dragon831

iTrader: (1)

I plan on getting an evox in the next few months. I currently have an 07 si and have no idea what this "2 step" clutch thing is, or 2 step launching. Anyone care to explain? Thanks in advance.

victoramone14

my understanding is:

factory installed protection for the clutch so u dont do the high revs and suddenly drop the clutch and do wicked burnouts but boil the clutch. it prevents the car from messing the clutch up or your tranny.
in other words u can launch the car from 0 at high revs.
if you try to drop the clutch at high revs it will delay the clutch until the engine is at low revs than the gear will kick in.

Stupid but Protective!

EvoHung

iTrader: (18)

2-step limits your revs to a specific rpm while building a good amount of boost so that you would get a better launch from a complete stop.

STi2EvoX

Ughh, no no no. The 2 step is just an rpm limiter when the clutch is depressed and the car is stopped of barely moving. It prevents the rpms from rising beyond like 5k so as to preserve the transmission. There is no boost built up during this process, as boost will normally only build when the engine is under load, i.e. clutch fully engaged and in gear. You are running on vacuum pressure when idling or in neutral and when the throttle is pressed all the way you will go to a state that is between negative vacuum and boost, which on most boost gauges is 0.

Once the clutch is engaged the car will then start building boost rapidly. This feature on the EVO is not a performance feature but rather a safety feature. It is designed solely to preserve the transmission from excessive driveline shock. Further adding to the saftey is a restrictor pill in the clutch master cylinder that slows the flow of hydraulic fluid to the clutch. This slows the engagement of the clutch when the clutch is let out too quickly. This is a useful protection feature that is designed to minimize driveline shock to the more costly transmision components, but at the expense of sacrificing the clutch.

Launching the EVO tends to destroy clutches as a result of this, especially when combined with the fact that mitsu puts in soft, crappy clutches in the evo. Upgrade the clutch ASAP if you plan on launching your car on a regular basis. I certainly don't recommend this unless you have a good clutch and a built tranny, but there are ecu programs like reflashes and stand alone engine management systems that can allow the car to build a certain amount of boost when in neutral for more "explosive" launches, but it is terrible for the tranny. USE AT YOUR OWN RISK! I hope that this clears up some of the misconceptions out there about the factory 2 step in the evo.

KillaItalian904

iTrader: (16)

Ok lets get this straight so no1 gets confoozed since everyone is saying different things.
YES- a two step is a form of a rev limit
YES- it is there to prevent drivetrain problems
NO- it is not 100% effective if its not used correctly
YES it does build boost off the line, if it didnt evos would be slower in the 1/4. What makes evos run such good times with bolt ons is its ability to launch out the hole very fast. watch a boost gauge while you are hitting the launch control and you definately should not be seing zero psi if you are then something is wrong.

REDEVO08

iTrader: (10)

I experienced this last night against an SRT-4..He was still seeing tailights but it like bogged out at first..

STi2EvoX

The car does not build boost until the clutch is let out. If you watch your boost gauge then you'll notice the gauge rising from negative vacuum up to 0. Going from -20 vac up to 0 is not the same as building boost. I assure you that if you look at your boost guage it will not read above 0 when in neutral. The way that the evo and sti make good 0-60 times is because of the lack of wheel spinnage compared to a rear or front wheel drive car, not because of building boost in neutral. You have to keep in mind that when the clutch is let out at 5k, once the engine sees the slightest amount of load it will start building boost rapidly. Yet again there are ecu tuning options included with many different kinds of reflashes and stand alones that will allow for boost to be built up in neutral but this puts a phenominal amount of stress on the transmission.

KillaItalian904

iTrader: (16)

ok i guess i will have to post video for you guys lol the car builds boost with no clutch applied, i tune my own vehicle with ecuflash and im using the vehicles standard stationary_Rev_limit (2step) feature. i run almost 12 psi with no clutch down yes it is a hack but since i have an 03 my car did not come with two step. i have worked on several local evos here and trust me when you two step your car is not in a neutral state of pressure... it should be in boost. evos are lower compression and without boost at high rpms you have NO HP

STi2EvoX

Like you said you are using ecuflash and this can be changed with that, but using the stock rpm limiter and using a modified parameter that allows the car to build boost in neutral are two entirely different things. A stock evo or sti, and well almost all turbo cars don't build boost in neutral. My sti didnt, my evo X doesn't, and I just called works tuning and they said that it doesn't either.

The guy I spoke with at works was just a salesman and not a tech, and wasn't entirely sure so while I was on the phone with him he went out and hopped in the evo 9 at their shop, turneded it on and floored it with the clutch pressed in. He came back and said, "yep, you're right. It only goes up to 0 from negative vac." I also called my friend with an evo 9 and he confirmed the same thing. If your's is building 12 psi of boost in neutral then you have it programmed to do so in the ecu.

You can still leave the 2 step rev limiter in place and alter the boost launch parameter, which is what it sounds like you have done. That doesn't mean that it is still the stock 2 step setup. Anyone else with an evo and a boost gauge want to chime in? This is ridiculous.

Robevo RS

iTrader: (16)

The tuned ECU 2 step is do help build boost. All my evo had it and we build it up over 10 psi.
Also it is help to do a launch easier since you dont have to look for the right RPM before you launch./ like in the old times /
Also when you tune the car actually you can tell the tuner where you want your rev limit for the 2 step.
/depends on many-thing, like whp -wtq- weight etc./

i think the factory 5500 rpm is just a rev limiter to prevent drive train damage.

STi2EvoX

The 2 step can be tuned via the ecu with whats called a studder box to change from 5k rpm mapping in the ecu to full throttle mapping to get the car going faster once the clutch is engaged. Or, you can go with an anti-lag setup to retard timing, enrichen the fuel mixture and build a certain amount of boost (around 10-15 psi max) for "explosive" launches, but it's terrible for the car. Without these ecu tuning changes the car will NOT build boost in neutral. This info came straight from AMS; I just got off the phone with them 5 minutes ago to confirm what I already knew to be true. This is undisputable, factual information.

Robevo RS

iTrader: (16)

anti lag is more then ecu tune and doesnt keep RPM at certain level. Don't mixed the two. The two step is less damaging then the anti lag and kind of launch control. The anti-lag is not.

STi2EvoX

Anti lag is all done via ecu through fuel enrichment, timing retardation, and boost build up. There is no physical/mechnical component in an anti lag setup. The 2 step (unless we are talking about 2 different things) from the factory is just an artificial rev limiter at 5k when the car is in neutral. Boost building via a studder box or anti-lag setup is a totally different parameter in the ecu, but can be used in conjunction with the factory 2 step rev limiter.

silver9mr

iTrader: (8)

so what im hearing from STi2EvoX is that he is saying that when my car is 2 stepping and my boost gauge is telling me that im making 10 lbs of boost that its actually not 10lbs of boost and its all my imagination lol

casper980

iTrader: (6)

Ok, I don't know that much but I have done research into the whole two step thing.

Yes there are 2 steps to it.
Yes the Car Builds Boost
Here are the steps

Step One = Rev limiter this is so you can stand on the throttle and keep the RPM's right where you want them.

Step Two = Anti-Lag, also known as the Bang-Bang system which effectively allows the turbo to build boost. Either at a stand still or while decelerating on the race track. Meaning foot off the gas on the brake and the turbo will continue to hold boost at what ever RPM you desire. However this method of holding boost is very hard on the engine. I am hoping someone that can explain this better will chime in.