SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Reflections on March 30, 2016, 11:03:53 PM
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Hello,
Who here runs nos on their boat?
I'm having a little problem past week with it, I can only get a 2-5 second burst with it when pushing the button and feel the nos kick in then it pops a little through the headers NOT violent then falls flat, I have timing set at 33, plugs are burning nice NO peppering or lean or rich, plugs are gapped right now at 32, we went from a 5-9 spread in jets and still does it.
we thought it might be the button and arming switch ( which were cheap low amp ones ) we switched those out to higher amps, but haven't taken boat out since sunday ( easter )
to see if that was the problem? I talked with a well known builder in my area he said bump gap down to 25, were gonna start off at 28 first, and plug the vacuum advance then try it out maybe tomorrow depending on weather. I tripled checked the wiring its fine and I am using a relay, we are stumped at this time what it could be? I'm even using a separate fuel pump electric holly blue with regulator and we flowed the fuel with a gauge for 61/2 pounds, and when we do hit the NOS its not dropping.
motor is a 468 BBC mild build, edelbrock performer 2.0 intake with a predator carb., Dist, 65,000 with a Mallory coil HEI 92 pump gas. I'm only wanting to squeeze 100-125 shot longer than 2-5 seconds.
Any other areas to check or suggestions?
Thanks for any info, or help
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What is the exact jetting on the tune up? Foger or plate? How much timing are you pulling on the shot? What coil?
Sent from McIntyre Park
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Apparently I didn't read the whole post. I would change the coil to a msd blaster 2 and see if that helps.
Sent from McIntyre Park
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sorry forgot to mention, its a plate, right now I forget what jets are in it now, have to check in the AM timing set at 33 total.
What is the exact jetting on the tune up? Foger or plate? How much timing are you pulling on the shot? What coil?
Sent from McIntyre Park
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sorry forgot to mention, its a plate, right now I forget what jets are in it now, have to check in the AM timing set at 33 total.
33 total sounds fine, make sure you are pulling at least 2 degrees for every 50 shot of nitrous you are spraying On the hit.
Sent from McIntyre Park
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you think I'm running out of voltage from the HEI?, that means I would have to run a points dist,?
Apparently I didn't read the whole post. I would change the coil to a msd blaster 2 and see if that helps.
Sent from McIntyre Park
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you think I'm running out of voltage from the HEI?, that means I would have to run a points dist,?
Why?
I think Jakes referring to coil saturation.
As for the vacuum advance, you don't need to plug the pot, but you will need to recheck timing. Oxidant plugging the port on the carburetor.
Check for a sticky regulator.
You will need to flow the N02 and verify pressure at the end.
GT
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Going out on a limb here, these guys for sure have more experience than I. However I haven't seen bottle temp mentioned yet?
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Nitrous.... Few things.
1. What is your current jetting
2. What plate are you running
3. What is your FLOWING fuel psi
4. What is your bottle pressure or temperature
Can you get us these 4 answers? Popping out the exhaust is typically rich, atleast in my experience. If you can get us the answers above we can help you out somemore
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Low voltage will also cause this condition you are describing
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What spark plugs as well.
Sent from McIntyre Park
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How are u retarding the timing ?
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How are u retarding the timing ?
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We use a MSD retard box