Does ls3 reduce timing at wot shifts?

[Higgs Boson]

Originally Posted by Turbo99

I agree, as I said you WILL hit the limiter if you do this. I don't care for my to be in the limiter, it is not the healthiest thing to do. When tour in the limiter it cuts spark so tour next combustion cycle will be richer and prolly burn more through the pipes and start killing your cats also. Just my opinion, if someone wants slam gears at WOT then go for it but you don't gain any time from it that's worth the wear.

nah. it doesnt cut spark, it just retards it. it can also cut fuel and close throttle if you want. it happens so fast nothing changes. only if you stay on the limiter for a long time.

just blipping it is no big deal, especially if its at 4k clutch in.....

just me ol 2.

[Turbo99]

Originally Posted by Higgs Boson

nah. it doesnt cut spark, it just retards it. it can also cut fuel and close throttle if you want. it happens so fast nothing changes. only if you stay on the limiter for a long time.

just blipping it is no big deal, especially if its at 4k clutch in.....

just me ol 2.

I am not sure on the stock limiter , but a 2 step type or after market rev limiter cuts spark.

[Higgs Boson]

Originally Posted by Turbo99

I am not sure on the stock limiter , but a 2 step type or after market rev limiter cuts spark.

you can even command how much spark it cuts in the tune.

[Turbo99]

Can you control the amount of fuel cut? That is more the issue as it will create heat on the exhaust side as it combusts in the pipes.

[pouncer72]

Originally Posted by Turbo99

Or I can put a auto in like you did and be a couple tenths faster and tell everyone how to drive a stick.

I switched to an auto because a stock TR6060 doesnt like to go from gate to gate at 7500 rpm (synchros wont keep up) , and yes, the auto is quicker. It's hardly your average setup


Also, stock limiter cuts fuel, spark, AND tps. You can command any of them on or off and adjust the 'hardness' of the limiter. To expand on what higgs said, there is also a neutral cut in place. By removing fuel and TPS cut out of the tune (and leaving spark), powershifting acts as a no lift shift since clutch in is registered as neutral in the pcm when your between gears, which has a very very low rpm limit (4000 if i recall). I can show you a screenshot of the applicable tables if you'd like.


Edit: Fuel cut is bad. Rich is fine. Fuel cut burns pistons. Turn it off, leave it off.

[Higgs Boson]

Originally Posted by Turbo99

Can you control the amount of fuel cut? That is more the issue as it will create heat on the exhaust side as it combusts in the pipes.

you can disable fuel cut

[Turbo99]

Originally Posted by pouncer72

I switched to an auto because a stock TR6060 doesnt like to go from gate to gate at 7500 rpm (synchros wont keep up) , and yes, the auto is quicker. It's hardly your average setup


Also, stock limiter cuts fuel, spark, AND tps. You can command any of them on or off and adjust the 'hardness' of the limiter. To expand on what higgs said, there is also a neutral cut in place. By removing fuel and TPS cut out of the tune (and leaving spark), powershifting acts as a no lift shift since clutch in is registered as neutral in the pcm when your between gears, which has a very very low rpm limit (4000 if i recall). I can show you a screenshot of the applicable tables if you'd like.


Edit: Fuel cut is bad. Rich is fine. Fuel cut burns pistons. Turn it off, leave it off.

This is more like it!! See most of the guys are more than likely talking about stock cars or tuned stock cars that prolly don't have any adjustments to the limiter.
So if the stock lmiter cuts fuel,spark, and tps, what allows the engine to continue to REV high? Or by cuts you mean it cuts back on all 3 but still has some amount of each?

[pouncer72]

Originally Posted by Turbo99

This is more like it!! See most of the guys are more than likely talking about stock cars or tuned stock cars that prolly don't have any adjustments to the limiter.
So if the stock lmiter cuts fuel,spark, and tps, what allows the engine to continue to REV high? Or by cuts you mean it cuts back on all 3 but still has some amount of each?

It cuts all 3 but not completely, its a progressive limiter. It doesnt kill your rpm at all, if you shift fast enough.

[pouncer72]

Mine is currently set to only throttle position. No wasted spark or fuel. If you notice a button labeled 'switchover delay' it lets you specify the time between the spark/fuel limiter kicking in and the tps limiter kicking in. On a stock tune, all 3 are enabled with a half second ramp-in.

[Turbo99]

Originally Posted by pouncer72

Mine is currently set to only throttle position. No wasted spark or fuel. If you notice a button labeled 'switchover delay' it lets you specify the time between the spark/fuel limiter kicking in and the tps limiter kicking in. On a stock tune, all 3 are enabled with a half second ramp-in.

I guess I am not following your set-up, if your not cutting fuel or spark what is cut on the TPS to make it a rev limiter? Are you saying that your TB shut at a certain RPM if maintained for a certain length of time?

[Higgs Boson]

Originally Posted by Turbo99

I guess I am not following your set-up, if your not cutting fuel or spark what is cut on the TPS to make it a rev limiter? Are you saying that your TB shut at a certain RPM if maintained for a certain length of time?

yes it will close the throttle.

[pouncer72]

Originally Posted by Turbo99

I guess I am not following your set-up, if your not cutting fuel or spark what is cut on the TPS to make it a rev limiter? Are you saying that your TB shut at a certain RPM if maintained for a certain length of time?

Yes, in the picture ETC = Electronic Throttle Control. It will actually close the TB. Its a 'softer' limiter then a spark limiter, but takes longer to recover since the TB has to mechanically open/shut. The computer closes throttle to limit RPM.

[formare]

Originally Posted by Turbo99

It just plain stupid to keep it to the floor. I call BS on not hitting a REV limiter too. If you are shifting at REDLINE and don't lift as soon as that clutch disengages it is gonna hit the limiter or you weren't taking the car to REDLINE no way around that. Either your short shifting it or your in the REV limiter is you don't lift off the throttle.

+1

[Turbo99]

Originally Posted by pouncer72

Yes, in the picture ETC = Electronic Throttle Control. It will actually close the TB. Its a 'softer' limiter then a spark limiter, but takes longer to recover since the TB has to mechanically open/shut. The computer closes throttle to limit RPM.

So this is your current set-up with the auto correct? Because that seems like it would not be what you want for a stick to do WOT shift as when it hits its going to have a longer delay to recover as you stated.

So what type of rev limter set-up would be the best for those trying to shift with out lifting, because now see all that it almost seems like I was thinking correctly that being in the limiter for a split second every shift will end up with some unburnt fuel in your pipes unless you cut alot of fuel or all but then you mentioned burning a piston on a lean out unless you cut alot of spark.....so at that point it brings me back to my original question, if you cut both of those then what allows your RPM to continue up?

[pouncer72]

Its auto. On a stick car a spark only limiter is best. Unburnt fuel in the pipes doesnt hurt anything, lack of fuel in the cylinder burns pistons.

[Higgs Boson]

Pouncer72 is right on here.

In fact, I have my m6 set up spark only. I set autos up as etc and spark. Will have to try etc only.

Turbo99, on higher powered cars sometimes you have to be careful because they can push through a spark only limiter. In any case, if you set it up to limit to 4k at clutch in you will be ok and not hit the 7k limiter, or whatever you have in place.

[Turbo99]

So I know if you have a straight race you don't care about CATs but I can promise you if you only cut spark and have CATs it will burn them out prematurely. I am sure some don't care but this one of those things where people will say they got some bad CATs or something not k nowing that this could be the cause.

Just saying a small factor. I do appriciate the info it did give me alittle insight on our limiters and how they can be adjusted.

[pouncer72]

Any car with a cam or boost will destroy an aftermarket cat sooner or later. Just the nature of the design.

[Higgs Boson]

Cats are for bone stock cars.

[Turbo99]

Originally Posted by pouncer72

Any car with a cam or boost will destroy an aftermarket cat sooner or later. Just the nature of the design.

I agree but I think unburt fuel or late burning fuel(in the pipes ) will make this happen sooner.
Like I said not a deal braker to alot of folks but most don't understand it.