the vcm OTR was 22kw gain without a tune, then more then likely gained the extra 20kw because the TM wasnt removing timing from the change in airflow it saw, if the tune was set without any TM torque reduction from factory the gains would be minimal from the tune but more from the OTR as even adding it to a stock tune can take out even more timing because it has even more torque to deal with and remove, if the limit is 200nm torque and u add more airflow it will increase the torque output so it will then have to remove even more timing to get back to the same 200nm limit,
i prob should have added once u are tuned then adding performance parts makes the bigger difference then the tune, the factory tune has limits that need to be removed to make use of any added airflow, also changing the intake then needs the MAF to be adjusted as it only suits the factory intake for fueling, the MAF dosnt tell the ecu how much air is flowing in its not a set figure, the frequency it puts out is against a table u can adjust that then tells the ecu how much airflow is going in so if u use a bigger intake diameter it will slow the airflow over the maf so it will read lower then it should so then has to be adjusted in the tune
It wouldn’t be the first time where a tune can unleash hidden power that the hardware could produce but the factory didn’t want people to have (as it was a preplanned tuned “upgrade” for the next models... masked by visible but useless hardware mods)... I vaguely remember Ford did this quote some years ago and owners found substantial gains with a tune to the dislike of the company.
In Holden’s case it sounds like the conservative, pollution compliant, warranty friendly and torque limited factory tune is there to be improved upon for better driver response without spending $$ on hardware. But for many, where’s the fun in that, nothing (for others) to see here, move on
Jokes aside, I’d be interested to know what removal of the factory’s warranty survivalist torque limited approach would result in if the engine was allowed to run free... would we get more torque down low? would throttle response be improved? How far could we advance timing and at what gain for what compromise (obviously tuning for only 98 but what else ESC kicking in all the time?).
It’s a reasonable question but companies are interested in selling so it’s hard to get an answer. That 22kw is an interesting figure but where, rpm wise, is the gain? I wouldn’t give two hoots if it was at 5300RPM as I don’t live there on the street but much more interested if it was at 1500 - 2000RPM.
So just curious how far the factory hardware can be pushed, especially down low, with only software fiddles without resorting to hardware mods.
As to MAF sensor, I’ve always understood it just measures air speed which then needs to be translated to an airflow volume via a look up table. As such changing plumbing requires changing tables to end up with a correct volume, otherwise the system gets more air than it calculates so you end up running lean... which the 02 sensors pick up and correct... how much margin the 02 sensors can correct via STFT and LTFT I have no idea as a limit must exist somewhere (Y2K anyone)... As is, it can’t be good to let the pollution system dictate the changed fuelling needs for a modded engine, hence the need to tune... But there is so so much I don’t understand and need to learn though it’s fascinating stuff... gotta start somewhere
(stuff was so much easier pre 74 where pollution issues didn’t exist and torque management was provided by the clutch, gearbox, driveshaft or diff exploding
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