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Does the rev limiter pull fuel or spark?

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Does the rev limiter pull fuel or spark?

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Dec 14, 2007 | 09:40 AM

#1

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Does the rev limiter pull fuel or spark?

just as the title says.

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Dec 14, 2007 | 09:58 AM

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BackinBlack02SS

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the stock rev limiter pulls fuel

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Dec 14, 2007 | 02:35 PM

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ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.

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Dec 14, 2007 | 02:49 PM

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I'll bet it does.

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Dec 15, 2007 | 03:50 PM

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Quote:

Originally Posted by tblu92

Yes--That's exactly the reaon for a LOW PRESSURE safety switch on the NOS fuel line to shut down the entire NOS system when fuel drops below a minimum setting--(most set around 30 PSI)

A low pressure safety switch wouldn't work in this situation (where the PCM pulls fuel)...the fuel gets pulled by keeping the injectors from firing, so if anything, your fuel pressure would increase in the system since it isn't going anywhere. The PCM isn't shutting off the fuel pump, and as long as that's pumping, you'll have at least 50+ psi in the rails...

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Dec 15, 2007 | 10:38 PM

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Quote:

Originally Posted by socmguy

ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.

Actually, the problem would be if you were running a WET shot, not dry. There is no harm in pumping unfueled nitrous through the motor. There would be a lot of harm in pumping a fueled nitrous shot with normal engine intake air not being fueled. In any event, the proper way would be to set the factory PCM rev limit above the nitrous rev limit.

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Dec 16, 2007 | 03:13 PM

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Quote:

Originally Posted by socmguy

ouch! so if you were spraying a dry shot and hit your rev limiter it would be bad news huh.

I am living proof of this. I had a high rpm (7000rpm) lean backfire with a 300rwhp shot, because of hitting the limiter and resulting lose of fuel. Now with that said, it was my own damn fault and not the dry hit, or the kit. I had decided that shifting without a window switch would be a cake walk. Didn't happen that way. When you don't shut the spray down the rpms will keep raising and take a bit to come down, so shifting at 6800rpm caused it to go up past limiter. Outcome was a hole or two in the manifold and bellows blown apart. Glad is wasn't a wet hit otherwise likely it would have been much worse.
Robert

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fuel, gm, hp, limit, limiter, limiters, ls1, ls3, pcm, raising, rev, spark, tacoma, tuners, type, work

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