hey, so im trying to get my nitrous setup all figured out before i bring it to the dyno but need a little help. first off, im running a eagle 383 w/ arias pistons, 11.4:1 compression, prc 5.3 heads, ms4, fast 92/90, and nitrous outlet 92mm plate. i want to run a 200 shot on it. i am pulling fuel from the rail for now. i have a walbro 255 pump. will i need race gas for a 200hp hit or will 93 be fine? whats jets do i need for a 200 shot? what plugs?
i will probably only spray the car on the dyno and at the track.

 

I would at least mix 5 gallons of race gas in the tank along with 93 to help with the nitrous. The jetting for the 200hp shot is 78N20 46Fuel. For the plugs you have 2 choices...first would be the BR7EF's ( Stock# 3346 ) and gap them around 33-35 and the second choice which would put on the very safe side of the line would be the BR8EF's ( stock# 1049 ).

 

You can run a 200 on pump gas, but you need to pull the correct amount of timing, and to be safe I would definitely run br8efs.

 

I'd put 8's in the car and run 50/50 with race gas/93. I'd also be really weary about only having a single pump and a stock regulator. I'd add a second pump, run a -8 feed, add a good regulator up front and use the stock feed as a return.

I'm being very cautious here, but it's what I'd do if I wanted to pull it off the rail. (I'm actually thinking about doing this now... Kind of tired with worrying with the stand alone system)

 

If you hook up an accumulator to the rail you may get buy. We tried a 200 off the rails of a 402 about 4-5 yrs ago. We knicked a few ground straps along the way on the left bank even with a fuel mix like Chris spoke of. The initial fuel drop from the nitrous turning on is the issue. Hooked up an accumulator to the rails and all was good. I would however like to see you switch to some type of dedicated fuel system. As far as plugs go, that is a tuner preference...

 

thanks for the info guys. but whats an accumulator? ryarbrough, why dont you like your standalone?

 

An accumulator is just a resivoir to provide more fuel volume in the rails so that the pressure drop is lessened when the fuel solenoid opens. I personally don't like using one, but it's worked for others in the past successfully.

As to your second question, I'm not going to spray a ton on the car. I'll probably stop around 250. With that I feel comfortable tuning out the O2's, throwing race gas in the tank, and having a good fuel system with a set of walboros and a front mounted regulator. There's nothing wrong with a stand alone, I'm just looking to try something new that might be a little simpler (and safer since I can run 100% race gas).

 

I run a dedicated fuel cell from NITROUSOUTLET. I run 116 in that and 110 in my tank. The dedicated fuel cell is added insurance that the motor gets plenty of fuel.

 

You think the fuel system you're talking about is safer and simpiler then a standalone? Please explain...
Also, Why don't you "personally" like using an accumulator?

 

Stand alone is safer and more tunable than what you are going to go to... No way would I go backwards like that...

LS1curt - If you are running stock rails, you will run it out of fuel without the accumulator... Personally, I would go to aftermarket rails, or better yet, a stand alone for the nitrous. That way you can fine tune the nitrous by being able to change fuel pressure in small increments...

 

The only reason I said safer is because I don't have to worry about the posibility of getting some crappy pump gas in the main tank (running pump gas in the tank and C16 in the fuel cell is one of the reasons us street car guys have gravitated towards a stand alone). Like I said, it allows me to run 100% C16 when I'm spraying the car (yes, I'll be tuning the car OL) rather than try to guess the amount of octane enrichment. I say simpler because you're only worrying about one fueling system. Key on, you've got 1000HP worth of fuel. I can look at one gauge (not two) to verify pressure. I can fill one tank (not two) with fuel. I also like the reliability factor of a walboro pump compared to the carb style electric pump I've got on the stand alone now. Am I being a little too careful on the last point, probably....

I do agree there are cons. The most notable is that I will lose some tunability due to having the kit be on a high pressure system. That's not a deal killer for me. I've got a carb style plate so jets are large and changes are easy. Also, I'll probably turn down the base FP on the regulator so I gain a very little bit of that back (it'll also gain me some resolution as far as IPW at idle on the 60lb injectors goes).

Is it the best solution for guys spraying 400, no. Do I agree that a stand alone has it's benefits over this style system, yes. Do I think that it's worth my time to at least give this a shot and see if I like it better, yes. My car is a semi-quick street car that is never going to have a "big" shot like that on it so I don't see the harm in doing this. Worst case scenario, I just add a second feed and regulator specifically for the kit (which I'll probably do anyway). I'm just giving it a shot, and If it fails miserably, I'll report back to that extent.

I don't personally like an accumulator (even though I agree they can serve a purpose) because I'd rather beef up the lines, rails, regulator, pump, etc. to have a more balanced fuel system than rely on an accumulator. I've seen them work great on a car or two, I just feel like it's sort of a "get-me-buy" until you upgrade the fuel system. I still remember when NX sent those things out with their under the injector DP kits so that everyone could spray 200 on a stock fuel system. That stuff scared me back then and still does now.

I agree that the stand alone definately has it's beneifits. It's safer because it's more tunable (especially running low pressure). If I came off sounding like I didn't agree with that I greatly apologize. I'm confident that at the level I'm at (the car won't get more than 250 on it) I'm capable of tuning it even on a high pressure system.

I completely agree with your advice to the OP.

 

Looks good...

 

okay, well looks like ill prob end up doing a decitated fuel setup in the future because i cant be putting to much more money into the car right now. whats the most you guys would spray through the stock rails? 150? 175? whats jets

 

It's more about total fuel flow. The more you make on motor the less of a shock from the nitrous the rails can take. What does the car make on motor?

 

i have not got the engine back from my engine builder yet, but i have similar mods as you, but with a 383 and 11.4:1 compression.

 

My 408 on a 150 shot went lean with stock rails...

 

Thanks man. Its still a work in progress. The new 408 I have is working great to. When I get as fast as your car then I will be satsified.
I run 110 sunco in the tank and c16 in the dedicated. Plan on spraying a 250 shot then moving up to a 300 shot before LSX.

 

Which injectors do you have?

ALSO THIS IS A RESPONSE TO THE GUY IN THIS POST.
My old set up on a 370 4 years ago I used to run a 150 shot off the rail and TNT wet kit I had a intank walbro 255 and ran 42lb green top injectors. Do you have aftermarket injectors? I would pick up some if you still plan on running off the rail. By the way I still run my 98 fuel rail no issues.

 

Car is gone now, but I had FAST 42# injectors, Racetronix pump with hotwire, a TNT wet kit off the stock rail with a FAST 90mm setup... I changed to a Vic Jr with rails, everything else the same, and wasn't lean any more... And I went on to put a carb plate setup on it and sprayed a 250 hit on it (times in sig) - the rails make a huge difference...

 

i have 42lb injectors with a 255 walbro