Rev Limiter
#3
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (3)
Join Date: Apr 2008
Location: Outside Portland Maine
Posts: 2,023
Total Cats: 19
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I was having the same problem, so I changed the rev limit to 5000 and wound it on up. It stopped just fine, but I did see it bouncing between 4900 and 5200 in megatune. The dash gauge isn't very accurate because now, with my rev limit set at 7200, the needle is burried pretty deep in the red section before MS cuts the fuel. Probably 7600 anyway.
#5
Elite Member
iTrader: (1)
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,642
Total Cats: 42
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
mine reads 7500 yet actual is more like 7250. I have AWD guages, but at idle it reads super perfect ...
#10
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (3)
Join Date: Apr 2008
Location: Outside Portland Maine
Posts: 2,023
Total Cats: 19
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Set it to 4000 and see if it works at all. If it's set at 4000 but the car still revs to 7k, something needs work but if it's set at 4k and revs to 4500 before it stops, you may just have to set your rev limit a little lower than you need.
#12
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (3)
Join Date: Apr 2008
Location: Outside Portland Maine
Posts: 2,023
Total Cats: 19
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Not to hijack the thread, but what exactly does the soft limit do? I tried playing with it when I was experimenting with a low rev limit but I didn't really notice any difference when I changed its values.
#13
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
My tach reads about 1000rpm short when I'm hard on the gas. If I slowly increased the throttle to redline, it's almost dead accurate... but at WOT, it can't keep up.
Numerous datalogs indicated my soft cut does hit at 6800 and full cut at 7000 (trying to get the motor to last another 8months at 15psi). I can feel the soft cut very obvious and that's when I shift. Tach is at 6k when I shift... about 800rpm off.
Numerous datalogs indicated my soft cut does hit at 6800 and full cut at 7000 (trying to get the motor to last another 8months at 15psi). I can feel the soft cut very obvious and that's when I shift. Tach is at 6k when I shift... about 800rpm off.
#14
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
At the soft cut setpoint, the ignition is retarded to 10 deg. or whatever the "absolute timing" parameter is set to. This results in a massive loss of torque (and hence rev-limited) which can be felt. If you keep the throttle buried for 5 seconds or whatever the "max time" parameter is set to (without hitting the hard cut within that period), the hard cut is activated.
For a turbocharged engine which is likely running close to 13-15 degrees timing at redline, the soft cut may not be as noticeable as on a NA car where the redline timing is more like 25-30 degrees. The NA car also starts to become airflow-challenged at its redline and has already dropped torque, whereas the turbo is supplying enough air (assuming a larger-than-necessary turbo) for the engine to "continue" revving. This is the reason you will hit the hard cut more often on a turbo car. If you want to feel the soft cut, reduce the absolute timing to 5 degrees, it will be more noticeable.
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM