe me Mike (Zin) has more credentials than ANYONE else here and maybe in the country when it comes to nitrous applications on vehicles. How many years now Mike have you been working with Mike Thermos?

Started @ NOS in 94, then Holley/NOS, then Earl's, then Nitrous Supply... Damn it has been a while! Too bad the automotive aftermarket isn't a place to get rich... for that you have to get into construction, right?

Mike

[bradp]

Started @ NOS in 94, then Holley/NOS, then Earl's, then Nitrous Supply... Damn it has been a while! Too bad the automotive aftermarket isn't a place to get rich... for that you have to get into construction, right?

Mike

LOL

[Ondonti]

If I felt like editing my pos TM server double post I would have it say "+1 mike marra"

[puppet]

If I felt like editing my pos TM server double post I would have it say "+1 mike marra"

Don't be so hasty ... the injectors should be able to offset the 55shot. As far as cylinder pressure goes .. he'd have that issue regardless. If Chris and Co. can make this happen in code, that'll be outstanding.

[contraption22]

I think it would be a great idea on provided that you have the extra head room in injector pulswidth to make it work without sacrificing idle quality, and two, you don't mind burning a chip and/or calling up who ever burns your cals and have them mail one to you everytime you want to jet up or down.

For me, if I want to change from a 50 shot to a 75 shot or 100 shot, it costs me about $10 in jets and 5 minutes in time to do that, all myself, at the track. Between passes. Even in the staging lanes.

[puppet]

Good points ... guess we'll have to see how this is going to be implemented in code.

[8valves]

I think it would be a great idea on provided that you have the extra head room in injector pulswidth to make it work without sacrificing idle quality, and two, you don't mind burning a chip and/or calling up who ever burns your cals and have them mail one to you everytime you want to jet up or down.

For me, if I want to change from a 50 shot to a 75 shot or 100 shot, it costs me about $10 in jets and 5 minutes in time to do that, all myself, at the track. Between passes. Even in the staging lanes.

I guess we'll all know what Mike is up to under his hood in the lanes before the next round of quick class!! HAHAHA!

[contraption22]

I guess we'll all know what Mike is up to under his hood in the lanes before the next round of quick class!! HAHAHA!

Yeah I have some plans for next season. A better intake manifold setup for direct port nitrous is on the list, as well as possibly a stronger bottom end and maybe a bigger turbo.

[8valves]

All great except then you'll have 4 times the jets to change, so your time will have easily increased another 5 minutes of down time! :-P

[puppet]

Brings up another good point, on this topic ... maybe Mike(zin) can address.
Individual cylinder tuning. I seems to me that a common (manifold, pre-manifold .. whatever) injection point of nitrous is better in that it saturates the air with O2 prior to CAT sensor(s). This also leaves just a fueling issue to balance cylinder to cylinder.

Since wet injection systems use the nitrous to atomize the fuel upon injection they are/have been "married" to each other whenever/wherever placed in the tract. Now in Mike M's case, he'll be tuning each cylinder for balance. Can/would that tuning operation go much easier separating the two components?

[zin]

Brings up another good point, on this topic ... maybe Mike(zin) can address.
Individual cylinder tuning. I seems to me that a common (manifold, pre-manifold .. whatever) injection point of nitrous is better in that it saturates the air with O2 prior to CAT sensor(s). This also leaves just a fueling issue to balance cylinder to cylinder.

Since wet injection systems use the nitrous to atomize the fuel upon injection they are/have been "married" to each other whenever/wherever placed in the tract. Now in Mike M's case, he'll be tuning each cylinder for balance. Can/would that tuning operation go much easier separating the two components?

You've got some good points, but in the end, putting both the nitrous and fuel into the runner is your best bet. With this configuration, you are all but assured that they will go into the cylinder they are sprayed towards.

The CAT is so slow that it I often wonder if it serves a useful purpose! Also, air temp sensors tend to add timing when they are cold, so that isn't a "feature" we'd want to exploit, thankfully they ARE so slow as to not create issues with systems that do "hit" them.

Nitrous will flow through the intake in pretty much the same manner/flow path as air (it is only slightly heavier than air), but that also means that if there is a flow balance problem with the intake, it can be amplified when the nitrous is on.

So far as the nitrous and fuel being "married", that lasts about as long as things are moving in a straight line, once it has to turn, fuel tends to drop out or splatter against the outside curve of the runner or other part of the intake, the more severe the turn, the more "loss" of fuel will occur. Then you have liquid fuel running through the intake. While not generally harmful in itself, the liquid fuel doesn't burn properly, effectively making things leaner, even though the proper lb/hr of fuel was injected. Most of the time, these "wet" systems have enough extra fuel from the system and the engine's injection to cover a lean hole and prevent a backfire or other damage. But the bigger the hit the less coverage you have and the more likely you are to have a lean-out/backfire. This is also why I generally recommend switching to a direct port system around 75-100 HP, which is about the point where distribution of fuel can start to become a real problem. It is also the point at which the smallest fuel jets will not be too much fuel. At 40+ PSI, even a .014" jet flows a lot of fuel!

We did do some experimenting with injection of the fuel in the runner with the bulk of the nitrous in the plenum, which made good HP, but was difficult to tune and still required gaseous nitrous at the nozzle to atomize the fuel. Exactly why it made better HP was never proven, but is thought to be due to two things, cooler/denser charge in the plenum allowed "more stuff" to get through the intake, the other is that the streams of nitrous pointed down the runners accelerated/entrained air improving the volumetric efficiency... But, in the end, the complication and marginal improvement of the system caused it to be abandon.

Hope that helps more than confuses!

Mike

[8valves]

Very interesting indeed, thank you Mike.

I've often been curious on dual power adder setups if the mixed nitrous/fuel flow changes based upon pressure in the intake. My basis of this comes from a higher pressure differential throughout the system, as in differences between center plenum to inside of tight radius, etc.

I wonder if that could also play role in distribution of the mixture? I know Dart has a wet flow bench that is amazing to see function, and the distribution of the fuel flow changed based upon depression setting IIRC. Certainly a high PR engine might have a similar effect?

Just thinking out loud I suppose.

[zin]

Very interesting indeed, thank you Mike.

I've often been curious on dual power adder setups if the mixed nitrous/fuel flow changes based upon pressure in the intake. My basis of this comes from a higher pressure differential throughout the system, as in differences between center plenum to inside of tight radius, etc.

I wonder if that could also play role in distribution of the mixture? I know Dart has a wet flow bench that is amazing to see function, and the distribution of the fuel flow changed based upon depression setting IIRC. Certainly a high PR engine might have a similar effect?

Just thinking out loud I suppose.

Any time we have a pressure differential there will be potential for flow un-balance. The differential has to come from something, either a restriction, turbulence, etc. Any of those things could turn the air/mix in an unpredictable direction, resulting in uneven cylinder to cylinder distribution.

I don't know if the pressure level will have a major effect on how the system performs, the higher pressure should make the fuel less volatile reducing it's desire to atomize, but we also tend to have a good deal of heat in the charge air so that may be canceling out this effect, at least to some extent.

It is pretty cool to watch fuel "materialize" when vacuum goes away. One day I'll build my own "wet flow" bench just so I can play around with this kind of thing... Now, where did I leave my winning lotto numbers....

Mike