How do you know how much octane you need?

 

What does your knock sensor say?

 

Lets try this a different way. What octane were you running at what boost level (and which turbo again)? Even with good gas, timing is a thing, post your timing table.

 

If i have a turbo, i run the highest octane available.

And then tune for it.

 

What's the price difference between a tank of higher octane fuel and an engine?

Asking for a friend.

 

Roughly the price of engine minus a cheap spark plug

 

Yikes.

 

I run 95RON, wanted to tune for low octane for the power level it will allow - higher octane here is a problem.


- I suspect something is wrong with the base timing - I run MS3 Basic and offsset on the ecu came out -13deg I do not know if it is true TDC... Could be the marking on the ATI are not true TDC of the engine.\ (I read that sevington showed the center mark on the ATI does not match the timing gear)
- After a few hundred km running with no boost I started tuning for boost, I noticed the boost run very linear upto 20psi @ redline.

This is the ignition map that came with the ecu:

MS3 Basic base map
I run this ignition map thinking it is very low, less then 10deg @ 200kpa...

Well, I wanted to check why the boost is so linear so I did run upto 20psi~ (linear) at redline... a few times, the afr was 11.5-12 all the time, I did not have my knock sensor earphone on :\ - no audible knock from the driver sit.
After those runs the engine start showing blow by - I believe it was hurt,

Another small thing:
My ignition setting was:
Rising edge on 99-05 Spark mode, I understand from Dimitrious that it should be Falling edge ...( it run ... what does it effect ?)

Thanks for the input guys.
Elior

 

Leading edge versus trailing edge could be worth several degrees of timing. It would make it advanced.

 

My lesson is:
- Find TRUE TDC and true tdc offset - base timing.
- Correct timing settings
- start with low timing in boost
- low boost to start with
- tune with my expensive knock sensor on

 

95 RON is generally considered to be about 90 (R+M)/2, which is the American standard of measurement.

 

So does this stay true even if the base timing is set using Rising? I just looked at my tune, set up spark three years ago and it is also set on rising. wondering if I have been close to meltdown.

 

Base timing is very important. When I throw boost at a motor, I physically verify it with a dial indicator, if the motor allows it.

 

na, what I am asking is: if I am on rising edge and set base timing, is my ignition going to be more advanced in boost than if I do the same with Falling edge?

 

The head is dead the block is good.

Can I use a non VVT head on VVT block ?...

 

why not?

 

 

Out of curiosity, do you have a log of when this happened? What were the specs for the block and head? Was it a stock vvt head? Any idea where in the range the vvt was?

Looks like this happened at 2 pistons, correct?

 

all 4, vvt was disabled...

 

wowww