Has anyone ever suggested making an N2O system that uses the cold start port on the 86-88 manifolds?

Seems like gm already did alot of work to get the ports there. All that would be left for you to do is seal the pluming to the place where the CSI sits and then to select orifices for the ports in each runner.

Maybe you couldent use them because you would have to mix the nitrous and fuel in the cold start passages (bad). Maybe you could make it a dry system and signal the ecm for more fuel through a prom burn. I assume there is some kind of patch out there that would allow you to signal the ecm through an unused or reprogrammed pin from a microswitch?

 

hmmm.. Thought about this some more and I dont think a wet injection would work because leaving that passage full of mix would be a bad idea.

However if the dry system was to work you would have to have a signal that the ECM could pick up and then use that signal to add a multiplier to the PW or something.

As you might be able to tell I am still a prom virgin but have all the hardware to burn and emulate ready for when I get the car back together. I was just looking for some alternatives to the NOS plate system for the TPI and had this crazy idea.

 

Sounds cool !
An adder to the PW to add the fuel, now all we need is the Nitrous to be "injector" controlled via a PW for flow rate.
Maybe use another driver with an output voltage that can be the added fuel reference signal (rather than ON/OFF)
Variable HP gain.


Just crazy talk...

 

As for the nitrous "injector" I was thinking of just sticking with a fixed amount from a soleniod and orifice. Just getting the PW adder for the fixed amount of giggle gas right would be tough enough for me!

 

Are the CSI ports individually running to each port already?
I never really looked at the passages.

 

Im pretty sure they do. They are little (like 1/8 inch) holes about halfway down in each port in the base.

 

Just dreaming...
Something like a variable pressure control valve to regulate the Nitrous amount. You'll probabably need to put in some orifices anyway just to keep the pressure to all cylinders equal and give the pressure control something to work against. They normally don't perform well under no load conditions.
A variable amount of nitrous with a matching increase in fuel adder would give you a nice way to tune without the "spash" and go way of doing it.
Also this would give full adjustment of the power adder that could be tuned in steps to go easy at first then dial it up to the max you think you can take.
Interesting...

 

I dont know anything here but its good to see at least someone is thinking about it besides me.

I was thinking you might not need orifices on the individual ports because putting the nitrous into the hot *** manifold if the passages are small should maintain a pretty good pressure all the way to each port. Cold the system would probably shoot most of the nitrous out the first couple runners but putting orifices in those holes halfway down the runners sounds like a nightmare to me. Guess you would just have to make sure to inject a buttload of juice to get it to all the ports!

I will go look at the passages tonight when I go home. I think the CSI fires into like a mini cast plenum on the underside of the manifold. this little plenum has access ports in the form of huge allen plugs. maybe I could take out the plugs and see what the internal volume looks like or even gain access to the individual distribution ports to put some orifices in there.

 

You may have to put the orifices in just to keep them all loading the same or you could run into uneven filling.

I'm not in the market currently to go with a nitrous setup but this is an interesting way to do it.
Let us know what it looks like in there. I'd like to see if there is a way to implement it like I said above. Only code will tell, not there yet.
There may come a time...

I'm holding out for a supercharger for now.
I like speed and nitrous would make me break many things, many times.


John

 

I have a non-CSI manifold laying in my shed right now. It has the holes in the runners that you describe, and the allen-plugged passage across the bottom. The passage plumbs directly into the exhaust side of the EGR valve flange. The CSI may inject into this passage, I don't know because I don't have a CSI manifold. I pulled the plugs out and they offer direct access to the small ports in the runners...I can only guess that the reason the plugs are there was for access to the bottom of the runner to drill the holes during production.


It could work, if you were to block off the EGR port at the runner flange and the valve. If uneven spray became an issue you could even tap the small ports in the runners to accept N2O jets or something similar.

 

GreatJ - I thought the EGR discharged from the holes just behind the throttle body? If what you say is true then this might be more work than I thought. I wanted to keep my egr but I suppose its not a big deal. Thanks for looking into the allen-plugged holes, I forgot to do it last night (g/f is hot!). Putting jets into the holes sounds atractive but I dont think you would want to fill that entire CSI/EGR manifold section with liquid N2O. I think most nitrous jets are designed to work with liquid on the pressure side and I highly doubt you could fill the entire section with liquid and get the fueling right when its filling. not to mention that that entire section of the aluminum manifold would drop in temp enough to most likely crack it.

I belive I have a solution though. I think you could run some nitrous hypo tubing in through the CSI port and have it run down the little manifold and exit at some strategic locations (right under the allen plugs). Then you have the ability to put the nitrous where you want it in relation to these little holes. Hell if you could get mini distribution blocks in there under the allen plugs you could run a line to each hole. At this point Im thinking it might just be easier to plum the manifold for a direct injection wet system but Ill keep thinking of ways to use the CSI passages because this is fun.

:lala:

 

The EGR valve itself does discharge into the plenum just behind the TB. The passage under the intake is plumbed off the EXHAUST side of the valve, BEFORE the valve, so it has exhaust gas flow all the time....even when the valve is closed. Maybe that's why they chose that passage for the CSI....it plumbs to all the runners and the airflow created by manifold vacuum would help distribute the fuel.......

 

I looked at mine last night and I think you might be right but it seems wierd that the egr crossover would be feeding exhaust into the runners all the time through these little holes? That and there are carbon deposits on the egr side port to the egr throttle body ports and on the crossover tube from the heads but I didnt see any carbon in the CSI hole or in the runners near the little holes. Im still not convinced that the exhaust crossover uses the same passage as the CSI. This weekend will tell me for sure when I can spend more than 5 seconds looking at it before the G/F drags me away.

 

Ya know....after taking a couple of measurements (depth of the passages from various sides) I think you're right, they are seperate. It looks like the EGR passage runs right across the top of the passage with the plugs, but doesn't connect to it. It doesn't miss it by much....maybe 1/8" by my measurements, but it does seem to miss it. So much for that theory.


It just seems odd that GM would spend the money punching the holes in the runners on a non-CSI manifold (like my '89 base.) They left the actual injector port closed, so why drill and tap the access holes, drill the small ports in the runners, and pay for the big allen head plugs for the passage? That's just not like GM.....it would have been much cheaper to leave the bosses under the manifold solid and not drill into the runners at all.


That's one thing I like about having a fiance who works the nightshift.....plenty of alone time to play with the toys.

 

I can't imagine distribution would be very good going this route.

 

GreatJ -- I looked at the manifold last night and you are right. I even went so far as to put some water down the CSI port and blew it out with a compressor. Sure enough the egr ports were dry but the insides of the runners were soaked.

Ok I think the best way to do this nitrous idea would be to have jets and hypo tubes to each of these ports with a solenoid mounted just outside the CSI port. That way liquid nitrous would make it all the way to the ports without freezing the manifold. all you would have to do is tap the little ports for jets and then bend all the tubing and distribution Y's. Not sure if this would cost less than the 600 or so it takes for a plate system but if you could get the fueling right you would be able to take alot more juice because the distribution would be so accurate.

 

Not to mention the fact that it would be nearly invisible to all but the closest inspection.....the solenoid would be under the plenum and you could run the feed line out the back and down the bellhousing. The throttle switch would be the only real giveaway, and I'm sure that could be taken care of. Hasn't there been talk of using an ECM output to control a nitrous system?

 

now THAT would be the cats ***!

If you could get the computer to trigger the system at WOT.

I am Wayyy to green with burning to know if this is possible but hopefully someone will jump in here and give ideas.

 

Ugh, this is supposed to be a PG rated forum.
Doc

 

I'm lost on that one, and just don't want to know.
Doc

 

Fire up the ole ecm bench and verify things, and away ya go.
Or just hope it all works and experiment with a live engine.

 

Ultimate TBI code for the SpeedReader has that: arming input, TPS% threshold, then an upper and lower RPM threshold (RPM window).

RBob.

 

Sorry Doc -- bad reference to american chopper.

Grumpy,

Is there any possibility that there is existing code (like A/C control or highway mode or something) that could be used to trigger a descrete multiplier to PW?

I would think that the A/C input would be a good place to trigger because I don't use A/C anymore. I just have never heard of a PW adder like that.

Also I dont think I'd like to try this for the first time on my engine running a dry shot. But I dont know how to build an ecm bench either.

Any chance this could be added to the source code of the 6e or any other code I could run on my 165?

 

Can be added to any mask. . .

RBob.

 

Cool -- then I will try to research this as much as I can.

One more question -- is there any code that could be used to augment the fuel PW for a dry system? I thought that there were many adders to the fuel PW in the 6e code that have the code arrive at the final PW. Maybe one of these could be copied or modified to change upon activation of the system to add the needed fuel.

 

I would make it a separate modifier. That would be the most straight forward and reliable method. If done that way it is just an easy matter of changing a single parameter when the urge for a bigger N2O jet is selected.

Just need to remember that the fueling is currently RPM based by being tied to DRPs. N2O needs the same mass of fuel no matter what RPM the engine is at. Easy conversion, just need to remember to have the code do it.

RBob.

 

Thanks RBob I will remember all this when it comes time to spray. As for now I must get the motor running and tuned properly for N/A operation. I think this nitrous experiment would happen some time this winter.

 

I have another idea for you. Put the NOS through the plate like normal and put a relay in the CSI wiring so that the CSI injector is activated by your microswitch that activates the NOS. That way when you hit it with NOS, you are also hitting it with more fuel.

Another way would be to use the Edelbrock intake that has the EGR port for the Corvette style hookup back by the distributor a well as the normal EGR port (do any of the other aftermarket manifolds have that?) and plumb in your NOS through that. Tie in the CSI the same way. That way you are getting equal NOS and fuel to each cylinder.... You may need to plug the vacuum line to the EGR valve (except when getting a smog check) so that it doesn't activate.

 

Capitan, Using the CSI for fuel injection would be a BAD idea I think. It is hard enough to keep the fuel in suspension with the plate system let alone try to get it through the CSI manifold maze.

I also do not want to buy a new manifold but if one had more egr ports Im not sure that would work either. The CSI manifold is the only one that connects to a separate hole for each runner, the egr just dumps to the upper plenum behind the TB.

 

My misunderstanding of a post up above. I thought it was mentioned there were plugs you could pull on the EGR side that would allow flow into the individual runners. I didn't remember ever seeing any, but I've missed things before. there are some weird threaded holes in my Edelbrock intake by each port that I have no clue what they are for......

If the ports behind the TB are the only outlet and drilling holes/removing plugs won't help, then obviously you can't do what I suggested....

If one knew the exact path of the EGR gasses to their front outlet, you could possibly drill holes in the runner passages down into the EGR channel.....