Scrappy_Brap

Anyone have any insight? I'm looking for a general ballpark of timing as I'm at a point where I am about ready to purchase my turbo goodies! The only thing that's holding me back is figuring out ignition timing (I want to have my ducks in a row before I jump in and go ***** deep)

Aaron Cake

iTrader: (1)

Approx 15 - 18 degrees at idle (assuming 1500 RPM or so) increasing to 25 degrees by 2500 RPM, adding 10 degrees on top of that in the cruise areas. Should be 30 degrees in the powerband up to atmospheric then drop down very quickly in boost. 15 degrees above atmospheric, down to 10 degrees one you are about 5 PSI. 10 degrees all the way in the boost area, adding a few degrees after about 6000 RPM.

Decel as in high vacuum bottom line of the map, 40 degrees.

Scrappy_Brap

I've recently watched a video talking about tuning a rotary, and one of the key points they made was to not chase power with ignition timing under high pressure applications.

So you're basically saying after 5psi to lock the timing at 10°, I just purchased an hx50 with a .96ar hot side, I'm going for a good powerband to just have a fun street car and the occasional weekend warrior type event.

GoodfellaFD3S

iTrader: (213)

Just popped in to say that I dig your username

Scrappy_Brap

Haha thanks man, my Instagram is Ratchet_Brap, seems to be an ongoing theme haha

Aaron Cake

iTrader: (1)

I believe I've made that exact statement before, that chasing power with timing is a dangerous game on a rotary and will not result in significant gains when we are talking about forced induction. Unlike those TV shows that show tuning of piston engines, where they stick an engine on a dyno, move the timing up 3 times and have found 100 more HP that way without even mentioning AFR ratios...

Yes, after about 5 PSI I am very conservative with timing and basically run it at 10 degrees until about 6000 RPM where I add a 2 - 3 degrees until about 15 PSI...where it drops to a flat 10 degrees again.

What tuning timing will give you is drivability and economy. Two things a bridgeport already sort of negates. Well, economy anyway. I'd have to check my split maps but if your ECU is capable of it, negative split at idle by some degree (check the stock RX-8 maps) can smooth things out but you're going to want to move to about 15 degrees of split by the time you are in the cruise range, carrying that to say 80 KpA or so where you gradually decrease split to zero at atmospheric then you want to be at 15 degrees again by the time you are at that 5 PSI.

Scrappy_Brap

I have ms3pro so I'm fairly confident the ecu can take whatever I need to throw at it when it comes to features and tuning,

I will try to find some rx8 maps and look at the split times

Aaron Cake

iTrader: (1)

Oh, yes, MS3 supports negative split.

Rx-7heaven

iTrader: (1)

Some great info here!

j9fd3s

iTrader: (3)

ive even seen some V8 tuners lately where they mention detonation/preignition. its a concern for them.

point two; i tuned a piston engine once, and its chamber is so "slow" that we maxed out the timing in the E6-GM and it still wanted more. with the rotary, and any piston engine that isn't s*%t the chamber will be a lot "faster" and you do not need a lot of timing. if you like an example this GM engine wanted like 60 degrees of ignition advance, and the 787B which is the raciest of the race cars only ran 25 degrees.

point three, you're tuning to make the engine happy and not have a bigger number on a spreadsheet. again the rotary runs -5 at idle, and 25 at max power, much different than a v8. the principals do work exactly the same though, if you run too much timing in a piston engine it'll knock and blow up just like a rotary will.

point four: cross triggering can be a problem on the rotary, you want to keep the plug wires away from each other, etc

FwkUiWN

iTrader: (1)

good info. There are plenty of rx8 timing maps on 8club.