Rev limiter on AEM? It has 2 rev limiters...? Please help!

SupraClaou

Supramania Contributor
Sep 1, 2006
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Athens,Greece
1st is fuel cut and 2nd is ignition cut on the AEM.

I have a 7800 rev limiter. On the AEM it is 7700 fuel cut and 7800 ignition cut.
Is that correct? I though it is better to leave the fuel run and cut the ignition first..

I would also like to pop some flames through my HKS Ti on the rev limiter xaxa...
 

IBoughtASupra

New Member
Mar 10, 2009
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Queens, NY
CajunKenny;1787498 said:
The AEM has a built in 2-Step?

Yes, pffff, noob.

:D

I know the V2 does as that is what I have to go on my 1JZ. You just go in the settings and adjust it accordingly. I play around with the software to get familiar with it so I can do a decent base tune without touching the timing, just air and fuel mixture. I have seen the two step option in the V2 software, I am not sure if V1 can do it.
 

toyotanos

What will we break today?
Staff member
Super Moderator
Nov 29, 2008
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Yep it does :)
OK, so this is the way I do my rev limiters, and I copied the way my tuner set it up. Ignition cut is what I prefer to hit first (7400rpm) and then shortly after my fuel cut limiter if the engine somehow makes it past. Not sure if it matters, but I feel safer cutting ignition and having a puff of smoke, rather than have the possibility of starving a cylinder of fuel.

To set up the 2-step limiter, go into the 'Setup' drop down, pull down to 'rev limiters' and select '2-step rev limiter' and then 'options'
-The menu it pulls up will give you the input for enabling the 2-step (usually a switch), 2-step fuel cut and ignition cut RPM's, 2step OK below VSS (uses vehicle speed to enable the 2-step, or to disable it in another way of thinking) and the retard rev rpm.
-There is also the 2-step rev limit wizard, this just determines how aggressive the engine does the cut (higher the number, the more aggressive the sound will be, and a more consistant RPM will be held. Lower levels may be more forgiving, but I'm not sure.


Here's the way I have mine set up, and it works pretty well. There are likely better ways to do it, but this is what I've come up with so far! *Don't blame me if you blow stuff up, please ;)
-I use a toggle switch to enable "2-step mode", only used for launching the car, otherwise its off. (I use switch #6 gnd=on. Basically ground switch #6 and its ready to go)

-Fuel/IG cut rpm works the same way as the main rev limiter its the rpm the computer will not go above. I set the fuel cut way high (8000rpm) and then the ignition cut wherever I want the 2-step to hold at. (mine is set for 8000 fuel, 3900 ignition)
-OK below VSS I use for my 2-step exit rpm (mine is set for 15mph, allows for some wheelspin)
-Retard rev is the rpm at which the computer retards the ignition timing a whole lot to make the exhaust valve into a blowtorch. Commonly known as antilag, this setting can burn a turbo up REALLY FAST due to the extreme heat involved! Use only if you know what you're getting into! WARNING WARNING WARNING!!!! If you mess this setting up and use it improperly you can and will cause engine and turbo damage! (mine is set for 3850rpm)

What that setup nets me is a 3900rpm launch RPM with 18-20lbs of boost, and the ability to feather the clutch as much as I want. The 2-step stops limiting at 15mph so I don't have to click a button off, which helps me a lot (kinda concentrated during that time :p )


As for the main rev limiter, I use 7400rpm ignition cut, 7800rpm fuel cut, and 12000rpm retard rev (I don't want antilag at redline ;) )
Be sure your rotating asembly can handle the RPM you set this for. If its stock, then leave it at 6500-6800. If you're built and fully balanced, and have good valvesprings you may be able to go higher.
-You can also program in a fuel cut pressure (similar to fuel cut on the stock system) If you know your tune is only good to 13psi, set the fuel cut load to 12-13psi so you don't blow stuff up. Remember- the factory put it there for a reason, why not enjoy the same safety with your spendy AEM?

Ask questions, I likely forgot a lot of stuff!
 

Enraged

A HG job took HOW long??
Mar 30, 2005
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Victoria, BC, Canada
IMHO setting the fuel cut pressure should be done right away, along with getting the engine started the first time. The tuner I dealt with first left it at 24psi even though I told him to set it at 16 or 17 (stock turbo, not much good after 15 psi). He then proceeded to overboost it and killed my clutch (it was already on its way out, but still).

I want to get traction control working too, just need to wire up a clean VSS signal.
 

SupraClaou

Supramania Contributor
Sep 1, 2006
846
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18
Athens,Greece
Nice and cool infos! Thanks guys.
What about big bam and flames through the exhaust when hitting the rev limiter?
I had this stuff when I had my rev limiter set at 7200 rpms. Now at 7800 rpms I don't. How's that?
It has to do with the turbo I run or with the AEM set up?