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Discussion Starter #1
okay this is the build i have in mind
tell me your opinion

d16a6 obx itbs
port match head to gasket
bisi valve spring
bisi 2.3 cam
bisi headers 2.5 exhaust
Arias piston combo
direct port dry nitrous
s300 ecu with jacob nitrous control
looking at using a .040 jet so like 250 shot
255 fuel pump

what do you think will it hold together.
 

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A 200+hp shot is possible, but its going to have to be in stages or progressive, and the whole setup is going to have to be optimized for nitrous.

Youre basically in the realm of a "nitrous motor", as in youre going to have to set it up to take the shot and its going to be shit without the nitrous.
Stuff like low compression, retarded ignition timing, long intake runners, over porting the exhaust ports, running oversized primaries on the header, and bizzar cam timing are all things youll need to do to successfully utilize a big shot, unfortunately all these things will further hurt the NA performance.


I would actaully stay away from the ITBs. This is a case where the stock manifold will probably be ideal as the runners are very long, and trust me, youre going to want to get the nozzles as far upstream as possible otherwise youre going to have serious reversion problems.
 

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Discussion Starter #3
why low compression i heard nitrous like high compression. and i though you want the nozzle as close as possible
 

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Everything likes high compression.
NA, Turbo, S/C, Nitrous, they all will make more power with higher CR, that doesnt mean that the engine is able to take it.

I have no idea where this notion of "Nitrous likes high compression" came from. If youre only going to run a small shot, then yes, you usually want to do a fairly high compression build (kinda like if you wanted to do a low boost build), but if you want to run a big shot the compression will have to be pretty mild.

Putting the nozzles as close as possible is the absolute worst thing you can do. With a small shot reversion wont be a big problem, but you are not letting it atomize as much as it could have if it was further back.
With a big shot reversion becomes a big problem, you literally will hit a wall where adding nitrous stops adding power, and then if you keep going it will actually start back flowing, this is what causes those "nitrous explosions" you hear about where it backfires in the intake manifold.

I can already tell that youre a bit in over your head with those goals.
I would suggest aiming for a nice 100 shot DP setup, maybe eventually work up to 125/150. That would just be a moderate NA build with the addition of nitrous, you have a lot more reasearch to do before undertaking a nitrous setup that will have a 300% increase over NA output.
 

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Discussion Starter #5
well thats why im asking now i been think about this for a while. but the thing is there isnt really alot of -KNOWLEDGEABLE ppl that like to share there nitrous experience and even just the mention of nitrous ppl start flaming and saying go turbo

but back to the topic compression whats a safe compression.. the my goal. you saying like 9.5 :1 btw im gonna wanna switch to e85 also.

as for the postion of the nitrous nozzle your suggestion it in the plenum or at the end of the runner before the plenum
 

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Well idealy you want them actually in the plenum, but reaching across so its going into the runner, this is good because it lets the nitrous flow well (not a sharp 90 degree turn)

Kinda like this:


Its hard to do though, so if you do just go with dry nozzles just try to mount them as close to the plenum as possible.


As for the compression, Its really hard to say.
I would be inclined to say that CR would be okay, but I just dont know. Id look at what kinda of compression a 350hp turbo build would merit and that would probably be a good starting point.
 

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formerly allnaturalrex
1989 honda crx si
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i would go with flat top pistons as well hmmm i have seen high comp big shot set-up on b-series and series on here that did very well but it was a 2 stage. search a member on here sn 24-7 think his name was on here. this wasn't a cookie cutter nitrous build

but full tilt is right about it suffering n/a wise if building a full on nitrous build the right way. once you get in the realm of getting into a hardcore nitrous build it take more then buying a kit. with nitrous its best bang for the buck but it will bite you in the ass if you dont do the proper thing. esp nozzle placement
 
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