I just built a 383 after taking out a head gasket on my old motor. before was running 50 to 150 with stock timming with no problems. my new motor is 12.5:1 It runs fine on pump gas on motor. But, what issues am I going to be looking at putting the nitous back on. Will I have to make a stand alone fuel system just for the nitous to run race gas when I spary? Or will I be able to just run it like I did before. the entire motor is forged. So I would like to run a 200 shot on the dyno and maybe on the track a time or two. but for the most part I want to run 125. Any advice about this would be great.

 

ANY nitrous on a 12.5 c/r is not wise. unless you back the timing off alot and run 105+ octane

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13.15@108 23MPG

 

I would run a seperate fuel system and back down the timing. Your best bet is to get the car on the dyno and adjust your timing where needed.

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95Z M6
383


and a few other mods

 

Nitrous on a 12.5:1 motor is plenty fine.
Just retard your timing a bit.
Don't know what system you have, but I'd go about -6 degrees with a 200 shot.
A separate system with some race gas would be a good idea if you don't want to run race gas in your regular fuel tank.

As for the spray on the dyno!
That's not a good idea, unless it's not going to go into an actual car.
The dyno (engine dyno's mainly) and hard on motors when you spray. Rods in particular.

Good luck
Dave

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If a little's good,
More is better,
And too much is just right!!!

 

Agreed! I wouldn't try tuning a Nitrous System on the dyno (Engine or Chassis). I've heard multiple stories of Nitrous Tune-Ups that work GREAT on the dyno, but result in disaster on the track. Difference being the load of the Dyno verus the load of the tire....

However I'd say start at ~8* retard and take it down from there.... What kind of pistons are they? Domes or Flattops? Fuel Octane should be Looked at and be in the 101-105 range.....

The Fuel system will partially depend on motor HP, but with the stock System (Lines etc) a 200hp system, on a stron motor could get sticky. I'd either want the dedicated Nitrous Fuel System, or a Completely Revamped Fuel system, With Braided Lines, and a nice Aeromotive/Weldon/etc pump, etc etc.

Good luck!

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Kurtis Tamez
LT4-396.com
97 Z28 LT4-396
94 Firehawk LT1-396
Team NW F-Body

 

I was just looking to she what numbers it would make on the dyno not really try to tune it unless it is unsafely out of tune. the fuel set up is stock except for a NOS brand in line pump and 30# injectors.

 

it would be a Rear wheel dyno not and engine dyno.

 

Run the car on the dyno with just the motor.
Don't spray it.
If you have a good system, like NX, the numbers will be right on with what jets you have in there. Unlike NOS where you'll be down considerably, from what you a suppose to have.

Good luck,
Dave

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If a little's good,
More is better,
And too much is just right!!!

 

Run the motor and nitrous on the same fuel. you dont want to start having different fuels in the combustion chamber. The nitrous will always find the easiest fuel to burn in the combustion chamber FIRST. IF you run the motor on 92, and 110 on the nitrous, the 92 will still ignite first when squeezing. Then you also run into different burn rates, etc. With 12.5 : 1 compression, I would run some 110 octane fuel, and spray 200 shot, NX kit ONLY, with about 2 degrees of retard. Probably close to about 34 degrees of total timing. If you want ot be super safe, pull 4 degrees. If you are using NOS nozzles, then start with about 8 degrees of retard.

 

I think the idea that you can't run N2O on the dyno must be a myth, as I've done it many times.

Rich Krause

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'95 Z-28 383 with Vortech, nitrous, etc.
"1FASTZ28"

 

For the average guy planning to run a 100-150hp system, and just throws the jets in, at the recommended pressures etc, sure its no problem.

When you're getting down to a larger system, and start reading the plugs, and playing with the A/F and N/F ratios alot more, and trying to tune on the dyno, everything can look GREAT on the dyno, but a Tuneup that worked so great on the dyno could be devestating on the track.....

I don't see any harm in running the system on the dyno. But I woudln't try to get that *killer tune-up* while on the rollers.
This is just relaying info I've gotten from a couple of sources that I trust.

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Kurtis Tamez
LT4-396.com
97 Z28 LT4-396
94 Firehawk LT1-396
Team NW F-Body