Rx_treme

This question is for the guys using the TC system. On the 3rd gen did you guys use the sheet that came with the module and interupt the injectors and fuel? Or did you use the alternative method and interupt the spark?

I am concerned about interupting the fuel.

Thanks

Rx_treme

artowar

iTrader: (1)

You really don't need to post the same question all over the Forum. You're just creating multiple discussions that will make it hard for you or anyone else to follow the topic. Don't worry-- people will see your post and respond.

In this case, if you're in doubt, post in the 3rd Gen Specific forum and the thread will be moved if the moderators feel it's appropriate.

enzo250

I don't have any experience with the race logic unit.
But from what i hear it will work fine. With fuel cut or spark cut.

my setup is with an autronic ecu. I can't use fuel cut but use spark cut instead. Works just the same, with the occasional flame or two out the exhaust.

jetenginedoctor

Enzo,

Are you not running fuel cut because of using pre-mix? If so, do you really feel that the period of time the injectors would be cut would really be enough to jeapordize the oiling of the seals when the TC kicks in??? Unless there is something terribly wrong, the TC should only cut fuel for a very short period of time in order to abate wheelspin. Do you really think that's the best way to do it?

Not trying to argue, just wondering what logic you followed to reach your decision to use ignition cut versus fuel cut.

BK

RICE RACING

The fuel injector cut out (precise metered cut !) is the best way of doing it son.

It is the best on the engine and will not cause any ill effects at all.

Racelogic is the only company who have the software to do correct fuel cut for a 4 injector 13B engine. Hook it up as per the data sheet and enjoy

It will result in still mixture going through the motor but it will be so lean that the car will not be able to fire a spark (hence no detonation) it is still enough to give you lubrication though which is why this method is so good. Ign cut results in massive wash down of chambers and seals and is hard on the engine (will wear allot).

All F1 cars use this method of traction control

P.S. Its a partial fuel trim as apposed to a fuel cut which still results in the engine being lubricated, it just is too lean to fire a spark....... its all in the software/harware mate.

RICE RACING

Brian

Autronic and Motec cant reliably do traction contol on a rotary engine

They dont take into account of the injector at either stage feeding the faces of two rotors, hence they factory recommend for ONLY using spark cut on a rotary.

Some have tried it and its not reliable, Racelogic is THE ONLY company who have a system specificaly written for a 13B engine running 4 fuel injectors

enzo250

Rice Summed it all up. I knew he would. LOL

BK, The reason i'm using ign cut on my autronic setup is because it's the only choice for me with the rotary. Fuel cut works fine in piston applications.

Rice summed it up. The Ecu doesn't take into account that the same injector is feeding multiple faces of the rotor.

Carl Byck

Thanks Peter, I am about to install the system in my Supra, I was not sure on the Rotary. My FC is nearly done, T66 .81 Q trim, 12" slicks all around, etc

jetenginedoctor

[brown-noses peter and enzo]Ah, I see. Learn something every day when I hang around smart guys!!![/brown-noses peter and enzo]



BK

paximus

iTrader: (1)

a few more questions about the TC.
does it work in conjuction with the power fc without any problems?
and i was just about to switch out my diff for a stronger one (kazz), but will this enable me to stick with my stock unit since the shock to the drivetrain wont be as hard (i have 450+rwhp)?
sorry, still learning about TC. but VERY interested.

87GTR

iTrader: (61)

have you guys got the TC working?

LT1RX7

To lean to fire a spark?? The plug provides the spark the gas merely burns. Did you mean to little fuel to cause combustion? That doesnt make sense to me. Combustion is going to occur if there is ANY fuel, air and spark the amounts of those three dictate the burn temp and rate.

I understand washing the seals with to much fuel but at the same time why would you take away fuel and cause a lean spike?

MARTIN

the spark ignite the fuel, not the air. So if there is considerably more air than fuel the spark wont do anything therefore the mixture wont ignite

LT1RX7

No **** the spark ignites the fuel not the air but the oxygen in the air is what allows the fuel to burn. No one ever said otherwise.

My point it WILL do something. ANY amount of fuel will burn it will just be lean(more air than fuel) and lean creates more heat(more oxygen equals higher burn temperature) and more detonation (premature firing of the combustion chanber). If you take away so much fuel that it wont ignite then there will be none to lube the seals because it will be zero fuel.

To see my point take a eye drop of fuel and put it in a dish. Light it, it still burns. No matter how little fuel there is, as long as there is fuel, air and a spark then you will get combustion. The only way to stop combustion is to completely elimate the fuel (no more oiling), air (cant do), spark (then the fuel washes the seals).

Smell what I am stepping in here?

Piranha

Dude, you don't know what you are talking about. Even on decel the EFI RX-7s still are burning fuel, but a VERY lean mixture. It will show up on a wideband, but probably not a standard O2 sensor. If you shut off all gas, the engine stumbles when fueling resumes.

I have a Microtech and I did turn off the fuel on decel to see how it acted.

Your Mr. Wizard experiment is WAY different, first of all, you're not simulating a combustion chamber, where air is being compressed, is hot, etc.

On top of that, LIQUID fuel doesn't even burn, it is the vapors. You learn that in high school chemestry man.

You're not going to get detonation from a small amount of fuel, if that's what you're trying to say by beating around the bush.

LT1RX7

I do know what I am talking about thank you very much I am a mechanical engineer. Apparently you do not know what you are talking about because you cant even properly spell Chemistry.

My comment was directed to Rice Racing who said that it would be to lean to fire a spark. I was explaining there is no way it wont burn if there is any amount of fuel/air/spark no matter how little fuel

We are saying the same thing just in a different way. I never said to cut fuel I agree that is a bad thing, again reread my post.

My experiment was a super over simplified example that no matter how little fuel you have you will still have combustion it will just be a smaller explosion. I wasnt trying to say it was the exact same conditions as a combustion chamber just trying to make a point.

Who ever said liquid fuel burns? Not me.

And I wasnt beating around the bush about detonation I came out and said it, again read my post. If you have a more lean mixture (a higher air/fuel ratio) you get a higher burn temperature (the fuel actually helps cool the combustion chamber if there is a sufficient amount but not in this case) which causes the combustion chamber to get hotter which causes detonation (premature firing of the combustion chamber).

I was merely stating that if there is ANY fuel in the combustion chamber with air at the time the plug fires you will get combustion. That is it. Rice racing was saying there would be so little fuel you wouldnt get combustion which is what I was responding to because it is wrong.

So next time please take the time to read what I wrote before jumping to conclusions, we are saying the same things for the most part.

A lot of people come on these kinds of forums and spout off about how they know everything. People then take that stuff as gospel and either pass it along to others that dont know or attempt to put it in practice. Usually it ends up with someone damaging something so that is why I said anything in the first place.

DamonB

Not true. Ever blown out a match? Ever dropped a lit match in a bucket of gasoline?

Both of these put out the fire even though in the first you are adding additional air to the combustion and in the second you are adding additional fuel to the combustion. The mere presence of fuel and air does not allow ignition, they must be in relative, suitable quantities.

You don't have to get rid of every single last molecule of gasoline out of the combustion chamber in order for there to be no support for its ignition.

The RaceLogic system's cutting of fuel to the rotary is not harmful to the motor and does not support detonation.

SPOautos

Its just not a problem cause its such a small amount. Temperature and BTU's are 2 different things. You can have a match or a blow torch both at the same temp but they put out different BTU's due to the volume.

BTW - How much did you guys pay for the Race Logic TC?

STEPHEN

Piranha

I spell one word wrong and I have no credibility, heh. That almost makes sense. Spelling=mechanical knowledge.

Just because you are a mechanical engineer doesn't mean you understand everything about engines and how things operate.

LT, you're saying it will DO something, when you push that, but in fact it is negligible. Be more specific next time, especially when you say you are "stepping in something." Maybe you went outside and stepped in dog ****, because I took your post as saying there is detonation going on.

drago86

I guess lt1rx7 has never heard of lean misfires. GO lean out the idle on your car, it will start to "miss", same idea, not enough fuel to ignite. the chamber is under huge compression, things dont like to burn under thoose conditions, also enough fuel actually has to make it to the area imediatly around the electrode to fire, and then there has to be sucessive fuel around that fuel to create a flame front, very lean = to spread apart of fuel molecules to light eachother off= no combustion.

medfly

wylie

http://www.racelogic.co.uk/techtrac.htm

LT1RX7

I think we are all saying the same thing I may have misunderstood the intent of what Rice Racing was saying.

As far as a lean misfire, I believe there is still combustion going on it is just in insufficient volume to do anything, which is exactly what SPO said.

However I do disagree with the dropping a match into a bucket of fuel. The fuel in a combustion chamber is in gas form not liquid and it would not cause the plug to not spark. That would take an EXTREME rich condition.

So when the Traction control "kicks in" does the car feel like it is stumbling? Or does it just feel down on power?

enzo250