so I was reading an article about the new HHR SS
 

and I sall it has flat shifting (they call it zero lift shifting) ability. pretty cool, ive never seen a factory car with that feature.

what the fuck is zero lift/flat shifting

the car lifts for you because of its electronic throttle? whats the difference?

wasn't that fire-breather shifting without the clutch?

Yeah the announcer said he only uses the clutch when moving the shifter across the gate, so he's slamming it from 1-2 and 3-4.

flat shifting = shifting while haveing the gas pedal floored. The car keeps the engine at a certian rpm when you do this to keep the turbo spooled.

its really flat shifting with anti lag on the HHR SS.

Doesnt the engine just cut ignition? thats how it usually works for the drag guys.

i assume theyd cut fuel not spark....

Wouldnt this be quite dangerous in case of any lingering gas?

edit: looked around a little, at least the UTEC standalone uses ignition cut, not fuel cut.

THeres no gas if they cut fuel.

thanks for clarifying :hsugh:
I suppose i was thinking in terms of nitrous, extra injectors, manifold mounted injectors.. that sort of thing ;)

Not every car has the injectors mounted in the head.

Either are ours ;)

Has anyone here implemented flat shifting with their megasquirt?

pumas FTW

Well, anyway, there is a strong possibility that there is going to be some fuel in between the injector and the inlet valve.

knock knock.. whos detonating?

Thats why fuel cutting rev limiters are bad mmmkay. ;)

remind me of my replicats, but i would love to have them in that color

I always thought cutting spark would be safer than fuel in case the fuel cut comes during and injector's cycle only adding a dash of the required fuel :dunno:

Yeah, its fun but the tranny does not like it too much, but then again my 5spd has been abused for 100k miles.

would you rather cut fuel, cylinder sparks and nothing happens

or

cut spark, injectors fill camber with fuel, then when you ignite again you backfire and blow flames out the tailpipe like an asshole?

A guy I know on the Suzuki Swift forums was using this feature on his MS-II'ed car.

I would rather cut ignition, both would be best, but if i had to choose, the risk of ping puts me of fuelcut.

there must be a reason that UTEC cuts spark, not fuel, right? I think we nailed that reason. Flat shift isnt nice to the engine/drivetrain from the start, who cares if you shoot some flames when using it? Doesen't seem to be a funktion to use with a ceramic cataclyst anyway.

Edit: If you are using MS, it seems like you can choose, fuel, spark or both, with the soft limit being drasticly retarded timing.

yeah braineack if my car shot flames i'd look like a le-mans car on the way to the grocery store!

how can you get detonation if there's no fuel to combust?

exactly^


HAIL YEAHHHH!!!! WOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!11

Problem is that it might be, mixture that didn't have time to get in the combustion chamber, but lingers on the other side of the inlet valve, when it opens, it goes in.

Nevermind, I haven't tried either, and it surely isnt anything you'd want for street driving. I just say, that it seems like standalone manifactors CUT IGNITION FOR A REASON.

Please, megasquirters, try it out, you can choose, cut fuel only, and monitor knock, prove me wrong please :)

These guys make flatshifters.
http://www.tekniqauto.com/US/tsport/tsport.htm

Read their info.
3. A fuel cut only system runs the risk of leaving small amounts of fuel flowing through the engine which may ignite risking lean burn and engine damage.

They also cut fuel, to eliminate flame shooting.

So, as I see it, cut fuel only -> knock knock
cut ignition only -> fire!

They should have some R/D behind their reasoning, don't you think?

If you are not convinced yet. Then i dont know how to convince you.

ignition cut sucks. I dont see where most manufacturers cut ignition....it's a cat killer.

so here's your argument....you are worried about a tiny pissing of fuel that may/may not burn when you don't want it to....

but you want to fill your chambers up with fuel during ignition cut and then roast marshmallows from the flames out your tail pipe. that doesn't worry you one bit.

i had spark cut turned on and when i hit overboost protection a few times i remember the bazooka i launched out of my tailpipes and all the insurgents ducking for cover. (and i wondered why my cat got clogged?). It's violent and loud when it ignites again, great for keeping turbos spooled on flatshift, no reason for it otherwise.

monitoring knock during this situation will be pointless....it will look my jagged pimply ass. becuase of all the noise from the rev limiter and then WWIII.

Im glad you skipped over the fucking line just above what your god damn copied:

1. A spark only system on an EFI car will allow raw fuel straight through the engine and will rapidly contaminate the catalytic converter and destroy it. Excess fuel will also wash the bores and contaminate the engine oil system risking long term bottom end damage.


:fawk::fawk::fawk::fawk::fawk::fawk::fawk::fawk::f awk::fawk::fawk::bang:

quoting myself "Doesen't seem to be a funktion to use with a ceramic cataclyst anyway"

but yeah, i think you got me.

A ceramic cat would survive it no hassle, and for a full drag car, where you'd like to use it, how many of those do you know that runs cats?

we are talking about the new HHR SS here. a street car running two or more cats from the factory, for the massed, for your mom to go get groceries, for you not to get laid in.

geeez, since you've gotten personal, now, I can't see wtf you cant just recognize that cutting fuel only would be dangerous? too much of a following here to change your erlier position?

If you look some post above, i said that cutting both is best, but if i had to choose, i'd cut ignition. Cat's are no worries unless you run some shitty ceramic cat (witch suck), and come on, long term damage, yeah, same long term damage the guys who run 11:1 a/f will see, as is common with flooding. If you are running flatshift, I'd think that you check your oil from time to time, no?

and yes, i left it out, posted the link so that all of you could see it, only quoted the one sentence that i was talking about.

you, are, stupid.

And thats why they probably cut both, so that they don't have to change ENGINES destroyed from knock, and CATS destroyed from exessive fuel.

no they just cut ignition. :bang:

thank you, right now, coming from you, i really don't think thats an insult.

And for the less gifted, here is a reminder of how it all started.
:jerkit:

actually this is how it started.

Deleted. Don't want to get involved.

SO.....

The article I read says "the flat shift on the HHR SS keeps the turbo spooled"

Thus I assumed it was a spark only cut?

:inout: