Ways to 'soften' stock rev limiter?
 

So I finally took my car to the track today for some drift practise.

One thing I experienced for the first time (as I was a good boy during break in) is how the ecu pulls the throttle right away for a good second or so (that's what I'm assuming its doing?) when you hit rev limit.

Have never experienced it before, and it is bloody awful, especially for drifting.

I ended up just working around it, but would really rather not have the second o death if I can help it.

Wondering if anyone has a fix? (That's not another flash/tune) local tuner doesn't have ecutek capability yet, and I have another track day on Saturday. :/

Have thought about bee-r limiter and setting this to a few hundred rpm before actual rev limit. But have just been advised ecu may detect misfiring and throw Cel.

Help!!

Yeah it sucks as most drive by wire cars use a throttle cut to control the hard rev limit. This mostly effects racers when trying to stretch a gear out.

Next to a Hydra EMS I'm not sure what else you can do since drifting tends to result in long periods on the rev limiter.

The stock ECU tune has a big hysteresis value. Depending on the rev limiter that is active, it's either 200 or 350rpm. Which means that the rev limiter kills the engine at the higher RPM value and then doesn't enable it until it drops to the low rpm value. This causes a rather lazy rev limiter behavior.

http://i85.photobucket.com/albums/k4.../revlimits.jpg

To fix it, all you need to do is set the ON and OFF RPM very close to each othern (within 50RPM). Or even set them to the same value. This will make the rev limiter softer and more usable. I suspect the calibration team at Subaru decided to set up the stock rev limiter to be feel violent so that it wouldn't encourage drivers to stay up there :)

FWIW, in our off-the-shelf Openflash maps we reduce hysteresis to 150RPM. Easy to change if you want something softer.

Is there anyway I can change this on my setup, with some downloadable software? I already have a flash and a cable, as I've gone FI recently.

Don't really want to have to go into the dealer to make these adjustments; if that is what you're suggesting; which I'm fairly sure you aren't.

What flash and cable do you have?

Ecutek. And the Australian flash for the Bullet supercharger and intercooler system and 98 RON fuel.

But, I'm fairly sure I'm locked out of making changes..

Just ask your tuner if he can make the change for you and send you a new file. Or are you just using a base file provided from Bullet? They may be happy to know how you do this and roll it out on all their tunes....

Yeah it's just the base tune. And local tuner is not able to talk to ecutek :/

They may also need to change the manifold pressure fuel cut resume value if your boosted.

We need to talk

Ok :)
So how about that new Miss America?

Wouldn't bang. Has pointy elbows.

Fine, I will take her..........:offtopic:

Well frankly, happy for her and the cultural melting thing, but having lived in NYC, there are way hotter Indian chics out there, fwiw.

I would have to guess there's something behind the shiv(my dads name incidentally ) and the deity derived company name? Or not?

So you're an ecutek shop?
I've looked at your 335 stuff before I sold that car.
Good to see you here.

If I sent you my flash, would you be able to make this modification, and then send it back to me to reflash?

Would certainly appreciate it if you were able to! Have another event on Saturday that I'd much rather do with this problem sorted.

Thanks in advance.

In all reality, if you're pegging rev limiter super hard you can either modulate throttle more or upshift.

Feathering throttle more will keep you off the rev limiter but there's more of a chance for you to grip up again. Upshifting is the best idea. If you're smacking the hell out of the limiter in 2nd, go up to 3rd. You won't be at super high rpms but chances are you'll still be able to spin the tires easy (kick the clutch once or twice to help if you have to) and just keep the throttle pinned.

The higher wheel speed from being in 3rd will help with angle and generate more tire smoke as well :)

Thanks. Aware of all of that.

It's more a case of wanting to fix it so I don't have to worry about it.

@diss7 - you should be able to talk to your tuner to set the field that was shown above.

I'm not that smart, but I think you would want set it to the same value and then you can use pedal modulation with predictability. If you're drifting, you're bouncing off the rev limiter all the time, you want predictability all the way up and not have a dead spot up top in which its waiting for RPMs to fall lower.

Only your Ecutek dealer can modify your ecu tune. So I can't be any help if you want to retain the ecutek flash. My suggestion is to make the jump to OpenFlash tablet so that these changes can be made without restriction at no cost. And more importantly, no license to fiddle with.

If I did that, could I load my current tune into it first and start from there? Sounds like the way to go.

Just paid $1300 for an ecutek licence. Makes you wonder what the point is when you can just go openflash :/

If you're current Ecutek tune isn't locked, you could save it on the tablet so you don't feel you "lost" it. But it cannot be edited at this time. Ecutek seems to apply some sort of security that doesn't allow their edited roms to validate when flashed with anything but their flashing software.

But I recommend flashing back to stock with your Ecutek cable, plugging in the OpenFlash Tablet and running our off the shelf maps as the rest of our customers. As long as you aren't turbo/supercharged (not supported yet), I think you'll be happier than you are right now.

I'm afraid that you had to learn that lesson :( But then again, the OpenFlash Tablet was just released last week so this option may not have existed when you made your purchase.

Shiv

I am supercharged :/

I'll contact the guys in Australia and see if they can make the adjustment for me, and report back.

So I managed to get the guys in Australia to make these changes.

But the problem is not really fixed.

When it hits rev limit now, the revs drop slightly, but the throttle is still pulled right back. It basically has enough throttle left to keep the revs just below rev limiter, then after a good couple of seconds, I get full throttle back and it surges forward until it hits cut again. The whole time my foot is flat down on the throttle.

If I hit rev limit during a drift, it dies and I lose my slide.

What it feels like is happening, is there is another parameter that times out the throttle after rev cut, and only allows you 5 or 10%. When grip racing, this is enough to keep the revs high, albeit at a cruise. However, when drifting/skidding, its not enough to keep anything going, so the rear grips up.

Any thoughts?

Bump. Any tips / ideas?

The silence from my tuner, tells me they are stumped.

I know what your talking about cuz sometimes comeing off base I am an ass and forget how short 1st is and it just falls on its face... But when at 1/4 and even when i went to a drift event I had traction control off and never had it happen...(yes i should shift before it hits it at the 1/4 but it only happened a couple times)

Yeah. It sucks. :(