In theory, the total power gain should be a result on increase airflow (slightly higher pressure and cooler air entering the engine) and also decreasing the amount of work the engine needs to perform on the intake stroke. They get about a 3% increase from the RB intake powerwise and usually the intake stroke costs the engine 50-66% overall efficiency - so I went with a 2% increase of airflow to be optimistic although its probably closer to 1%.

VE always needs to be corrected to standard temp and pressure to be comparable.


Good work on cracking that throttle afr closed loop map. I always hoped the more people we can get discussing things the more we will all understand

 

Just to reiterate my findings as well as many others, the easiest power to be found is within timing split. and being my first rotary tuning project, I wondered how much of an effect it REALLY is... An example I encountered... I thought I had a good timing map. Then backtracked a couple of flashes that didn't have my trailing map done, and I brought my primary timng with, which left me with a large split. A couple of curious runs that were low power above 7k, and below 4k, I found my trailing map was "stock" , so ALL I did was advance my trailing map and only my trailing map, and the power increase was substancial... At this point would you agree, that the map change would NOT change the amount of air entering the engine, thereby not changing VE but infact changing power output? Maybe I am not getting it, but I see VE, as airflow, not power harnessed. Filling the chamber, doesn't mean you are getting all the power to be had because that measurement is airflow in, not power out. For arguements sake, if we killed ignition, and kept WOT, measured the air, it would be, well whatever the figure 80 - 100%, but NO POWER. So, maybe I am not realising what the ACTUAL definition is, but this is how I think of it. I confused this point for a little while, while tuning my STI. I tried a tune from a competitor,and it would overboost around 3500, resulting in a higher load value, ie VE up to 3.14, but I would generate more torque with my mapping peaking around 3.07. Which puzzled me for a bit, I kept wanting to hit their load values, because I THOUGHT that meant more power... in actuality, it IS NOT more power, BUT the capacity to create more power, IF the other variables permit... ironicly looking back at that map, they just added some boost pressure, and retarded the whole timing table, not just at high loads were it would be needed to keep from knocking on pump gas. They made max airflow, safe, but not effective. If ALL you looked at was "LOAD" , it would LOOK more powerful. Anyway, it's late, my brain is coasting from working in the shop allday, doing finishing touches on my lawnmower rebuild, tomorrow I get to mow the lawn again,the grass is getting pretty high here. , I I just reread a bit of that last post rotor, yes I agree, the RB intake could very easily increase airflow like you said, and possibly make more power... I was just thinking that the extra air doesn't ALWAYS mean extra power. That doesn't even touch on the ram air effect...It's late, my eyes burn, more horsepower talk tomorrow.


One last thought, I am experimenting with some ridiculously high timing valuse at 36 @ 6k to 52 @ 9k, I haven't caught any knock yet, it may be just around the corner though. what is everybody else running?

 

there are several ways to make more power... getting more air in more easily, getting the exhaust out more easily, and optimizing how well the engine utilizes the air and fuel (afr and timing).

Timing is a tricky situation. Typically in a rotray the rules for NA engines have been that power is always found in the split and that advancing the leading plugs is not beneficial and could actually cause damage to the apex seals if its advanced too far. Typically 5 degrees of split was good for power. I was told by two top tuners that 15 degrees is what the renesis likes however Cobb goe with 5 degrees as thats what they say makes the best power.

My results have been unconclusive without sufficient dyno time....

 

I don't adjust the MAF on NA vehicles in the +150 g/sec range unless the entire curve is off.
Even then, its usually less than 2%

Here is Razz' actual MAF curve:

 

Forgot about this one...

So you tried my new software yet rotor? You may find the concept pretty similar to your process described - just a LOT more data; and I account for things like AFR latency etc.

I still say scale the MAF first... not the injectors - because you are trying to find the "holes" in your tune.... the airflow holes are easier to spot - because regardless of gear - if at 2 volts, you're always 4-5% off.... guess what that means?

 

Bump for some good info.

 

seriously ... good job on all your stuff