11P rev limit issues

[Gareth]

Had the race car on the dyno again last night and had issues with what seems to be soft cut rev limit that we couldn't get rid of...

Running Ecotec V6, 11p on 424 pcm, Vlad might be able chime in with the exact name of the scalar we where looking at but it was something like 'EST rpm limit spark cut?', the limiting we are seeing at 5600rpm seems more like a fuel cut...

Any ideas?

[antus]

Have a look at the logs and see what cut flags go active. Also see if injector duty cycle drops to 0%. If neither occur, its a mechanical or electrical fault. If DC does drop to 0% and no cut flags go active it could be a pcm fault. Ive seen similar where logged DC did drop to 0% on a faulty 808 which was resolved by replacing the computer.

[vlad01]

Issue seemed to be a hard fuel cut under driving but free revving the set rpm limiter works as normal, cleanly revs well past 7K when we set the limiter up there. but soon as its driving, hit 5600 rpm and just cuts.

Already have the road speed limiter set at 255Km/h and the dyno only ever got to 210 and also checked the actual registered road speed in TP and it was only 140km/h (taller diff) So that can't be it.

Soft cut is about 650 rpm under the main cut and works as it should.

G you need to do a log and post up the bin and ADX and log file.

It was getting pretty late at night so we didn't get to it.

[Gareth]

my eyes still feel like they're on the ends of springs...

OSE_$11P V104 CAKH V6_E85_VH_Ecotec after dyno ve smoothing 7000 limit-11-5-17.bin

(64 KiB) Downloaded 286 times

OSE_$11P V104.xdf

(851.27 KiB) Downloaded 289 times

OSE_$11P V104 1Bar_CalcVE_E85.adx

(165.6 KiB) Downloaded 268 times

11.05.2017.xdl

(512.9 KiB) Downloaded 285 times

[vlad01]

lol

[vlad01]

I don't see anything wrong nor any cutting of any sort. All I see is you lifting the throttle at 4900 rpm ever time. Are you sure you didn't just have the dyno end speed set too low?

[antus]

The MAP and injection all keep going up but the RPMs do not continue to increase. Nothing in the log indicates the engine is failing but it looks like the load on the engine continues to increase holding the revs solid eg the dyno is the limiter. The AFRs also look smooth and correct and do not indicate any wasted fuel/misfire.

Green is injector duty cycle %, purple is injection milliseconds.

[vlad01]

Anyway here is a slightly massaged tune. Fixed up some of the spark map in the mid areas as well as extrapolated the full load timing into the previously un-reached rpm

Also did the same with the VE table. It didn't really go beyond 5600-6000 rpm at all in most areas.


Also found a fuel cut return scalar which was set at 5700 so I set it 6800 (200 under the upper limit)
I don't think that was the issue as it would mean we would have needed to exceed the limit set in the first place before the cut returned to fueling. try it out and see how it goes. Maybe set the dyno speed at something stupid like 250km/h and see if it still did what it did yesterday.

[Gareth]

The dyno software instructs you when to get out of the throttle, power was stopping from the engine before this happened, in other words the upper set limits of the dyno speed limit hadn't been met.

Another thought though, the dyno software gave me hell last night when logging with tp, and on top of that we had another shitty USB to dyno interface failure so possibly it is the dyno causing this, never had that sort of issue before.

[VL400]

My bet is its running out of spark. Plug gaps or ignition energy. Wont rev WOT but will at lighter throttle/load is typical of this.

No wideband in the log?