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View Poll Results: Factory rev limiters?
Ignition cut 11 52.38%
Fuel cut 10 47.62%
Voters: 21. You may not vote on this poll

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Old 04-29-2008, 12:44 AM   #1
rice h8r
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Question Factory rev limiter, ignition cut or fuel cut?

I always thought that stock rev limiters cut the fuel pump, but my friend says that even on factory systems it cuts the ignition.

http://en.wikipedia.org/wiki/Rev_limiter

which one is it?
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Old 04-29-2008, 12:50 AM   #2
Ozzman
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I know my honda shuts off the injectors to induce the rev limit. I'm pretty sure the stock subaru rev-limiter uses the same method.
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Old 04-29-2008, 12:54 AM   #3
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why would it cut the fuel pump what exactly would that accomplish?

either its injectors (herro lean) or spark cut 9which I'm going to hope most vehicles are nowdays)
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Old 04-29-2008, 12:56 AM   #4
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I would bet ignition cut, it may be kind of unsafe to cut fuel under boost. ???



Then again the ecu could cut fuel and ignition at the same time...

Last edited by 2slofouru; 04-29-2008 at 01:05 AM.
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Old 04-29-2008, 12:57 AM   #5
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I know S2k's cut fuel(at the injector I assume).
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Old 04-29-2008, 09:18 AM   #6
Chuck H
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Pretty sure that most factory rev limiters, including turbo Subies are fuel cut. That's why you don't want to sit there bouncing off the rev limiter like you can with an ignition cut aftermarket launch control.
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Old 04-29-2008, 09:36 AM   #7
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We get fuel cut and eventually it closes the throttle body.
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Old 04-29-2008, 09:44 AM   #8
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I'm pretty sure it just applies the brakes--just like traction control.
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Old 04-29-2008, 09:45 AM   #9
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If it only cut ignition and not fuel, where would all that gas go?
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Old 04-29-2008, 09:48 AM   #10
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Quote:
Originally Posted by waktasz View Post
If it only cut ignition and not fuel, where would all that gas go?
It stays in the cylinder until the next spark, and then you get a TON of power. That's the whole reason to bounce off the rev limiter when launching.
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Old 04-29-2008, 09:59 AM   #11
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Quote:
Originally Posted by Asinine View Post
It stays in the cylinder until the next spark, and then you get a TON of power. That's the whole reason to bounce off the rev limiter when launching.
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Old 04-29-2008, 10:02 AM   #12
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Quote:
Originally Posted by Asinine View Post
I'm pretty sure it just applies the brakes--just like traction control.
More specifically, the cylinder piston brake are activated at about 250 rpm beyond redline. The brakes slow the pistons down, the same way they do with traction control.
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Old 04-29-2008, 10:16 AM   #13
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if it was ignition cut, stage 2 ers would sound like they had Bee*R rev limiters at the rev limit.
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Old 04-29-2008, 10:26 AM   #14
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Quote:
Originally Posted by Asinine View Post
It stays in the cylinder until the next spark, and then you get a TON of power. That's the whole reason to bounce off the rev limiter when launching.


reality is it gets sent back to the gas tank
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Old 04-29-2008, 04:44 PM   #15
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Not all cars have a return line. Doesn't it just spray into the cylinder, hence the crazy after firing on cars with aftermarket ignition cut rev limiters?
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Old 04-29-2008, 04:54 PM   #16
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SRT-4s have a spark cut. Fuel still build ups then shoots flames while bouncing off of the rev limiter as the spark fires again.
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Old 04-29-2008, 04:59 PM   #17
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Quote:
Originally Posted by Asinine View Post
It stays in the cylinder until the next spark, and then you get a TON of power. That's the whole reason to bounce off the rev limiter when launching.
hahha
im pretty sure a lot of the unburnt mixture goes out the exhaust valve and eventually ignites in, or prior to the turbine (due to enormous heat) thereby inducing spool. that's why you do it at launch or coming out of a corner. As anti-lag srategy
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Old 04-29-2008, 09:01 PM   #18
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Funny how many posters are saying fuel cut, but by vote ignition cut is winning 2 to 1 so far...
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Old 04-29-2008, 09:59 PM   #19
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I'm pretty sure the reason most manufacturers use fuel cut revlimiters is for emissions purposes and to make sure you don't blow out a cat when it gets soaked in fuel bouncing off an ignition cut, then when you finally get out of the limiter all that fuel ignites in the cat thus severly shortening its lifespan if done repeatedly.
Using a fuel cut for the revlimiter prevents this problem. Bouncing off the fuel cut ocasionally and for a breif second or two won't hurt the pistons.
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Old 04-29-2008, 10:04 PM   #20
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Quote:
Originally Posted by Ozzman View Post
I'm pretty sure the reason most manufacturers use fuel cut revlimiters is for emissions purposes and to make sure you don't blow out a cat when it gets soaked in fuel bouncing off an ignition cut, then when you finally get out of the limiter all that fuel ignites in the cat thus severly shortening its lifespan if done repeatedly.
Using a fuel cut for the revlimiter prevents this problem. Bouncing off the fuel cut ocasionally and for a breif second or two won't hurt the pistons.
What about detonation?
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