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nitrous question

2 July 2000
Raleigh, NC
Have any of you guys that are running the RM nitrous setup (or nitrous period) thought of switching jets to run an 80 or maybe even 90 shot? What in your opinion will the stock motor and fuel system handle comfortably keeping the dry shot setup? Always looking for more hp
Thanks for any advice.

Some folks have rejetted to 100 shots with no other mods. Talk to Randy @ RM Racing and he can give you the lowdown on what you need to go to 100 or even higher.

- Lud
I have friends with lots of modded Civics that run NOS and a safe rule they use is your NOS shot should be half of the HP your motor comes stock. For example, 160 hp civic Si motor can take 80 shot NOS. So if their rule holds true the NSX with 290 should be able to take around 150 shot.

My friend has a 94 civic si that has 130 HP and he runs 80 Shot with all stock internals. He just turned his timing down 2 degrees, runs colder plugs, and its been fine.

[This message has been edited by PUREVIL (edited 06 October 2000).]
I had Randy @ RM personally install my 70 HP NOS and I asked him about going to a 100 HP setup and he said to do it he would have to drop the gas tank and re- route the lines and suggested staying with the 70 HP.
I'm running a 70 shot and would not recommend going higher without changing your fuel pump. When the NOS is first starting to spray, it takes time for your fuel system to catch up with the additional fuel required to keep your air/fuel ratio in the middle (Stoich). I had my car on a dyno with an air/fuel probe in the tailpipe. As soon as the NOS begins to flow, the motor tends to run lean until the fuel return is pinched off and the pressure starts to rise. If you were to add a 100hp jet with your stock pump, the time needed for the fuel side to recover will be increased enough that the motor will be running leaner longer. This to me is not safe, as I do not know how much the stock pistons and/or rings can take before problems begin.

If you want to run more than a 70 shot, I would suggest running a direct port system or going with a larger fuel pump.

YOu can easily run more power if you set it up correctly!!
The stock motor will handle a bigger shot, but the fuel system and computer will not. You could easily run 100 shot and probably a 150 (might go to forged pistons at that point), but you would have to go to a wet system or upgrade the fuel system. I personally believe that any motor with significant upgrades should have a progammable engine management system, like Haltech, Speed Pro or Motec. You can then go to as big a pump and injectors as you would like. Also, you can put the car on the dyno and re-tune it precisely any time you change a mod.
Thanks for all the replies guys. I talked to Randy at RM and he informed me of his fuel setup to run the bigger shot. Sounds very high tech and what he said made sense but $1,000??? What would be the side effects of just running a bigger fuel pump? Would this cause a super rich mixture the rest of the time (when not using the nitrous)? Thanks for the help.