RPM Limiter at Launch?

[Hulty]

I have the opportunity to do free quarter mile drags at a local track this weekend and it requires that I pose a question to those on SOF.

What's the deal with the rev limiter that is in place while stopped? Unless I'm doing at least a few MPH my Sonic won't allow me to rev the engine past 3K RPM(appx.?). What gives?

Please enlighten me, this seems like a huge hindrance in a drag scenario or just having fun in general.

Thanks all!

 

[ahtoxa]

I've seen this on many cars in the past few years. Generally, revving high with no load isn't good for the motor, as has been my understanding. That, and it limits people doing dumb and destructive things with their cars, thus I'm sure, it limits warranty claims that can't be proven as customer fault, which manufacturer ends up paying for.

 

[Hulty]

You have a M/T, do you find it hinders a fast take off?

 

[ahtoxa]

No, but I also don't launch anywhere near 3k RPM, nor do I take the car to a quarter mile track.

 

[littleturbo]

I haven't seen it hinder my take off. But it does require a little feathering of the clutch to get a good launch. What I have done in the past (gm cars) that have the rev limiter is just slipping the clutch just a fraction. I know it's not healthy for the clutch but I can notice a large increase in acceleration in doing so vs. No clutch feathering. Thus the reason I attemp to drive it as normal as I can without feathering the clutch. That being said it's hard to drive normal in the sonic it's a large go cart and we all know they are a blast to drive.

 

[///ChevySonic\\\]

I thought the tune got rid of all that nonsense? Although I don't believe you will get a launch above 3k much better.

 

[Stew]

I've found my best practice launches (haven't been to a track yet) are putting the pedal to the floor and when it gets to around 2500 launch while feathering the clutch for a moment or two to keep the rpms from dropping.

Grip at the track is so different than the street though, I'm sure I'd need a few practice runs to get the feel of the different surface. It would make me cringe to launch by dropping the clutch in the Sonic though, I can visualize teeth shearing off of gears, splines, etc.

 

[Hulty]

I thought the tune got rid of all that nonsense? Although I don't believe you will get a launch above 3k much better.

I would have thought that the tune would have alleviated that as well, but no.

The only reason why i'm wondering is because the throttle response when stopped doesn't seem any different than stock, the engine still rolls into the rev's versus when you're cruisin' at speed the response is immediate. That's why I even posed this question to begin with. I don't want to pop the clutch by any means, but it seems next to impossible to get immediate acceleration from 0-10mph so I was trying anything I could. Seems like no matter how fast you make it, you're always going to lose a second off the line regardless.

 

[ChrisJ]

I've put 41,000 miles on my Sonic and had no clue it had a rev limited at 3K when the clutch was disengaged.

 

[Hulty]

I've put 41,000 miles on my Sonic and had no clue it had a rev limited at 3K when the clutch was disengaged.

So, does that mean you discovered it now or no?

 

[laborsmith]

I suspect it more likely means he does not sit in his driveway revving the engine for the purpose of hearing the bpv blow off.

But I could be wrong!


Laborsmith

 

[Colin]

Discovered this "feature" while at the strip last year. To be honest if anything it was beneficial for me, almost like launch control. Held the rpm's at a good spot for leaving the line with minimal wheel spin.

Good luck at the track, make sure to post your times at the 1/4 mile thread in the motor sport forum!

 

[ChrisJ]

So, does that mean you discovered it now or no?

Nope,
Only because you told me about it but as others have said I don't rev me engine without a load on it.

 

[Victory Red RS]

With HPTuners you can set the RPM's to whatever you want. Think I have mine set to 3200 right now.

 

[HollywoodTurbo]

My 2012 1.4 mt does not limit the RPMs at a stop... weird

 

[wasteoffilm]

My 2012 1.4 mt does not limit the RPMs at a stop... weird

Same here...

I was under the impression it was only on the automatic cars.

 

[slicethis2]

My 2012 1.4 mt does not limit the RPMs at a stop... weird

My 2013 1.4 MT has the rev-limiter at stop. Further, it is different if the clutch is depressed. Maybe they realized the issue after the 2012's were out and updated it for 2013's and up??

 

[ss2000slp]

Nope. My 2012 limits it to 4k. Had it for two years now and never noticed. Just went out and tried it for curiosity sake.

 

[HollywoodTurbo]

Nope. My 2012 limits it to 4k. Had it for two years now and never noticed. Just went out and tried it for curiosity sake.

Is this with pressing the clutch or not pressing the clutch pedal?

 

[Nuhgets]

My 13 rev limits to 4k, too, regardless of clutch position. Once I'm moving, though, I can rev all the way to 6k (did it once just to test).

I've found a sweet spot for launching and it seems to work pretty good; keeping the RPMs around 3k and then feathering the clutch. I'm too scared to just drop the clutch entirely.