fjbiker86

I am posting this question on here because the gasser forums I have been on do not know anything about EGTs and You dieselers know everything about everything!! So I was hopeing someone could help me out please.I have a 1996 Dodge 5.9l and I am going to run a wet nitrous system. I have been told that it is easy to burn up pistons if there is not enough fuel being combined with the nitrous under combustion. So my plan is to run 2 EGT gauges 1 for each side and mounted on the hottest cylinders to keep track of how hot things are getting. Does anyone know what are safe EGT's for my gasser stock pistons?? And if you have better ideas for the EGT set up please let me know. Thanks for taking the time to read this whimpy gasser question.
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(cant afford a diesel)

one54ton

ummmmmmmmmm ok........

BigBlue

The beauty of a wet system is that it injects the extra fuel needed to make sure that you don't run to lean. Jet the nozzle to whatever is specified in the directions and you should be fine. If you want, go one jet richer on the fuel side just to be safe.

ramtd02

gasser egt's are actually quite close to the diesel's. diesel contais about 40% more energy than gas, and the diesel is 25% more efficient. subsequently that difference in efficiency makes up for the energy diff. So I would put a gasser at about 1300 max obtained with 1600 spikes. just as our cummins are run

HOHN

EGT is just as way to tune rich/lean. The lower you can get it, the better.

Gassers don't burn up from running too lean on the bottle, per se. You'll actually observe LOWER Egt when a nitrous system is running lean.

The reason lean nitrous burns up engines is that the rate of combustion gets way too fast, acting almost like super-low octane fuel. This causes HUGE pressure spikes in the cylinder, like detonation (usually it *is* detonation).

The pressure spikes result in huge peak cylinder temps and pressures, and THIS is what melts the pistons and burns valves.

...And you'll observe lower EGT the whole time this is happening!!

IN gassers, the higher the EGT, the "safer" it is in terms of not being into detonation. Unfortunately, high EGT in gassers also makes low hp and bad performance all around.

BB is right-- jet your "wet" nitrous system to be a little on the rich side.

Too rich costs you hp.

Too lean can cost you your engine!

rockjeep73

So it sounds like monitoring EGT way not be the best way to tune a gasser for rich/lean conditions while using nitrous. Would an air/fuel monitor work better for tuning with nitrous?

fjbiker86

thats what I was kinda thinking but i dont know much about the air fuel monitor's...where would the probe even mount ?

BigBlue

Your best bet is to install a wideband O2 sensor and have your air/fuel gauge reading off of that. If I'm correct, the best mixture is about 12.5-13.1 is where a lot of people have it. I THINK. Do some research on it though. The best way to tune it is to put the car on the dyno and let them custom tune the ECM if they can. If not, they can at least hook up a wide band and get your air/fuel mixture and then you can play with the jets.

Ph4tty

Here's Dynojet's wideband sensor: http://www.widebandcommander.com/

Are you going to play with the timing too?

Ph4tty

02 sensor in the header?

HOHN

Wideband sensors are nice to have, but notoriously unreliable (fragile).

The problem that frustrated me most with tuning gassers was the TERRIBLE mixture distribution on a carbureted V-8. So you're always having to run some cylinder too lean to keep from burning up the lean cylinders.

EFI is *so* much better in that regard. Makes nitrous tuning a snap. Even better when it's ECM-controlled.

check out the FAST fuel injection setups. Even better than the Accel/DFI setups.

fjbiker86

From what I have read I dont need to do timing if I stay under a 150 shot

88bird

that's BULL SHIZNIT NOS INSTRUCTIONS page 17 states and i quote....

IMPORTANT! Ignition timing should be retarded approximately 2 degrees per 50 HP increase due to nitrous oxide injection.
Start with the engine’s best total timing and reduce from there. Use the initial settings, which are 2-3 degrees
more retarded than you expect to be optimum.
Example: Total Ignition Timing without Nitrous------------------------- 38°
100 HP Increase from Nitrous-------2°/50HP-------------------------- 4° Retard
Initial Safety Margin------------------------------------------------- 2° Retard
Initial Timing with Nitrous-------------------------------------------- 32°

read up on it b 4 u try it..... like stated before it's better to be a little rich than lean..... and invest in a nice LM1 wideband setup it'll pay for it self in the long run....