abohler

Wanted to put it out there and get some opinions on how much the stock motor can take nitrous wise. I am currently running 100 shot or so. Spraying with WOT and RPM window switch from 3k to 6.8k. Just cut out the secondary cats and resonator to get some more air flow, also running joe z intake and afe dry filter. I have seen guys like Mr slay run 175 and he didn't seem to have any issues. I want to get it up higher, and some people are saying 200 with a standalone fuel cell with c16. Any thoughts are greatly appreciated.

H60Driver

I wouldn't spray anything over 100 unless you get a standalone fuel cell. With no way to retard your timing I wouldn't risk it.

abohler

That was one of the things I mentioned above. I am adding a standalone with C16. Wondering how long it will take me to throw a rod if I go as high as 200.

rselby

whats your time and trap speeds now with 100 shot or rwhp,, have similar set up as you and N02 has crossed my mind

v8sten

iTrader: (1)

C16 is a leaded fuel and will clog up your o2 sensors

I8ABMR

I would also keep it at the 100 shot point to play it safe unless you want to take it to the next level with the fuel cell.

MRxSLAYx

With gutted primary cats, an exhaust system that gets rid of the secondary cats, and ms109 you can run a 200 shot without an issue as long as you can properly tune the nitrous system. If there are any issues on the exhaust side, you will have detonation in the #1 cylinder.

I wouldnt recommended a dedicated nitrous fuel cel for pushing a big nitrous shot on a street car. Mixing C16 with pump gas though a dedicated system will result in a greatly inferior fuel

abohler

I do want to keep this street ready without running straight race gas all the time. I do want a standalone, what you think I could pull off?

v8sten

iTrader: (1)

OK I am no chemist, I can only tell from my own experiences. I have talked to VP, Nitrous Outlet, Holley (NOS), and Wilson Manifolds (Nitrous ProFlow) about this very thing. My other car is a 86 Mustang with a 383 small block Chevy in it. I sprayed a 275hp NOS Big Shot plate kit on it for years. No detonation issues, never backfired, never popped and stuttered. No issues with the nitrous or fuel system at all. I ran 93 octane pump gas in the main fuel tank and C16 in the 1 gal cell up front. After I refresh my motor I plan on adding another kit and spraying upwards to 500hp. >>>> THIS IS A PUMP GAS STREET CAR <<<< difference is I plan on running C23 in the dedicated fuel cell to accommodate for the difference.

All Im saying is I have done it for years, so I do not see a problem with mixing the fuels and neither do any of the manufactures I stated above. Only problem I see with running C16 in our cars is running a leaded fuel thru cats and clogging the O2 sensors.

MRxSLAYx

I wouldn't spray more than 175 on a mixed fuel. Unless your going to go through the lengths that ive gone through to make the car tunable, the standalone ECU isnt going to come easy. My other 2UR is pretty much a 1800hp ready crate engine at this point.

Your experiences with your SBC are understandable, but the 2UR is a competently different motor. I dont know anyone who is going to recommend spraying a large shot on a 11.8:1 motor with high timing using sub 100 octane fuel. If we could tune the car for nitrous, the cell would be a viable option.

MYISF

So from all the back and forth above am I too understand that a conservative approach to NOS for the ISF is a 100 shot on the stock fuel system...correct?

Now if you want more than 100 it sounds like it could get more complicated with tuning and fuel...correct???

MYISF

Per the reply below (bold) what do you mean by issues on the exhaust side???

abohler

So All in all you think I could go up to 175 with a standalone cell, and gutted/deleted cats? I am planning on running a degree or 2 colder plugs as well to keep it safe. Would you suggest considering getting better rods to go up a bit, or at that point should I just reconsider revamping the whole motor?

Also, I have seen a lot of your project with the 2ur motor, what are you doing for an ecu in the high hp motor?

v8sten

iTrader: (1)

I understand the tuning issue. I was just merely stating that you can mix the fuels. It was stated above that it would not be a good idea, ive been doing it for years. thats it. the timing and compression issue i completly understand, i was just stating the cats and o2 sensors would be hating life when you run C16 LEADED fuel thru them. there are perfectly good UNLEADED race fuels that would work and the o2 sensors and cats would be happy.

abohler

A few more questions for input.

1. Any other better ideas for fuel in a standalone rather than c16? I have deleted 2 of my cats and will gut the front 2 on the stock manifolds. Will this suffice to avoid issues with the leaded fuel?

2. Run a progressive controller. I am currently running an rpm window switch to shut off at 6800rpm, will having more control during a pass with a progressive controller help if spraying a large shot? I have received the suggestion as well to have the nitrous kick in later ie moving the rpm window from 3k to 3500 or later with a larger shot. So in essence more nitrous in a smaller window. Just looking for some ideas.

3. Setup wideband. I am fairly new to the wideband approach. I know you can get afr readings so you know you are safe. I am also aware if the afr goes into an unsafe region it can close the nitrous solenoid to avoid issues. Any opinions?