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Webinar 048 VS 258 rotary ignition timing.

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Hi Andre

I own a rotary 13b semi pp in a purpose built race car.

As with any race car having the smoothest power delivery is crucial.

I see the the ignition tables between the 2 webinars are very different

The adaptronic looks as though the cells are tuned more individually with more small changes between the cells,

The link seems to be a much more basic ignition table.

My ignition table is just set numbers for the complete load range ie 11.6psi is 14degrees from 0rpm to 8000 rpm and thats how the map is.

While no steady state was done to make this ignition map and is fine at wide open throttle, Im worried when I put it on my dyno and start steady state and the lower rpm im going to run into high ignition numbers ie 3500rpm will have 14 degrees of timing.

Lots of debate that you only need a real basic ignition table for rotarys. Is there any benefit going through steady state upto 80% throttle in your opinion or with rotaries not being that crucial to timing and gains its not worth it?

Cheers

I've only a peripheral knowledge of the engine (sorry), but from what I understand...

With any engine the timing should be correct for the best use of the fuel to provide torque/power with the Wankel being no different.

Too much advance will cause excessive pressure spikes - the Wankel is not immune to this and it's not that unusual to see problems such as 'dented' rotors or damaged seals. Retarded will increase exhaust gas temperatures, and they're already known for that, which can overheat the coolant seals, and there is a risk of deforming the housings around the exhaust in extreme cases.

It's more messing around, but the best thing to do is map it properly. If not that, do a basic 2D map with full load timing vs rpm.

While not optimal obviously you should be fine unless you're also running EXTREMELY rich with that timing. I'd also just blanket 25* in vacuum up to atmosphere and pull a degree or so for every pound of boost down to 12* at 12 psi depending on fuel as your baseline. Crank it up or dial it back as the dyno tells you from there.

Awsome cheers.

Yea my main concern was going into steady state to tune the fueling and having issues with higher numbers like this in the lower rpm/load.

With most tuners I have seen here none have done steady state tuning its all been ramp runs. So I was wondering if steady state tuning a rotary was even worth it. But for sure steady state tuning fuel will be helpful at the least.

Steady state is definitely worth it, though less so. I may be misunderstanding your quandry but I'd also point out that unless you're significantly on boost at that RPM your 14* at low load isn't what I'd consider a very 'high'/advanced number.

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